# Delx Commerce EVM Legacy Fee Check

> Delx Commerce EVM Legacy Fee Check is a paid API for AI agents from commerce.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-01).

Validates whether a legacy EVM transaction's gas fee falls within a specified budget ceiling, returning a pass/fail result with verifiable evidence.

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/evm-legacy-fee-check?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-commerce-evm-legacy-fee-check-305f58c2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9UM7PzUZD3qNdvlb8qAdS

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 delx-commerce-evm-legacy-fee-check-305f58c2 -d '<json body>'
```

Example prompt: Before I send this Ethereum transaction, check if a gas limit of 21000 at a gas price of 10000000000 wei stays within my maximum fee of 21000000000000 wei.

## When to prefer this

Choose this endpoint when you need a lightweight, verifiable, stateless preflight check for EVM legacy-style transactions (type 0) before submission — especially in agentic pipelines where tamper-evident evidence (SHA-256 input hash, no-retention confirmation) is required. It is ideal for cost-guard logic in automated workflows that must provably confirm fee compliance without retaining any input data. Prefer this over on-chain simulation when you only need a fee ceiling check and want a fast, cheap, off-chain result with cryptographic auditability.

## Known failure modes

- Missing required fields (gas_limit, gas_price_wei, or maximum_fee_wei) result in validation error
- Non-numeric or malformed wei strings may cause parse errors
- gas_price_wei or maximum_fee_wei strings exceeding 8192 characters are rejected
- Payment failure via x402 protocol blocks the request
- Fee exceeds ceiling returns within_budget: false with status 'fail' (not an error, but a negative result)

## How this service works

Pay-per-result APIs for agents. No signup. Exact price. Verifiable delivery. USDC on Base + Solana via x402.

## Output

Returns a JSON object indicating whether the computed fee (gas_limit × gas_price_wei) falls within the maximum_fee_wei ceiling. Includes a boolean 'within_budget' field, the computed 'fee_ceiling_wei', an overall 'status' (pass/fail), and a tamper-evident evidence block containing the SHA-256 hash of the inputs, confirmation that no data was retained, and the count of external calls made (always 0).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "gas_limit": {
   "type": "integer",
   "description": "Gas Limit supplied to EVM Legacy Fee Check; used only for this bounded calculation and processed in memory without retention."
  },
  "gas_price_wei": {
   "type": "string",
   "maxLength": 8192,
   "description": "Gas Price Wei supplied to EVM Legacy Fee Check; used only for this bounded calculation and processed in memory without retention."
  },
  "maximum_fee_wei": {
   "type": "string",
   "maxLength": 8192,
   "description": "Maximum Fee Wei supplied to EVM Legacy Fee Check; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "within_budget": true,
   "fee_ceiling_wei": "21000000000000"
  },
  "schema": "delx/util-evm-legacy-fee-check/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "3f479705a06db86ca332b2883b0bc646d76b8b39f7fea2aa864a00ee6e549ded",
   "external_calls": 0
  },
  "operation": "evm_preflight:evm_legacy_fee_check"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-evm-legacy-fee-check-305f58c2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from commerce.delx.ai](https://www.zero.xyz/host/commerce.delx.ai/llms.txt)