# LLM Response Citation Extractor

> LLM Response Citation Extractor is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Extracts and identifies citations, references, and sourced claims from LLM-generated text responses

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/llm_response_citation_extract/invoke
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/llm-response-citation-extractor-b01a0b2e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_M_CvZgItIS4aHk7Em1TSR

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 llm-response-citation-extractor-b01a0b2e -d '<json body>'
```

Example prompt: I have this long AI-generated research summary and I want you to extract all the citations and referenced sources from it — can you pull out every citation mentioned in the text and return them as structured data?

## When to prefer this

Choose this endpoint when you need to programmatically extract citations and source references from LLM-generated text at scale via a pay-per-call API, especially in RAG pipelines, research workflows, or fact-checking agents where attribution and source traceability matter. Prefer it over manual parsing when you need structured, machine-readable citation output from free-form AI responses.

## Known failure modes

- Malformed or non-JSON request_json input returns a validation error
- LLM response text with no citations returns empty citation list with warnings
- Input exceeding 65,536 character limit is rejected
- Ambiguous in-text references may be missed or misidentified
- Payment failure via x402 protocol prevents execution

## 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 extracted citation data, along with a status field indicating success, warnings about verifying caller-supplied data, a service_id, and a full receipt with payment and execution metadata including requestId, executionId, and a resultSha256 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": "llm_response_citation_extract",
   "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": "llm_response_citation_extract",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "5000",
   "resultSha256": "c528ef1141727c7a84ef895b9168746d0c4cc53d622f123a7aa308650fe00a39",
   "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/llm-response-citation-extractor-b01a0b2e/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)