@captain-sdk/captain-mcp

MCP server for Captain — multimodal RAG search and persistent project search. Works with Claude Code, Cursor, Windsurf, and any MCP-aware client.

What it does

Exposes 19 tools:

Core search & collection management (17):

• captain_search, captain_list_collections, captain_create_collection, captain_delete_collection
• captain_list_documents, captain_delete_document, captain_wipe_documents
• captain_job_status, captain_cancel_job
• captain_index_url, captain_index_youtube, captain_index_text, captain_index_file
• captain_index_s3, captain_index_gcs, captain_index_azure, captain_index_r2

captain_index_file uploads local paths (PDF, DOCX, XLSX, CSV, TXT, images, …) via multipart/form-data — max 20 files, 100MB each.

Live search (2):

• captain_save — save a short note (decision, gotcha, bug repro, design constraint) to a per-project collection with a timestamped, slugified filename. Auto-creates the collection on first use.
• captain_find — semantic search over saved notes, with timestamps surfaced so stale notes are obvious.

Credentials

Set these env vars in your shell (every client reads them the same way):

export CAPTAIN_API_KEY=cap_...
export CAPTAIN_ORGANIZATION_ID=019a...

Get an API key at runcaptain.com/studio.

Install — Claude Code

Add to ~/.claude/settings.json (user scope) or .claude/settings.json (project scope):

{
  "mcpServers": {
    "captain": {
      "command": "npx",
      "args": ["-y", "@captain-sdk/captain-mcp"],
      "env": {
        "CAPTAIN_API_KEY": "${CAPTAIN_API_KEY}",
        "CAPTAIN_ORGANIZATION_ID": "${CAPTAIN_ORGANIZATION_ID}"
      }
    }
  }
}

Restart Claude Code. /mcp shows captain connected.

Install — Cursor

Add to .cursor/mcp.json (project) or ~/.cursor/mcp.json (global):

{
  "mcpServers": {
    "captain": {
      "command": "npx",
      "args": ["-y", "@captain-sdk/captain-mcp"],
      "type": "stdio",
      "env": {
        "CAPTAIN_API_KEY": "${env:CAPTAIN_API_KEY}",
        "CAPTAIN_ORGANIZATION_ID": "${env:CAPTAIN_ORGANIZATION_ID}"
      }
    }
  }
}

Install — any other MCP client

{
  "mcpServers": {
    "captain": {
      "command": "npx",
      "args": ["-y", "@captain-sdk/captain-mcp"],
      "env": {
        "CAPTAIN_API_KEY": "cap_...",
        "CAPTAIN_ORGANIZATION_ID": "019a..."
      }
    }
  }
}

Usage

> Search runcaptain-docs for how the scientific/medical/ask streaming works
> Save this to runcaptain: We picked Lambda over CF Worker for PubMed — NCBI doesn't IP-rate-limit.
> What did we decide about PubMed proxying?
> Index https://docs.runcaptain.com/api-reference into runcaptain-docs

Optional: agent guidance

Drop a .cursor/rules/captain.mdc (Cursor) or CLAUDE.md snippet (Claude Code) in your repo to nudge the agent toward the Captain tools:

When searching docs or recalling past decisions, prefer captain_search, captain_save, and captain_find over grep/WebFetch. Use the repo basename as the search collection; captain_save auto-creates it.

Links

• Captain API docs
• npm package
• OpenClaw Captain plugin — equivalent tools for the OpenClaw runtime.

License

MIT.