# Delx Commerce — EVM Nonce Gap Check

> Delx Commerce — EVM Nonce Gap 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).

Checks whether the gap between a pending nonce and a proposed nonce on an EVM chain is within an acceptable maximum, and whether a nonce replacement is possible.

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/evm-nonce-gap-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-nonce-gap-check-3da77911
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9Vk4AxYp7_DFgFs1lt0Hh

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-nonce-gap-check-3da77911 -d '<json body>'
```

Example prompt: Before I broadcast this Ethereum transaction, check if the nonce gap is safe — my pending nonce is 42, the proposed nonce is 44, and my maximum allowed gap is 1.

## When to prefer this

Use this endpoint when an AI agent or automated system needs to validate EVM transaction nonce sequencing before broadcasting, particularly to avoid stuck or dropped transactions caused by nonce gaps. Ideal for preflight checks in agent-driven transaction pipelines where nonce ordering is critical. Prefer this over manual calculation when you need a verifiable, privacy-preserving, pay-per-use check with no signup or state retention.

## Known failure modes

- Missing or invalid integer inputs may result in computation errors
- Gap check returning within_budget:false when gap exceeds maximum_gap parameter
- possible_replacement:false when nonce gap disqualifies replacement
- Network or payment failure via x402 protocol preventing the call from completing

## How this service works

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

## Output

Returns the computed nonce gap size, a boolean indicating whether the gap is within the specified maximum budget, and a boolean indicating whether a nonce replacement is possible. Also includes metadata confirming no data was retained and no external calls were made.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "maximum_gap": {
   "type": "integer",
   "description": "Maximum Gap supplied to EVM Nonce Gap Check; used only for this bounded calculation and processed in memory without retention."
  },
  "pending_nonce": {
   "type": "integer",
   "description": "Pending Nonce supplied to EVM Nonce Gap Check; used only for this bounded calculation and processed in memory without retention."
  },
  "proposed_nonce": {
   "type": "integer",
   "description": "Proposed Nonce supplied to EVM Nonce Gap Check; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "gap": 2,
   "within_budget": false,
   "possible_replacement": false
  },
  "schema": "delx/util-evm-nonce-gap-check/v1",
  "status": "advisory",
  "evidence": {
   "retained": false,
   "input_sha256": "b9889d09b1009c8b22542a020475a3b907ede762b24f2fafec69d286c024edfd",
   "external_calls": 0
  },
  "operation": "evm_preflight:evm_nonce_gap_check"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-evm-nonce-gap-check-3da77911/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)