agentic_mcp library

Model Context Protocol for the agentic framework.

Two directions, one vocabulary. McpClient turns a remote server's tools into ordinary Tool objects that every agent in the framework already knows how to run; McpServer publishes your own ToolRegistry to any MCP client.

import 'package:agentic_mcp/agentic_mcp.dart';

final client = McpClient(
  transport: McpHttpTransport(endpoint: Uri.parse('https://…/mcp')),
);
await client.initialize();

await registerMcpTools(client, registry, prefix: 'fs');
// The agent now has the server's tools, and knows nothing about MCP.

The subprocess transport lives in package:agentic_mcp/io.dart, because it imports dart:io and this library must stay usable on the web.

Classes

InMemoryTransport: A transport whose two halves are wired directly together.
JsonRpcError: A JSON-RPC failure.
JsonRpcErrorCode: Error codes defined by JSON-RPC 2.0 itself.
JsonRpcMessage: Classifies a decoded JSON-RPC message.
JsonRpcNotification: A message that expects no response.
JsonRpcNotificationMessage: An incoming notification.
JsonRpcRequest: A call that expects a response.
JsonRpcRequestMessage: An incoming request.
JsonRpcResponse: What a request returned.
JsonRpcResponseMessage: An incoming response.
McpCapabilities: What a peer says it can do.
McpClient: A session with one MCP server.
McpEvent: Base for every MCP event.
McpHttpTransport: Talks to an MCP server over Streamable HTTP.
McpImplementation: Who is speaking, and what version of it.
McpMethod: Every method name in the protocol.
McpNotificationReceived: The server sent a notification.
McpPrompt: A prompt template a server offers.
McpPromptArgument: One argument of a prompt template.
McpPromptResult: A rendered prompt template.
McpResource: Something a server can be asked to read.
McpResourceContents: The contents of one resource.
McpResourceTemplate: A family of resources addressed by a URI template.
McpServer: Serves a ToolRegistry over the Model Context Protocol.
McpSessionInfo: What the server said when the session opened.
McpSessionOpened: A session was negotiated.
McpTool: A tool that runs on an MCP server.
McpToolAnnotations: Hints a server gives about how a tool behaves.
McpToolCalled: A tool call on a server finished.
McpToolCallResult: What a tool call returned.
McpToolDescriptor: A tool as the server describes it.
McpToolsDiscovered: Tools were discovered from a server.
McpTransport: Carries JSON-RPC messages to and from a peer.

Constants

kJsonRpcVersion → const String: The only JSON-RPC version MCP speaks.
kLatestProtocolVersion → const String: The revision this package proposes.
kProtocolVersionHeader → const String: Header carrying the negotiated protocol revision.
kReservedHeaders → const Set<String>: The default initialize headers a client sends.
kSessionIdHeader → const String: Header carrying the session identifier.
kSupportedProtocolVersions → const List<String>: Protocol revisions this package can speak, newest first.

Functions

contentPartFromMcp(JsonMap block) → ContentPart?: Converts one MCP content block into a ContentPart.
contentPartsFromMcp(Object? blocks) → List<ContentPart>: Converts a list of MCP content blocks.
contentPartsToMcp(Iterable<ContentPart> parts) → List<Object?>: Converts a list of content parts.
contentPartToMcp(ContentPart part) → JsonMap?: Converts a ContentPart into an MCP content block.
isSupportedProtocolVersion(String version) → bool: Whether version is one this package can speak.
mcpTools(McpClient client, {String? prefix, Set<String> include = const <String>{}, Set<String> exclude = const <String>{}, Set<String> approvalRequired = const <String>{}, Duration? timeout, AgenticContext? context}) → Future<List<McpTool>>: Discovers a server's tools and wraps each one.
negotiateProtocolVersion(String serverVersion) → String?: Picks the newest revision both sides understand.
registerMcpTools(McpClient client, ToolRegistry registry, {String? prefix, Set<String> include = const <String>{}, Set<String> exclude = const <String>{}, Set<String> approvalRequired = const <String>{}, Duration? timeout, bool replace = false, AgenticContext? context}) → Future<List<String>>: Discovers and registers a server's tools in one step.
renderMcpContent(Object? blocks) → String: Renders MCP content blocks as the plain text a model reads.

Typedefs

McpRequestHandler = Future<JsonMap> Function(JsonRpcRequest request, AgenticContext context): Handles a request the server sent to the client.
McpResourceProvider = Future<List<JsonMap>> Function(AgenticContext context): Supplies the resources a server offers.
McpResourceReader = Future<List<JsonMap>?> Function(String uri, AgenticContext context): Reads one resource by URI, or returns null if it does not exist.

agentic_mcp library

Classes

Constants

Functions

Typedefs

agentic_mcp package

agentic_mcp library