acp

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 Go to latest Published: Feb 27, 2026 License: Apache-2.0 Imports: 12 Imported by: 18

README

Agent Client Protocol

ACP Go SDK

Go library for the Agent Client Protocol (ACP) - a standardized communication protocol between code editors and AI‑powered coding agents.

Learn more about the protocol itself at https://agentclientprotocol.com.

Installation

go get github.com/coder/acp-go-sdk@v0.10.8

Get Started

Understand the Protocol

Start by reading the official ACP documentation to understand the core concepts and protocol specification.

Try the Examples

The examples directory contains simple implementations of both Agents and Clients in Go. You can run them from your terminal or connect to external ACP agents.

  • go run ./example/agent starts a minimal ACP agent over stdio.
  • go run ./example/claude-code demonstrates bridging to Claude Code.
  • go run ./example/client connects to a running agent and streams a sample turn.
  • go run ./example/gemini bridges to the Gemini CLI in ACP mode (flags: -model, -sandbox, -debug, -gemini /path/to/gemini).

You can watch the interaction by running go run ./example/client locally.

Explore the API

Browse the Go package docs on pkg.go.dev for detailed API documentation:

If you're building an Agent:

  • Implement the acp.Agent interface (and optionally acp.AgentLoader for session/load).
  • Create a connection with acp.NewAgentSideConnection(agent, os.Stdout, os.Stdin).
  • Send updates and make client requests using the returned connection.

If you're building a Client:

  • Implement the acp.Client interface (and optionally acp.ClientTerminal for terminal features).
  • Launch or connect to your Agent process (stdio), then create a connection with acp.NewClientSideConnection(client, stdin, stdout).
  • Call Initialize, NewSession, and Prompt to run a turn and stream updates.

Helper constructors are provided to reduce boilerplate when working with union types:

  • Content blocks: acp.TextBlock, acp.ImageBlock, acp.AudioBlock, acp.ResourceLinkBlock, acp.ResourceBlock.
  • Tool content: acp.ToolContent, acp.ToolDiffContent, acp.ToolTerminalRef.
  • Utility: acp.Ptr[T] for pointer fields in request/update structs.
Extension methods

ACP supports extension methods for custom JSON-RPC methods whose names start with _. Use them to add functionality without conflicting with future ACP versions.

Handling inbound extension methods

Implement acp.ExtensionMethodHandler on your Agent or Client. Your handler will be invoked for any incoming method starting with _.

// HandleExtensionMethod handles ACP extension methods (names starting with "_").
func (a MyAgent) HandleExtensionMethod(ctx context.Context, method string, params json.RawMessage) (any, error) {
	switch method {
	case "_example.com/hello":
		var p struct {
			Name string `json:"name"`
		}
		if err := json.Unmarshal(params, &p); err != nil {
			return nil, err
		}
		return map[string]any{"greeting": "hello " + p.Name}, nil
	default:
		return nil, acp.NewMethodNotFound(method)
	}
}

Note: Per the ACP spec, unknown extension notifications should be ignored. This SDK suppresses noisy logs for unhandled extension notifications that return “Method not found”.

Calling extension methods

From either side, use CallExtension / NotifyExtension on the connection.

raw, err := conn.CallExtension(ctx, "_example.com/hello", map[string]any{"name": "world"})
if err != nil {
	return err
}

var resp struct {
	Greeting string `json:"greeting"`
}
if err := json.Unmarshal(raw, &resp); err != nil {
	return err
}

if err := conn.NotifyExtension(ctx, "_example.com/progress", map[string]any{"pct": 50}); err != nil {
	return err
}
Advertising extension support via _meta

ACP uses the _meta field inside capability objects as the negotiation/advertising surface for extensions.

  • Client -> Agent: InitializeRequest.ClientCapabilities.Meta
  • Agent -> Client: InitializeResponse.AgentCapabilities.Meta

Keys traceparent, tracestate, and baggage are reserved in _meta for W3C trace context/OpenTelemetry compatibility.

Study a Production Implementation

For a complete, production‑ready integration, see the Gemini CLI Agent which exposes an ACP interface. The Go example client example/gemini demonstrates connecting to it via stdio.

Resources

License

Apache 2.0. See LICENSE.

Documentation

Overview

Package acp provides Go types and connection plumbing for the Agent Client Protocol (ACP). It contains generated dispatchers, outbound helpers, shared request/response types, and related utilities used by agents and clients to communicate over ACP.

Example (Agent)

Example_agent wires the Agent to stdio so an external client can connect via this process' stdin/stdout. 

package main

import (
	"context"
	"os"
)

// agentExample mirrors the go/example/agent flow in a compact form.
// It streams a short message, demonstrates a tool call + permission,
// then ends the turn.
type agentExample struct{ conn *AgentSideConnection }

var _ Agent = (*agentExample)(nil)

// SetSessionMode implements Agent.
func (a *agentExample) SetSessionMode(ctx context.Context, params SetSessionModeRequest) (SetSessionModeResponse, error) {
	return SetSessionModeResponse{}, nil
}

// SetSessionConfigOption implements Agent.
func (a *agentExample) SetSessionConfigOption(ctx context.Context, params SetSessionConfigOptionRequest) (SetSessionConfigOptionResponse, error) {
	return SetSessionConfigOptionResponse{}, nil
}

func (a *agentExample) SetAgentConnection(c *AgentSideConnection) { a.conn = c }

func (agentExample) Authenticate(ctx context.Context, _ AuthenticateRequest) (AuthenticateResponse, error) {
	return AuthenticateResponse{}, nil
}

func (agentExample) Initialize(ctx context.Context, _ InitializeRequest) (InitializeResponse, error) {
	return InitializeResponse{
		ProtocolVersion:   ProtocolVersionNumber,
		AgentCapabilities: AgentCapabilities{LoadSession: false},
	}, nil
}
func (agentExample) Cancel(ctx context.Context, _ CancelNotification) error { return nil }
func (agentExample) NewSession(ctx context.Context, _ NewSessionRequest) (NewSessionResponse, error) {
	return NewSessionResponse{SessionId: SessionId("sess_demo")}, nil
}

func (a *agentExample) Prompt(ctx context.Context, p PromptRequest) (PromptResponse, error) {
	// Stream an initial agent message.
	_ = a.conn.SessionUpdate(ctx, SessionNotification{
		SessionId: p.SessionId,
		Update:    UpdateAgentMessageText("I'll help you with that."),
	})

	// Announce a tool call.
	_ = a.conn.SessionUpdate(ctx, SessionNotification{
		SessionId: p.SessionId,
		Update: StartToolCall(
			ToolCallId("call_1"),
			"Modifying configuration",
			WithStartKind(ToolKindEdit),
			WithStartStatus(ToolCallStatusPending),
			WithStartLocations([]ToolCallLocation{{Path: "/project/config.json"}}),
			WithStartRawInput(map[string]any{"path": "/project/config.json"}),
		),
	})

	// Ask the client for permission to proceed with the change.
	resp, _ := a.conn.RequestPermission(ctx, RequestPermissionRequest{
		SessionId: p.SessionId,
		ToolCall: ToolCallUpdate{
			ToolCallId: ToolCallId("call_1"),
			Title:      Ptr("Modifying configuration"),
			Kind:       Ptr(ToolKindEdit),
			Status:     Ptr(ToolCallStatusPending),
			Locations:  []ToolCallLocation{{Path: "/project/config.json"}},
			RawInput:   map[string]any{"path": "/project/config.json"},
		},
		Options: []PermissionOption{
			{Kind: PermissionOptionKindAllowOnce, Name: "Allow", OptionId: PermissionOptionId("allow")},
			{Kind: PermissionOptionKindRejectOnce, Name: "Reject", OptionId: PermissionOptionId("reject")},
		},
	})

	if resp.Outcome.Selected != nil && string(resp.Outcome.Selected.OptionId) == "allow" {
		// Mark tool call completed and stream a final message.
		_ = a.conn.SessionUpdate(ctx, SessionNotification{
			SessionId: p.SessionId,
			Update: UpdateToolCall(
				ToolCallId("call_1"),
				WithUpdateStatus(ToolCallStatusCompleted),
				WithUpdateRawOutput(map[string]any{"success": true}),
			),
		})
		_ = a.conn.SessionUpdate(ctx, SessionNotification{
			SessionId: p.SessionId,
			Update:    UpdateAgentMessageText("Done."),
		})
	}

	return PromptResponse{StopReason: StopReasonEndTurn}, nil
}

// Example_agent wires the Agent to stdio so an external client
// can connect via this process' stdin/stdout.
func main() {
	ag := &agentExample{}
	asc := NewAgentSideConnection(ag, os.Stdout, os.Stdin)
	ag.SetAgentConnection(asc)
	// In a real program, block until the peer disconnects:
	// <-asc.Done()
}
Example (Client)

Example_client launches the Go agent example, negotiates protocol, opens a session, and sends a simple prompt. 

package main

import (
	"context"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
)

// clientExample mirrors go/example/client in a compact form: prints
// streamed updates, handles simple file ops, and picks the first
// permission option.
type clientExample struct{}

var _ Client = (*clientExample)(nil)

func (clientExample) RequestPermission(ctx context.Context, p RequestPermissionRequest) (RequestPermissionResponse, error) {
	if len(p.Options) == 0 {
		return RequestPermissionResponse{
			Outcome: RequestPermissionOutcome{
				Cancelled: &RequestPermissionOutcomeCancelled{},
			},
		}, nil
	}
	return RequestPermissionResponse{
		Outcome: RequestPermissionOutcome{
			Selected: &RequestPermissionOutcomeSelected{OptionId: p.Options[0].OptionId},
		},
	}, nil
}

func (clientExample) SessionUpdate(ctx context.Context, n SessionNotification) error {
	u := n.Update
	switch {
	case u.AgentMessageChunk != nil:
		c := u.AgentMessageChunk.Content
		if c.Text != nil {
			fmt.Print(c.Text.Text)
		}
	case u.ToolCall != nil:
		title := u.ToolCall.Title
		fmt.Printf("\n[tool] %s (%s)\n", title, u.ToolCall.Status)
	case u.ToolCallUpdate != nil:
		fmt.Printf("\n[tool] %s -> %v\n", u.ToolCallUpdate.ToolCallId, u.ToolCallUpdate.Status)
	}
	return nil
}

func (clientExample) WriteTextFile(ctx context.Context, p WriteTextFileRequest) (WriteTextFileResponse, error) {
	if !filepath.IsAbs(p.Path) {
		return WriteTextFileResponse{}, fmt.Errorf("path must be absolute: %s", p.Path)
	}
	if dir := filepath.Dir(p.Path); dir != "" {
		_ = os.MkdirAll(dir, 0o755)
	}
	return WriteTextFileResponse{}, os.WriteFile(p.Path, []byte(p.Content), 0o644)
}

func (clientExample) ReadTextFile(ctx context.Context, p ReadTextFileRequest) (ReadTextFileResponse, error) {
	if !filepath.IsAbs(p.Path) {
		return ReadTextFileResponse{}, fmt.Errorf("path must be absolute: %s", p.Path)
	}
	b, err := os.ReadFile(p.Path)
	if err != nil {
		return ReadTextFileResponse{}, err
	}
	content := string(b)
	if p.Line != nil || p.Limit != nil {
		lines := strings.Split(content, "\n")
		start := 0
		if p.Line != nil && *p.Line > 0 {
			if *p.Line-1 > 0 {
				start = *p.Line - 1
			}
			if start > len(lines) {
				start = len(lines)
			}
		}
		end := len(lines)
		if p.Limit != nil && *p.Limit > 0 && start+*p.Limit < end {
			end = start + *p.Limit
		}
		content = strings.Join(lines[start:end], "\n")
	}
	return ReadTextFileResponse{Content: content}, nil
}

// Terminal interface implementations (minimal stubs for examples)
func (clientExample) CreateTerminal(ctx context.Context, p CreateTerminalRequest) (CreateTerminalResponse, error) {
	// Return a dummy terminal id
	return CreateTerminalResponse{TerminalId: "t-1"}, nil
}

func (clientExample) KillTerminalCommand(ctx context.Context, p KillTerminalCommandRequest) (KillTerminalCommandResponse, error) {
	return KillTerminalCommandResponse{}, nil
}

func (clientExample) ReleaseTerminal(ctx context.Context, p ReleaseTerminalRequest) (ReleaseTerminalResponse, error) {
	return ReleaseTerminalResponse{}, nil
}

func (clientExample) TerminalOutput(ctx context.Context, p TerminalOutputRequest) (TerminalOutputResponse, error) {
	// Provide non-empty output to satisfy validation
	return TerminalOutputResponse{Output: "ok", Truncated: false}, nil
}

func (clientExample) WaitForTerminalExit(ctx context.Context, p WaitForTerminalExitRequest) (WaitForTerminalExitResponse, error) {
	return WaitForTerminalExitResponse{}, nil
}

// Example_client launches the Go agent example, negotiates protocol,
// opens a session, and sends a simple prompt.
func main() {
	ctx := context.Background()
	cmd := exec.Command("go", "run", "./example/agent")
	stdin, _ := cmd.StdinPipe()
	stdout, _ := cmd.StdoutPipe()
	_ = cmd.Start()

	conn := NewClientSideConnection(clientExample{}, stdin, stdout)
	_, _ = conn.Initialize(ctx, InitializeRequest{
		ProtocolVersion: ProtocolVersionNumber,
		ClientCapabilities: ClientCapabilities{
			Fs: FileSystemCapability{
				ReadTextFile:  true,
				WriteTextFile: true,
			},
			Terminal: true,
		},
	})
	sess, _ := conn.NewSession(ctx, NewSessionRequest{
		Cwd:        "/",
		McpServers: []McpServer{},
	})
	_, _ = conn.Prompt(ctx, PromptRequest{
		SessionId: sess.SessionId,
		Prompt:    []ContentBlock{TextBlock("Hello, agent!")},
	})

	_ = cmd.Process.Kill()
}
Example (Gemini)

Example_gemini connects to a Gemini CLI speaking ACP over stdio, then initializes, opens a session, and sends a prompt. 

package main

import (
	"context"
	"fmt"
	"os/exec"
)

// geminiClient mirrors go/example/gemini in brief: prints text chunks and
// selects the first permission option. File ops are no-ops here.
type geminiClient struct{}

var _ Client = (*geminiClient)(nil)

func (geminiClient) RequestPermission(ctx context.Context, p RequestPermissionRequest) (RequestPermissionResponse, error) {
	if len(p.Options) == 0 {
		return RequestPermissionResponse{Outcome: RequestPermissionOutcome{Cancelled: &RequestPermissionOutcomeCancelled{}}}, nil
	}
	return RequestPermissionResponse{Outcome: RequestPermissionOutcome{Selected: &RequestPermissionOutcomeSelected{OptionId: p.Options[0].OptionId}}}, nil
}

func (geminiClient) SessionUpdate(ctx context.Context, n SessionNotification) error {
	if n.Update.AgentMessageChunk != nil {
		c := n.Update.AgentMessageChunk.Content
		if c.Text != nil {
			fmt.Print(c.Text.Text)
		}
	}
	return nil
}

func (geminiClient) ReadTextFile(ctx context.Context, _ ReadTextFileRequest) (ReadTextFileResponse, error) {
	return ReadTextFileResponse{}, nil
}

func (geminiClient) WriteTextFile(ctx context.Context, _ WriteTextFileRequest) (WriteTextFileResponse, error) {
	return WriteTextFileResponse{}, nil
}

// Terminal interface implementations (minimal stubs for examples)
func (geminiClient) CreateTerminal(ctx context.Context, p CreateTerminalRequest) (CreateTerminalResponse, error) {
	return CreateTerminalResponse{TerminalId: "t-1"}, nil
}

func (geminiClient) KillTerminalCommand(ctx context.Context, p KillTerminalCommandRequest) (KillTerminalCommandResponse, error) {
	return KillTerminalCommandResponse{}, nil
}

func (geminiClient) ReleaseTerminal(ctx context.Context, p ReleaseTerminalRequest) (ReleaseTerminalResponse, error) {
	return ReleaseTerminalResponse{}, nil
}

func (geminiClient) TerminalOutput(ctx context.Context, p TerminalOutputRequest) (TerminalOutputResponse, error) {
	return TerminalOutputResponse{Output: "ok", Truncated: false}, nil
}

func (geminiClient) WaitForTerminalExit(ctx context.Context, p WaitForTerminalExitRequest) (WaitForTerminalExitResponse, error) {
	return WaitForTerminalExitResponse{}, nil
}

// Example_gemini connects to a Gemini CLI speaking ACP over stdio,
// then initializes, opens a session, and sends a prompt.
func main() {
	ctx := context.Background()
	cmd := exec.Command("gemini", "--experimental-acp")
	stdin, _ := cmd.StdinPipe()
	stdout, _ := cmd.StdoutPipe()
	_ = cmd.Start()

	conn := NewClientSideConnection(geminiClient{}, stdin, stdout)
	_, _ = conn.Initialize(ctx, InitializeRequest{
		ProtocolVersion: ProtocolVersionNumber,
		ClientCapabilities: ClientCapabilities{
			Fs: FileSystemCapability{
				ReadTextFile:  true,
				WriteTextFile: true,
			},
			Terminal: true,
		},
	})
	sess, _ := conn.NewSession(ctx, NewSessionRequest{
		Cwd:        "/",
		McpServers: []McpServer{},
	})
	_, _ = conn.Prompt(ctx, PromptRequest{
		SessionId: sess.SessionId,
		Prompt:    []ContentBlock{TextBlock("list files")},
	})
}

Index

Examples

Constants

View Source 
const (
	AgentMethodAuthenticate           = "authenticate"
	AgentMethodInitialize             = "initialize"
	AgentMethodSessionCancel          = "session/cancel"
	AgentMethodSessionFork            = "session/fork"
	AgentMethodSessionList            = "session/list"
	AgentMethodSessionLoad            = "session/load"
	AgentMethodSessionNew             = "session/new"
	AgentMethodSessionPrompt          = "session/prompt"
	AgentMethodSessionResume          = "session/resume"
	AgentMethodSessionSetConfigOption = "session/set_config_option"
	AgentMethodSessionSetMode         = "session/set_mode"
	AgentMethodSessionSetModel        = "session/set_model"
)

Agent method names

View Source 
const (
	ClientMethodFsReadTextFile           = "fs/read_text_file"
	ClientMethodFsWriteTextFile          = "fs/write_text_file"
	ClientMethodSessionRequestPermission = "session/request_permission"
	ClientMethodSessionUpdate            = "session/update"
	ClientMethodTerminalCreate           = "terminal/create"
	ClientMethodTerminalKill             = "terminal/kill"
	ClientMethodTerminalOutput           = "terminal/output"
	ClientMethodTerminalRelease          = "terminal/release"
	ClientMethodTerminalWaitForExit      = "terminal/wait_for_exit"
)

Client method names

View Source 
const ProtocolVersionNumber = 1

ProtocolVersionNumber is the ACP protocol version supported by this SDK.

Variables

This section is empty.

Functions

func Ptr 

func Ptr[T any](v T) *T

Ptr returns a pointer to v.

func SendRequest 

func SendRequest[T any](c *Connection, ctx context.Context, method string, params any) (T, error)

SendRequest sends a JSON-RPC request and returns a typed result. For methods that do not return a result, use SendRequestNoResult instead.

Types

type Agent 

type Agent interface {
	// Request parameters for the authenticate method.
	//
	// Specifies which authentication method to use.
	Authenticate(ctx context.Context, params AuthenticateRequest) (AuthenticateResponse, error)
	// Request parameters for the initialize method.
	//
	// Sent by the client to establish connection and negotiate capabilities.
	//
	// See protocol docs: [Initialization](https://agentclientprotocol.com/protocol/initialization)
	Initialize(ctx context.Context, params InitializeRequest) (InitializeResponse, error)
	// Notification to cancel ongoing operations for a session.
	//
	// See protocol docs: [Cancellation](https://agentclientprotocol.com/protocol/prompt-turn#cancellation)
	Cancel(ctx context.Context, params CancelNotification) error
	// Request parameters for creating a new session.
	//
	// See protocol docs: [Creating a Session](https://agentclientprotocol.com/protocol/session-setup#creating-a-session)
	NewSession(ctx context.Context, params NewSessionRequest) (NewSessionResponse, error)
	// Request parameters for sending a user prompt to the agent.
	//
	// Contains the user's message and any additional context.
	//
	// See protocol docs: [User Message](https://agentclientprotocol.com/protocol/prompt-turn#1-user-message)
	Prompt(ctx context.Context, params PromptRequest) (PromptResponse, error)
	// Request parameters for setting a session configuration option.
	SetSessionConfigOption(ctx context.Context, params SetSessionConfigOptionRequest) (SetSessionConfigOptionResponse, error)
	// Request parameters for setting a session mode.
	SetSessionMode(ctx context.Context, params SetSessionModeRequest) (SetSessionModeResponse, error)
}

type AgentCapabilities 

type AgentCapabilities struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Whether the agent supports 'session/load'.
	//
	// Defaults to false if unset.
	LoadSession bool `json:"loadSession,omitempty"`
	// MCP capabilities supported by the agent.
	//
	// Defaults to {"http":false,"sse":false} if unset.
	McpCapabilities McpCapabilities `json:"mcpCapabilities,omitempty"`
	// Prompt capabilities supported by the agent.
	//
	// Defaults to {"audio":false,"embeddedContext":false,"image":false} if unset.
	PromptCapabilities PromptCapabilities `json:"promptCapabilities,omitempty"`
	// Defaults to {} if unset.
	SessionCapabilities SessionCapabilities `json:"sessionCapabilities,omitempty"`
}

Capabilities supported by the agent.

Advertised during initialization to inform the client about available features and content types.

See protocol docs: [Agent Capabilities](https://agentclientprotocol.com/protocol/initialization#agent-capabilities)

func (AgentCapabilities) MarshalJSON 

func (v AgentCapabilities) MarshalJSON() ([]byte, error)

func (*AgentCapabilities) UnmarshalJSON 

func (v *AgentCapabilities) UnmarshalJSON(b []byte) error

type AgentError added in v0.10.8 

type AgentError struct {
	Error Error     `json:"error"`
	Id    RequestId `json:"id"`
}

type AgentExperimental 

type AgentExperimental interface {
	// **UNSTABLE**
	//
	// This capability is not part of the spec yet, and may be removed or changed at any point.
	//
	// Request parameters for forking an existing session.
	//
	// Creates a new session based on the context of an existing one, allowing
	// operations like generating summaries without affecting the original session's history.
	//
	// Only available if the Agent supports the 'session.fork' capability.
	UnstableForkSession(ctx context.Context, params UnstableForkSessionRequest) (UnstableForkSessionResponse, error)
	// **UNSTABLE**
	//
	// This capability is not part of the spec yet, and may be removed or changed at any point.
	//
	// Request parameters for listing existing sessions.
	//
	// Only available if the Agent supports the 'listSessions' capability.
	UnstableListSessions(ctx context.Context, params UnstableListSessionsRequest) (UnstableListSessionsResponse, error)
	// **UNSTABLE**
	//
	// This capability is not part of the spec yet, and may be removed or changed at any point.
	//
	// Request parameters for resuming an existing session.
	//
	// Resumes an existing session without returning previous messages (unlike 'session/load').
	// This is useful for agents that can resume sessions but don't implement full session loading.
	//
	// Only available if the Agent supports the 'session.resume' capability.
	UnstableResumeSession(ctx context.Context, params UnstableResumeSessionRequest) (UnstableResumeSessionResponse, error)
	// **UNSTABLE**
	//
	// This capability is not part of the spec yet, and may be removed or changed at any point.
	//
	// Request parameters for setting a session model.
	UnstableSetSessionModel(ctx context.Context, params UnstableSetSessionModelRequest) (UnstableSetSessionModelResponse, error)
}

AgentExperimental defines unstable methods that are not part of the official spec. These may change or be removed without notice.

type AgentLoader 

type AgentLoader interface {
	// Request parameters for loading an existing session.
	//
	// Only available if the Agent supports the 'loadSession' capability.
	//
	// See protocol docs: [Loading Sessions](https://agentclientprotocol.com/protocol/session-setup#loading-sessions)
	LoadSession(ctx context.Context, params LoadSessionRequest) (LoadSessionResponse, error)
}

AgentLoader defines optional support for loading sessions. Implement and advertise the capability to enable 'session/load'.

type AgentNotification 

type AgentNotification struct {
	Method string `json:"method"`
	Params any    `json:"params,omitempty"`
}

func (*AgentNotification) Validate added in v0.10.8 

func (v *AgentNotification) Validate() error

type AgentRequest 

type AgentRequest struct {
	Id     RequestId `json:"id"`
	Method string    `json:"method"`
	Params any       `json:"params,omitempty"`
}

func (*AgentRequest) Validate added in v0.10.8 

func (v *AgentRequest) Validate() error

type AgentResponse 

type AgentResponse struct {
	Result *AgentResult `json:"-"`
	Error  *AgentError  `json:"-"`
}

func (AgentResponse) MarshalJSON 

func (u AgentResponse) MarshalJSON() ([]byte, error)

func (*AgentResponse) UnmarshalJSON 

func (u *AgentResponse) UnmarshalJSON(b []byte) error

type AgentResult added in v0.10.8 

type AgentResult struct {
	Id RequestId `json:"id"`
	// All possible responses that an agent can send to a client.
	//
	// This enum is used internally for routing RPC responses. You typically won't need
	// to use this directly - the responses are handled automatically by the connection.
	//
	// These are responses to the corresponding 'ClientRequest' variants.
	Result any `json:"result"`
}

type AgentSideConnection 

type AgentSideConnection struct {
	// contains filtered or unexported fields
}

AgentSideConnection represents the agent's view of a connection to a client.

func NewAgentSideConnection 

func NewAgentSideConnection(agent Agent, peerInput io.Writer, peerOutput io.Reader) *AgentSideConnection

NewAgentSideConnection creates a new agent-side connection bound to the provided Agent implementation.

func (*AgentSideConnection) CallExtension added in v0.10.8 

func (c *AgentSideConnection) CallExtension(ctx context.Context, method string, params any) (json.RawMessage, error)

CallExtension sends an ACP extension-method request (method names starting with "_") from an agent to its client.

func (*AgentSideConnection) CreateTerminal 

func (c *AgentSideConnection) CreateTerminal(ctx context.Context, params CreateTerminalRequest) (CreateTerminalResponse, error)

func (*AgentSideConnection) Done 

func (c *AgentSideConnection) Done() <-chan struct{}

Done exposes a channel that closes when the peer disconnects.

func (*AgentSideConnection) KillTerminalCommand 

func (c *AgentSideConnection) KillTerminalCommand(ctx context.Context, params KillTerminalCommandRequest) (KillTerminalCommandResponse, error)

func (*AgentSideConnection) NotifyExtension added in v0.10.8 

func (c *AgentSideConnection) NotifyExtension(ctx context.Context, method string, params any) error

NotifyExtension sends an ACP extension-method notification (method names starting with "_") from an agent to its client.

func (*AgentSideConnection) ReadTextFile 

func (c *AgentSideConnection) ReadTextFile(ctx context.Context, params ReadTextFileRequest) (ReadTextFileResponse, error)

func (*AgentSideConnection) ReleaseTerminal 

func (c *AgentSideConnection) ReleaseTerminal(ctx context.Context, params ReleaseTerminalRequest) (ReleaseTerminalResponse, error)

func (*AgentSideConnection) RequestPermission 

func (c *AgentSideConnection) RequestPermission(ctx context.Context, params RequestPermissionRequest) (RequestPermissionResponse, error)

func (*AgentSideConnection) SessionUpdate 

func (c *AgentSideConnection) SessionUpdate(ctx context.Context, params SessionNotification) error

func (*AgentSideConnection) SetLogger 

func (c *AgentSideConnection) SetLogger(l *slog.Logger)

SetLogger directs connection diagnostics to the provided logger.

func (*AgentSideConnection) TerminalOutput 

func (c *AgentSideConnection) TerminalOutput(ctx context.Context, params TerminalOutputRequest) (TerminalOutputResponse, error)

func (*AgentSideConnection) WaitForTerminalExit 

func (c *AgentSideConnection) WaitForTerminalExit(ctx context.Context, params WaitForTerminalExitRequest) (WaitForTerminalExitResponse, error)

func (*AgentSideConnection) WriteTextFile 

func (c *AgentSideConnection) WriteTextFile(ctx context.Context, params WriteTextFileRequest) (WriteTextFileResponse, error)

type Annotations 

type Annotations struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta         map[string]any `json:"_meta,omitempty"`
	Audience     []Role         `json:"audience,omitempty"`
	LastModified *string        `json:"lastModified,omitempty"`
	Priority     *float64       `json:"priority,omitempty"`
}

Optional annotations for the client. The client can use annotations to inform how objects are used or displayed

type AudioContent 

type AudioContent struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta        map[string]any `json:"_meta,omitempty"`
	Annotations *Annotations   `json:"annotations,omitempty"`
	Data        string         `json:"data"`
	MimeType    string         `json:"mimeType"`
}

Audio provided to or from an LLM.

type AuthMethod 

type AuthMethod struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Optional description providing more details about this authentication method.
	Description *string `json:"description,omitempty"`
	// Unique identifier for this authentication method.
	Id string `json:"id"`
	// Human-readable name of the authentication method.
	Name string `json:"name"`
}

Describes an available authentication method.

type AuthenticateRequest 

type AuthenticateRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The ID of the authentication method to use.
	// Must be one of the methods advertised in the initialize response.
	MethodId string `json:"methodId"`
}

Request parameters for the authenticate method.

Specifies which authentication method to use.

func (*AuthenticateRequest) Validate 

func (v *AuthenticateRequest) Validate() error

type AuthenticateResponse 

type AuthenticateResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
}

Response to the 'authenticate' method.

func (*AuthenticateResponse) Validate 

func (v *AuthenticateResponse) Validate() error

type AvailableCommand 

type AvailableCommand struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Human-readable description of what the command does.
	Description string `json:"description"`
	// Input for the command if required
	Input *AvailableCommandInput `json:"input,omitempty"`
	// Command name (e.g., 'create_plan', 'research_codebase').
	Name string `json:"name"`
}

Information about a command.

type AvailableCommandInput 

type AvailableCommandInput struct {
	// All text that was typed after the command name is provided as input.
	Unstructured *UnstructuredCommandInput `json:"-"`
}

The input specification for a command.

func (AvailableCommandInput) MarshalJSON 

func (u AvailableCommandInput) MarshalJSON() ([]byte, error)

func (*AvailableCommandInput) UnmarshalJSON 

func (u *AvailableCommandInput) UnmarshalJSON(b []byte) error

type AvailableCommandsUpdate added in v0.10.8 

type AvailableCommandsUpdate struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Commands the agent can execute
	AvailableCommands []AvailableCommand `json:"availableCommands"`
}

Available commands are ready or have changed

type BlobResourceContents 

type BlobResourceContents struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta     map[string]any `json:"_meta,omitempty"`
	Blob     string         `json:"blob"`
	MimeType *string        `json:"mimeType,omitempty"`
	Uri      string         `json:"uri"`
}

Binary resource contents.

type CancelNotification 

type CancelNotification struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The ID of the session to cancel operations for.
	SessionId SessionId `json:"sessionId"`
}

Notification to cancel ongoing operations for a session.

See protocol docs: [Cancellation](https://agentclientprotocol.com/protocol/prompt-turn#cancellation)

func (*CancelNotification) Validate 

func (v *CancelNotification) Validate() error

type Client 

type Client interface {
	// Request to read content from a text file.
	//
	// Only available if the client supports the 'fs.readTextFile' capability.
	ReadTextFile(ctx context.Context, params ReadTextFileRequest) (ReadTextFileResponse, error)
	// Request to write content to a text file.
	//
	// Only available if the client supports the 'fs.writeTextFile' capability.
	WriteTextFile(ctx context.Context, params WriteTextFileRequest) (WriteTextFileResponse, error)
	// Request for user permission to execute a tool call.
	//
	// Sent when the agent needs authorization before performing a sensitive operation.
	//
	// See protocol docs: [Requesting Permission](https://agentclientprotocol.com/protocol/tool-calls#requesting-permission)
	RequestPermission(ctx context.Context, params RequestPermissionRequest) (RequestPermissionResponse, error)
	// Notification containing a session update from the agent.
	//
	// Used to stream real-time progress and results during prompt processing.
	//
	// See protocol docs: [Agent Reports Output](https://agentclientprotocol.com/protocol/prompt-turn#3-agent-reports-output)
	SessionUpdate(ctx context.Context, params SessionNotification) error
	// Request to create a new terminal and execute a command.
	CreateTerminal(ctx context.Context, params CreateTerminalRequest) (CreateTerminalResponse, error)
	// Request to kill a terminal command without releasing the terminal.
	KillTerminalCommand(ctx context.Context, params KillTerminalCommandRequest) (KillTerminalCommandResponse, error)
	// Request to get the current output and status of a terminal.
	TerminalOutput(ctx context.Context, params TerminalOutputRequest) (TerminalOutputResponse, error)
	// Request to release a terminal and free its resources.
	ReleaseTerminal(ctx context.Context, params ReleaseTerminalRequest) (ReleaseTerminalResponse, error)
	// Request to wait for a terminal command to exit.
	WaitForTerminalExit(ctx context.Context, params WaitForTerminalExitRequest) (WaitForTerminalExitResponse, error)
}

type ClientCapabilities 

type ClientCapabilities struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// File system capabilities supported by the client.
	// Determines which file operations the agent can request.
	//
	// Defaults to {"readTextFile":false,"writeTextFile":false} if unset.
	Fs FileSystemCapability `json:"fs,omitempty"`
	// Whether the Client support all 'terminal/*' methods.
	//
	// Defaults to false if unset.
	Terminal bool `json:"terminal,omitempty"`
}

Capabilities supported by the client.

Advertised during initialization to inform the agent about available features and methods.

See protocol docs: [Client Capabilities](https://agentclientprotocol.com/protocol/initialization#client-capabilities)

func (ClientCapabilities) MarshalJSON 

func (v ClientCapabilities) MarshalJSON() ([]byte, error)

func (*ClientCapabilities) UnmarshalJSON 

func (v *ClientCapabilities) UnmarshalJSON(b []byte) error

type ClientError added in v0.10.8 

type ClientError struct {
	Error Error     `json:"error"`
	Id    RequestId `json:"id"`
}

type ClientExperimental 

type ClientExperimental interface{}

ClientExperimental defines unstable methods that are not part of the official spec. These may change or be removed without notice.

type ClientNotification 

type ClientNotification struct {
	Method string `json:"method"`
	Params any    `json:"params,omitempty"`
}

func (*ClientNotification) Validate added in v0.10.8 

func (v *ClientNotification) Validate() error

type ClientRequest 

type ClientRequest struct {
	Id     RequestId `json:"id"`
	Method string    `json:"method"`
	Params any       `json:"params,omitempty"`
}

func (*ClientRequest) Validate added in v0.10.8 

func (v *ClientRequest) Validate() error

type ClientResponse 

type ClientResponse struct {
	Result *ClientResult `json:"-"`
	Error  *ClientError  `json:"-"`
}

func (ClientResponse) MarshalJSON 

func (u ClientResponse) MarshalJSON() ([]byte, error)

func (*ClientResponse) UnmarshalJSON 

func (u *ClientResponse) UnmarshalJSON(b []byte) error

type ClientResult added in v0.10.8 

type ClientResult struct {
	Id RequestId `json:"id"`
	// All possible responses that a client can send to an agent.
	//
	// This enum is used internally for routing RPC responses. You typically won't need
	// to use this directly - the responses are handled automatically by the connection.
	//
	// These are responses to the corresponding 'AgentRequest' variants.
	Result any `json:"result"`
}

type ClientSideConnection 

type ClientSideConnection struct {
	// contains filtered or unexported fields
}

ClientSideConnection provides the client's view of the connection and implements Agent calls.

func NewClientSideConnection 

func NewClientSideConnection(client Client, peerInput io.Writer, peerOutput io.Reader) *ClientSideConnection

NewClientSideConnection creates a new client-side connection bound to the provided Client implementation.

func (*ClientSideConnection) Authenticate 

func (c *ClientSideConnection) Authenticate(ctx context.Context, params AuthenticateRequest) (AuthenticateResponse, error)

func (*ClientSideConnection) CallExtension added in v0.10.8 

func (c *ClientSideConnection) CallExtension(ctx context.Context, method string, params any) (json.RawMessage, error)

CallExtension sends an ACP extension-method request (method names starting with "_") from a client to its agent.

func (*ClientSideConnection) Cancel 

func (c *ClientSideConnection) Cancel(ctx context.Context, params CancelNotification) error

func (*ClientSideConnection) Done 

func (c *ClientSideConnection) Done() <-chan struct{}

Done exposes a channel that closes when the peer disconnects.

func (*ClientSideConnection) Initialize 

func (c *ClientSideConnection) Initialize(ctx context.Context, params InitializeRequest) (InitializeResponse, error)

func (*ClientSideConnection) LoadSession 

func (c *ClientSideConnection) LoadSession(ctx context.Context, params LoadSessionRequest) (LoadSessionResponse, error)

func (*ClientSideConnection) NewSession 

func (c *ClientSideConnection) NewSession(ctx context.Context, params NewSessionRequest) (NewSessionResponse, error)

func (*ClientSideConnection) NotifyExtension added in v0.10.8 

func (c *ClientSideConnection) NotifyExtension(ctx context.Context, method string, params any) error

NotifyExtension sends an ACP extension-method notification (method names starting with "_") from a client to its agent.

func (*ClientSideConnection) Prompt 

func (c *ClientSideConnection) Prompt(ctx context.Context, params PromptRequest) (PromptResponse, error)

func (*ClientSideConnection) SetLogger 

func (c *ClientSideConnection) SetLogger(l *slog.Logger)

SetLogger directs connection diagnostics to the provided logger.

func (*ClientSideConnection) SetSessionConfigOption added in v0.10.8 

func (c *ClientSideConnection) SetSessionConfigOption(ctx context.Context, params SetSessionConfigOptionRequest) (SetSessionConfigOptionResponse, error)

func (*ClientSideConnection) SetSessionMode 

func (c *ClientSideConnection) SetSessionMode(ctx context.Context, params SetSessionModeRequest) (SetSessionModeResponse, error)

func (*ClientSideConnection) UnstableForkSession added in v0.10.8 

func (c *ClientSideConnection) UnstableForkSession(ctx context.Context, params UnstableForkSessionRequest) (UnstableForkSessionResponse, error)

func (*ClientSideConnection) UnstableListSessions added in v0.10.8 

func (c *ClientSideConnection) UnstableListSessions(ctx context.Context, params UnstableListSessionsRequest) (UnstableListSessionsResponse, error)

func (*ClientSideConnection) UnstableResumeSession added in v0.10.8 

func (c *ClientSideConnection) UnstableResumeSession(ctx context.Context, params UnstableResumeSessionRequest) (UnstableResumeSessionResponse, error)

func (*ClientSideConnection) UnstableSetSessionModel added in v0.10.8 

func (c *ClientSideConnection) UnstableSetSessionModel(ctx context.Context, params UnstableSetSessionModelRequest) (UnstableSetSessionModelResponse, error)

type ConfigOptionUpdate added in v0.10.8 

type ConfigOptionUpdate struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The full set of configuration options and their current values.
	ConfigOptions []SessionConfigOption `json:"configOptions"`
}

Session configuration options have been updated.

type Connection 

type Connection struct {
	// contains filtered or unexported fields
}

Connection is a simple JSON-RPC 2.0 connection over line-delimited JSON.

func NewConnection 

func NewConnection(handler MethodHandler, peerInput io.Writer, peerOutput io.Reader) *Connection

func (*Connection) Done 

func (c *Connection) Done() <-chan struct{}

Done returns a channel that is closed when the underlying reader loop exits (typically when the peer disconnects or the input stream is closed).

func (*Connection) SendNotification 

func (c *Connection) SendNotification(ctx context.Context, method string, params any) error

func (*Connection) SendRequestNoResult 

func (c *Connection) SendRequestNoResult(ctx context.Context, method string, params any) error

SendRequestNoResult sends a JSON-RPC request that returns no result payload.

func (*Connection) SetLogger 

func (c *Connection) SetLogger(l *slog.Logger)

SetLogger installs a logger used for internal connection diagnostics. If unset, logs are written via the default logger.

type Content added in v0.10.8 

type Content struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The actual content block.
	Content ContentBlock `json:"content"`
}

Standard content block (text, images, resources).

type ContentBlock 

type ContentBlock struct {
	// Text content. May be plain text or formatted with Markdown.
	//
	// All agents MUST support text content blocks in prompts.
	// Clients SHOULD render this text as Markdown.
	Text *ContentBlockText `json:"-"`
	// Images for visual context or analysis.
	//
	// Requires the 'image' prompt capability when included in prompts.
	Image *ContentBlockImage `json:"-"`
	// Audio data for transcription or analysis.
	//
	// Requires the 'audio' prompt capability when included in prompts.
	Audio *ContentBlockAudio `json:"-"`
	// References to resources that the agent can access.
	//
	// All agents MUST support resource links in prompts.
	ResourceLink *ContentBlockResourceLink `json:"-"`
	// Complete resource contents embedded directly in the message.
	//
	// Preferred for including context as it avoids extra round-trips.
	//
	// Requires the 'embeddedContext' prompt capability when included in prompts.
	Resource *ContentBlockResource `json:"-"`
}

func AudioBlock 

func AudioBlock(data string, mimeType string) ContentBlock

AudioBlock constructs an inline audio content block with base64-encoded data.

func ImageBlock 

func ImageBlock(data string, mimeType string) ContentBlock

ImageBlock constructs an inline image content block with base64-encoded data.

func ResourceBlock 

func ResourceBlock(res EmbeddedResourceResource) ContentBlock

ResourceBlock wraps an embedded resource as a content block.

func ResourceLinkBlock 

func ResourceLinkBlock(name string, uri string) ContentBlock

ResourceLinkBlock constructs a resource_link content block with a name and URI.

func TextBlock 

func TextBlock(text string) ContentBlock

TextBlock constructs a text content block.

func (ContentBlock) MarshalJSON 

func (u ContentBlock) MarshalJSON() ([]byte, error)

func (*ContentBlock) UnmarshalJSON 

func (u *ContentBlock) UnmarshalJSON(b []byte) error

func (*ContentBlock) Validate 

func (u *ContentBlock) Validate() error

type ContentBlockAudio 

type ContentBlockAudio struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta        map[string]any `json:"_meta,omitempty"`
	Annotations *Annotations   `json:"annotations,omitempty"`
	Data        string         `json:"data"`
	MimeType    string         `json:"mimeType"`
	Type        string         `json:"type"`
}

Audio data for transcription or analysis.

Requires the 'audio' prompt capability when included in prompts.

type ContentBlockImage 

type ContentBlockImage struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta        map[string]any `json:"_meta,omitempty"`
	Annotations *Annotations   `json:"annotations,omitempty"`
	Data        string         `json:"data"`
	MimeType    string         `json:"mimeType"`
	Type        string         `json:"type"`
	Uri         *string        `json:"uri,omitempty"`
}

Images for visual context or analysis.

Requires the 'image' prompt capability when included in prompts.

type ContentBlockResource 

type ContentBlockResource struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta        map[string]any           `json:"_meta,omitempty"`
	Annotations *Annotations             `json:"annotations,omitempty"`
	Resource    EmbeddedResourceResource `json:"resource"`
	Type        string                   `json:"type"`
}

Complete resource contents embedded directly in the message.

Preferred for including context as it avoids extra round-trips.

Requires the 'embeddedContext' prompt capability when included in prompts. 

type ContentBlockResourceLink struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta        map[string]any `json:"_meta,omitempty"`
	Annotations *Annotations   `json:"annotations,omitempty"`
	Description *string        `json:"description,omitempty"`
	MimeType    *string        `json:"mimeType,omitempty"`
	Name        string         `json:"name"`
	Size        *int           `json:"size,omitempty"`
	Title       *string        `json:"title,omitempty"`
	Type        string         `json:"type"`
	Uri         string         `json:"uri"`
}

References to resources that the agent can access.

All agents MUST support resource links in prompts.

type ContentBlockText 

type ContentBlockText struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta        map[string]any `json:"_meta,omitempty"`
	Annotations *Annotations   `json:"annotations,omitempty"`
	Text        string         `json:"text"`
	Type        string         `json:"type"`
}

Content blocks represent displayable information in the Agent Client Protocol.

They provide a structured way to handle various types of user-facing content—whether it's text from language models, images for analysis, or embedded resources for context.

Content blocks appear in: - User prompts sent via 'session/prompt' - Language model output streamed through 'session/update' notifications - Progress updates and results from tool calls

This structure is compatible with the Model Context Protocol (MCP), enabling agents to seamlessly forward content from MCP tool outputs without transformation.

See protocol docs: Content(https://agentclientprotocol.com/protocol/content) Text content. May be plain text or formatted with Markdown.

All agents MUST support text content blocks in prompts. Clients SHOULD render this text as Markdown.

type ContentChunk added in v0.10.8 

type ContentChunk struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// A single item of content
	Content ContentBlock `json:"content"`
}

A streamed item of content

type Cost added in v0.10.8 

type Cost struct {
	// Total cumulative cost for session.
	Amount float64 `json:"amount"`
	// ISO 4217 currency code (e.g., "USD", "EUR").
	Currency string `json:"currency"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Cost information for a session.

type CreateTerminalRequest 

type CreateTerminalRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Array of command arguments.
	Args []string `json:"args,omitempty"`
	// The command to execute.
	Command string `json:"command"`
	// Working directory for the command (absolute path).
	Cwd *string `json:"cwd,omitempty"`
	// Environment variables for the command.
	Env []EnvVariable `json:"env,omitempty"`
	// Maximum number of output bytes to retain.
	//
	// When the limit is exceeded, the Client truncates from the beginning of the output
	// to stay within the limit.
	//
	// The Client MUST ensure truncation happens at a character boundary to maintain valid
	// string output, even if this means the retained output is slightly less than the
	// specified limit.
	OutputByteLimit *int `json:"outputByteLimit,omitempty"`
	// The session ID for this request.
	SessionId SessionId `json:"sessionId"`
}

Request to create a new terminal and execute a command.

func (*CreateTerminalRequest) Validate 

func (v *CreateTerminalRequest) Validate() error

type CreateTerminalResponse 

type CreateTerminalResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The unique identifier for the created terminal.
	TerminalId string `json:"terminalId"`
}

Response containing the ID of the created terminal.

func (*CreateTerminalResponse) Validate 

func (v *CreateTerminalResponse) Validate() error

type CurrentModeUpdate added in v0.10.8 

type CurrentModeUpdate struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The ID of the current mode
	CurrentModeId SessionModeId `json:"currentModeId"`
}

The current mode of the session has changed

See protocol docs: [Session Modes](https://agentclientprotocol.com/protocol/session-modes)

type Diff added in v0.10.8 

type Diff struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The new content after modification.
	NewText string `json:"newText"`
	// The original content (None for new files).
	OldText *string `json:"oldText,omitempty"`
	// The file path being modified.
	Path string `json:"path"`
}

A diff representing file modifications.

Shows changes to files in a format suitable for display in the client UI.

See protocol docs: Content(https://agentclientprotocol.com/protocol/tool-calls#content)

type EmbeddedResource 

type EmbeddedResource struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta        map[string]any           `json:"_meta,omitempty"`
	Annotations *Annotations             `json:"annotations,omitempty"`
	Resource    EmbeddedResourceResource `json:"resource"`
}

The contents of a resource, embedded into a prompt or tool call result.

type EmbeddedResourceResource 

type EmbeddedResourceResource struct {
	TextResourceContents *TextResourceContents `json:"-"`
	BlobResourceContents *BlobResourceContents `json:"-"`
}

Resource content that can be embedded in a message.

func (EmbeddedResourceResource) MarshalJSON 

func (u EmbeddedResourceResource) MarshalJSON() ([]byte, error)

func (*EmbeddedResourceResource) UnmarshalJSON 

func (u *EmbeddedResourceResource) UnmarshalJSON(b []byte) error

type EnvVariable 

type EnvVariable struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The name of the environment variable.
	Name string `json:"name"`
	// The value to set for the environment variable.
	Value string `json:"value"`
}

An environment variable to set when launching an MCP server.

type Error added in v0.6.3 

type Error struct {
	// A number indicating the error type that occurred.
	// This must be an integer as defined in the JSON-RPC specification.
	Code ErrorCode `json:"code"`
	// Optional primitive or structured value that contains additional information about the error.
	// This may include debugging information or context-specific details.
	Data any `json:"data,omitempty"`
	// A string providing a short description of the error.
	// The message should be limited to a concise single sentence.
	Message string `json:"message"`
}

JSON-RPC error object.

Represents an error that occurred during method execution, following the JSON-RPC 2.0 error object specification with optional additional data.

See protocol docs: [JSON-RPC Error Object](https://www.jsonrpc.org/specification#error_object)

type ErrorCode added in v0.10.8 

type ErrorCode struct {
	// **Parse error**: Invalid JSON was received by the server.
	// An error occurred on the server while parsing the JSON text.
	ParseError *ErrorCodeParseError `json:"-"`
	// **Invalid request**: The JSON sent is not a valid Request object.
	InvalidRequest *ErrorCodeInvalidRequest `json:"-"`
	// **Method not found**: The method does not exist or is not available.
	MethodNotFound *ErrorCodeMethodNotFound `json:"-"`
	// **Invalid params**: Invalid method parameter(s).
	InvalidParams *ErrorCodeInvalidParams `json:"-"`
	// **Internal error**: Internal JSON-RPC error.
	// Reserved for implementation-defined server errors.
	InternalError *ErrorCodeInternalError `json:"-"`
	// **Authentication required**: Authentication is required before this operation can be performed.
	AuthenticationRequired *ErrorCodeAuthenticationRequired `json:"-"`
	// **Resource not found**: A given resource, such as a file, was not found.
	ResourceNotFound *ErrorCodeResourceNotFound `json:"-"`
	// Other undefined error code.
	Other *ErrorCodeOther `json:"-"`
}

func (ErrorCode) MarshalJSON added in v0.10.8 

func (u ErrorCode) MarshalJSON() ([]byte, error)

func (*ErrorCode) UnmarshalJSON added in v0.10.8 

func (u *ErrorCode) UnmarshalJSON(b []byte) error

type ErrorCodeAuthenticationRequired added in v0.10.8 

type ErrorCodeAuthenticationRequired int

**Authentication required**: Authentication is required before this operation can be performed.

type ErrorCodeInternalError added in v0.10.8 

type ErrorCodeInternalError int

**Internal error**: Internal JSON-RPC error. Reserved for implementation-defined server errors.

type ErrorCodeInvalidParams added in v0.10.8 

type ErrorCodeInvalidParams int

**Invalid params**: Invalid method parameter(s).

type ErrorCodeInvalidRequest added in v0.10.8 

type ErrorCodeInvalidRequest int

**Invalid request**: The JSON sent is not a valid Request object.

type ErrorCodeMethodNotFound added in v0.10.8 

type ErrorCodeMethodNotFound int

**Method not found**: The method does not exist or is not available.

type ErrorCodeOther added in v0.10.8 

type ErrorCodeOther int

Other undefined error code.

type ErrorCodeParseError added in v0.10.8 

type ErrorCodeParseError int

Predefined error codes for common JSON-RPC and ACP-specific errors.

These codes follow the JSON-RPC 2.0 specification for standard errors and use the reserved range (-32000 to -32099) for protocol-specific errors. **Parse error**: Invalid JSON was received by the server. An error occurred on the server while parsing the JSON text.

type ErrorCodeResourceNotFound added in v0.10.8 

type ErrorCodeResourceNotFound int

**Resource not found**: A given resource, such as a file, was not found.

type ExtNotification added in v0.10.8 

type ExtNotification any

Allows the Agent to send an arbitrary notification that is not part of the ACP spec. Extension notifications provide a way to send one-way messages for custom functionality while maintaining protocol compatibility.

See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility) ExtNotification is a union or complex schema; represented generically.

type ExtRequest added in v0.10.8 

type ExtRequest any

Allows for sending an arbitrary request that is not part of the ACP spec. Extension methods provide a way to add custom functionality while maintaining protocol compatibility.

See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility) ExtRequest is a union or complex schema; represented generically.

type ExtResponse added in v0.10.8 

type ExtResponse any

Allows for sending an arbitrary response to an ['ExtRequest'] that is not part of the ACP spec. Extension methods provide a way to add custom functionality while maintaining protocol compatibility.

See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility) ExtResponse is a union or complex schema; represented generically.

type ExtensionMethodHandler added in v0.10.8 

type ExtensionMethodHandler interface {
	HandleExtensionMethod(ctx context.Context, method string, params json.RawMessage) (any, error)
}

ExtensionMethodHandler can be implemented by either an Agent or a Client.

ACP extension methods are JSON-RPC methods whose names begin with "_". They provide a stable namespace for custom functionality that is not part of the core ACP spec.

If the method is unrecognized, implementations should return NewMethodNotFound(method).

See: https://agentclientprotocol.com/protocol/extensibility#extension-methods

type FileSystemCapability 

type FileSystemCapability struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Whether the Client supports 'fs/read_text_file' requests.
	//
	// Defaults to false if unset.
	ReadTextFile bool `json:"readTextFile,omitempty"`
	// Whether the Client supports 'fs/write_text_file' requests.
	//
	// Defaults to false if unset.
	WriteTextFile bool `json:"writeTextFile,omitempty"`
}

Filesystem capabilities supported by the client. File system capabilities that a client may support.

See protocol docs: [FileSystem](https://agentclientprotocol.com/protocol/initialization#filesystem)

func (FileSystemCapability) MarshalJSON 

func (v FileSystemCapability) MarshalJSON() ([]byte, error)

func (*FileSystemCapability) UnmarshalJSON 

func (v *FileSystemCapability) UnmarshalJSON(b []byte) error

type HttpHeader 

type HttpHeader struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The name of the HTTP header.
	Name string `json:"name"`
	// The value to set for the HTTP header.
	Value string `json:"value"`
}

An HTTP header to set when making requests to the MCP server.

type ImageContent 

type ImageContent struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta        map[string]any `json:"_meta,omitempty"`
	Annotations *Annotations   `json:"annotations,omitempty"`
	Data        string         `json:"data"`
	MimeType    string         `json:"mimeType"`
	Uri         *string        `json:"uri,omitempty"`
}

An image provided to or from an LLM.

type Implementation added in v0.6.3 

type Implementation struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Intended for programmatic or logical use, but can be used as a display
	// name fallback if title isn’t present.
	Name string `json:"name"`
	// Intended for UI and end-user contexts — optimized to be human-readable
	// and easily understood.
	//
	// If not provided, the name should be used for display.
	Title *string `json:"title,omitempty"`
	// Version of the implementation. Can be displayed to the user or used
	// for debugging or metrics purposes. (e.g. "1.0.0").
	Version string `json:"version"`
}

Metadata about the implementation of the client or agent. Describes the name and version of an MCP implementation, with an optional title for UI representation.

type InitializeRequest 

type InitializeRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Capabilities supported by the client.
	//
	// Defaults to {"fs":{"readTextFile":false,"writeTextFile":false},"terminal":false} if unset.
	ClientCapabilities ClientCapabilities `json:"clientCapabilities,omitempty"`
	// Information about the Client name and version sent to the Agent.
	//
	// Note: in future versions of the protocol, this will be required.
	ClientInfo *Implementation `json:"clientInfo,omitempty"`
	// The latest protocol version supported by the client.
	ProtocolVersion ProtocolVersion `json:"protocolVersion"`
}

Request parameters for the initialize method.

Sent by the client to establish connection and negotiate capabilities.

See protocol docs: [Initialization](https://agentclientprotocol.com/protocol/initialization)

func (InitializeRequest) MarshalJSON 

func (v InitializeRequest) MarshalJSON() ([]byte, error)

func (*InitializeRequest) UnmarshalJSON 

func (v *InitializeRequest) UnmarshalJSON(b []byte) error

func (*InitializeRequest) Validate 

func (v *InitializeRequest) Validate() error

type InitializeResponse 

type InitializeResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Capabilities supported by the agent.
	//
	// Defaults to {"loadSession":false,"mcpCapabilities":{"http":false,"sse":false},"promptCapabilities":{"audio":false,"embeddedContext":false,"image":false},"sessionCapabilities":{}} if unset.
	AgentCapabilities AgentCapabilities `json:"agentCapabilities,omitempty"`
	// Information about the Agent name and version sent to the Client.
	//
	// Note: in future versions of the protocol, this will be required.
	AgentInfo *Implementation `json:"agentInfo,omitempty"`
	// Authentication methods supported by the agent.
	//
	// Defaults to [] if unset.
	AuthMethods []AuthMethod `json:"authMethods"`
	// The protocol version the client specified if supported by the agent,
	// or the latest protocol version supported by the agent.
	//
	// The client should disconnect, if it doesn't support this version.
	ProtocolVersion ProtocolVersion `json:"protocolVersion"`
}

Response to the 'initialize' method.

Contains the negotiated protocol version and agent capabilities.

See protocol docs: [Initialization](https://agentclientprotocol.com/protocol/initialization)

func (InitializeResponse) MarshalJSON 

func (v InitializeResponse) MarshalJSON() ([]byte, error)

func (*InitializeResponse) UnmarshalJSON 

func (v *InitializeResponse) UnmarshalJSON(b []byte) error

func (*InitializeResponse) Validate 

func (v *InitializeResponse) Validate() error

type KillTerminalCommandRequest 

type KillTerminalCommandRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The session ID for this request.
	SessionId SessionId `json:"sessionId"`
	// The ID of the terminal to kill.
	TerminalId string `json:"terminalId"`
}

Request to kill a terminal command without releasing the terminal.

func (*KillTerminalCommandRequest) Validate 

func (v *KillTerminalCommandRequest) Validate() error

type KillTerminalCommandResponse 

type KillTerminalCommandResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
}

Response to terminal/kill command method

func (*KillTerminalCommandResponse) Validate 

func (v *KillTerminalCommandResponse) Validate() error

type LoadSessionRequest 

type LoadSessionRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The working directory for this session.
	Cwd string `json:"cwd"`
	// List of MCP servers to connect to for this session.
	McpServers []McpServer `json:"mcpServers"`
	// The ID of the session to load.
	SessionId SessionId `json:"sessionId"`
}

Request parameters for loading an existing session.

Only available if the Agent supports the 'loadSession' capability.

See protocol docs: [Loading Sessions](https://agentclientprotocol.com/protocol/session-setup#loading-sessions)

func (*LoadSessionRequest) Validate 

func (v *LoadSessionRequest) Validate() error

type LoadSessionResponse 

type LoadSessionResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Initial session configuration options if supported by the Agent.
	ConfigOptions []SessionConfigOption `json:"configOptions,omitempty"`
	// **UNSTABLE**
	//
	// This capability is not part of the spec yet, and may be removed or changed at any point.
	//
	// Initial model state if supported by the Agent
	Models *SessionModelState `json:"models,omitempty"`
	// Initial mode state if supported by the Agent
	//
	// See protocol docs: [Session Modes](https://agentclientprotocol.com/protocol/session-modes)
	Modes *SessionModeState `json:"modes,omitempty"`
}

Response from loading an existing session.

func (*LoadSessionResponse) Validate 

func (v *LoadSessionResponse) Validate() error

type McpCapabilities 

type McpCapabilities struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Agent supports ['McpServer::Http'].
	//
	// Defaults to false if unset.
	Http bool `json:"http,omitempty"`
	// Agent supports ['McpServer::Sse'].
	//
	// Defaults to false if unset.
	Sse bool `json:"sse,omitempty"`
}

MCP capabilities supported by the agent

func (McpCapabilities) MarshalJSON 

func (v McpCapabilities) MarshalJSON() ([]byte, error)

func (*McpCapabilities) UnmarshalJSON 

func (v *McpCapabilities) UnmarshalJSON(b []byte) error

type McpServer 

type McpServer struct {
	// HTTP transport configuration
	//
	// Only available when the Agent capabilities indicate 'mcp_capabilities.http' is 'true'.
	Http *McpServerHttpInline `json:"-"`
	// SSE transport configuration
	//
	// Only available when the Agent capabilities indicate 'mcp_capabilities.sse' is 'true'.
	Sse *McpServerSseInline `json:"-"`
	// Stdio transport configuration
	//
	// All Agents MUST support this transport.
	Stdio *McpServerStdio `json:"-"`
}

func (McpServer) MarshalJSON 

func (u McpServer) MarshalJSON() ([]byte, error)

func (*McpServer) UnmarshalJSON 

func (u *McpServer) UnmarshalJSON(b []byte) error

type McpServerHttp 

type McpServerHttp struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// HTTP headers to set when making requests to the MCP server.
	Headers []HttpHeader `json:"headers"`
	// Human-readable name identifying this MCP server.
	Name string `json:"name"`
	// URL to the MCP server.
	Url string `json:"url"`
}

HTTP transport configuration for MCP.

type McpServerHttpInline added in v0.10.8 

type McpServerHttpInline struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// HTTP headers to set when making requests to the MCP server.
	Headers []HttpHeader `json:"headers"`
	// Human-readable name identifying this MCP server.
	Name string `json:"name"`
	Type string `json:"type"`
	// URL to the MCP server.
	Url string `json:"url"`
}

Configuration for connecting to an MCP (Model Context Protocol) server.

MCP servers provide tools and context that the agent can use when processing prompts.

See protocol docs: [MCP Servers](https://agentclientprotocol.com/protocol/session-setup#mcp-servers) HTTP transport configuration

Only available when the Agent capabilities indicate 'mcp_capabilities.http' is 'true'.

type McpServerSse 

type McpServerSse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// HTTP headers to set when making requests to the MCP server.
	Headers []HttpHeader `json:"headers"`
	// Human-readable name identifying this MCP server.
	Name string `json:"name"`
	// URL to the MCP server.
	Url string `json:"url"`
}

SSE transport configuration for MCP.

type McpServerSseInline added in v0.10.8 

type McpServerSseInline struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// HTTP headers to set when making requests to the MCP server.
	Headers []HttpHeader `json:"headers"`
	// Human-readable name identifying this MCP server.
	Name string `json:"name"`
	Type string `json:"type"`
	// URL to the MCP server.
	Url string `json:"url"`
}

SSE transport configuration

Only available when the Agent capabilities indicate 'mcp_capabilities.sse' is 'true'.

type McpServerStdio added in v0.6.3 

type McpServerStdio struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Command-line arguments to pass to the MCP server.
	Args []string `json:"args"`
	// Path to the MCP server executable.
	Command string `json:"command"`
	// Environment variables to set when launching the MCP server.
	Env []EnvVariable `json:"env"`
	// Human-readable name identifying this MCP server.
	Name string `json:"name"`
}

Stdio transport configuration for MCP.

type MethodHandler 

type MethodHandler func(ctx context.Context, method string, params json.RawMessage) (any, *RequestError)

type ModelId 

type ModelId string

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

A unique identifier for a model.

type ModelInfo 

type ModelInfo struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Optional description of the model.
	Description *string `json:"description,omitempty"`
	// Unique identifier for the model.
	ModelId ModelId `json:"modelId"`
	// Human-readable name of the model.
	Name string `json:"name"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Information about a selectable model.

type NewSessionRequest 

type NewSessionRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The working directory for this session. Must be an absolute path.
	Cwd string `json:"cwd"`
	// List of MCP (Model Context Protocol) servers the agent should connect to.
	McpServers []McpServer `json:"mcpServers"`
}

Request parameters for creating a new session.

See protocol docs: [Creating a Session](https://agentclientprotocol.com/protocol/session-setup#creating-a-session)

func (*NewSessionRequest) Validate 

func (v *NewSessionRequest) Validate() error

type NewSessionResponse 

type NewSessionResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Initial session configuration options if supported by the Agent.
	ConfigOptions []SessionConfigOption `json:"configOptions,omitempty"`
	// **UNSTABLE**
	//
	// This capability is not part of the spec yet, and may be removed or changed at any point.
	//
	// Initial model state if supported by the Agent
	Models *SessionModelState `json:"models,omitempty"`
	// Initial mode state if supported by the Agent
	//
	// See protocol docs: [Session Modes](https://agentclientprotocol.com/protocol/session-modes)
	Modes *SessionModeState `json:"modes,omitempty"`
	// Unique identifier for the created session.
	//
	// Used in all subsequent requests for this conversation.
	SessionId SessionId `json:"sessionId"`
}

Response from creating a new session.

See protocol docs: [Creating a Session](https://agentclientprotocol.com/protocol/session-setup#creating-a-session)

func (*NewSessionResponse) Validate 

func (v *NewSessionResponse) Validate() error

type PermissionOption 

type PermissionOption struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Hint about the nature of this permission option.
	Kind PermissionOptionKind `json:"kind"`
	// Human-readable label to display to the user.
	Name string `json:"name"`
	// Unique identifier for this permission option.
	OptionId PermissionOptionId `json:"optionId"`
}

An option presented to the user when requesting permission.

type PermissionOptionId 

type PermissionOptionId string

Unique identifier for a permission option.

type PermissionOptionKind 

type PermissionOptionKind string

The type of permission option being presented to the user.

Helps clients choose appropriate icons and UI treatment. 

const (
	PermissionOptionKindAllowOnce    PermissionOptionKind = "allow_once"
	PermissionOptionKindAllowAlways  PermissionOptionKind = "allow_always"
	PermissionOptionKindRejectOnce   PermissionOptionKind = "reject_once"
	PermissionOptionKindRejectAlways PermissionOptionKind = "reject_always"
)

type Plan 

type Plan struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The list of tasks to be accomplished.
	//
	// When updating a plan, the agent must send a complete list of all entries
	// with their current status. The client replaces the entire plan with each update.
	Entries []PlanEntry `json:"entries"`
}

An execution plan for accomplishing complex tasks.

Plans consist of multiple entries representing individual tasks or goals. Agents report plans to clients to provide visibility into their execution strategy. Plans can evolve during execution as the agent discovers new requirements or completes tasks.

See protocol docs: [Agent Plan](https://agentclientprotocol.com/protocol/agent-plan)

type PlanEntry 

type PlanEntry struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Human-readable description of what this task aims to accomplish.
	Content string `json:"content"`
	// The relative importance of this task.
	// Used to indicate which tasks are most critical to the overall goal.
	Priority PlanEntryPriority `json:"priority"`
	// Current execution status of this task.
	Status PlanEntryStatus `json:"status"`
}

A single entry in the execution plan.

Represents a task or goal that the assistant intends to accomplish as part of fulfilling the user's request. See protocol docs: [Plan Entries](https://agentclientprotocol.com/protocol/agent-plan#plan-entries)

type PlanEntryPriority 

type PlanEntryPriority string

Priority levels for plan entries.

Used to indicate the relative importance or urgency of different tasks in the execution plan. See protocol docs: [Plan Entries](https://agentclientprotocol.com/protocol/agent-plan#plan-entries) 

const (
	PlanEntryPriorityHigh   PlanEntryPriority = "high"
	PlanEntryPriorityMedium PlanEntryPriority = "medium"
	PlanEntryPriorityLow    PlanEntryPriority = "low"
)

type PlanEntryStatus 

type PlanEntryStatus string

Status of a plan entry in the execution flow.

Tracks the lifecycle of each task from planning through completion. See protocol docs: [Plan Entries](https://agentclientprotocol.com/protocol/agent-plan#plan-entries) 

const (
	PlanEntryStatusPending    PlanEntryStatus = "pending"
	PlanEntryStatusInProgress PlanEntryStatus = "in_progress"
	PlanEntryStatusCompleted  PlanEntryStatus = "completed"
)

type PromptCapabilities 

type PromptCapabilities struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Agent supports ['ContentBlock::Audio'].
	//
	// Defaults to false if unset.
	Audio bool `json:"audio,omitempty"`
	// Agent supports embedded context in 'session/prompt' requests.
	//
	// When enabled, the Client is allowed to include ['ContentBlock::Resource']
	// in prompt requests for pieces of context that are referenced in the message.
	//
	// Defaults to false if unset.
	EmbeddedContext bool `json:"embeddedContext,omitempty"`
	// Agent supports ['ContentBlock::Image'].
	//
	// Defaults to false if unset.
	Image bool `json:"image,omitempty"`
}

Prompt capabilities supported by the agent in 'session/prompt' requests.

Baseline agent functionality requires support for ['ContentBlock::Text'] and ['ContentBlock::ResourceLink'] in prompt requests.

Other variants must be explicitly opted in to. Capabilities for different types of content in prompt requests.

Indicates which content types beyond the baseline (text and resource links) the agent can process.

See protocol docs: [Prompt Capabilities](https://agentclientprotocol.com/protocol/initialization#prompt-capabilities)

func (PromptCapabilities) MarshalJSON 

func (v PromptCapabilities) MarshalJSON() ([]byte, error)

func (*PromptCapabilities) UnmarshalJSON 

func (v *PromptCapabilities) UnmarshalJSON(b []byte) error

type PromptRequest 

type PromptRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The blocks of content that compose the user's message.
	//
	// As a baseline, the Agent MUST support ['ContentBlock::Text'] and ['ContentBlock::ResourceLink'],
	// while other variants are optionally enabled via ['PromptCapabilities'].
	//
	// The Client MUST adapt its interface according to ['PromptCapabilities'].
	//
	// The client MAY include referenced pieces of context as either
	// ['ContentBlock::Resource'] or ['ContentBlock::ResourceLink'].
	//
	// When available, ['ContentBlock::Resource'] is preferred
	// as it avoids extra round-trips and allows the message to include
	// pieces of context from sources the agent may not have access to.
	Prompt []ContentBlock `json:"prompt"`
	// The ID of the session to send this user message to
	SessionId SessionId `json:"sessionId"`
}

Request parameters for sending a user prompt to the agent.

Contains the user's message and any additional context.

See protocol docs: [User Message](https://agentclientprotocol.com/protocol/prompt-turn#1-user-message)

func (*PromptRequest) Validate 

func (v *PromptRequest) Validate() error

type PromptResponse 

type PromptResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Indicates why the agent stopped processing the turn.
	StopReason StopReason `json:"stopReason"`
	// **UNSTABLE**
	//
	// This capability is not part of the spec yet, and may be removed or changed at any point.
	//
	// Token usage for this turn (optional).
	Usage *Usage `json:"usage,omitempty"`
}

Response from processing a user prompt.

See protocol docs: [Check for Completion](https://agentclientprotocol.com/protocol/prompt-turn#4-check-for-completion)

func (*PromptResponse) Validate 

func (v *PromptResponse) Validate() error

type ProtocolVersion 

type ProtocolVersion int

Protocol version identifier.

This version is only bumped for breaking changes. Non-breaking changes should be introduced via capabilities.

type ReadTextFileRequest 

type ReadTextFileRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Maximum number of lines to read.
	Limit *int `json:"limit,omitempty"`
	// Line number to start reading from (1-based).
	Line *int `json:"line,omitempty"`
	// Absolute path to the file to read.
	Path string `json:"path"`
	// The session ID for this request.
	SessionId SessionId `json:"sessionId"`
}

Request to read content from a text file.

Only available if the client supports the 'fs.readTextFile' capability.

func (*ReadTextFileRequest) Validate 

func (v *ReadTextFileRequest) Validate() error

type ReadTextFileResponse 

type ReadTextFileResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta    map[string]any `json:"_meta,omitempty"`
	Content string         `json:"content"`
}

Response containing the contents of a text file.

func (*ReadTextFileResponse) Validate 

func (v *ReadTextFileResponse) Validate() error

type ReleaseTerminalRequest 

type ReleaseTerminalRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The session ID for this request.
	SessionId SessionId `json:"sessionId"`
	// The ID of the terminal to release.
	TerminalId string `json:"terminalId"`
}

Request to release a terminal and free its resources.

func (*ReleaseTerminalRequest) Validate 

func (v *ReleaseTerminalRequest) Validate() error

type ReleaseTerminalResponse 

type ReleaseTerminalResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
}

Response to terminal/release method

func (*ReleaseTerminalResponse) Validate 

func (v *ReleaseTerminalResponse) Validate() error

type RequestError 

type RequestError struct {
	Code    int    `json:"code"`
	Message string `json:"message"`
	Data    any    `json:"data,omitempty"`
}

RequestError represents a JSON-RPC error response.

func NewAuthRequired 

func NewAuthRequired(data any) *RequestError

func NewInternalError 

func NewInternalError(data any) *RequestError

func NewInvalidParams 

func NewInvalidParams(data any) *RequestError

func NewInvalidRequest 

func NewInvalidRequest(data any) *RequestError

func NewMethodNotFound 

func NewMethodNotFound(method string) *RequestError

func NewParseError 

func NewParseError(data any) *RequestError

func NewRequestCancelled added in v0.10.8 

func NewRequestCancelled(data any) *RequestError

func (*RequestError) Error 

func (e *RequestError) Error() string

type RequestId added in v0.10.8 

type RequestId struct {
	Null   *RequestIdNull   `json:"-"`
	Number *RequestIdNumber `json:"-"`
	Str    *RequestIdStr    `json:"-"`
}

func (RequestId) MarshalJSON added in v0.10.8 

func (u RequestId) MarshalJSON() ([]byte, error)

func (*RequestId) UnmarshalJSON added in v0.10.8 

func (u *RequestId) UnmarshalJSON(b []byte) error

type RequestIdNull added in v0.10.8 

type RequestIdNull struct{}

JSON RPC Request Id

An identifier established by the Client that MUST contain a String, Number, or NULL value if included. If it is not included it is assumed to be a notification. The value SHOULD normally not be Null [1] and Numbers SHOULD NOT contain fractional parts [2]

The Server MUST reply with the same value in the Response object if included. This member is used to correlate the context between the two objects.

[1] The use of Null as a value for the id member in a Request object is discouraged, because this specification uses a value of Null for Responses with an unknown id. Also, because JSON-RPC 1.0 uses an id value of Null for Notifications this could cause confusion in handling.

[2] Fractional parts may be problematic, since many decimal fractions cannot be represented exactly as binary fractions.

type RequestIdNumber added in v0.10.8 

type RequestIdNumber int

type RequestIdStr added in v0.10.8 

type RequestIdStr string

type RequestPermissionOutcome 

type RequestPermissionOutcome struct {
	// The prompt turn was cancelled before the user responded.
	//
	// When a client sends a 'session/cancel' notification to cancel an ongoing
	// prompt turn, it MUST respond to all pending 'session/request_permission'
	// requests with this 'Cancelled' outcome.
	//
	// See protocol docs: [Cancellation](https://agentclientprotocol.com/protocol/prompt-turn#cancellation)
	Cancelled *RequestPermissionOutcomeCancelled `json:"-"`
	// The user selected one of the provided options.
	Selected *RequestPermissionOutcomeSelected `json:"-"`
}

func NewRequestPermissionOutcomeCancelled 

func NewRequestPermissionOutcomeCancelled() RequestPermissionOutcome

NewRequestPermissionOutcomeCancelled constructs a RequestPermissionOutcome using the 'cancelled' variant.

func NewRequestPermissionOutcomeSelected 

func NewRequestPermissionOutcomeSelected() RequestPermissionOutcome

NewRequestPermissionOutcomeSelected constructs a RequestPermissionOutcome using the 'selected' variant.

func (RequestPermissionOutcome) MarshalJSON 

func (u RequestPermissionOutcome) MarshalJSON() ([]byte, error)

func (*RequestPermissionOutcome) UnmarshalJSON 

func (u *RequestPermissionOutcome) UnmarshalJSON(b []byte) error

func (*RequestPermissionOutcome) Validate 

func (u *RequestPermissionOutcome) Validate() error

type RequestPermissionOutcomeCancelled 

type RequestPermissionOutcomeCancelled struct {
	Outcome string `json:"outcome"`
}

The outcome of a permission request. The prompt turn was cancelled before the user responded.

When a client sends a 'session/cancel' notification to cancel an ongoing prompt turn, it MUST respond to all pending 'session/request_permission' requests with this 'Cancelled' outcome.

See protocol docs: [Cancellation](https://agentclientprotocol.com/protocol/prompt-turn#cancellation)

type RequestPermissionOutcomeSelected 

type RequestPermissionOutcomeSelected struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The ID of the option the user selected.
	OptionId PermissionOptionId `json:"optionId"`
	Outcome  string             `json:"outcome"`
}

The user selected one of the provided options.

type RequestPermissionRequest 

type RequestPermissionRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Available permission options for the user to choose from.
	Options []PermissionOption `json:"options"`
	// The session ID for this request.
	SessionId SessionId `json:"sessionId"`
	// Details about the tool call requiring permission.
	ToolCall ToolCallUpdate `json:"toolCall"`
}

Request for user permission to execute a tool call.

Sent when the agent needs authorization before performing a sensitive operation.

See protocol docs: [Requesting Permission](https://agentclientprotocol.com/protocol/tool-calls#requesting-permission)

func (*RequestPermissionRequest) Validate 

func (v *RequestPermissionRequest) Validate() error

type RequestPermissionResponse 

type RequestPermissionResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The user's decision on the permission request.
	Outcome RequestPermissionOutcome `json:"outcome"`
}

Response to a permission request.

func (*RequestPermissionResponse) Validate 

func (v *RequestPermissionResponse) Validate() error
type ResourceLink struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta        map[string]any `json:"_meta,omitempty"`
	Annotations *Annotations   `json:"annotations,omitempty"`
	Description *string        `json:"description,omitempty"`
	MimeType    *string        `json:"mimeType,omitempty"`
	Name        string         `json:"name"`
	Size        *int           `json:"size,omitempty"`
	Title       *string        `json:"title,omitempty"`
	Uri         string         `json:"uri"`
}

A resource that the server is capable of reading, included in a prompt or tool call result.

type Role 

type Role string

The sender or recipient of messages and data in a conversation. 

const (
	RoleAssistant Role = "assistant"
	RoleUser      Role = "user"
)

type SelectedPermissionOutcome added in v0.10.8 

type SelectedPermissionOutcome struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The ID of the option the user selected.
	OptionId PermissionOptionId `json:"optionId"`
}

The user selected one of the provided options.

type SessionAvailableCommandsUpdate added in v0.6.3 

type SessionAvailableCommandsUpdate struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Commands the agent can execute
	AvailableCommands []AvailableCommand `json:"availableCommands"`
	SessionUpdate     string             `json:"sessionUpdate"`
}

Available commands are ready or have changed

type SessionCapabilities added in v0.10.8 

type SessionCapabilities struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// **UNSTABLE**
	//
	// This capability is not part of the spec yet, and may be removed or changed at any point.
	//
	// Whether the agent supports 'session/fork'.
	Fork *SessionForkCapabilities `json:"fork,omitempty"`
	// **UNSTABLE**
	//
	// This capability is not part of the spec yet, and may be removed or changed at any point.
	//
	// Whether the agent supports 'session/list'.
	List *SessionListCapabilities `json:"list,omitempty"`
	// **UNSTABLE**
	//
	// This capability is not part of the spec yet, and may be removed or changed at any point.
	//
	// Whether the agent supports 'session/resume'.
	Resume *SessionResumeCapabilities `json:"resume,omitempty"`
}

Session capabilities supported by the agent.

As a baseline, all Agents **MUST** support 'session/new', 'session/prompt', 'session/cancel', and 'session/update'.

Optionally, they **MAY** support other session methods and notifications by specifying additional capabilities.

Note: 'session/load' is still handled by the top-level 'load_session' capability. This will be unified in future versions of the protocol.

See protocol docs: [Session Capabilities](https://agentclientprotocol.com/protocol/initialization#session-capabilities)

type SessionConfigGroupId added in v0.10.8 

type SessionConfigGroupId string

Unique identifier for a session configuration option value group.

type SessionConfigId added in v0.10.8 

type SessionConfigId string

Unique identifier for a session configuration option.

type SessionConfigOption added in v0.10.8 

type SessionConfigOption struct {
	// Single-value selector (dropdown).
	Select *SessionConfigOptionSelect `json:"-"`
}

func NewSessionConfigOptionSelect added in v0.10.8 

func NewSessionConfigOptionSelect() SessionConfigOption

NewSessionConfigOptionSelect constructs a SessionConfigOption using the 'select' variant.

func (SessionConfigOption) MarshalJSON added in v0.10.8 

func (u SessionConfigOption) MarshalJSON() ([]byte, error)

func (*SessionConfigOption) UnmarshalJSON added in v0.10.8 

func (u *SessionConfigOption) UnmarshalJSON(b []byte) error

func (*SessionConfigOption) Validate added in v0.10.8 

func (u *SessionConfigOption) Validate() error

type SessionConfigOptionCategory added in v0.10.8 

type SessionConfigOptionCategory struct {
	// Unknown / uncategorized selector.
	Other *SessionConfigOptionCategoryOther `json:"-"`
}

func (SessionConfigOptionCategory) MarshalJSON added in v0.10.8 

func (u SessionConfigOptionCategory) MarshalJSON() ([]byte, error)

func (*SessionConfigOptionCategory) UnmarshalJSON added in v0.10.8 

func (u *SessionConfigOptionCategory) UnmarshalJSON(b []byte) error

type SessionConfigOptionCategoryOther added in v0.10.8 

type SessionConfigOptionCategoryOther string

Semantic category for a session configuration option.

This is intended to help Clients distinguish broadly common selectors (e.g. model selector vs session mode selector vs thought/reasoning level) for UX purposes (keyboard shortcuts, icons, placement). It MUST NOT be required for correctness. Clients MUST handle missing or unknown categories gracefully.

Category names beginning with '_' are free for custom use, like other ACP extension methods. Category names that do not begin with '_' are reserved for the ACP spec. Unknown / uncategorized selector.

type SessionConfigOptionSelect added in v0.10.8 

type SessionConfigOptionSelect struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Optional semantic category for this option (UX only).
	Category *SessionConfigOptionCategory `json:"category,omitempty"`
	// The currently selected value.
	CurrentValue SessionConfigValueId `json:"currentValue"`
	// Optional description for the Client to display to the user.
	Description *string `json:"description,omitempty"`
	// Unique identifier for the configuration option.
	Id SessionConfigId `json:"id"`
	// Human-readable label for the option.
	Name string `json:"name"`
	// The set of selectable options.
	Options SessionConfigSelectOptions `json:"options"`
	Type    string                     `json:"type"`
}

A session configuration option selector and its current state. Single-value selector (dropdown).

type SessionConfigOptionUpdate added in v0.10.8 

type SessionConfigOptionUpdate struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The full set of configuration options and their current values.
	ConfigOptions []SessionConfigOption `json:"configOptions"`
	SessionUpdate string                `json:"sessionUpdate"`
}

Session configuration options have been updated.

type SessionConfigSelect added in v0.10.8 

type SessionConfigSelect struct {
	// The currently selected value.
	CurrentValue SessionConfigValueId `json:"currentValue"`
	// The set of selectable options.
	Options SessionConfigSelectOptions `json:"options"`
}

A single-value selector (dropdown) session configuration option payload.

type SessionConfigSelectGroup added in v0.10.8 

type SessionConfigSelectGroup struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Unique identifier for this group.
	Group SessionConfigGroupId `json:"group"`
	// Human-readable label for this group.
	Name string `json:"name"`
	// The set of option values in this group.
	Options []SessionConfigSelectOption `json:"options"`
}

A group of possible values for a session configuration option.

type SessionConfigSelectOption added in v0.10.8 

type SessionConfigSelectOption struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Optional description for this option value.
	Description *string `json:"description,omitempty"`
	// Human-readable label for this option value.
	Name string `json:"name"`
	// Unique identifier for this option value.
	Value SessionConfigValueId `json:"value"`
}

A possible value for a session configuration option.

type SessionConfigSelectOptions added in v0.10.8 

type SessionConfigSelectOptions struct {
	// A flat list of options with no grouping.
	Ungrouped *SessionConfigSelectOptionsUngrouped `json:"-"`
	// A list of options grouped under headers.
	Grouped *SessionConfigSelectOptionsGrouped `json:"-"`
}

func (SessionConfigSelectOptions) MarshalJSON added in v0.10.8 

func (u SessionConfigSelectOptions) MarshalJSON() ([]byte, error)

func (*SessionConfigSelectOptions) UnmarshalJSON added in v0.10.8 

func (u *SessionConfigSelectOptions) UnmarshalJSON(b []byte) error

type SessionConfigSelectOptionsGrouped added in v0.10.8 

type SessionConfigSelectOptionsGrouped []SessionConfigSelectGroup

A list of options grouped under headers.

type SessionConfigSelectOptionsUngrouped added in v0.10.8 

type SessionConfigSelectOptionsUngrouped []SessionConfigSelectOption

Possible values for a session configuration option. A flat list of options with no grouping.

type SessionConfigValueId added in v0.10.8 

type SessionConfigValueId string

Unique identifier for a session configuration option value.

type SessionCurrentModeUpdate added in v0.6.3 

type SessionCurrentModeUpdate struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The ID of the current mode
	CurrentModeId SessionModeId `json:"currentModeId"`
	SessionUpdate string        `json:"sessionUpdate"`
}

The current mode of the session has changed

See protocol docs: [Session Modes](https://agentclientprotocol.com/protocol/session-modes)

type SessionForkCapabilities added in v0.10.8 

type SessionForkCapabilities struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Capabilities for the 'session/fork' method.

By supplying '{}' it means that the agent supports forking of sessions.

type SessionId 

type SessionId string

A unique identifier for a conversation session between a client and agent.

Sessions maintain their own context, conversation history, and state, allowing multiple independent interactions with the same agent.

See protocol docs: [Session ID](https://agentclientprotocol.com/protocol/session-setup#session-id)

type SessionInfoUpdate added in v0.10.8 

type SessionInfoUpdate struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Human-readable title for the session. Set to null to clear.
	Title *string `json:"title,omitempty"`
	// ISO 8601 timestamp of last activity. Set to null to clear.
	UpdatedAt *string `json:"updatedAt,omitempty"`
}

Update to session metadata. All fields are optional to support partial updates.

Agents send this notification to update session information like title or custom metadata. This allows clients to display dynamic session names and track session state changes.

type SessionListCapabilities added in v0.10.8 

type SessionListCapabilities struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
}

Capabilities for the 'session/list' method.

By supplying '{}' it means that the agent supports listing of sessions.

Further capabilities can be added in the future for other means of filtering or searching the list.

type SessionMode 

type SessionMode struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta        map[string]any `json:"_meta,omitempty"`
	Description *string        `json:"description,omitempty"`
	Id          SessionModeId  `json:"id"`
	Name        string         `json:"name"`
}

A mode the agent can operate in.

See protocol docs: [Session Modes](https://agentclientprotocol.com/protocol/session-modes)

type SessionModeId 

type SessionModeId string

Unique identifier for a Session Mode.

type SessionModeState 

type SessionModeState struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The set of modes that the Agent can operate in
	AvailableModes []SessionMode `json:"availableModes"`
	// The current mode the Agent is in.
	CurrentModeId SessionModeId `json:"currentModeId"`
}

The set of modes and the one currently active.

type SessionModelState 

type SessionModelState struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The set of models that the Agent can use
	AvailableModels []ModelInfo `json:"availableModels"`
	// The current model the Agent is in.
	CurrentModelId ModelId `json:"currentModelId"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

The set of models and the one currently active.

type SessionNotification 

type SessionNotification struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The ID of the session this update pertains to.
	SessionId SessionId `json:"sessionId"`
	// The actual update content.
	Update SessionUpdate `json:"update"`
}

Notification containing a session update from the agent.

Used to stream real-time progress and results during prompt processing.

See protocol docs: [Agent Reports Output](https://agentclientprotocol.com/protocol/prompt-turn#3-agent-reports-output)

func (*SessionNotification) Validate 

func (v *SessionNotification) Validate() error

type SessionResumeCapabilities added in v0.10.8 

type SessionResumeCapabilities struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Capabilities for the 'session/resume' method.

By supplying '{}' it means that the agent supports resuming of sessions.

type SessionSessionInfoUpdate added in v0.10.8 

type SessionSessionInfoUpdate struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta          map[string]any `json:"_meta,omitempty"`
	SessionUpdate string         `json:"sessionUpdate"`
	// Human-readable title for the session. Set to null to clear.
	Title *string `json:"title,omitempty"`
	// ISO 8601 timestamp of last activity. Set to null to clear.
	UpdatedAt *string `json:"updatedAt,omitempty"`
}

Session metadata has been updated (title, timestamps, custom metadata)

type SessionToolCallUpdate added in v0.6.3 

type SessionToolCallUpdate struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Replace the content collection.
	Content []ToolCallContent `json:"content,omitempty"`
	// Update the tool kind.
	Kind *ToolKind `json:"kind,omitempty"`
	// Replace the locations collection.
	Locations []ToolCallLocation `json:"locations,omitempty"`
	// Update the raw input.
	RawInput any `json:"rawInput,omitempty"`
	// Update the raw output.
	RawOutput     any    `json:"rawOutput,omitempty"`
	SessionUpdate string `json:"sessionUpdate"`
	// Update the execution status.
	Status *ToolCallStatus `json:"status,omitempty"`
	// Update the human-readable title.
	Title *string `json:"title,omitempty"`
	// The ID of the tool call being updated.
	ToolCallId ToolCallId `json:"toolCallId"`
}

Update on the status or results of a tool call.

type SessionUpdate 

type SessionUpdate struct {
	// A chunk of the user's message being streamed.
	UserMessageChunk *SessionUpdateUserMessageChunk `json:"-"`
	// A chunk of the agent's response being streamed.
	AgentMessageChunk *SessionUpdateAgentMessageChunk `json:"-"`
	// A chunk of the agent's internal reasoning being streamed.
	AgentThoughtChunk *SessionUpdateAgentThoughtChunk `json:"-"`
	// Notification that a new tool call has been initiated.
	ToolCall *SessionUpdateToolCall `json:"-"`
	// Update on the status or results of a tool call.
	ToolCallUpdate *SessionToolCallUpdate `json:"-"`
	// The agent's execution plan for complex tasks.
	// See protocol docs: [Agent Plan](https://agentclientprotocol.com/protocol/agent-plan)
	Plan *SessionUpdatePlan `json:"-"`
	// Available commands are ready or have changed
	AvailableCommandsUpdate *SessionAvailableCommandsUpdate `json:"-"`
	// The current mode of the session has changed
	//
	// See protocol docs: [Session Modes](https://agentclientprotocol.com/protocol/session-modes)
	CurrentModeUpdate *SessionCurrentModeUpdate `json:"-"`
	// Session configuration options have been updated.
	ConfigOptionUpdate *SessionConfigOptionUpdate `json:"-"`
	// Session metadata has been updated (title, timestamps, custom metadata)
	SessionInfoUpdate *SessionSessionInfoUpdate `json:"-"`
	// **UNSTABLE**
	//
	// This capability is not part of the spec yet, and may be removed or changed at any point.
	//
	// Context window and cost update for the session.
	UsageUpdate *SessionUsageUpdate `json:"-"`
}

func StartEditToolCall 

func StartEditToolCall(id ToolCallId, title string, path string, content any, opts ...ToolCallStartOpt) SessionUpdate

StartEditToolCall constructs a 'tool_call' update for editing content: kind=edit, status=pending, locations=[{path}], rawInput={path, content}.

func StartReadToolCall 

func StartReadToolCall(id ToolCallId, title string, path string, opts ...ToolCallStartOpt) SessionUpdate

StartReadToolCall constructs a 'tool_call' update for reading a file: kind=read, status=pending, locations=[{path}], rawInput={path}.

func StartToolCall 

func StartToolCall(id ToolCallId, title string, opts ...ToolCallStartOpt) SessionUpdate

StartToolCall constructs a tool_call update with required fields and applies optional modifiers.

func UpdateAgentMessage 

func UpdateAgentMessage(content ContentBlock) SessionUpdate

UpdateAgentMessage constructs an agent_message_chunk update with the given content.

func UpdateAgentMessageText 

func UpdateAgentMessageText(text string) SessionUpdate

UpdateAgentMessageText constructs an agent_message_chunk update from text.

func UpdateAgentThought 

func UpdateAgentThought(content ContentBlock) SessionUpdate

UpdateAgentThought constructs an agent_thought_chunk update with the given content.

func UpdateAgentThoughtText 

func UpdateAgentThoughtText(text string) SessionUpdate

UpdateAgentThoughtText constructs an agent_thought_chunk update from text.

func UpdatePlan 

func UpdatePlan(entries ...PlanEntry) SessionUpdate

UpdatePlan constructs a plan update with the provided entries.

func UpdateToolCall 

func UpdateToolCall(id ToolCallId, opts ...ToolCallUpdateOpt) SessionUpdate

UpdateToolCall constructs a tool_call_update with the given ID and applies optional modifiers.

func UpdateUserMessage 

func UpdateUserMessage(content ContentBlock) SessionUpdate

UpdateUserMessage constructs a user_message_chunk update with the given content.

func UpdateUserMessageText 

func UpdateUserMessageText(text string) SessionUpdate

UpdateUserMessageText constructs a user_message_chunk update from text.

func (SessionUpdate) MarshalJSON 

func (u SessionUpdate) MarshalJSON() ([]byte, error)

func (*SessionUpdate) UnmarshalJSON 

func (u *SessionUpdate) UnmarshalJSON(b []byte) error

func (*SessionUpdate) Validate 

func (u *SessionUpdate) Validate() error

type SessionUpdateAgentMessageChunk 

type SessionUpdateAgentMessageChunk struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// A single item of content
	Content       ContentBlock `json:"content"`
	SessionUpdate string       `json:"sessionUpdate"`
}

A chunk of the agent's response being streamed.

type SessionUpdateAgentThoughtChunk 

type SessionUpdateAgentThoughtChunk struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// A single item of content
	Content       ContentBlock `json:"content"`
	SessionUpdate string       `json:"sessionUpdate"`
}

A chunk of the agent's internal reasoning being streamed.

type SessionUpdatePlan 

type SessionUpdatePlan struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The list of tasks to be accomplished.
	//
	// When updating a plan, the agent must send a complete list of all entries
	// with their current status. The client replaces the entire plan with each update.
	Entries       []PlanEntry `json:"entries"`
	SessionUpdate string      `json:"sessionUpdate"`
}

The agent's execution plan for complex tasks. See protocol docs: [Agent Plan](https://agentclientprotocol.com/protocol/agent-plan)

type SessionUpdateToolCall 

type SessionUpdateToolCall struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Content produced by the tool call.
	Content []ToolCallContent `json:"content,omitempty"`
	// The category of tool being invoked.
	// Helps clients choose appropriate icons and UI treatment.
	Kind ToolKind `json:"kind,omitempty"`
	// File locations affected by this tool call.
	// Enables "follow-along" features in clients.
	Locations []ToolCallLocation `json:"locations,omitempty"`
	// Raw input parameters sent to the tool.
	RawInput any `json:"rawInput,omitempty"`
	// Raw output returned by the tool.
	RawOutput     any    `json:"rawOutput,omitempty"`
	SessionUpdate string `json:"sessionUpdate"`
	// Current execution status of the tool call.
	Status ToolCallStatus `json:"status,omitempty"`
	// Human-readable title describing what the tool is doing.
	Title string `json:"title"`
	// Unique identifier for this tool call within the session.
	ToolCallId ToolCallId `json:"toolCallId"`
}

Notification that a new tool call has been initiated.

type SessionUpdateUserMessageChunk 

type SessionUpdateUserMessageChunk struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// A single item of content
	Content       ContentBlock `json:"content"`
	SessionUpdate string       `json:"sessionUpdate"`
}

Different types of updates that can be sent during session processing.

These updates provide real-time feedback about the agent's progress.

See protocol docs: [Agent Reports Output](https://agentclientprotocol.com/protocol/prompt-turn#3-agent-reports-output) A chunk of the user's message being streamed.

type SessionUsageUpdate added in v0.10.8 

type SessionUsageUpdate struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Cumulative session cost (optional).
	Cost          *Cost  `json:"cost,omitempty"`
	SessionUpdate string `json:"sessionUpdate"`
	// Total context window size in tokens.
	Size int `json:"size"`
	// Tokens currently in context.
	Used int `json:"used"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Context window and cost update for the session.

type SetSessionConfigOptionRequest added in v0.10.8 

type SetSessionConfigOptionRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The ID of the configuration option to set.
	ConfigId SessionConfigId `json:"configId"`
	// The ID of the session to set the configuration option for.
	SessionId SessionId `json:"sessionId"`
	// The ID of the configuration option value to set.
	Value SessionConfigValueId `json:"value"`
}

Request parameters for setting a session configuration option.

func (*SetSessionConfigOptionRequest) Validate added in v0.10.8 

func (v *SetSessionConfigOptionRequest) Validate() error

type SetSessionConfigOptionResponse added in v0.10.8 

type SetSessionConfigOptionResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The full set of configuration options and their current values.
	ConfigOptions []SessionConfigOption `json:"configOptions"`
}

Response to 'session/set_config_option' method.

func (*SetSessionConfigOptionResponse) Validate added in v0.10.8 

func (v *SetSessionConfigOptionResponse) Validate() error

type SetSessionModeRequest 

type SetSessionModeRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The ID of the mode to set.
	ModeId SessionModeId `json:"modeId"`
	// The ID of the session to set the mode for.
	SessionId SessionId `json:"sessionId"`
}

Request parameters for setting a session mode.

func (*SetSessionModeRequest) Validate 

func (v *SetSessionModeRequest) Validate() error

type SetSessionModeResponse 

type SetSessionModeResponse struct {
	Meta map[string]any `json:"_meta,omitempty"`
}

Response to 'session/set_mode' method.

func (*SetSessionModeResponse) Validate 

func (v *SetSessionModeResponse) Validate() error

type StopReason 

type StopReason string

Reasons why an agent stops processing a prompt turn.

See protocol docs: [Stop Reasons](https://agentclientprotocol.com/protocol/prompt-turn#stop-reasons) 

const (
	StopReasonEndTurn         StopReason = "end_turn"
	StopReasonMaxTokens       StopReason = "max_tokens"
	StopReasonMaxTurnRequests StopReason = "max_turn_requests"
	StopReasonRefusal         StopReason = "refusal"
	StopReasonCancelled       StopReason = "cancelled"
)

type Terminal added in v0.10.8 

type Terminal struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta       map[string]any `json:"_meta,omitempty"`
	TerminalId string         `json:"terminalId"`
}

Embed a terminal created with 'terminal/create' by its id.

The terminal must be added before calling 'terminal/release'.

See protocol docs: Terminal(https://agentclientprotocol.com/protocol/terminals)

type TerminalExitStatus 

type TerminalExitStatus struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The process exit code (may be null if terminated by signal).
	ExitCode *int `json:"exitCode,omitempty"`
	// The signal that terminated the process (may be null if exited normally).
	Signal *string `json:"signal,omitempty"`
}

Exit status of a terminal command.

type TerminalOutputRequest 

type TerminalOutputRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The session ID for this request.
	SessionId SessionId `json:"sessionId"`
	// The ID of the terminal to get output from.
	TerminalId string `json:"terminalId"`
}

Request to get the current output and status of a terminal.

func (*TerminalOutputRequest) Validate 

func (v *TerminalOutputRequest) Validate() error

type TerminalOutputResponse 

type TerminalOutputResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Exit status if the command has completed.
	ExitStatus *TerminalExitStatus `json:"exitStatus,omitempty"`
	// The terminal output captured so far.
	Output string `json:"output"`
	// Whether the output was truncated due to byte limits.
	Truncated bool `json:"truncated"`
}

Response containing the terminal output and exit status.

func (*TerminalOutputResponse) Validate 

func (v *TerminalOutputResponse) Validate() error

type TextContent 

type TextContent struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta        map[string]any `json:"_meta,omitempty"`
	Annotations *Annotations   `json:"annotations,omitempty"`
	Text        string         `json:"text"`
}

Text provided to or from an LLM.

type TextResourceContents 

type TextResourceContents struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta     map[string]any `json:"_meta,omitempty"`
	MimeType *string        `json:"mimeType,omitempty"`
	Text     string         `json:"text"`
	Uri      string         `json:"uri"`
}

Text-based resource contents.

type ToolCall 

type ToolCall struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Content produced by the tool call.
	Content []ToolCallContent `json:"content,omitempty"`
	// The category of tool being invoked.
	// Helps clients choose appropriate icons and UI treatment.
	Kind ToolKind `json:"kind,omitempty"`
	// File locations affected by this tool call.
	// Enables "follow-along" features in clients.
	Locations []ToolCallLocation `json:"locations,omitempty"`
	// Raw input parameters sent to the tool.
	RawInput any `json:"rawInput,omitempty"`
	// Raw output returned by the tool.
	RawOutput any `json:"rawOutput,omitempty"`
	// Current execution status of the tool call.
	Status ToolCallStatus `json:"status,omitempty"`
	// Human-readable title describing what the tool is doing.
	Title string `json:"title"`
	// Unique identifier for this tool call within the session.
	ToolCallId ToolCallId `json:"toolCallId"`
}

Represents a tool call that the language model has requested.

Tool calls are actions that the agent executes on behalf of the language model, such as reading files, executing code, or fetching data from external sources.

See protocol docs: [Tool Calls](https://agentclientprotocol.com/protocol/tool-calls)

type ToolCallContent 

type ToolCallContent struct {
	// Standard content block (text, images, resources).
	Content *ToolCallContentContent `json:"-"`
	// File modification shown as a diff.
	Diff *ToolCallContentDiff `json:"-"`
	// Embed a terminal created with 'terminal/create' by its id.
	//
	// The terminal must be added before calling 'terminal/release'.
	//
	// See protocol docs: [Terminal](https://agentclientprotocol.com/protocol/terminals)
	Terminal *ToolCallContentTerminal `json:"-"`
}

func ToolContent 

func ToolContent(block ContentBlock) ToolCallContent

ToolContent wraps a content block as tool-call content.

func ToolDiffContent 

func ToolDiffContent(path string, newText string, oldText ...string) ToolCallContent

ToolDiffContent constructs a diff tool-call content. If oldText is omitted, the field is left empty.

func ToolTerminalRef 

func ToolTerminalRef(terminalID string) ToolCallContent

ToolTerminalRef constructs a terminal reference tool-call content.

func (ToolCallContent) MarshalJSON 

func (u ToolCallContent) MarshalJSON() ([]byte, error)

func (*ToolCallContent) UnmarshalJSON 

func (u *ToolCallContent) UnmarshalJSON(b []byte) error

func (*ToolCallContent) Validate 

func (u *ToolCallContent) Validate() error

type ToolCallContentContent 

type ToolCallContentContent struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The actual content block.
	Content ContentBlock `json:"content"`
	Type    string       `json:"type"`
}

Content produced by a tool call.

Tool calls can produce different types of content including standard content blocks (text, images) or file diffs.

See protocol docs: Content(https://agentclientprotocol.com/protocol/tool-calls#content) Standard content block (text, images, resources).

type ToolCallContentDiff 

type ToolCallContentDiff struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The new content after modification.
	NewText string `json:"newText"`
	// The original content (None for new files).
	OldText *string `json:"oldText,omitempty"`
	// The file path being modified.
	Path string `json:"path"`
	Type string `json:"type"`
}

File modification shown as a diff.

type ToolCallContentTerminal 

type ToolCallContentTerminal struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta       map[string]any `json:"_meta,omitempty"`
	TerminalId string         `json:"terminalId"`
	Type       string         `json:"type"`
}

Embed a terminal created with 'terminal/create' by its id.

The terminal must be added before calling 'terminal/release'.

See protocol docs: Terminal(https://agentclientprotocol.com/protocol/terminals)

type ToolCallId 

type ToolCallId string

Unique identifier for a tool call within a session.

type ToolCallLocation 

type ToolCallLocation struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Optional line number within the file.
	Line *int `json:"line,omitempty"`
	// The file path being accessed or modified.
	Path string `json:"path"`
}

A file location being accessed or modified by a tool.

Enables clients to implement "follow-along" features that track which files the agent is working with in real-time.

See protocol docs: [Following the Agent](https://agentclientprotocol.com/protocol/tool-calls#following-the-agent)

type ToolCallStartOpt 

type ToolCallStartOpt func(tc *SessionUpdateToolCall)

func WithStartContent 

func WithStartContent(c []ToolCallContent) ToolCallStartOpt

WithStartContent sets the initial content for a tool_call start update.

func WithStartKind 

func WithStartKind(k ToolKind) ToolCallStartOpt

WithStartKind sets the kind for a tool_call start update.

func WithStartLocations 

func WithStartLocations(l []ToolCallLocation) ToolCallStartOpt

WithStartLocations sets file locations and, if a single path is provided and rawInput is empty, mirrors it as rawInput.path.

func WithStartRawInput 

func WithStartRawInput(v any) ToolCallStartOpt

WithStartRawInput sets rawInput for a tool_call start update.

func WithStartRawOutput 

func WithStartRawOutput(v any) ToolCallStartOpt

WithStartRawOutput sets rawOutput for a tool_call start update.

func WithStartStatus 

func WithStartStatus(s ToolCallStatus) ToolCallStartOpt

WithStartStatus sets the status for a tool_call start update.

type ToolCallStatus 

type ToolCallStatus string

Execution status of a tool call.

Tool calls progress through different statuses during their lifecycle.

See protocol docs: [Status](https://agentclientprotocol.com/protocol/tool-calls#status) 

const (
	ToolCallStatusPending    ToolCallStatus = "pending"
	ToolCallStatusInProgress ToolCallStatus = "in_progress"
	ToolCallStatusCompleted  ToolCallStatus = "completed"
	ToolCallStatusFailed     ToolCallStatus = "failed"
)

type ToolCallUpdate 

type ToolCallUpdate struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Replace the content collection.
	Content []ToolCallContent `json:"content,omitempty"`
	// Update the tool kind.
	Kind *ToolKind `json:"kind,omitempty"`
	// Replace the locations collection.
	Locations []ToolCallLocation `json:"locations,omitempty"`
	// Update the raw input.
	RawInput any `json:"rawInput,omitempty"`
	// Update the raw output.
	RawOutput any `json:"rawOutput,omitempty"`
	// Update the execution status.
	Status *ToolCallStatus `json:"status,omitempty"`
	// Update the human-readable title.
	Title *string `json:"title,omitempty"`
	// The ID of the tool call being updated.
	ToolCallId ToolCallId `json:"toolCallId"`
}

An update to an existing tool call.

Used to report progress and results as tools execute. All fields except the tool call ID are optional - only changed fields need to be included.

See protocol docs: [Updating](https://agentclientprotocol.com/protocol/tool-calls#updating)

func (*ToolCallUpdate) Validate 

func (t *ToolCallUpdate) Validate() error

type ToolCallUpdateOpt 

type ToolCallUpdateOpt func(tu *SessionToolCallUpdate)

func WithUpdateContent 

func WithUpdateContent(c []ToolCallContent) ToolCallUpdateOpt

WithUpdateContent replaces the content collection for a tool_call_update.

func WithUpdateKind 

func WithUpdateKind(k ToolKind) ToolCallUpdateOpt

WithUpdateKind sets the kind for a tool_call_update.

func WithUpdateLocations 

func WithUpdateLocations(l []ToolCallLocation) ToolCallUpdateOpt

WithUpdateLocations replaces the locations collection for a tool_call_update.

func WithUpdateRawInput 

func WithUpdateRawInput(v any) ToolCallUpdateOpt

WithUpdateRawInput sets rawInput for a tool_call_update.

func WithUpdateRawOutput 

func WithUpdateRawOutput(v any) ToolCallUpdateOpt

WithUpdateRawOutput sets rawOutput for a tool_call_update.

func WithUpdateStatus 

func WithUpdateStatus(s ToolCallStatus) ToolCallUpdateOpt

WithUpdateStatus sets the status for a tool_call_update.

func WithUpdateTitle 

func WithUpdateTitle(t string) ToolCallUpdateOpt

WithUpdateTitle sets the title for a tool_call_update.

type ToolKind 

type ToolKind string

Categories of tools that can be invoked.

Tool kinds help clients choose appropriate icons and optimize how they display tool execution progress.

See protocol docs: [Creating](https://agentclientprotocol.com/protocol/tool-calls#creating) 

const (
	ToolKindRead       ToolKind = "read"
	ToolKindEdit       ToolKind = "edit"
	ToolKindDelete     ToolKind = "delete"
	ToolKindMove       ToolKind = "move"
	ToolKindSearch     ToolKind = "search"
	ToolKindExecute    ToolKind = "execute"
	ToolKindThink      ToolKind = "think"
	ToolKindFetch      ToolKind = "fetch"
	ToolKindSwitchMode ToolKind = "switch_mode"
	ToolKindOther      ToolKind = "other"
)

type UnstableCancelRequestNotification added in v0.10.8 

type UnstableCancelRequestNotification struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The ID of the request to cancel.
	RequestId RequestId `json:"requestId"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Notification to cancel an ongoing request.

See protocol docs: [Cancellation](https://agentclientprotocol.com/protocol/cancellation)

func (*UnstableCancelRequestNotification) Validate added in v0.10.8 

func (v *UnstableCancelRequestNotification) Validate() error

type UnstableForkSessionRequest added in v0.10.8 

type UnstableForkSessionRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The working directory for this session.
	Cwd string `json:"cwd"`
	// List of MCP servers to connect to for this session.
	McpServers []McpServer `json:"mcpServers,omitempty"`
	// The ID of the session to fork.
	SessionId SessionId `json:"sessionId"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Request parameters for forking an existing session.

Creates a new session based on the context of an existing one, allowing operations like generating summaries without affecting the original session's history.

Only available if the Agent supports the 'session.fork' capability.

func (*UnstableForkSessionRequest) Validate added in v0.10.8 

func (v *UnstableForkSessionRequest) Validate() error

type UnstableForkSessionResponse added in v0.10.8 

type UnstableForkSessionResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Initial session configuration options if supported by the Agent.
	ConfigOptions []SessionConfigOption `json:"configOptions,omitempty"`
	// **UNSTABLE**
	//
	// This capability is not part of the spec yet, and may be removed or changed at any point.
	//
	// Initial model state if supported by the Agent
	Models *UnstableSessionModelState `json:"models,omitempty"`
	// Initial mode state if supported by the Agent
	//
	// See protocol docs: [Session Modes](https://agentclientprotocol.com/protocol/session-modes)
	Modes *SessionModeState `json:"modes,omitempty"`
	// Unique identifier for the newly created forked session.
	SessionId SessionId `json:"sessionId"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Response from forking an existing session.

func (*UnstableForkSessionResponse) Validate added in v0.10.8 

func (v *UnstableForkSessionResponse) Validate() error

type UnstableListSessionsRequest added in v0.10.8 

type UnstableListSessionsRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Opaque cursor token from a previous response's nextCursor field for cursor-based pagination
	Cursor *string `json:"cursor,omitempty"`
	// Filter sessions by working directory. Must be an absolute path.
	Cwd *string `json:"cwd,omitempty"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Request parameters for listing existing sessions.

Only available if the Agent supports the 'listSessions' capability.

func (*UnstableListSessionsRequest) Validate added in v0.10.8 

func (v *UnstableListSessionsRequest) Validate() error

type UnstableListSessionsResponse added in v0.10.8 

type UnstableListSessionsResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Opaque cursor token. If present, pass this in the next request's cursor parameter
	// to fetch the next page. If absent, there are no more results.
	NextCursor *string `json:"nextCursor,omitempty"`
	// Array of session information objects
	Sessions []UnstableSessionInfo `json:"sessions"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Response from listing sessions.

func (*UnstableListSessionsResponse) Validate added in v0.10.8 

func (v *UnstableListSessionsResponse) Validate() error

type UnstableModelId added in v0.10.8 

type UnstableModelId string

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

A unique identifier for a model.

type UnstableModelInfo added in v0.10.8 

type UnstableModelInfo struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Optional description of the model.
	Description *string `json:"description,omitempty"`
	// Unique identifier for the model.
	ModelId UnstableModelId `json:"modelId"`
	// Human-readable name of the model.
	Name string `json:"name"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Information about a selectable model.

type UnstableResumeSessionRequest added in v0.10.8 

type UnstableResumeSessionRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The working directory for this session.
	Cwd string `json:"cwd"`
	// List of MCP servers to connect to for this session.
	McpServers []McpServer `json:"mcpServers,omitempty"`
	// The ID of the session to resume.
	SessionId SessionId `json:"sessionId"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Request parameters for resuming an existing session.

Resumes an existing session without returning previous messages (unlike 'session/load'). This is useful for agents that can resume sessions but don't implement full session loading.

Only available if the Agent supports the 'session.resume' capability.

func (*UnstableResumeSessionRequest) Validate added in v0.10.8 

func (v *UnstableResumeSessionRequest) Validate() error

type UnstableResumeSessionResponse added in v0.10.8 

type UnstableResumeSessionResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Initial session configuration options if supported by the Agent.
	ConfigOptions []SessionConfigOption `json:"configOptions,omitempty"`
	// **UNSTABLE**
	//
	// This capability is not part of the spec yet, and may be removed or changed at any point.
	//
	// Initial model state if supported by the Agent
	Models *UnstableSessionModelState `json:"models,omitempty"`
	// Initial mode state if supported by the Agent
	//
	// See protocol docs: [Session Modes](https://agentclientprotocol.com/protocol/session-modes)
	Modes *SessionModeState `json:"modes,omitempty"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Response from resuming an existing session.

func (*UnstableResumeSessionResponse) Validate added in v0.10.8 

func (v *UnstableResumeSessionResponse) Validate() error

type UnstableSessionInfo added in v0.10.8 

type UnstableSessionInfo struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The working directory for this session. Must be an absolute path.
	Cwd string `json:"cwd"`
	// Unique identifier for the session
	SessionId SessionId `json:"sessionId"`
	// Human-readable title for the session
	Title *string `json:"title,omitempty"`
	// ISO 8601 timestamp of last activity
	UpdatedAt *string `json:"updatedAt,omitempty"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Information about a session returned by session/list

type UnstableSessionModelState added in v0.10.8 

type UnstableSessionModelState struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The set of models that the Agent can use
	AvailableModels []UnstableModelInfo `json:"availableModels"`
	// The current model the Agent is in.
	CurrentModelId UnstableModelId `json:"currentModelId"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

The set of models and the one currently active.

type UnstableSetSessionModelRequest added in v0.10.8 

type UnstableSetSessionModelRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The ID of the model to set.
	ModelId UnstableModelId `json:"modelId"`
	// The ID of the session to set the model for.
	SessionId SessionId `json:"sessionId"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Request parameters for setting a session model.

func (*UnstableSetSessionModelRequest) Validate added in v0.10.8 

func (v *UnstableSetSessionModelRequest) Validate() error

type UnstableSetSessionModelResponse added in v0.10.8 

type UnstableSetSessionModelResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Response to 'session/set_model' method.

func (*UnstableSetSessionModelResponse) Validate added in v0.10.8 

func (v *UnstableSetSessionModelResponse) Validate() error

type UnstructuredCommandInput 

type UnstructuredCommandInput struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// A hint to display when the input hasn't been provided yet
	Hint string `json:"hint"`
}

All text that was typed after the command name is provided as input.

type Usage added in v0.10.8 

type Usage struct {
	// Total cache read tokens.
	CachedReadTokens *int `json:"cachedReadTokens,omitempty"`
	// Total cache write tokens.
	CachedWriteTokens *int `json:"cachedWriteTokens,omitempty"`
	// Total input tokens across all turns.
	InputTokens int `json:"inputTokens"`
	// Total output tokens across all turns.
	OutputTokens int `json:"outputTokens"`
	// Total thought/reasoning tokens
	ThoughtTokens *int `json:"thoughtTokens,omitempty"`
	// Sum of all token types across session.
	TotalTokens int `json:"totalTokens"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Token usage information for a prompt turn.

type UsageUpdate added in v0.10.8 

type UsageUpdate struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// Cumulative session cost (optional).
	Cost *Cost `json:"cost,omitempty"`
	// Total context window size in tokens.
	Size int `json:"size"`
	// Tokens currently in context.
	Used int `json:"used"`
}

**UNSTABLE**

This capability is not part of the spec yet, and may be removed or changed at any point.

Context window and cost update for a session.

type WaitForTerminalExitRequest 

type WaitForTerminalExitRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The session ID for this request.
	SessionId SessionId `json:"sessionId"`
	// The ID of the terminal to wait for.
	TerminalId string `json:"terminalId"`
}

Request to wait for a terminal command to exit.

func (*WaitForTerminalExitRequest) Validate 

func (v *WaitForTerminalExitRequest) Validate() error

type WaitForTerminalExitResponse 

type WaitForTerminalExitResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The process exit code (may be null if terminated by signal).
	ExitCode *int `json:"exitCode,omitempty"`
	// The signal that terminated the process (may be null if exited normally).
	Signal *string `json:"signal,omitempty"`
}

Response containing the exit status of a terminal command.

func (*WaitForTerminalExitResponse) Validate 

func (v *WaitForTerminalExitResponse) Validate() error

type WriteTextFileRequest 

type WriteTextFileRequest struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
	// The text content to write to the file.
	Content string `json:"content"`
	// Absolute path to the file to write.
	Path string `json:"path"`
	// The session ID for this request.
	SessionId SessionId `json:"sessionId"`
}

Request to write content to a text file.

Only available if the client supports the 'fs.writeTextFile' capability.

func (*WriteTextFileRequest) Validate 

func (v *WriteTextFileRequest) Validate() error

type WriteTextFileResponse 

type WriteTextFileResponse struct {
	// The _meta property is reserved by ACP to allow clients and agents to attach additional
	// metadata to their interactions. Implementations MUST NOT make assumptions about values at
	// these keys.
	//
	// See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)
	Meta map[string]any `json:"_meta,omitempty"`
}

Response to 'fs/write_text_file'

func (*WriteTextFileResponse) Validate 

func (v *WriteTextFileResponse) Validate() error

Source Files

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Directories

Path Synopsis
cmd
generate module
example
agent command
claude-code command
client command
gemini command

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