# SignalHarness Orderbook Depth

> SignalHarness Orderbook Depth 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).

Retrieves or analyzes orderbook depth data for a given trading asset or market, returning bid/ask depth information via a paid agent-native API.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/orderbook_depth/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-orderbook-depth-4dd83ef0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qEaWs_qhcVXjLH6PnBF8i

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-orderbook-depth-4dd83ef0 -d '<json body>'
```

Example prompt: Pull the current orderbook depth for BTC/USDC — I need to see the bid and ask walls before placing a large order.

## When to prefer this

Choose this endpoint when you need real-time or near-real-time orderbook depth data for crypto or DeFi markets and are operating in an agent-native, micropayment-enabled (x402/USDC) context. Prefer this over manual exchange API calls when your agent needs a single, standardized interface with verifiable receipts and on-chain payment provenance.

## Known failure modes

- Invalid or malformed orderbook_depth_request string returns an error
- Unsupported trading pair or market identifier yields empty or warning-only response
- Payment failure (USDC not received) results in 402 response before execution
- Rate limiting or service unavailability returns a non-succeeded status
- Request string too short (< 2 chars) or too long (> 65536 chars) fails schema validation

## 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 orderbook depth result, any warnings, evidence scope, service ID, and a detailed receipt including payment info, network, latency, execution IDs, and a SHA-256 result hash for verification.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "The order book is caller supplied and may be stale or incomplete."
   ],
   "service_id": "orderbook_depth",
   "evidence_scope": "caller_supplied_data",
   "orderbook_depth": "{\"ask_depth\":{\"levels\":1,\"notional\":\"303\",\"quantity\":\"3\"},\"best_ask\":\"101\",\"best_bid\":\"99\",\"bid_depth\":{\"levels\":1,\"notional\":\"198\",\"quantity\":\"2\"},\"level_limit\":10}"
  },
  "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": "orderbook_depth",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "10000",
   "resultSha256": "2f888a22a08e204522b8353d3fd26d3fff83a7e6d732802741098d1ec11be9e1",
   "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-orderbook-depth-4dd83ef0/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)