cap_mcp_client / cap_mcp_server

Client source: cap_mcp_client.ccomponents/claw_capabilities/cap_mcp_client/src/cap_mcp_client.c · header: cap_mcp_client.hcomponents/claw_capabilities/cap_mcp_client/include/cap_mcp_client.h · Skill: SKILL.mdcomponents/claw_capabilities/cap_mcp_client/skills/cap_mcp_client/SKILL.md

Server source: cap_mcp_server.ccomponents/claw_capabilities/cap_mcp_server/src/cap_mcp_server.c · header: cap_mcp_server.hcomponents/claw_capabilities/cap_mcp_server/include/cap_mcp_server.h · Skill: SKILL.mdcomponents/claw_capabilities/cap_mcp_server/skills/cap_mcp_server/SKILL.md

Overview

ESP-Claw implements Model Context Protocol (MCP) support through two components, cap_mcp_client and cap_mcp_server:

• cap_mcp_client: allows the LLM to discover and call tools exposed by remote MCP servers
• cap_mcp_server: exposes the device’s own Capabilities as a local MCP server for external MCP clients

cap_mcp_client

Tool description

Tool ID	Description
mcp_list_tools	List available tools on a remote MCP server
mcp_call_tool	Call a specified tool on a remote MCP server
mcp_discover	Discover MCP servers advertised on the local network

Tool parameters

mcp_list_tools

Parameter	Type	Required	Description
server_url	string	Yes	MCP server URL
endpoint	string		MCP endpoint path
cursor	string		Pagination cursor

mcp_call_tool

Parameter	Type	Required	Description
server_url	string	Yes	MCP server URL
tool_name	string	Yes	Tool name to call
endpoint	string		MCP endpoint path
arguments	object		Arguments passed to the tool

mcp_discover

Parameter	Type	Required	Description
timeout_ms	integer		Discovery timeout
include_self	boolean		Whether to include this device itself

Group information

Property	Value
Group ID	cap_mcp_client
Default LLM-visible	No (requires Skill activation)
Tool count	3

cap_mcp_server

Overview

cap_mcp_server is a CLAW_CAP_KIND_HYBRID Capability with lifecycle management. After start, it creates a local MCP server instance and exposes the device’s registered Capabilities as MCP tools for discovery and invocation by external MCP clients on the LAN, such as desktop IDEs or other ESP-Claw devices.

Features

• Supports MCP SSE (Server-Sent Events) transport
• Automatically maps device Capabilities to MCP tools
• Supports mDNS advertisement for LAN discovery
• Provides a full lifecycle (init -> start -> stop)

Group information

Property	Value
Group ID	cap_mcp_server
Default LLM-visible	No
Tool count	0 (server only; no LLM-callable tools exposed)

Tip

When cap_mcp_client and cap_mcp_server are used together, multiple ESP-Claw devices can form a distributed Agent network, discovering and calling one another’s capabilities through MCP.