Crate agentkit_mcp 

Model Context Protocol integration for agentkit, built on top of rmcp.

This crate exposes:

• McpServerConfig / McpTransportBinding / StdioTransportConfig / StreamableHttpTransportConfig — declarative transport configuration.
• McpConnection — a live, single-server connection wrapping rmcp::service::RunningService.
• McpServerManager — multi-server lifecycle, discovery, catalog diffing, and auth replay.
• McpServerHandle, [McpToolExecutor], McpToolAdapter, McpResourceHandle, McpPromptHandle, McpCapabilityProvider — bridges into the agentkit Tool / capabilities systems.

Wire-protocol types (CallToolResult, ReadResourceResult, Content, ToolAnnotations, Prompt, sampling/elicitation/roots payloads, …) are re-exported from rmcp::model directly — there is no parallel agentkit-side vocabulary. As rmcp tracks new MCP spec revisions, those types and their fields propagate into agentkit unchanged.

Structs

AuthRequest

An auth challenge raised by an MCP server during a tool call, resource read, prompt fetch, or connection handshake.

CallToolResult

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. The result of a tool call operation.

GetPromptResult

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

LoggingCapability

Logging sub-capability. Spec reserves the key with no defined sub-fields yet.

McpAnnotations

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

McpCancelledNotificationParam

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

McpCapabilityProvider

A CapabilityProvider that surfaces MCP tools, resources, and prompts.

McpClientCapabilities

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

McpClientChannels

Channels paired with an McpClientHandler returned by McpHandlerConfig::build.

McpClientHandler

rmcp ClientHandler used by McpConnection.

McpConnectAllSettled

Best-effort outcome returned by McpServerManager::connect_all_settled.

McpConnection

A live connection to a single MCP server, wrapping an rmcp::service::RunningService.

McpCreateElicitationResult

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. The result returned by a client in response to an elicitation request.

McpCreateMessageRequestParams

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Parameters for creating a message through LLM sampling.

McpCreateMessageResult

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Result of sampling/createMessage (SEP-1577). The result of a sampling/createMessage request containing the generated response.

McpDiscoverySnapshot

A snapshot of all capabilities discovered from a single MCP server.

McpElicitationCapability

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Elicitation allows servers to request interactive input from users during tool execution. This capability indicates that a client can handle elicitation requests and present appropriate UI to users for collecting the requested information.

McpErrorContext

Context describing which server / method / input produced the invocation error currently being inspected by McpErrorResponder::handle.

McpFormElicitationCapability

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Capability for handling elicitation requests from servers. Elicitation allows servers to request interactive input from users during tool execution. This capability indicates that a client can handle elicitation requests and present appropriate UI to users for collecting the requested information.

McpHandlerConfig

Configuration applied to every McpClientHandler this crate builds on behalf of a connection or McpServerManager.

McpImplementation

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

McpListRootsResult

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

McpLoggingMessageNotificationParam

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Parameters for a logging message notification

McpProgressNotificationParam

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

McpPrompt

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. A prompt that can be used to generate text from a model

McpPromptHandle

Adapter exposing a single MCP prompt as a PromptProvider.

McpRawResource

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Represents a resource in the extension with metadata

McpResourceHandle

Adapter exposing a single MCP resource as a ResourceProvider.

McpResourceUpdatedNotificationParam

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Parameters for a resource update notification

McpRoot

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

McpRootsCapabilities

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

McpSamplingCapability

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Sampling capability with optional sub-capabilities (SEP-1577).

McpSamplingMessage

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. A message in a sampling conversation, containing a role and content.

McpServerCapabilities

Capabilities advertised by an MCP server during the initialize handshake.

McpServerConfig

Full configuration for a single MCP server.

McpServerConnectionError

Connection failure for one server returned by McpServerManager::connect_all_settled.

McpServerHandle

A connected MCP server together with its configuration and snapshot.

McpServerId

Unique identifier for a registered MCP server.

McpServerManager

Manages the lifecycle of one or more MCP servers.

McpServerOptions

Per-server lifecycle options used by McpServerManager.

McpSetLevelRequestParams

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Parameters for setting the logging level

McpSse

Re-export of the SSE event/error types referenced by McpHttpClient::get_stream.

McpTool

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. A tool that can be used by a model.

McpToolAdapter

Adapter exposing an MCP tool as an agentkit Tool.

McpToolAnnotations

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Additional properties describing a Tool to clients.

McpUrlElicitationCapability

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Capability for URL mode elicitation.

PromptArgument

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Represents a prompt argument that can be passed to customize the prompt

PromptMessage

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. A message in a prompt conversation

PromptsCapability

Prompts sub-capability flags from the MCP initialize response.

RawAudioContent

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

RawEmbeddedResource

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

RawImageContent

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

RawTextContent

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

ReadResourceResult

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Result containing the contents of a read resource

ResourcesCapability

Resources sub-capability flags from the MCP initialize response.

StdioTransportConfig

Configuration for an MCP server that communicates over standard I/O.

StreamableHttpTransportConfig

Configuration for an MCP server that communicates over the MCP Streamable HTTP transport.

ToolsCapability

Tools sub-capability flags from the MCP initialize response.

UrlElicitationData

Typed payload for the URL elicitation error case.

Enums

AuthOperation

The MCP operation that triggered an AuthRequest.

AuthResolution

Outcome of an AuthRequest after the host’s McpAuthResponder runs.

ErrorResponderOutcome

Decision returned by an McpErrorResponder.

McpCatalogEvent

Catalog and lifecycle events emitted by McpServerManager.

McpCreateElicitationRequestParams

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Parameters for creating an elicitation request to gather user input.

McpElicitationAction

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Represents the possible actions a user can take in response to an elicitation request.

McpError

Errors produced by MCP transport, protocol, and lifecycle operations.

McpInvocationError

Typed view of a JSON-RPC error returned by an MCP server for an invoked method.

McpLoggingLevel

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Logging levels supported by the MCP protocol

McpMethod

Typed dispatch for MCP requests that may surface auth or invocation errors. Each peer call constructs the matching variant; [auth_request_from_signal] converts to a public AuthOperation (typed for the four common cases, AuthOperation::McpOther for the long tail). The same value is also exposed to McpErrorResponder implementations via McpErrorContext::method.

McpOperationResult

The result of replaying an MCP operation after auth resolution.

McpResourceContents

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

McpServerEvent

Server-pushed events broadcast to every McpConnection::subscribe_events receiver.

McpServerNotification

Server-originated catalog notifications observed by McpClientHandler.

McpSseError

Re-export of the SSE event/error types referenced by McpHttpClient::get_stream.

McpStreamableHttpError

Re-exports of the rmcp Streamable HTTP transport types used by McpHttpClient implementations.

McpStreamableHttpPostResponse

Re-exports of the rmcp Streamable HTTP transport types used by McpHttpClient implementations.

McpToolNamespace

Strategy used to derive the agentkit-side tool name for an MCP tool.

McpTransportBinding

Selects which transport an MCP server should use.

PromptMessageContent

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Content types that can be included in prompt messages

PromptMessageRole

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc. Represents the role of a message sender in a prompt conversation

RawContent

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

Traits

McpAuthResponder

Host-supplied resolver for MCP auth challenges.

McpElicitationResponder

Pluggable handler invoked when an MCP server issues elicitation/create.

McpErrorResponder

Userland hook invoked when an MCP server returns a JSON-RPC error for an invoked method.

McpHttpClient

Pluggable HTTP transport for the MCP Streamable HTTP client.

McpRootsProvider

Pluggable handler invoked when an MCP server issues roots/list.

McpSamplingResponder

Pluggable handler invoked when an MCP server issues sampling/createMessage.

Type Aliases

AudioContent

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

ClientJsonRpcMessage

Re-export of the JSON-RPC client→server envelope handed to McpHttpClient::post_message.

Content

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

EmbeddedResource

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

ImageContent

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

McpPromptDescriptor

Alias for McpPrompt.

McpResource

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.

McpResourceDescriptor

Alias for McpResource.

McpSseStream

Type alias for the SSE stream returned by McpHttpClient::get_stream.

McpToolDescriptor

Alias for McpTool.

TextContent

Re-exports of the rmcp wire-protocol types this crate now surfaces directly instead of wrapping. Pull these in to pattern-match on tool annotations, content blocks, structured tool output, embedded resources, sampling / elicitation requests, progress and log notifications, etc.