x402 Requirement Drift Diff

Detects changes to the scheme, network, asset, atomic amount, receiver, resource, or advertised extensions in two caller-supplied requirements. It performs no payment, signature, or network operation.

Use when

An agent must compare x402 terms before retrying a payment.
A seller response may have changed its amount, receiver, network, or resource.

Do not use when

A payment must be signed, verified, settled, or transferred.
Either requirement cannot be normalized into the published schema.

Invocation contract

HTTP: /v1/tools/x402-requirement-drift-diff
Version: 0.1.0
Mode: lookup
Idempotency: not required
Retention: Both normalized requirement snapshots are compared in memory and are not retained.
Tested with: x402 v2 requirement snapshots, CAIP-2 networks

Positive and negative examples

{
  "input": {
    "before": {
      "scheme": "exact",
      "network": "eip155:8453",
      "asset": "USDC",
      "amount_atomic": "1000",
      "pay_to": "0x1111111111111111111111111111111111111111",
      "resource": "https://api.example.invalid/job",
      "extensions": [
        "payment-identifier"
      ]
    },
    "after": {
      "scheme": "exact",
      "network": "eip155:8453",
      "asset": "USDC",
      "amount_atomic": "2000",
      "pay_to": "0x1111111111111111111111111111111111111111",
      "resource": "https://api.example.invalid/job",
      "extensions": [
        "payment-identifier"
      ]
    }
  },
  "output": {
    "changed": true,
    "changed_fields": [
      "amount_atomic"
    ],
    "before_fingerprint": "sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
    "after_fingerprint": "sha256:bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
    "commercial_terms_changed": true,
    "retry_binding_changed": false
  },
  "negative": [
    {
      "scenario": "A payment must be signed, verified, settled, or transferred.",
      "expected_error": "INVALID_INPUT",
      "charged": false
    }
  ]
}

Deterministic errors

Code	Retry	Charged	Recovery
INVALID_INPUT	false	false	Correct the request to match input_schema.
TOOL_PAUSED	true	false	Wait for the operator to resume the tool.
RATE_LIMITED	true	false	Retry after the response Retry-After interval.
DEPENDENCY_UNAVAILABLE	true	false	Retry with the same idempotency identity.

Full machine manifest

The HTTP, OpenAPI, MCP, llms.txt, and ARD descriptions are generated from this same registry record.

Open JSON manifest →