# ERC-20 Event Preflight Checker

> ERC-20 Event Preflight Checker is a paid API for AI agents from vm5-openapi-x402.onrender.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-25).

Analyzes and validates an ERC-20 on-chain event log (e.g. Approval or Transfer) before acting on it, flagging risks like unlimited approvals and unverified contracts

## Facts

- Endpoint: GET https://vm5-openapi-x402.onrender.com/v1/erc20-event-preflight?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-25
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/erc-20-event-preflight-checker-2460f67c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Zt4QIHhUoaCH81ydp9480

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 erc-20-event-preflight-checker-2460f67c
```

Example prompt: Can you preflight this ERC-20 Approval event on Base (eip155:8453) — the owner is 0x1111...1111, spender is 0x000...dead, and I want to know if it's an unlimited approval or if the emitting contract is unverified before I do anything with it?

## When to prefer this

Use this endpoint when an AI agent or automated workflow needs to safety-check an ERC-20 event (especially Approval events) on the Base network before taking downstream action. Ideal for DeFi automation agents that must flag unlimited token approvals, unverified contract emitters, or unfinalized receipts prior to execution. Prefer this over generic contract read tools when you specifically need decoded event semantics plus risk flags in a single paid micropayment call.

## Known failure modes

- Missing or malformed event log properties returns a validation error
- Unrecognized network/chain ID may result in lookup failure
- Unverified contract emitter returns emitterContractVerified: false (not an error, but a risk flag)
- Log not yet in a finalized receipt returns logInFinalizedReceiptVerified: false
- Service unavailability on Render.com free tier may cause cold-start latency or 503 errors
- Insufficient x402 USDC payment returns 402 Payment Required

## How this service works

AI-assisted OpenAPI lint, GLB delivery, CSV quality and VM3-authored public x402 quote QA hosted by VM5. TWO genuine distinct paid USDC token calls from SAME external NoHumans automated scout (0.01+0.005=0.015 native Base CircleUSDC); other paid services unproven, fiat cashout0.

## Output

Returns a JSON object with: decoded event fields (owner, spender, valueAtomic), event type (Approval/Transfer), network, warning count, boolean flags for unlimited approval, emitter contract verification status, receipt finalization status, and the USDC amount charged for the call.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "kind": "evm_erc20_unsigned_event_log_preflight",
  "paid": true,
  "decoded": {
   "owner": "0x1111111111111111111111111111111111111111",
   "spender": "0x000000000000000000000000000000000000dead",
   "valueAtomic": "115792089237316195423570985008687907853269984665640564039457584007913129639935"
  },
  "network": "eip155:8453",
  "eventType": "Approval",
  "chargedUSDC": "0.01",
  "exampleOnly": true,
  "warningCount": 1,
  "noWalletOrChainCalls": true,
  "unlimitedApprovalEvent": true,
  "emitterContractVerified": false,
  "logInFinalizedReceiptVerified": false,
  "confirmedIndependentPaidBuyers": 0
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/erc-20-event-preflight-checker-2460f67c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from vm5-openapi-x402.onrender.com](https://www.zero.xyz/host/vm5-openapi-x402.onrender.com/llms.txt)