# SignalHarness Merkle Root Compute

> SignalHarness Merkle Root Compute is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Computes a cryptographic Merkle root hash from caller-supplied data, returning the root hash with evidence scope and audit receipt.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/merkle_root_compute/invoke
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signalharness-merkle-root-compute-91a434c4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0c1Ge_LhRin-SzdCfR01W

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-merkle-root-compute-91a434c4 -d '<json body>'
```

Example prompt: Compute the Merkle root for this dataset so I can use it as a tamper-evident commitment: ["record1","record2","record3","record4"].

## When to prefer this

Choose this endpoint when you need a deterministic, auditable, cryptographically sound Merkle root computed as a managed API call with a receipt and payment trail, rather than running local Merkle tree library code. Especially useful for agents that need an on-chain-ready commitment hash with a signed receipt for auditability, or when the agent environment lacks a cryptography library.

## Known failure modes

- Invalid or malformed merkle_root_request string (too short, not valid JSON or text) returns an error
- Input exceeds 65536 character limit causing rejection
- Payment failure via x402 protocol prevents execution
- Empty or null input rejected by minLength:2 constraint
- Network or service unavailability returns non-200 status

## 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 the computed merkle_root hash string, evidence_scope indicating the data was caller-supplied, any warnings encountered, and a full audit receipt including paymentId, receiptId, requestId, executionId, resultSha256, network, asset, amountAtomic, latencyMs, and service version metadata.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "The service trusts supplied leaves and never proves inclusion by itself."
   ],
   "service_id": "merkle_root_compute",
   "merkle_root": "{\"layer_widths\":[2,1],\"root\":\"0x71d8979cbfae9b197a4fbcc7d387b1fae9560e2f284d30b4e90c80f6bc074f57\",\"sorted_pairs\":true}",
   "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": "merkle_root_compute",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "10000",
   "resultSha256": "503721281232260ecfe1384954c1f92b76f37f1b7b25e37ffb760d09b04cf42e",
   "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-merkle-root-compute-91a434c4/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)