# PayAI EVM Transaction Pre-Sign Safety Check

> PayAI EVM Transaction Pre-Sign Safety Check is a paid API for AI agents from payai.agentstools.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Analyzes a raw EVM transaction before signing — decoding calldata, checking scam blocklists, simulating reverts, and returning an allow/warn/block verdict with a 0-100 risk score.

## Facts

- Endpoint: POST https://payai.agentstools.dev/tx/raw
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/payai-evm-transaction-pre-sign-safety-check-cdce560c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZYigAVeJJXmb66YKdj4oa

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 payai-evm-transaction-pre-sign-safety-check-cdce560c -d '<json body>'
```

Example prompt: Before I sign this transaction, can you run a safety check on it? It's going to contract 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Base with calldata 0x095ea7b3...ffffffff — let me know if it's safe, warn me of any suspicious approvals, and give me a risk score.

## When to prefer this

Use this endpoint when an AI agent or wallet needs to gate-check any raw EVM transaction before signing — especially for token approvals, transfers, or contract interactions on supported chains. Prefer this over generic RPC calls when you need a structured allow/warn/block verdict, decoded calldata semantics, and scam blocklist coverage in a single call without building your own transaction analysis pipeline.

## Known failure modes

- Unknown or undecodable calldata may result in limited analysis with incomplete effect fields
- Invalid or malformed contract address returns an error
- Unsupported network enum value returns a validation error
- Simulation (eth_call) may fail if the sender address is not provided or the node is unavailable
- Scam blocklist may not cover newly deployed malicious contracts

## How this service works

Pre-sign safety verdict for a raw EVM transaction. Decodes the calldata against a known-signature registry, shows known-pattern effects (approval delta, transfer target), dry-runs eth_call for revert, checks scam-blocklist and approval-hygiene, and returns allow, warn or block plus a 0-100 risk. Risk indicators, not advice.

## Output

Returns a safety verdict of 'allow', 'warn', or 'block', a numeric risk score from 0 to 100, decoded calldata effects (approval delta, transfer target), a dry-run revert status, and scam blocklist and approval hygiene findings. All outputs are risk indicators, not financial advice.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "to": {
   "type": "string",
   "description": "Destination contract address"
  },
  "data": {
   "type": "string",
   "description": "0x-prefixed calldata hex"
  },
  "from": {
   "type": "string",
   "description": "Optional sender address (enables allowance delta)"
  },
  "value": {
   "type": "string",
   "description": "Optional native value in wei"
  },
  "network": {
   "enum": [
    "base",
    "ethereum",
    "arbitrum",
    "optimism",
    "polygon",
    "bnb"
   ],
   "type": "string",
   "description": "EVM network the transaction is for (default base)"
  },
  "simulate": {
   "type": "boolean",
   "description": "Dry-run eth_call for revert (default true)"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/payai-evm-transaction-pre-sign-safety-check-cdce560c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from payai.agentstools.dev](https://www.zero.xyz/host/payai.agentstools.dev/llms.txt)