Tachikoma MCP Server

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What it does

This extension registers tachikoma as an MCP server via contributes.mcpServers. Copilot Chat (and any other MCP client that reads the VS Code registry) picks up 27 tools at launch — without you editing mcp.json by hand.

The MCP transport is a stdio↔SSE bridge (tachikoma-mcp-server ≥ 1.2.0 on npm) spawned by VS Code. It reads your auth from the session file written by the Tachikoma Collab extension, so there are no tokens in your VS Code settings.

The 1.2.0 bridge reconnects forever with exponential backoff, re-reads the session file on token rotation (collab 4.4.0+ refreshes it every 10 min without manual reconnect), and re-pushes the active context list on every workspace change.

Quick start

1. Click an install badge above (or search Tachikoma MCP Server in the VS Code Extensions panel).
2. Install Tachikoma Collab as well — it's a hard dependency.
3. On first activation, the extension prompts you to enable chat.mcp.enabled (VS Code ignores MCP servers contributed by extensions until this setting is on). Click Enable → it sets the setting in user scope and offers to reload the window.
4. Cmd+Shift+P → Tachikoma: Connect to Computer.
5. Status bar shows ⚡ Tachikoma MCP when ready. The MCP panel lists 27 tools.

If you dismissed the prompt and the MCP panel is empty, run Tachikoma MCP: Enable VS Code MCP support from the command palette, or toggle chat.mcp.enabled in Settings yourself.

Status bar & commands

The right-side status bar item reflects session health:

Click → menu: Reconnect, Show Logs, Status.

Commands (all callable from the palette):

• Tachikoma MCP: Reconnect — refresh the session token from Collab
• Tachikoma MCP: Show Logs — open the OutputChannel
• Tachikoma MCP: Show Menu — same as clicking the status bar

Tools

Code intelligence (indexing.*)

Workflow (workflow.*)

query_knowledge, transition_state, create_plan, create_task, create_artifact, complete_work_item, run_query, run_parallel_queries, queue_parallel_task, execute_queued_tasks, get_ray_status — Ray-backed agent-loop primitives.

Active context = no context_path needed

When you open a workspace folder mapped to a tachikoma context, Collab adds it to activeContexts. The bridge pushes that list to the server. For any indexing.* call that omits context_path, the server fills it from the first active context — your agent doesn't need to know context paths.

Manual install (without the extension)

If you don't want this extension, add to .vscode/mcp.json directly:

{
  "servers": {
    "tachikoma": {
      "command": "npx",
      "args": ["-y", "tachikoma-mcp-server"]
    }
  }
}

You'll still need Tachikoma Collab for auth — or set TACHIKOMA_TOKEN + TACHIKOMA_SSE_URL in the env.

Architecture

  Copilot Chat / any MCP client
            │ stdio JSON-RPC
            ▼
  tachikoma-mcp-server (npx, auto-spawned)
            │ SSE + POST (Bearer)
            ▼
  tachikoma server (FastAPI, /api/mcp)
            ▲
            │ reads ~/.tachikoma/mcp-session.json
            │
  Tachikoma Collab (this extension's hard dep)

Troubleshooting

Requirements

• VS Code 1.99+ (for contributes.mcpServers)
• Node 18+ (for the npm bridge that VS Code auto-runs)
• A running tachikoma server with indexed contexts
• The Tachikoma Collab extension installed and connected

License

MIT