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mcp

package
v0.0.27 Latest Latest
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 Go to latest Published: Jul 7, 2026 License: Apache-2.0 Imports: 1 Imported by: 21

Documentation

Overview

Package mcp is a drop-in compatibility shim for github.com/mark3labs/mcp-go/mcp.

It exists so that ToolHive and its sibling projects can migrate off mcp-go and onto the official Model Context Protocol Go SDK (github.com/modelcontextprotocol/go-sdk) by swapping imports rather than rewriting call sites: replace 

github.com/mark3labs/mcp-go/mcp

with 

github.com/stacklok/toolhive-core/mcpcompat/mcp

while keeping the existing import alias. The companion packages mcpcompat/server, mcpcompat/client and mcpcompat/client/transport reimplement mcp-go's protocol machinery on top of the official SDK; this package supplies the data types those APIs exchange.

Migration strategy

The types and helpers below are currently re-exported from mcp-go via type aliases and value assignments. This guarantees byte-for-byte wire and source compatibility during the transition: the aliased symbols ARE mcp-go's, so existing struct-literal construction, field access and custom JSON marshaling behave identically.

This file is the single chokepoint that still references mcp-go. The end goal is to remove the mcp-go dependency from the tree entirely. To get there, each alias here is replaced by a standalone definition (copied from the mcp-go source, same JSON tags and marshaling). Because consumers only ever see the symbols in this package, that swap is transparent to them. The wire-format golden tests in this package pin the exact JSON shape of every re-exported type and are what make the alias-to-standalone conversion safe.

Scope

Only the subset of mcp-go's mcp package that ToolHive actually uses is re-exported. Unused surface (sampling, roots, completion, tasks, logging-level control, the fluent schema builder beyond WithDescription/WithString/Required, etc.) is intentionally omitted and can be added on demand.

Stability: Alpha.

Index

Constants

View Source 
const (
	MethodInitialize             = mcpgo.MethodInitialize
	MethodToolsList              = mcpgo.MethodToolsList
	MethodToolsCall              = mcpgo.MethodToolsCall
	MethodResourcesList          = mcpgo.MethodResourcesList
	MethodResourcesTemplatesList = mcpgo.MethodResourcesTemplatesList
	MethodResourcesRead          = mcpgo.MethodResourcesRead
	MethodPromptsList            = mcpgo.MethodPromptsList
	MethodPromptsGet             = mcpgo.MethodPromptsGet
	MethodListRoots              = mcpgo.MethodListRoots
	MethodSetLogLevel            = mcpgo.MethodSetLogLevel
	MethodPing                   = mcpgo.MethodPing
	MethodElicitationCreate      = mcpgo.MethodElicitationCreate

	// MethodNotificationInitialized indicates the client finished initialization.
	MethodNotificationInitialized = mcpgo.MethodNotificationInitialized
)

MCP method names.

View Source 
const (
	PARSE_ERROR        = mcpgo.PARSE_ERROR
	INVALID_REQUEST    = mcpgo.INVALID_REQUEST
	METHOD_NOT_FOUND   = mcpgo.METHOD_NOT_FOUND
	INVALID_PARAMS     = mcpgo.INVALID_PARAMS
	INTERNAL_ERROR     = mcpgo.INTERNAL_ERROR
	RESOURCE_NOT_FOUND = mcpgo.RESOURCE_NOT_FOUND
)

JSON-RPC / MCP error codes.

View Source 
const (
	RoleUser      = mcpgo.RoleUser
	RoleAssistant = mcpgo.RoleAssistant
)

Message roles.

View Source 
const (
	ElicitationResponseActionAccept  = mcpgo.ElicitationResponseActionAccept
	ElicitationResponseActionDecline = mcpgo.ElicitationResponseActionDecline
	ElicitationResponseActionCancel  = mcpgo.ElicitationResponseActionCancel
)

Elicitation response actions.

View Source 
const JSONRPC_VERSION = mcpgo.JSONRPC_VERSION

JSONRPC_VERSION is the JSON-RPC version used by MCP ("2.0").

View Source 
const LATEST_PROTOCOL_VERSION = mcpgo.LATEST_PROTOCOL_VERSION

LATEST_PROTOCOL_VERSION mirrors mcp-go's latest supported protocol version.

Variables

View Source 
var (
	// NewRequestId wraps a raw id value in a RequestId.
	NewRequestId = mcpgo.NewRequestId //nolint:revive // name intentionally matches mcp-go for drop-in compatibility.
	// NewJSONRPCErrorDetails builds a JSONRPCErrorDetails value.
	NewJSONRPCErrorDetails = mcpgo.NewJSONRPCErrorDetails
	// NewJSONRPCResultResponse builds a successful JSONRPCResponse.
	NewJSONRPCResultResponse = mcpgo.NewJSONRPCResultResponse
)

JSON-RPC message constructors.

View Source 
var (
	NewTextContent      = mcpgo.NewTextContent
	NewImageContent     = mcpgo.NewImageContent
	NewAudioContent     = mcpgo.NewAudioContent
	NewEmbeddedResource = mcpgo.NewEmbeddedResource
	NewResourceLink     = mcpgo.NewResourceLink
)

Content constructors.

View Source 
var (
	AsTextContent          = mcpgo.AsTextContent
	AsImageContent         = mcpgo.AsImageContent
	AsAudioContent         = mcpgo.AsAudioContent
	AsEmbeddedResource     = mcpgo.AsEmbeddedResource
	AsTextResourceContents = mcpgo.AsTextResourceContents
	AsBlobResourceContents = mcpgo.AsBlobResourceContents
)

Content type-assertion helpers.

View Source 
var (
	NewTool              = mcpgo.NewTool
	NewToolWithRawSchema = mcpgo.NewToolWithRawSchema
	WithDescription      = mcpgo.WithDescription
	WithString           = mcpgo.WithString
	Required             = mcpgo.Required
	Description          = mcpgo.Description

	NewToolResultText           = mcpgo.NewToolResultText
	NewToolResultError          = mcpgo.NewToolResultError
	NewToolResultStructuredOnly = mcpgo.NewToolResultStructuredOnly
)

Tool builders and result constructors.

View Source 
var (
	NewPrompt             = mcpgo.NewPrompt
	WithPromptDescription = mcpgo.WithPromptDescription
)

Prompt builders.

View Source 
var ErrMethodNotFound = mcpgo.ErrMethodNotFound

ErrMethodNotFound indicates the requested method does not exist.

View Source 
var GetTextFromContent = mcpgo.GetTextFromContent

GetTextFromContent extracts text from a content value, if any.

View Source 
var NewMetaFromMap = mcpgo.NewMetaFromMap

NewMetaFromMap builds a *Meta from a raw map.

View Source 
var UnmarshalContent = mcpgo.UnmarshalContent

UnmarshalContent decodes a single JSON content object into the concrete mcp.Content implementation (TextContent, ImageContent, ...). It is used by the client shim to populate the Content interface fields of PromptMessage, which mcp-go cannot unmarshal generically.

Functions

This section is empty.

Types

type Annotated 

type Annotated = mcpgo.Annotated

Annotated is the base carrying optional Annotations.

type Annotations 

type Annotations = mcpgo.Annotations

Annotations describe audience/priority/lastModified for content.

type AudioContent 

type AudioContent = mcpgo.AudioContent

AudioContent is base64-encoded audio content.

type BlobResourceContents 

type BlobResourceContents = mcpgo.BlobResourceContents

BlobResourceContents is base64 blob resource contents.

type CallToolParams 

type CallToolParams = mcpgo.CallToolParams

CallToolParams are the params of a tool call.

type CallToolRequest 

type CallToolRequest = mcpgo.CallToolRequest

CallToolRequest is a request to invoke a tool.

type CallToolResult 

type CallToolResult = mcpgo.CallToolResult

CallToolResult is the result of a tool call.

type ClientCapabilities 

type ClientCapabilities = mcpgo.ClientCapabilities

ClientCapabilities represents capabilities a client may support.

type Content 

type Content = mcpgo.Content

Content is a polymorphic content element (text/image/audio/resource/...).

type ElicitationParams 

type ElicitationParams = mcpgo.ElicitationParams

ElicitationParams are the params of an elicitation.

type ElicitationRequest 

type ElicitationRequest = mcpgo.ElicitationRequest

ElicitationRequest is a server->client elicitation request.

type ElicitationResponse 

type ElicitationResponse = mcpgo.ElicitationResponse

ElicitationResponse is the user's response payload.

type ElicitationResponseAction 

type ElicitationResponseAction = mcpgo.ElicitationResponseAction

ElicitationResponseAction indicates accept/decline/cancel.

type ElicitationResult 

type ElicitationResult = mcpgo.ElicitationResult

ElicitationResult is the result of an elicitation.

type EmbeddedResource 

type EmbeddedResource = mcpgo.EmbeddedResource

EmbeddedResource embeds a resource in content.

type EmptyResult 

type EmptyResult = mcpgo.EmptyResult

EmptyResult is an empty MCP result (e.g. the response to ping).

type GetPromptParams 

type GetPromptParams = mcpgo.GetPromptParams

GetPromptParams are the params of a get.

type GetPromptRequest 

type GetPromptRequest = mcpgo.GetPromptRequest

GetPromptRequest gets a prompt.

type GetPromptResult 

type GetPromptResult = mcpgo.GetPromptResult

GetPromptResult is the get response.

type ImageContent 

type ImageContent = mcpgo.ImageContent

ImageContent is base64-encoded image content.

type Implementation 

type Implementation = mcpgo.Implementation

Implementation describes the name and version of an MCP implementation.

type InitializeParams 

type InitializeParams = mcpgo.InitializeParams

InitializeParams are the params of an initialize request.

type InitializeRequest 

type InitializeRequest = mcpgo.InitializeRequest

InitializeRequest is sent by the client to begin initialization.

type InitializeResult 

type InitializeResult = mcpgo.InitializeResult

InitializeResult is the server's response to initialize.

type JSONRPCError 

type JSONRPCError = mcpgo.JSONRPCError

JSONRPCError is a JSON-RPC error response.

type JSONRPCErrorDetails 

type JSONRPCErrorDetails = mcpgo.JSONRPCErrorDetails

JSONRPCErrorDetails carries the code/message/data of a JSON-RPC error.

type JSONRPCMessage 

type JSONRPCMessage = mcpgo.JSONRPCMessage

JSONRPCMessage is any JSON-RPC request/response/notification/error.

type JSONRPCNotification 

type JSONRPCNotification = mcpgo.JSONRPCNotification

JSONRPCNotification is a JSON-RPC notification (no response expected).

type JSONRPCResponse 

type JSONRPCResponse = mcpgo.JSONRPCResponse

JSONRPCResponse is a successful JSON-RPC response.

type ListPromptsRequest 

type ListPromptsRequest = mcpgo.ListPromptsRequest

ListPromptsRequest requests the prompt list.

type ListPromptsResult 

type ListPromptsResult = mcpgo.ListPromptsResult

ListPromptsResult is the prompt list response.

type ListResourceTemplatesRequest 

type ListResourceTemplatesRequest = mcpgo.ListResourceTemplatesRequest

ListResourceTemplatesRequest requests the resource-template list.

type ListResourceTemplatesResult 

type ListResourceTemplatesResult = mcpgo.ListResourceTemplatesResult

ListResourceTemplatesResult is the resource-template list response.

type ListResourcesRequest 

type ListResourcesRequest = mcpgo.ListResourcesRequest

ListResourcesRequest requests the resource list.

type ListResourcesResult 

type ListResourcesResult = mcpgo.ListResourcesResult

ListResourcesResult is the resource list response.

type ListToolsRequest 

type ListToolsRequest = mcpgo.ListToolsRequest

ListToolsRequest requests the tool list.

type ListToolsResult 

type ListToolsResult = mcpgo.ListToolsResult

ListToolsResult is the tool list response.

type MCPMethod 

type MCPMethod = mcpgo.MCPMethod

MCPMethod is the type of MCP method-name constants.

type Meta 

type Meta = mcpgo.Meta

Meta is metadata attached to a request's parameters or a result.

type Notification 

type Notification = mcpgo.Notification

Notification is the base of a JSON-RPC notification (method + params).

type NotificationParams 

type NotificationParams = mcpgo.NotificationParams

NotificationParams carries a notification's params.

type PingRequest 

type PingRequest = mcpgo.PingRequest

PingRequest is a ping request.

type Prompt 

type Prompt = mcpgo.Prompt

Prompt describes a prompt template.

type PromptArgument 

type PromptArgument = mcpgo.PromptArgument

PromptArgument is a prompt template argument.

type PromptMessage 

type PromptMessage = mcpgo.PromptMessage

PromptMessage is a message within a prompt result.

type PromptOption 

type PromptOption = mcpgo.PromptOption

PromptOption configures a Prompt built via NewPrompt.

type PropertyOption 

type PropertyOption = mcpgo.PropertyOption

PropertyOption configures a schema property.

type ReadResourceParams 

type ReadResourceParams = mcpgo.ReadResourceParams

ReadResourceParams are the params of a read.

type ReadResourceRequest 

type ReadResourceRequest = mcpgo.ReadResourceRequest

ReadResourceRequest reads a resource by URI.

type ReadResourceResult 

type ReadResourceResult = mcpgo.ReadResourceResult

ReadResourceResult is the read response.

type Request 

type Request = mcpgo.Request

Request is the base type embedded in protocol request messages.

type RequestId 

type RequestId = mcpgo.RequestId //nolint:revive // name intentionally matches mcp-go for drop-in compatibility.

RequestId is a JSON-RPC request identifier.

type RequestParams 

type RequestParams = mcpgo.RequestParams

RequestParams is the base params type carrying _meta.

type Resource 

type Resource = mcpgo.Resource

Resource is a readable resource.

type ResourceContents 

type ResourceContents = mcpgo.ResourceContents

ResourceContents is the contents of a resource (text or blob). 

type ResourceLink = mcpgo.ResourceLink

ResourceLink links to a resource.

type ResourceTemplate 

type ResourceTemplate = mcpgo.ResourceTemplate

ResourceTemplate is a URI-templated resource description.

type Result 

type Result = mcpgo.Result

Result is the base type embedded in protocol result messages.

type Role 

type Role = mcpgo.Role

Role is the role of a sampling/prompt message ("user"/"assistant").

type ServerCapabilities 

type ServerCapabilities = mcpgo.ServerCapabilities

ServerCapabilities represents capabilities a server may support.

type TextContent 

type TextContent = mcpgo.TextContent

TextContent is text content.

type TextResourceContents 

type TextResourceContents = mcpgo.TextResourceContents

TextResourceContents is text resource contents.

type Tool 

type Tool = mcpgo.Tool

Tool describes a callable tool.

type ToolAnnotation 

type ToolAnnotation = mcpgo.ToolAnnotation

ToolAnnotation carries tool behavior hints.

type ToolInputSchema 

type ToolInputSchema = mcpgo.ToolInputSchema

ToolInputSchema is a tool's input JSON schema.

type ToolOption 

type ToolOption = mcpgo.ToolOption

ToolOption configures a Tool built via NewTool.

type ToolOutputSchema 

type ToolOutputSchema = mcpgo.ToolOutputSchema

ToolOutputSchema is a tool's output JSON schema.

Source Files

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