# presign.hergertsynthora.com Transaction Pre-Sign Security Verdict

> presign.hergertsynthora.com Transaction Pre-Sign Security Verdict is a paid API for AI agents from presign.hergertsynthora.com, paid per call via x402, $0.015/call, status unknown (last checked 2026-09-14).

Returns an allow/warn/block security verdict before an agent signs a blockchain transaction, detecting unlimited approvals, honeypot tokens, sanctioned addresses, and phishing recipients.

## Facts

- Endpoint: POST https://presign.hergertsynthora.com/service
- Price: $0.015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/presign-hergertsynthora-com-transaction-pre-sign-security-verdict-87f0f86e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yLHWcqpI_XG_0yWLmChFp

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 presign-hergertsynthora-com-transaction-pre-sign-security-verdict-87f0f86e -d '<json body>'
```

Example prompt: Before you sign this Base transaction to contract 0xabc123... with calldata 0xd0e30c0b..., run a security check on it — I want to make sure there are no unlimited approvals, honeypot risks, or sanctioned addresses involved.

## When to prefer this

Use this endpoint as a last-mile guard immediately before an autonomous agent signs or approves any on-chain transaction, especially when interacting with unknown tokens or contracts. Prefer this over generic contract scanners when you need a combined verdict covering both token-level risks (honeypot, tax, mintable) and address-level risks (sanctions, phishing) in a single call with cryptographic provenance. Ideal for DeFi agents that need to catch unlimited approvals and sanctioned recipients automatically.

## Known failure modes

- Invalid or malformed calldata (0x...) returns a decode error
- Unsupported chain returns a validation error — only 'base' and 'ethereum' are accepted
- Missing both 'token' and 'to'/'data' fields returns a parameter error
- Downstream GoPlus, Chainalysis, or TRM API unavailability may cause partial or failed verdicts
- Payment failure (insufficient USDC balance on Base) returns a 402 Payment Required

## How this service works

Pre-sign security verdict for autonomous agents: before an agent SIGNS and settles a transaction, get an allow/warn/block verdict with reasons. Decodes the calldata to catch UNLIMITED approvals (spender can drain the token without further signatures), and cross-checks the token (honeypot, mintable, pausable, hidden owner, blacklist, buy/sell tax via GoPlus) and the spender/recipient (phishing, blacklist, sanctions via GoPlus address-security + Chainalysis + TRM). Use it as a last-mile guard before approving a token or signing a tx. Ed25519-signed provenance. 0.015 USDC on Base. POST {"chain":"base","to":"0x..","data":"0x.."} to verify a tx before signing, or {"chain":"base","token":"0x.."} to verify a token before approving.

## Output

A signed (Ed25519) security verdict of allow, warn, or block, accompanied by structured reasons explaining any detected risks such as unlimited approval scope, honeypot token flags (mintable, pausable, hidden owner, blacklist, buy/sell tax), phishing or sanctioned spender/recipient addresses, and decoded calldata details. Costs 0.015 USDC on Base per call.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "to": {
   "type": "string",
   "description": "Target contract of the tx to be signed (0x...); for approve/transfer this is the token being approved/moved"
  },
  "data": {
   "type": "string",
   "description": "Raw calldata (0x...) of the tx to be signed — decoded to detect unlimited approvals and the spender/recipient"
  },
  "chain": {
   "enum": [
    "base",
    "ethereum"
   ],
   "type": "string",
   "description": "Chain (default base)"
  },
  "token": {
   "type": "string",
   "description": "Token contract to verify before approving (0x...); use instead of to/data when you only want a token check"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "niche": "presign",
  "result": {
   "chain": "base",
   "intent": "approve(address,uint256)",
   "reasons": [
    "APPROVE ILIMITADO a 0x1111...: el spender podra vaciar el token sin mas firmas"
   ],
   "spender": "0x1111...",
   "verdict": "block",
   "token_flags": {
    "trust_list": true,
    "is_honeypot": false
   },
   "spender_risk": {
    "address": "0x1111...",
    "chainalysis_sanctioned": false
   },
   "checked_token": "0x8335..."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/presign-hergertsynthora-com-transaction-pre-sign-security-verdict-87f0f86e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from presign.hergertsynthora.com](https://www.zero.xyz/host/presign.hergertsynthora.com/llms.txt)