mcp

type Broadcaster ¶

type Broadcaster interface {
	// Subscribe registers a new subscriber and returns a Subscription. The caller
	// must Close the subscription when done.
	Subscribe(ctx context.Context) (Subscription, error)
	// Publish delivers an event to all current subscribers.
	Publish(ev any)
	// Close closes the broadcaster and all current subscriptions.
	Close() error
}

Broadcaster provides a minimal, concurrency-safe publish/subscribe abstraction used by generated MCP adapters to stream server-initiated events (for example status notifications and resource updates). Implementations must allow Subscribe, Publish and Close to be called from multiple goroutines.

The event payload type is intentionally untyped (any) so generated packages can publish values of their locally-generated result types without creating cyclic dependencies across packages.

Close terminates the broadcaster and all active subscriptions. After Close, future Subscribe calls succeed with a closed Subscription and Publish becomes a no-op.

func NewChannelBroadcaster(buf int, drop bool) Broadcaster

type CallRequest ¶

type CallRequest struct {
	// Suite identifies the MCP toolset (server name) associated with the tool.
	Suite string
	// Tool is the MCP-local tool identifier (without the suite prefix).
	Tool string
	// Payload is the JSON-encoded tool arguments produced by the runtime.
	Payload json.RawMessage
}

CallRequest describes the toolset/tool invocation issued by the runtime.

type CallResponse ¶

type CallResponse struct {
	// Result is the JSON payload returned by the MCP server.
	Result json.RawMessage
	// Structured carries the full structured MCP content payload, including text
	// items that may also contribute to Result.
	Structured json.RawMessage
}

CallResponse captures the MCP tool result returned by the caller.

func NormalizeToolCallResponse(textParts []string, structured any, fallbackResult any) (CallResponse, error)

type Caller ¶

type Caller interface {
	CallTool(ctx context.Context, req CallRequest) (CallResponse, error)
}

Caller invokes MCP tools on behalf of the runtime-generated adapters. It is implemented by transport-specific clients (stdio, HTTP streaming, etc.).

type CallerFunc ¶

type CallerFunc func(ctx context.Context, req CallRequest) (CallResponse, error)

CallerFunc adapts a function to implement Caller.

func (f CallerFunc) CallTool(ctx context.Context, req CallRequest) (CallResponse, error)

type HTTPOptions ¶

type HTTPOptions struct {
	Endpoint      string
	Client        *http.Client
	ClientName    string
	ClientVersion string
	InitTimeout   time.Duration
}

HTTPOptions configures the HTTP Caller.

type Notification ¶

type Notification struct {
	Type    string  `json:"type"`
	Message *string `json:"message,omitempty"`
	Data    any     `json:"data,omitempty"`
}

Notification describes a server-initiated status update that can be broadcast to connected MCP clients via the Events stream. It carries a machine-usable type, an optional human-readable message, and optional structured data.

type SessionCaller ¶

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

SessionCaller implements Caller by wrapping an MCP SDK ClientSession. It is used by transport-specific callers (stdio, HTTP, SSE) to unify tool invocation.

func NewHTTPCaller(ctx context.Context, opts HTTPOptions) (*SessionCaller, error)

func NewSSECaller(ctx context.Context, opts HTTPOptions) (*SessionCaller, error)

func NewSessionCaller(session *mcp.ClientSession, cancel context.CancelFunc) *SessionCaller

func NewStdioCaller(ctx context.Context, opts StdioOptions) (*SessionCaller, error)

func (c *SessionCaller) CallTool(ctx context.Context, req CallRequest) (CallResponse, error)

func (c *SessionCaller) Close() error

type StdioOptions ¶

type StdioOptions struct {
	Command       string
	Args          []string
	Env           []string
	Dir           string
	ClientName    string
	ClientVersion string
	InitTimeout   time.Duration
}

StdioOptions configures the stdio-based MCP caller.

type StreamableHTTPSessions ¶

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

StreamableHTTPSessions tracks issued MCP session IDs and active long-lived listeners for generated streamable HTTP transports.

func NewStreamableHTTPSessions() *StreamableHTTPSessions

func (s *StreamableHTTPSessions) HasIssued() bool

func (s *StreamableHTTPSessions) Issue(sessionID string)

func (s *StreamableHTTPSessions) RegisterListener(sessionID string, cancel context.CancelFunc) (func(), error)

func (s *StreamableHTTPSessions) Terminate(sessionID string) error

func (s *StreamableHTTPSessions) Validate(sessionID string) error

type Subscription ¶

type Subscription interface {
	// C returns a receive-only channel for events.
	C() <-chan any
	// Close unregisters the subscription.
	Close() error
}

Subscription represents a live registration with a Broadcaster.

The channel returned by C delivers events in publish order. The channel is closed when either Close is called on the subscription or the owning Broadcaster is closed. Close is idempotent and safe to call multiple times.