MCP server

MCP expose side — Murmur agents callable as MCP tools by Claude Desktop / Cursor / the MCP Inspector / any other MCP-aware client. Behind the murmur-runtime[mcp-server] extra.

pip install 'murmur-runtime[mcp-server]'

The two opt-in tiers (surface + per-agent) live as methods on AgentServer. The value type for an enrollment is exposed for users who want to construct the registry programmatically; the register_mcp(...) method is the usual path. See the MCP concept page for the end-to-end usage pattern.

AgentServer.register_mcp

register_mcp(agent, *, tool_name=None, description=None) -> None

Enrolls an agent for MCP exposure. Distinct from register() (which is HTTP-only). Auto-registers the agent on the runtime so the bridge can dispatch by name. Re-enrollment under the same tool_name replaces.

Argument	Default	Effect
agent	—	The Murmur agent to expose.
tool_name	agent.name	Public MCP tool name. Override when the operator-facing name differs from the agent's internal one.
description	First line of agent.instructions, truncated to 200 chars	Human-readable summary the calling LLM uses to decide when to invoke the tool.

AgentServer.serve_mcp

serve_mcp(*, transport="stdio", server_name="murmur", instructions=None, host="127.0.0.1", port=8765) -> None

Async — blocks until the transport exits. Builds a fresh FastMCP per call so multiple invocations on the same server work cleanly.

Raises RegistryError when no agents are enrolled — silently starting an empty MCP server would mask a misconfiguration.

Argument	Default	Effect
transport	"stdio"	"stdio" for desktop clients; "http" for remote/hosted use.
server_name	"murmur"	Reported to MCP clients in the server identification handshake.
instructions	None	Free-text guidance shown to the calling LLM (alongside per-tool descriptions).
host / port	"127.0.0.1" / 8765	HTTP transport only. Ignored for stdio.

MCPEnrollment

MCPEnrollment

One agent enrolled for MCP exposure.

The :attr:agent is held by reference; :class:AgentServer is responsible for ensuring it's also registered with the runtime so the bridge can dispatch via runtime.run.

agent instance-attribute

agent: Agent

The Murmur agent this enrollment exposes. Must also be registered with the runtime (runtime.register(agent) or server.register(agent) — the bridge dispatches by name).

tool_name class-attribute instance-attribute

tool_name: str = Field(min_length=1)

Public tool name shown to MCP clients. Defaults to agent.name when not overridden — but operators usually want a distinct outward-facing name (e.g. agent "researcher-v3" → tool "research").

description class-attribute instance-attribute

description: str = Field(min_length=1)

Human-readable description sent to MCP clients in the tool list. Defaults to agent.instructions truncated when not overridden. LLMs reading the tool catalogue use this to decide when to call the tool — make it specific.