MCP: Compatibility

The protocol contract

Rousseau's MCP server (internal/mcp/server.go) speaks JSON-RPC 2.0 over stdio and advertises the tools declared in internal/mcp/tools.go. It handles these methods:

• initialize — returns ServerCapabilities.Tools.
• initialized — notification, no reply.
• ping — returns {}.
• tools/list — returns the four tools in insertion order.
• tools/call — invokes a tool handler, returns ToolsCallResult with content and isError.
• resources/list, prompts/list — return empty arrays (see roadmap notes below).
• shutdown — returns {}.

Any MCP host that speaks stdio JSON-RPC and calls the four methods above is compatible.

Tested clients

Unknown / untested but likely compatible: zed, windsurf, aider. If your host supports the MCP stdio spec, rousseau will work.

Claude Desktop

Edit claude_desktop_config.json (path above) and add:

{
  "mcpServers": {
    "rousseau": {
      "command": "/usr/local/bin/rousseau",
      "args": ["mcp"]
    }
  }
}

Restart Claude Desktop. The four rousseau_* tools show up in the tool picker on the next chat session.

For per-workspace state, add an env override:

{
  "mcpServers": {
    "rousseau-work": {
      "command": "/usr/local/bin/rousseau",
      "args": ["--config", "/home/seb/.config/rousseau/work.yaml", "mcp"]
    }
  }
}

Claude CLI

Point the CLI at a config:

claude --mcp-config <(cat <<'JSON'
{
  "mcpServers": {
    "rousseau": {
      "command": "rousseau",
      "args": ["mcp"]
    }
  }
}
JSON
)

Or bake it into ~/.claude/config.json under an mcpServers block using the same shape.

Continue.dev

Add to ~/.continue/config.json:

{
  "mcpServers": [
    {
      "name": "rousseau",
      "command": "rousseau",
      "args": ["mcp"]
    }
  ]
}

Continue picks up the tools on the next model call.

Cursor

Cursor exposes MCP registration in its Settings > MCP UI. Register a new server named rousseau with command rousseau and args mcp. No config file editing required.

Codeium

Codeium's MCP support ships behind a feature flag in recent versions of the IDE extension. Consult the extension's docs — the registration is again a command / args pair.

Environment variables and secrets

Because rousseau's MCP surface is read-only over the session store, it does not need provider credentials. ANTHROPIC_API_KEY and similar are unused by rousseau mcp — only by the transport / chat daemons that generate sessions.

Common issues

• "Server exited immediately." Rousseau's mcp command opens state.path. If the file isn't writable, the process exits non-zero. Run rousseau mcp from a shell to see the exact error.
• "Unknown tool: rousseau_search_sessions." The host cached an older tool list. Restart the host.
• Duplicate registration. If two rousseau servers are registered with the same name, only the last one wins.

Resources and prompts

resources/list and prompts/list currently return empty. The Exposed resources page tracks the roadmap for exposing sessions as MCP resources.

Related

• MCP — the umbrella reference.
• MCP: Exposed tools — every tool signature.
• MCP: Exposed resources — roadmap.
• Tutorial: Expose tools via MCP — worked example.