# SignalHarness AI Answer Source Audit

> SignalHarness AI Answer Source Audit is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-15).

Audits the sourcing and attribution quality of AI-generated answers, flagging unsupported claims and evidence gaps in caller-supplied data.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/ai_answer_source_audit/invoke
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signalharness-ai-answer-source-audit-a37abece
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_kp2S0ZiwPNw2dANJyx4SA

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 signalharness-ai-answer-source-audit-a37abece -d '<json body>'
```

Example prompt: Can you audit this AI-generated answer and tell me whether its sources and claims are properly supported? Here's the answer JSON: {"question":"What is the capital of France?","answer":"Paris","source":"Wikipedia"}

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-call audit of AI-generated answer quality and source attribution without building a full fact-checking pipeline. It is especially useful for agents that produce or relay LLM outputs and need a fast integrity check before surfacing results to end users. Prefer it over general web search or citation tools when you already have structured answer JSON and want an analysis of its evidentiary basis rather than fresh source retrieval.

## Known failure modes

- Malformed or non-JSON request_json input returns a validation error
- Input exceeding 65,536 characters is rejected
- Ambiguous or incomplete evidence data may result in low-confidence analysis with generic warnings
- Payment failure on the x402 protocol prevents execution
- Caller-supplied data is not independently verified — results reflect only what was provided

## How this service works

Explore 330 pay-per-call x402 API services and 27 agent-native digital products, with Base USDC pricing, secure Polar checkout, and free discovery.

## Output

Returns a JSON object containing an analysis_json field with detailed audit findings, a list of warnings about unverified or caller-supplied claims, an evidence_scope label (e.g. 'caller_supplied_data'), plus a payment receipt with execution metadata including latency, payment ID, and a SHA-256 result hash for integrity verification.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "request_json": {
   "type": "string",
   "maxLength": 65536,
   "minLength": 2
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "Verify the caller-supplied data before relying on this result."
   ],
   "service_id": "ai_answer_source_audit",
   "analysis_json": "{\"example\":\"schema-valid caller-supplied data\"}",
   "evidence_scope": "caller_supplied_data"
  },
  "status": "succeeded",
  "receipt": {
   "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
   "usage": [],
   "status": "succeeded",
   "network": "eip155:8453",
   "artifacts": [],
   "endedAtMs": 0,
   "latencyMs": 0,
   "paymentId": "example-payment",
   "receiptId": "example-receipt",
   "requestId": "example-request",
   "serviceId": "ai_answer_source_audit",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "30000",
   "resultSha256": "99186689a1780324b80359df4ee84368e9598b01fbe389d96f9c7a532d5558a1",
   "serviceVersion": "1.0.0",
   "settlementReference": "0x0000000000000000000000000000000000000000000000000000000000000000"
  },
  "artifacts": [],
  "requestId": "example-request",
  "executionId": "example-execution"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/signalharness-ai-answer-source-audit-a37abece/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from signalharness.ai](https://www.zero.xyz/host/signalharness.ai/llms.txt)