# EVM Transaction Pre-Sign Safety Screener

> EVM Transaction Pre-Sign Safety Screener is a paid API for AI agents from api.agentstools.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Decodes and risk-scores a raw EVM transaction before signing — checking calldata, approval deltas, scam blocklists, and revert risk — returning allow/warn/block with a 0-100 risk score.

## Facts

- Endpoint: POST https://api.agentstools.dev/tx/raw
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-transaction-pre-sign-safety-screener-cd1928cb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_x1rmLnXSg4fK9F-odaPIA

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 evm-transaction-pre-sign-safety-screener-cd1928cb -d '<json body>'
```

Example prompt: Before I sign this transaction, screen it for me — it's going to contract 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Ethereum with calldata 0x095ea7b3...0xffffffff and no ETH value. Tell me the risk score and whether I should allow, warn, or block it.

## When to prefer this

Use this endpoint when an AI agent or wallet needs a pre-submission safety gate for raw EVM transactions — especially for DeFi interactions, token approvals, or any transaction received from an external source. Prefer this over generic contract explorers when you need a machine-readable allow/warn/block verdict with a numeric risk score, approval delta analysis, and revert simulation in a single call. It is particularly valuable in agentic workflows where the agent must autonomously decide whether to proceed with a transaction without human review.

## Known failure modes

- Invalid or non-0x-prefixed calldata returns a decode error
- Unknown contract address not in signature registry results in unrecognized calldata label
- Unsupported network enum value returns a validation error
- Simulation failure if the node is unreachable or the block state is stale
- Missing required 'to' field returns 400 bad request
- High-latency response if the target network RPC is congested

## 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 structured JSON object with a top-level verdict of allow, warn, or block; a numeric risk score from 0 to 100; decoded calldata intent (function name, known pattern); approval delta and transfer target if applicable; revert status from dry-run simulation; and a list of risk indicators such as scam-blocklist hits or approval-hygiene flags. Does not constitute financial or legal 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/evm-transaction-pre-sign-safety-screener-cd1928cb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.agentstools.dev](https://www.zero.xyz/host/api.agentstools.dev/llms.txt)