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a2a_pack.mcp.server

Core MCP JSON-RPC handler — transport-agnostic.

The handler maps the MCP wire protocol onto an :class:A2AAgent:

  • initialize advertises tool support and echoes the server identity from the agent's :class:AgentCard.
  • tools/list enumerates the agent's skills.
  • tools/call dispatches into :meth:A2AAgent.invoke_json.

A transport (stdio, HTTP) calls :meth:MCPServer.handle with each decoded JSON-RPC message and forwards the returned dict back to the client. Notifications return None.

MCPServer (class)

MCPServer(agent: 'A2AAgent', *, context_builder: 'ContextBuilder | None' = None) -> 'None'

Transport-agnostic MCP request handler for an :class:A2AAgent.

__init__ (method)

__init__(self, agent: 'A2AAgent', *, context_builder: 'ContextBuilder | None' = None) -> 'None'

Initialize self. See help(type(self)) for accurate signature.

handle (method)

handle(self, message: 'dict[str, Any]') -> 'dict[str, Any] | None'

Dispatch one JSON-RPC message. Returns response or None for notifications.

parse_message (function)

parse_message(raw: 'str | bytes') -> 'dict[str, Any]'

Parse a JSON-RPC frame; raises :class:_MCPError with PARSE_ERROR.

skills_to_tools (function)

skills_to_tools(agent: 'A2AAgent') -> 'list[dict[str, Any]]'

Render the agent's skills as MCP tool descriptors.

tool_call_error (function)

tool_call_error(message: 'str') -> 'dict[str, Any]'

Wrap a tool-side failure as an MCP CallToolResult with isError=true.

tool_call_result (function)

tool_call_result(spec: 'SkillSpec', value: 'Any') -> 'dict[str, Any]'

Wrap a skill return value as an MCP CallToolResult.

Source: apps/a2a/a2a_pack/mcp/server.py