# Delx Commerce — EVM Gas Limit Headroom Check

> Delx Commerce — EVM Gas Limit Headroom 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).

Calculates whether a given gas limit provides sufficient headroom over an estimated gas cost for an EVM transaction, returning the headroom amount and fraction.

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/evm-gas-limit-headroom?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-gas-limit-headroom-check-e833e94b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QWEgfoI308RrxGFQB4TDt

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-gas-limit-headroom-check-e833e94b -d '<json body>'
```

Example prompt: Before I submit this transaction, check if a gas limit of 250000 gives me enough headroom over an estimated gas usage of 210000 — I want to know the headroom amount and whether it's sufficient.

## When to prefer this

Use this endpoint when you need a fast, verifiable, zero-retention preflight check on EVM gas parameters before submitting a transaction. Prefer it over manual calculation when you need a cryptographic evidence receipt (input SHA-256) proving the check was performed honestly and without external data leakage, especially in automated agent workflows where auditability matters.

## Known failure modes

- Missing or non-integer gas_limit or estimated_gas fields returns a validation error
- gas_limit of zero may cause divide-by-zero or undefined fraction
- estimated_gas exceeding gas_limit returns sufficient=false with negative or zero headroom
- Payment failure via x402 protocol blocks the request before computation

## 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 with: a boolean 'sufficient' indicating if the gas limit covers the estimate with adequate headroom, 'headroom_gas' (absolute gas units of headroom), 'headroom_fraction' (fraction of gas limit that is headroom), plus evidence fields including a SHA-256 hash of the input and confirmation of zero data retention and no external calls.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "gas_limit": {
   "type": "integer",
   "description": "Gas Limit supplied to EVM Gas Limit Headroom; used only for this bounded calculation and processed in memory without retention."
  },
  "estimated_gas": {
   "type": "integer",
   "description": "Estimated Gas supplied to EVM Gas Limit Headroom; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "sufficient": true,
   "headroom_gas": 4200,
   "headroom_fraction": 0.2
  },
  "schema": "delx/util-evm-gas-limit-headroom/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "dd71c79c3c5455d122b7167969700e4587770c75519ca55c82bfc04e7433381e",
   "external_calls": 0
  },
  "operation": "evm_preflight:evm_gas_limit_headroom"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-evm-gas-limit-headroom-check-e833e94b/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)