# Delx EVM Fee Cap Order Check

> Delx EVM Fee Cap Order Check is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Validates that EVM gas fee parameters are correctly ordered (max_fee_per_gas >= max_priority_fee_per_gas) for preflight transaction checks.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/evm-fee-cap-order-check
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-evm-fee-cap-order-check-5127a6fa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pnz0WlfT1M49cdshvzeqz

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-evm-fee-cap-order-check-5127a6fa -d '<json body>'
```

Example prompt: Before I submit this Ethereum transaction, can you check that my gas fee parameters are correctly ordered — max fee per gas is 2000000000 wei and max priority fee per gas is 100000000 wei?

## When to prefer this

Choose this endpoint when you need a lightweight, stateless, in-memory preflight check to confirm EVM gas fee ordering correctness before broadcasting a transaction. It is ideal when you need an auditable evidence trail (including input hash and zero data retention guarantees) and want a simple pass/fail check rather than full gas estimation or simulation.

## Known failure modes

- Invalid or non-numeric wei string values cause parsing errors
- max_priority_fee_per_gas_wei greater than max_fee_per_gas_wei returns ordered: false with a fail status
- Missing required fields result in a validation error response
- Malformed JSON body returns an HTTP 400 error

## How this service works

EVM Fee Cap Order Check: EVM Fee Cap Order Check checks that the priority fee cap does not exceed the total fee cap from bounded caller-supplied values without an external provider. Call EVM Fee Cap Order Check before signing, submitting, replacing, or accepting an EVM/Base transaction assembled from caller-owned data. Returns normalized transaction evidence, calculated budget or shape findings, and a fail-closed preflight status for EVM Fee Cap Order Check as versioned deterministic JSON. Pric…

## Output

Returns a JSON object indicating whether the fee parameters are correctly ordered (ordered: true/false), echoes back the provided wei values, a status field ('pass' or 'fail'), and an evidence block confirming no data retention and no external calls were made.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "max_fee_per_gas_wei": {
   "type": "string",
   "maxLength": 8192,
   "description": "Max Fee Per Gas Wei supplied to EVM Fee Cap Order Check; used only for this bounded calculation and processed in memory without retention."
  },
  "max_priority_fee_per_gas_wei": {
   "type": "string",
   "maxLength": 8192,
   "description": "Max Priority Fee Per Gas Wei supplied to EVM Fee Cap Order Check; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "ordered": true,
   "max_fee_per_gas_wei": "2000000000",
   "max_priority_fee_per_gas_wei": "100000000"
  },
  "schema": "delx/util-evm-fee-cap-order-check/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "b04dce361f99458031086c658ad3571d192c3729ea28ea2ccad5d3960a15eaf2",
   "external_calls": 0
  },
  "operation": "evm_preflight:evm_fee_cap_order_check"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-evm-fee-cap-order-check-5127a6fa/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)