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, decision-grade signals across five domains — 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 (OpenTimestamps, Bitcoin-anchored). The agent decides. Payment settles directly to the provider wallet.

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

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

Tool	Price	What
gauge_catalog	free	All signals + queryable entities
gauge_preview	free	Coverage, pricing menu, bundle lists
gauge_sample	free	A full sample record (what paid looks like)
gauge_river_free	free	Raw US river reading (USGS site id)
gauge_flood_risk	$0.05	Flood-risk/anomaly record vs official thresholds + seasonal anomaly + hash
gauge_region	$0.10	City bundle: air + precipitation + river + cross-check
gauge_crop_drought	$0.10	Agriculture triangle: drought (USDM) + heat/GDD + crop VHI
gauge_grid_stress	$0.10	Power grid triangle: demand + renewables + energy inflation
gauge_route_disruption	$0.10	Shipping triangle: route disruption + sea state + AIS throughput
gauge_filing_check	$0.10	Regulatory-filing triangle: 8-K + late filing + Form 4 insider

19 signals across hydrology, air quality, precipitation, agriculture, power grid, shipping, regulatory filing.

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)

Key	Required	Description
EVM_PRIVATE_KEY	for paid tools	0x Base-mainnet wallet key; needs a little USDC (EIP-3009 gasless, no ETH).
GAUGE_BASE_URL	no	Default https://aeml-x402.zeabur.app.
GAUGE_MAX_USDC	no	Atomic per-call cap. Default 120000 ($0.12).

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

Verify (zero-trust)

Every paid record carries record_hash (canonical sha256) + Merkle root + OpenTimestamps (Bitcoin). Re-check via POST /verify or /proof/:record_hash at the GAUGE service.

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:

  npm publish
  mcp-publisher login github
  mcp-publisher publish
  

MIT · AEML-DS Vanished-Data Exchange