mcp-gauge — MCP server for GAUGE (verifiable signals, pay-per-call in USDC via x402)

Give any MCP host (Claude Desktop, Cursor, MCP-compatible agents) access to GAUGE's verifiable, screening-level signals across many domains (weather, drought, agriculture, power grid, shipping, regulatory filings, and more) — and let the agent pay per call in USDC on Base via x402 (EIP-3009 gasless, no API key, no signup).

Pure description — official-source facts (USGS / NOAA / EPA / CAMS / ERA5 / FRED / Open-Meteo Marine / SEC EDGAR) + back-testable statistics + record_hash (canonical sha256, recomputable offline). The agent decides. Payment settles directly to the provider wallet.

Backed by the GAUGE service at https://aeml-x402.zeabur.app.

Part of Truth Bear 🐻 — GAUGE is the data engine behind Truth Bear, the natural-language front desk for AI agents and SMBs. Ask in plain language, get the official fact + its source + a verifiable record_hash — no prediction, no advice, the rest is your call. An analyst, not a commander. Front desk: https://gauge-frontdesk.zeabur.app · discovery: /.well-known/x402, /llms.txt.

Why MCP + x402

• Discovery is free and open (MCP): any MCP host lists these tools with zero setup.
• Payment is crypto (x402): the agent pays USDC only when it calls a paid tool.
• Free tools (gauge_catalog, gauge_preview, gauge_sample, gauge_river_free) need no wallet — try before you buy.

Tools

130+ signals (and growing) across hydrology, air quality, precipitation, agriculture, power grid, shipping and regulatory filing — with global coverage (US plus Argentina, Brazil, China, India, Ukraine, EU and more). Check the live set anytime via the free gauge_catalog tool.

Two ways to connect (they are different servers)

Pick the remote one if you don't want to put a private key in your MCP host config.

Install & configure

Requires Node 18+. The MCP host runs the server over stdio. Install straight from GitHub — no npm account, no signup (the built dist/ is committed):

npx -y github:CHANGCHINFU/mcp-gauge

Claude Desktop

Add to claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/, Windows: %APPDATA%\Claude\):

{
  "mcpServers": {
    "gauge": {
      "command": "npx",
      "args": ["-y", "github:CHANGCHINFU/mcp-gauge"],
      "env": {
        "EVM_PRIVATE_KEY": "0xYOUR_BASE_WALLET_KEY_WITH_A_LITTLE_USDC"
      }
    }
  }
}

Omit EVM_PRIVATE_KEY to use free tools only (catalog / preview / sample / river).

Cursor / other MCP hosts / Claude Code

• Claude Code: claude mcp add gauge -- npx -y github:CHANGCHINFU/mcp-gauge (add --env EVM_PRIVATE_KEY=0x… for paid tools).
• Cursor / others: command npx -y github:CHANGCHINFU/mcp-gauge, transport stdio, optional EVM_PRIVATE_KEY env.

From source

git clone https://github.com/CHANGCHINFU/mcp-gauge && cd mcp-gauge
npm install && npm run build
node dist/index.js        # stdio

Once published to npm the package name is mcp-gauge-x402 (npx -y mcp-gauge-x402); until then use the GitHub form above.

Config (env)

Handle the private key like any hot-wallet secret; fund it with a small USDC balance only.

Verify (zero-trust)

Every paid record carries a record_hash — the canonical sha256 of the record's core fields, which you can recompute yourself offline. Re-check a record via POST /verify, or look a hash up with GET /proof/:record_hash or the free GET /gauge/verify?format=json&hash=…, at the GAUGE service.

Bitcoin / OpenTimestamps anchoring: RETIRED. It was ruled out of implementation on 2026-07-23 and was never actually stamped. Earlier versions of this README advertised it — that was wrong, and this corrects it. What you actually get: integrity from record_hash, and timeliness from the official source_ref plus observed_at. The ots_status field is a legacy compatibility field and stays pending forever. The live service says the same thing in GET /proof/:record_hash → proof.bitcoin_anchoring.

Distribution (maintainers)

• GitHub install (primary, no npm account): users run npx -y github:CHANGCHINFU/mcp-gauge.
• awesome-mcp-servers: submit a PR to a curated MCP server list for discoverability (no npm needed).
• MCP Registry (optional, needs npm): publish mcp-gauge-x402 to npm, then server.json is ready for the MCP publisher:
  Terminal

  Copy

  npm publish
  mcp-publisher login github
  mcp-publisher publish
  

MIT · AEML-DS Vanished-Data Exchange