# SignalHarness Address Validate

> SignalHarness Address Validate 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).

Validates a postal or shipping address and returns a structured validation result with warnings about potential issues

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/address_validate/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/signalharness-address-validate-a5b3edb9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YR3j_Oifex_NUoAWu29d6

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-address-validate-a5b3edb9 -d '<json body>'
```

Example prompt: Can you validate this address for me — '1600 Pennsylvania Avenue NW, Washington, DC 20500' — and let me know if there are any issues with it?

## When to prefer this

Choose this endpoint when you need a quick, per-call address validation with a micro-payment model ($0.005 USDC) and no subscription required. It is especially useful for AI agents operating on the x402 payment protocol over the Base network, where each call is independently paid and receipted. Prefer it over geocoding APIs when the goal is deliverability validation rather than coordinate lookup, and over batch validation services when you need real-time single-address checks with an auditable on-chain receipt.

## Known failure modes

- Empty or too-short address string (minLength 2) returns a validation error
- Malformed JSON request body causes a 400-level error
- Payment not attached or insufficient USDC amount causes a 402 Payment Required response
- Address string exceeding 65536 characters is rejected
- Ambiguous or completely fictional address may return warnings rather than a hard failure
- Network or settlement failure on Base (eip155:8453) may cause payment to not settle

## 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 'address_validation' field with the validation verdict, a 'warnings' array listing any detected issues (e.g. missing unit number, unrecognized city), an 'evidence_scope' indicating the data source used (caller_supplied_data), and a full payment receipt including network, paymentId, latencyMs, and a SHA-256 result hash for auditability.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "Format validation does not prove ownership, activity, or safety."
   ],
   "service_id": "address_validate",
   "evidence_scope": "caller_supplied_data",
   "address_validation": "{\"kind\":\"evm\",\"normalized\":\"0x0000000000000000000000000000000000000001\",\"valid\":true}"
  },
  "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": "address_validate",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "5000",
   "resultSha256": "4fe9987a987fb6c70c30c808a20840f7b32688abb8c485a93a85cfb165146876",
   "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-address-validate-a5b3edb9/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)