# SYNTHORA PayTo Preflight Verifier

> SYNTHORA PayTo Preflight Verifier is a paid API for AI agents from payto-preflight.hergertsynthora.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Verifies a payTo address against the live registry before executing an x402 payment, detecting hijacking, stale endpoints, and unknown resources.

## Facts

- Endpoint: POST https://payto-preflight.hergertsynthora.com/service
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synthora-payto-preflight-verifier-893699cc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RAb1becDu9rZXvUreE08b

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 synthora-payto-preflight-verifier-893699cc -d '<json body>'
```

Example prompt: Before I pay that x402 endpoint at https://onchain.hergertsynthora.com/service, run a preflight check to make sure the payTo address 0x10800a5a5B9d72251566EC651E862A8b4B427dE0 is still correct and hasn't been hijacked — the expected chain is eip155:8453.

## When to prefer this

Use this endpoint before executing any x402 payment on Base when you need sub-200ms deterministic validation that the payTo address has not been hijacked or rotated. Prefer it over manual registry lookups when your agent operates in automated payment pipelines where payTo tampering would result in irreversible fund loss. Ideal for agentic workflows that must validate payment destinations without making external network calls beyond this service.

## Known failure modes

- payTo address mismatch — live address differs from expected, verdict is not safe
- endpoint URL not found in registry — unknown resource error
- stale endpoint — freshness_s exceeds acceptable threshold
- chain mismatch — chain_ok returns false when expected chain differs from registry
- malformed 0x address input causes validation error
- service returns non-200 if x402 payment header is missing or invalid

## How this service works

x402 PayTo Pre-Flight: verify a payTo address against the live registry before paying. Detects payTo hijacking, stale endpoints and unknown resources. Deterministic, <200ms, no external network. 0.001 USDC via x402 on Base. SYNTHORA.

## Output

Returns a JSON object with a verdict ('safe' or otherwise), whether the live payTo address exactly matches the expected address, the active status of the endpoint, a freshness timestamp in seconds, the network and asset details, and a human-readable reason string explaining the result.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "chain": {
   "type": "string",
   "description": "expected chain, e.g. eip155:8453"
  },
  "endpoint_url": {
   "type": "string",
   "description": "endpoint resource URL to verify"
  },
  "expected_payTo": {
   "type": "string",
   "description": "expected payTo address (0x...)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "niche": "payto_preflight",
  "result": {
   "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
   "active": true,
   "reason": "payTo vivo coincide con el esperado, endpoint active y fresco",
   "source": "scout_resource",
   "matched": true,
   "network": "eip155:8453",
   "verdict": "safe",
   "chain_ok": true,
   "endpoint": "https://onchain.hergertsynthora.com/service",
   "price_usd": 0.001,
   "checked_at": "2026-08-07T21:00:00Z",
   "live_payTo": "0xEf879BFD6C4AccB8F795136de90246e1EC245e06",
   "match_kind": "exact",
   "freshness_s": 120,
   "expected_payTo": "0xEf879BFD6C4AccB8F795136de90246e1EC245e06"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synthora-payto-preflight-verifier-893699cc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from payto-preflight.hergertsynthora.com](https://www.zero.xyz/host/payto-preflight.hergertsynthora.com/llms.txt)