# Delx Base Gas Price Staleness Check

> Delx Base Gas Price Staleness Check is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Determines whether a previously quoted Base (L2) gas price is still fresh by comparing its age against a maximum allowed staleness threshold.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/base-gas-price-staleness
- 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/delx-base-gas-price-staleness-check-e970ba86
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qPUS5ROUC4DWt64HGrnTN

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-base-gas-price-staleness-check-e970ba86 -d '<json body>'
```

Example prompt: Check if the gas price I quoted at epoch 1710001000 is still fresh — it's now epoch 1710001090 and my maximum allowed staleness is 120 seconds.

## When to prefer this

Use this endpoint when your agent needs a deterministic, in-memory, zero-side-effect staleness gate before submitting EVM transactions on Base L2. Prefer it over rolling your own timestamp arithmetic when you need a traceable evidence receipt (input SHA-256, retained:false, external_calls:0) for auditability in automated blockchain workflows.

## Known failure modes

- Missing required fields (now_epoch, quoted_at_epoch, or maximum_age_seconds) result in a validation error
- Negative age if now_epoch is before quoted_at_epoch — may return an error or unexpected result
- Non-integer epoch values cause schema validation failure
- Payment failure (insufficient USDC balance) blocks the call with a 402 response

## How this service works

Base Gas Price Staleness: Base Gas Price Staleness checks the age of a caller-supplied gas quote before use from bounded caller-supplied values without an external provider. Call Base Gas Price Staleness 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 Base Gas Price Staleness as versioned deterministic JSON. Price: $0.…

## Output

Returns a JSON object indicating whether the gas price quote is fresh (boolean), how many seconds old it is (age_seconds), an overall pass/fail status, and an evidence block confirming no data was retained and no external calls were made. The operation field identifies this as an EVM preflight staleness check.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "now_epoch": {
   "type": "integer",
   "description": "Now Epoch supplied to Base Gas Price Staleness; used only for this bounded calculation and processed in memory without retention."
  },
  "quoted_at_epoch": {
   "type": "integer",
   "description": "Quoted At Epoch supplied to Base Gas Price Staleness; used only for this bounded calculation and processed in memory without retention."
  },
  "maximum_age_seconds": {
   "type": "integer",
   "description": "Maximum Age Seconds supplied to Base Gas Price Staleness; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "fresh": true,
   "age_seconds": 60
  },
  "schema": "delx/util-base-gas-price-staleness/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "71423649bb9f78764df45bb5a8b4de2c13085d598094d66b005c77f6181eac9f",
   "external_calls": 0
  },
  "operation": "evm_preflight:base_gas_price_staleness"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-base-gas-price-staleness-check-e970ba86/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)