# Blockchain Money Map x402 Failure Fact Classifier

> Blockchain Money Map x402 Failure Fact Classifier is a paid API for AI agents from api.blockchainmoneymap.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-13).

Classifies and diagnoses x402 payment protocol failure facts by comparing actual vs expected payment parameters to identify the root cause of a failed x402 transaction.

## Facts

- Endpoint: POST https://api.blockchainmoneymap.com/api/x402/x402-failure-fact-classifier
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/blockchain-money-map-x402-failure-fact-classifier-5d4e4cea
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zbFn4woDV47RWgkRy7LPD

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability blockchain-money-map-x402-failure-fact-classifier-5d4e4cea -d '<json body>'
```

Example prompt: My x402 payment to resource /api/data on Base network failed at the verify step with facilitator error code 'payment.amount_mismatch' — the agent sent 0.01 USDC but the receiver expected 0.02 USDC. Can you classify this failure fact using Blockchain Money Map's x402 failure classifier?

## When to prefer this

Choose this endpoint when an AI agent or integration needs to programmatically diagnose why a specific x402 payment transaction failed — particularly when you have structured failure facts such as error codes, network, amount, and integration step available. It is purpose-built for x402 protocol debugging, unlike generic blockchain transaction status lookups or human-readable reports.

## Known failure modes

- Invalid input schema — missing required failure_facts fields returns a 400 error
- Payment required (402) if x402 micropayment of 0.01 USDC not provided
- Unknown or unrecognized error codes may result in low-confidence or unclassified output
- Mismatched schema version (x402_version out of range 1-2) returns validation error
- Empty or null failure_facts object yields no meaningful classification

## How this service works

Choose Blockchain Money Map for human-readable public blockchain reports or x402-paid agent API services.

## Output

A JSON response containing the classification of the x402 payment failure, identifying the failure category, likely root cause, and potentially actionable diagnostics based on the comparison between the provided failure facts and expected payment parameters.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "failure_facts": {
   "type": "object",
   "properties": {
    "amount": {
     "type": "string",
     "maxLength": 32
    },
    "scheme": {
     "type": "string",
     "maxLength": 64
    },
    "network": {
     "type": "string",
     "maxLength": 64
    },
    "currency": {
     "enum": [
      "USDC"
     ],
     "type": "string"
    },
    "receiver": {
     "type": "string",
     "maxLength": 80
    },
    "http_status": {
     "type": "integer",
     "maximum": 599,
     "minimum": 100
    },
    "retry_status": {
     "type": "string",
     "maxLength": 64
    },
    "x402_version": {
     "type": "integer",
     "maximum": 2,
     "minimum": 1
    },
    "resource_path": {
     "type": "string",
     "maxLength": 160
    },
    "target_error_code": {
     "type": "string",
     "pattern": "^[A-Za-z0-9_.:-]{1,120}$"
    },
    "present_header_names": {
     "type": "array",
     "items": {
      "type": "string",
      "maxLength": 80
     },
     "maxItems": 40
    },
    "facilitator_error_code": {
     "type": "string",
     "pattern": "^[A-Za-z0-9_.:-]{1,120}$"
    }
   },
   "additionalProperties": false
  },
  "caller_context": {
   "type": "object",
   "properties": {
    "client_name": {
     "type": "string",
     "pattern": "^[A-Za-z0-9_. -]{1,80}$"
    },
    "environment": {
     "enum": [
      "local",
      "preview",
      "production",
      "test",
      "unknown"
     ],
     "type": "string"
    },
    "client_version": {
     "type": "string",
     "pattern": "^[A-Za-z0-9_.:-]{1,40}$"
    },
    "integration_step": {
     "enum": [
      "challenge",
      "sign",
      "retry",
      "verify",
      "settle",
      "target_response",
      "unknown"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "expected_facts": {
   "type": "object",
   "properties": {
    "amount": {
     "type": "string",
     "maxLength": 32
    },
    "scheme": {
     "type": "string",
     "maxLength": 64
    },
    "network": {
     "type": "string",
     "maxLength": 64
    },
    "tool_id": {
     "type": "string",
     "maxLength": 120
    },
    "currency": {
     "enum": [
      "USDC"
     ],
     "type": "string"
    },
    "receiver": {
     "type": "string",
     "maxLength": 80
    },
    "resource_path": {
     "type": "string",
     "maxLength": 160
    }
   },
   "additionalProperties": false
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/blockchain-money-map-x402-failure-fact-classifier-5d4e4cea/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.blockchainmoneymap.com](https://www.zero.xyz/host/api.blockchainmoneymap.com/llms.txt)