# SignalHarness RRF Merge Search Results

> SignalHarness RRF Merge Search Results is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.015/call, status unknown (last checked 2026-09-15).

Merges multiple ranked search result lists into a single unified ranking using Reciprocal Rank Fusion (RRF)

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/search_result_rrf_merge/invoke
- Price: $0.015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signalharness-rrf-merge-search-results-3c64a005
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_svOWTwnOlNDusAahDuvWZ

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-rrf-merge-search-results-3c64a005 -d '<json body>'
```

Example prompt: I have results from three different search systems — BM25, semantic embeddings, and a keyword index — can you merge them into one unified ranked list using reciprocal rank fusion?

## When to prefer this

Use this endpoint when you have multiple ranked result lists from heterogeneous retrieval systems (e.g., BM25 + dense vector search) and need to merge them into a single coherent ranking without training a learned ranker. Ideal for hybrid search pipelines, RAG systems, or any scenario where results from different sources must be reconciled into one ordered list using a parameter-free, robust fusion method.

## Known failure modes

- Malformed or invalid JSON in request_json field causes rejection
- Input ranked lists with incompatible formats or missing rank fields
- Empty or null result lists produce empty merged output
- Exceeding the 65536 character limit on request_json triggers validation error
- 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

A JSON object containing the merged, re-ranked results produced by Reciprocal Rank Fusion across all input ranked lists, along with a service receipt including payment confirmation, execution metadata, and a SHA256 result hash for verification. Warnings may be included if input data could not be fully verified.

## 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": "search_result_rrf_merge",
   "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": "search_result_rrf_merge",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "15000",
   "resultSha256": "bb185871b0f0937c9a6619ee9411914c6c7c8e1b4b2c44d705432861da7aff1d",
   "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-rrf-merge-search-results-3c64a005/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)