API reference

Quickstart

# x402: your agent pays $0.01 automatically
curl https://walletbureau.com/v1/score/0x…

# or with a prepaid key
curl -H "Authorization: Bearer atk_…" \
     https://walletbureau.com/v1/score/0x…

One GET, one JSON, stable schema. Pay per call with x402 — no account, no invoice, no minimum. Or use a prepaid API key.

MCP server

The same check as a tool your agent can call. The package ships ready-to-run JavaScript — no build step, no install scripts, no native modules — and exposes two tools: check_counterparty (one check, $0.01) and get_service_stats (free). The price is read from the live API at startup, so the tool annotation your agent sees is the price it will pay.

# Claude Code
claude mcp add walletbureau -- npx -y @walletbureau/mcp

# Claude Desktop, Cursor and other clients: mcpServers entry
"walletbureau": { "command": "npx", "args": ["-y", "@walletbureau/mcp"] }

How a check is paid for depends on the environment, and nothing has to be switched by hand. If both are set, the prepaid key wins — its balance is already paid for.

Package on npm → Source on GitHub →

Endpoints

Response schema

Generated from the published JSON Schema. The demo and the paid endpoint return the same shape; fields are only ever added, never renamed or removed.

{
  "address": "0x8f3a1c2b9d4e5f60718293a4b5c6d7e8f9a0b1c2",
  "score": 34,
  "verdict": "avoid",
  "flags": [
    { "code": "new_address", "severity": "high",
      "reason": "First seen in x402/EIP-3009 data 4 days ago (younger than 7 days)" }
  ],
  "stats": {
    "first_seen": "2026-08-06T09:12:44.000Z",
    "tx_in": 128, "tx_out": 3,
    "volume_in_usd": "604.31", "volume_out_usd": "12.05",
    "distinct_payers": 128,
    "confidence_basis": "confirmed+probable"
  },
  "meta": {
    "computed_at": "2026-08-10T18:00:02.000Z",
    "cache_age_seconds": 312,
    "api_version": "v1",
    "disclaimer": "Risk signals, not accusations. Methodology: https://walletbureau.com/methodology"
  }
}

Error codes

Every error returns JSON with a stable machine-readable <code>error</code> field and a human-readable <code>message</code>. Match on <code>error</code>, not on the message text.

Paying with x402

Call the endpoint without credentials, receive 402 Payment Required, settle $0.01 in USDC on Base through the x402 flow, and repeat the request. No account, no invoice, no minimum.

curl -i https://walletbureau.com/v1/score/0x…
HTTP/1.1 402 Payment Required

API keys

A prepaid key skips the payment round-trip. Send it as a bearer token. Keys are issued by hand for now — write to us.

curl -H "Authorization: Bearer atk_…" \
     https://walletbureau.com/v1/score/0x…

Rate limits