# EVM Gas Cost Ceiling Calculator

> EVM Gas Cost Ceiling Calculator is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Computes the maximum possible gas cost (fee ceiling) in wei for an EVM transaction given a gas limit and max fee per gas, without retaining any input data.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/evm-gas-cost-ceiling
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-gas-cost-ceiling-calculator-e202285a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rkRhQb9no-JHPelLAqF-a

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-gas-cost-ceiling-calculator-e202285a -d '<json body>'
```

Example prompt: Before I submit this Ethereum transaction, calculate the gas cost ceiling — my gas limit is 21000 and my max fee per gas is 2000000000 wei.

## When to prefer this

Use this endpoint when an AI agent needs a safe, auditable, stateless upper-bound on EVM transaction fees before submitting on-chain — especially when you need evidence of no data retention (via SHA-256 input hash and retained:false flag). Prefer over on-chain gas estimation RPC calls when you want a simple, paid, governed micro-service with no external calls and verifiable evidence.

## Known failure modes

- Missing or invalid gas_limit integer returns a validation error
- max_fee_per_gas_wei exceeding string length of 8192 characters is rejected
- Non-numeric or malformed max_fee_per_gas_wei string causes a parse error
- Extremely large values may produce arithmetic overflow errors

## How this service works

EVM Gas Cost Ceiling: EVM Gas Cost Ceiling calculates a worst-case native fee from gas limit and fee cap from bounded caller-supplied values without an external provider. Call EVM Gas Cost Ceiling 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 Gas Cost Ceiling as versioned deterministic JSON. Price: $0.001 USDC vi…

## Output

Returns a JSON object containing the computed fee ceiling in wei, the echoed gas limit, a SHA-256 hash of the inputs for auditability, confirmation that no data was retained, and a count of zero external calls — providing a tamper-evident, bounded gas cost estimate.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "gas_limit": {
   "type": "integer",
   "description": "Gas Limit supplied to EVM Gas Cost Ceiling; used only for this bounded calculation and processed in memory without retention."
  },
  "max_fee_per_gas_wei": {
   "type": "string",
   "maxLength": 8192,
   "description": "Max Fee Per Gas Wei supplied to EVM Gas Cost Ceiling; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "gas_limit": 21000,
   "fee_ceiling_wei": "42000000000000"
  },
  "schema": "delx/util-evm-gas-cost-ceiling/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "19061cf987ca5901459acb5789767ddf5192ab7d107094a556164762a62044c7",
   "external_calls": 0
  },
  "operation": "evm_preflight:evm_gas_cost_ceiling"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-gas-cost-ceiling-calculator-e202285a/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)