api402x.com

Live 402 challenge

Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.

{
  "what": "Reads a Gnosis Safe's live spending authority straight from the chain -- current owner set, threshold, enabled modules and transaction guard -- and compares it against the same Safe's state at an earlier block, flagging added/removed owners, added/removed modules and threshold changes. Needs no stored baseline and no subscription: the earlier state is read from chain history on the same call, so the very first request already answers 'has this changed'. Why pay instead of reading it yourself: the historical reads only work on archive-capable endpoints (several common public RPCs refuse them outright or serve pruned state), an enabled module can move funds with no owner signatures at all, and the block where the change landed is narrowed by binary search over chain history rather than assumed. Modules are expanded recursively, not listed flat: a module is often an EIP-1167 minimal proxy, and a module can itself be a Safe with its own owners and threshold. The canonical Safe transaction service returns 404 for a module address, so nothing below the first level is available from it. Worked example in the declared response: a Safe that reads as 1-of-1 with no guard is in fact governed through a module by a separate 2-of-8 Safe. No verdicts are attached — an enabled module is not an alarm by itself. Required query parameters: chain_id and address.",
  "asset": "USDC",
  "error": "payment_required",
  "price": "$0.005",
  "accepts": [
    {
      "payTo": "0x63bc58472a8449eDd1d1af0B0c03cFc7c832Da2f",
      "price": "$0.005",
      "scheme": "exact",
      "network": "eip155:8453"
    },
    {
      "payTo": "0x63bc58472a8449eDd1d1af0B0c03cFc7c832Da2f",
      "price": {
        "asset": "0xfde4C96c8593536E31F229ea8F37b2Ada2699bb2",
        "extra": {
          "assetTransferMethod": "permit2"
        },
        "amount": "5000"
      },
      "scheme": "exact",
      "network": "eip155:8453"
    },
    {
      "payTo": "0x63bc58472a8449eDd1d1af0B0c03cFc7c832Da2f",
      "price": {
        "asset": "0x50c5725949A6F0c72E6C4a641F24049A917DB0Cb",
        "extra": {
          "supportsEip2612": true,
          "assetTransferMethod": "permit2"
        },
        "amount": "5000000000000000"
      },
      "scheme": "exact",
      "network": "eip155:8453"
    }
  ],
  "example": "https://api402x.com/safe-signer-drift?chain_id=1&address=0x91c32893216dE3eA0a55ABb9851f581d4503d39b",
  "network": "eip155:8453",
  "openapi": "https://api402x.com/openapi.json",
  "how_to_pay": "x402: signed payment challenge is in the `payment-required` response header. No API key and no subscription — pay per call in USDC on Base.",
  "x402Version": 2,
  "free_preview": "https://api402x.com/safe-signer-drift/preview",
  "authoritative": "payment-required header; this body is a duplicate for clients that read the body",
  "response_schema": "https://api402x.com/openapi.json — the full JSON Schema for this response. It is not repeated in the payment-required header because response headers have a hard 16 KB limit in common HTTP clients and this response is large. The header still carries a complete worked example of the shape."
}

Accepts

The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.

[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0xE606AE66542D4F1A56AA551841db41e3ECd26816",
    "amount": "30000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  }
]

Provenance

Seen in the source catalog

2026-08-14 00:30Z

Last indexed by Roundhouse

2026-09-21 14:45Z

Last enriched (probe, favicon, geo)

2026-09-18 08:45Z

x402 version

2

Max timeout

300s

Liveness probe

HTTP 402