@bolthub/mcp

The bolthub MCP server. One entry in your MCP client config; behind it, three kinds of tool source sharing one wallet and one Lightning budget:

• The bolthub marketplace — search, inspect, and call every listed API (search_apis, get_api_details, preview_cost, call_api, plus the Node Launcher tools).
• Specific L402 gateways — a gateway's OpenAPI endpoints become directly-named tools.
• Your other MCP servers — local or remote, proxied transparently: free tools pass straight through; a tool that answers with an L402 payment challenge is paid inside your budget and retried.

Replaces @bolthub/mcp-registry and @bolthub/mcp-bridge (both deprecated — migration below).

Source: signaltech-org/bolthub-sdk · Docs: docs.bolthub.ai

Quick start

Add to your MCP client config (Cursor, Claude Desktop, OpenClaw, etc.):

{
  "mcpServers": {
    "bolthub": {
      "command": "npx",
      "args": ["-y", "@bolthub/mcp"],
      "env": { "NWC_URI": "<your-nwc-connection-string>" }
    }
  }
}

With no config file this runs in marketplace mode: every listed bolthub API is available to your agent through the meta-tools. New listings appear automatically; no config changes, ever.

The full setup: one config file

~/.bolthub/mcp.json — the mcpServers block is the exact shape your MCP client already uses, so paste your existing entries in wholesale:

{
  "marketplace": true,
  "gateways": ["https://btc-intel.gw.bolthub.ai"],
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/Users/me/notes"]
    },
    "remote-tools": {
      "url": "https://tools.example.com/mcp",
      "headers": { "Authorization": "Bearer …" }
    }
  },
  "budget":     { "sat": 10000 },   // lifetime ceiling for this run, ALL sources combined
  "maxPerCall": { "sat": 500 },     // per-call ceiling
  "namespace":  "prefix",           // "prefix" (default) or "flat"
  "telemetry":  false               // reserved; v1 sends nothing anywhere
}

Then point the client at it:

{
  "mcpServers": {
    "bolthub": {
      "command": "npx",
      "args": ["-y", "@bolthub/mcp", "--config", "~/.bolthub/mcp.json"],
      "env": { "PHOENIXD_URL": "…", "PHOENIXD_PASSWORD": "…" }
    }
  }
}

What the agent sees

• Marketplace meta-tools, unprefixed: search_apis, get_api_details, preview_cost, call_api, deploy_node, node_status.
• Gateway endpoints, prefixed by gateway slug: btc-intel__get_v1_history_candles, ….
• Downstream MCP tools, prefixed by their config key: filesystem__read_file, ….

Two servers can both expose a search tool — prefixing keeps them apart. namespace: "flat" passes bare names through instead and fails at startup on any collision (a tool is never silently shadowed).

Wallet (optional)

Set ONE of these in the server's env:

PHOENIXD_URL + PHOENIXD_PASSWORD     (recommended, fast <200ms)
LND_REST_HOST + LND_MACAROON         (fastest, <200ms)
LNBITS_URL + LNBITS_ADMIN_KEY        (fast, <300ms)
NWC_URI                              (easiest, but slower 1-3s)

No wallet is not an error: free tools and marketplace search keep working; paid calls return their payment challenge with a setup hint.

One budget, hard guarantee

budget.sat caps what the server can spend over its lifetime — across gateway calls, call_api, and paid downstream MCP tools combined. Reservations are synchronous, so concurrent calls on different sources can't jointly overspend. budget.sat: 0 is valid and means "free tools only". The agent can never lift the ceiling; refusals come back as clean "Payment refused" results.

Every payment logs one line to stderr (your local audit trail). The telemetry flag is reserved: v1 sends nothing anywhere, on or off; if a future version adds an opt-in ingest it will carry { scheme, asset, amount } only — no tool arguments, no resource identity.

Migrating from @bolthub/mcp-registry / @bolthub/mcp-bridge

Remove the old entries from your client config rather than stacking them next to this one — a nested bolthub bin inside mcpServers would pay from its own wallet env, invisible to the shared budget (the server warns at startup if it spots this).

Notes & limits (v1)

• Proxies MCP tools only — no resources, prompts, or sampling passthrough yet.
• The downstream tool list is snapshotted at startup; hot add/remove needs a restart.
• A downstream that fails to start is skipped with a stderr warning; the rest keep serving.
• Everything logs to stderr, never stdout (stdout is the MCP channel).

License

MIT