payload402

Live 402 challenge

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

{
  "llms": "/llms.txt",
  "asset": "USDC on Base",
  "error": "payment_required",
  "price": "$0.005",
  "network": "eip155:8453",
  "openapi": "/openapi.json",
  "service": "payload402",
  "when_to_use": "Before npm install or adding a dependency — one package name@version → license, spdx, compatible (yes/no/unknown). Stop if compatible=no (copyleft/unknown). Not legal or SBOM advice.",
  "agent_scenario": "Agent about to run npm install left-pad@1.0.0 — check license first, proceed only if compatible=yes.",
  "example_request": "/license/check?package=lodash&version=4.17.21"
}

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": "0x555379f9F4750EB34ffc8b3DAf8eda2eA0F6d112",
    "amount": "5000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "type": "http",
        "method": "GET",
        "queryParams": {
          "pkg": "lodash",
          "version": "4.17.21"
        }
      },
      "output": {
        "type": "json",
        "example": {
          "spdx": "MIT",
          "policy": "permissive-default",
          "reason": "Permissive license matches permissive-default policy",
          "source": "npm-registry",
          "license": "MIT",
          "package": "lodash",
          "version": "4.17.21",
          "compatible": "yes",
          "disclaimer": "Triage indicator only, not legal or compliance advice"
        }
      }
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "input"
      ],
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method"
          ],
          "properties": {
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "GET"
              ],
              "type": "string"
            },
            "queryParams": {
              "type": "object",
              "required": [
                "pkg"
              ],
              "properties": {
                "pkg": {
                  "type": "string",
                  "description": "npm package name"
                },
                "version": {
                  "type": "string",
                  "description": "Optional semver (default latest)"
                }
              }
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object"
            }
          }
        }
      }
    }
  }
}

Provenance

Seen in the source catalog

2026-09-15 09:41Z

Last indexed by Roundhouse

2026-09-24 07:20Z

Last enriched (probe, favicon, geo)

2026-09-23 20:45Z

x402 version

2

Max timeout

300s

Liveness probe

HTTP 402