Model Context Protocol (MCP)

The Model Context Protocol (MCP) is an open standard for connecting LLMs to external systems. CodeCompanion implements the parts of it that help you code: running servers and using their tools and prompts.

Usage

Default servers start when you open your first chat buffer, and their tools are added to it. Start or stop any server with the /mcp slash command.

Once a server is running, its tools are available in the chat buffer, and its prompts can be added with the /mcp-prompts slash command.

ACP agents don't use CodeCompanion's MCP client. Instead, your servers can be passed to the agent.

Implementation

Feature	Supported	Details
Transport: Stdio	✅
Transport: Streamable HTTP	❌
Basic: Cancellation	✅	On timeout, or when you cancel
Basic: Progress	❌
Basic: Task	❌
Client: Roots	✅	Disabled by default
Client: Sampling	❌
Client: Elicitation	❌
Server: Completion	❌
Server: Pagination	✅
Server: Prompts	✅	Text content from user messages only
Server: Resources	❌
Server: Tools	✅	Text content only
Server: Tool list changed notification	❌

Protocol Version

CodeCompanion implements MCP version 2025-11-25.

See Also

• Model Context Protocol Specification - The official MCP documentation
• Configuring MCP Servers - Adding servers and overriding their tools