databroker MCP server

databroker-mcp-server

Give any MCP-capable agent (Claude Desktop, Claude Code, Cursor, etc) pay-per-call access to MossForge DataBroker — UK vehicle MOT intelligence, UK-wide reliability analytics — with x402 USDC micropayments on Base mainnet handled automatically. No API keys, no subscription: fund a wallet, ask questions.

Tools

Payments are never automatic. databroker_fetch and databroker_batch_create always quote the price first — nothing is paid until the tool is called again with confirm: true. Every paid call is also capped by DATABROKER_MAX_USDC (default 0.50); a call priced above the cap is declined before anything is paid.

Payment approval is enforced by the server, not by the calling model, on clients that support it. Immediately before any payment, this server sends an MCP elicitation request through the connected client, asking the human directly to approve or decline the exact charge — independent of whatever confirm value the model passed. Claude Code (CLI) supports this as of v2.1.76; other clients (Claude Desktop, Cursor, etc.) may not yet.

If the connected client doesn't advertise elicitation support, the server falls back to the pre-elicitation guarantee — confirm: true from the calling model, still capped by DATABROKER_MAX_USDC — rather than blocking every paid call. Set DATABROKER_REQUIRE_ELICITATION=true to instead hard-block paid calls on clients without elicitation support, if you know your client supports it and want the stricter guarantee. The server logs which mode is active on startup and the first time a non-elicitation client connects.

Setup

1. Create a fresh EOA wallet and fund it with a few USDC on Base mainnet (plus nothing else — no ETH needed; EIP-3009 transfers are gasless for the payer).

2. Add to Claude Desktop (claude_desktop_config.json):

{
  "mcpServers": {
    "databroker": {
      "command": "npx",
      "args": ["-y", "@mossforge/databroker-mcp"],
      "env": {
        "DATABROKER_BASE_URL": "https://api.databroker.mossforge.dev",
        "DATABROKER_WALLET_KEY": "0x...",
        "DATABROKER_MAX_USDC": "0.50"
      }
    }
  }
}

claude mcp add --transport stdio \
  --env DATABROKER_BASE_URL=https://api.databroker.mossforge.dev \
  --env DATABROKER_WALLET_KEY=0x... \
  databroker -- npx -y @mossforge/databroker-mcp

1. Ask: "Should I buy this 2018 Golf, reg AB18 CDE? Check its MOT history and whether the mileage looks genuine."

Who holds the wallet

Two signer providers are supported, set via DATABROKER_SIGNER:

• raw (default) — a private key you hold, read from DATABROKER_WALLET_KEY. Zero setup beyond a funded wallet, but the key material is only as safe as this process's environment, and the spend cap is enforced by this codebase alone.
• cdp — pays from a Coinbase CDP-managed wallet. No private key ever touches this process; CDP signs remotely and can enforce spend policies (session caps, allowed tokens) at the custodian layer. Requires a CDP account and CDP_API_KEY_ID / CDP_API_KEY_SECRET / CDP_WALLET_SECRET, plus npm install @coinbase/cdp-sdk (it's an optional dependency, not installed by default).

Security notes

• Use a dedicated, low-balance wallet. In raw mode the key never leaves your machine; payments are signed locally via the @x402/* v2 protocol stack (@x402/fetch + @x402/core/client + @x402/evm/exact/client), producing EIP-3009 transferWithAuthorization payloads.
• The per-call cap (DATABROKER_MAX_USDC) is the blast radius for any single call and is checked before any payment is sent — a call priced above it is declined, not charged. Total exposure is otherwise the wallet balance — keep it small.
• Every paid call goes through a quote first: databroker_fetch and databroker_batch_create never spend money unless called again with confirm: true.
• On top of that, when the connected client advertises MCP elicitation support, every payment also requires a human to explicitly accept a prompt sent by the server itself, naming the exact URL and USDC amount — enforced in code (confirmWithHuman in lib.ts), not left to the calling model's judgement. On clients without elicitation support this extra check is skipped (see DATABROKER_REQUIRE_ELICITATION below if you'd rather it fail closed instead).

Env vars