# PreFlight Oracle Freshness Check

> PreFlight Oracle Freshness Check is a paid API for AI agents from meryol-agenticmarket-x402.hf.space, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Checks whether a Chainlink or on-chain price feed is fresh and safe to use before an agent signs a transaction dependent on that oracle price.

## Facts

- Endpoint: GET https://meryol-agenticmarket-x402.hf.space/oracle/freshness/%7Bchain%7D/%7Bfeed%7D
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/preflight-oracle-freshness-check-f7301cdf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_SXE_BFyXUp5pGooCz0WLU

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 preflight-oracle-freshness-check-f7301cdf
```

Example prompt: Before I execute this ETH/USD trade on Base, can you check whether the ETH/USD Chainlink feed at 0x71041dddad3595f9ced3dccfbe3d1f4b0a16bb70 is fresh and safe to use right now?

## When to prefer this

Use this endpoint when an agent needs to verify that an on-chain price oracle is fresh and reliable before signing any transaction that depends on that price — especially on EVM chains like Ethereum, Base, Arbitrum, or Optimism. Prefer this over generic price-fetch endpoints when the agent's primary concern is oracle liveness and staleness risk, not just the price value itself.

## Known failure modes

- Invalid chain identifier returns 404 or error response
- Unknown or unsupported feed address returns error
- Feed address exists but has never updated — staleness could be very large
- Network timeout if the RPC node is unavailable
- Stale feed flagged as is_safe_to_use: false with high staleness_seconds

## How this service works

Pre-trade & pre-sign checks for autonomous agents: everything an agent verifies BEFORE signing a transaction — token due diligence, calldata red-flag decoding, oracle freshness, holder concentration, bridge routing with executable calldata, cross-venue perp funding, gas and price sanity checks. EVM chains: Ethereum, Base, Arbitrum, Optimism.

## Output

Returns the oracle feed's current scaled price, description (e.g. 'ETH / USD'), decimal precision, last update timestamp, staleness in seconds, a boolean is_safe_to_use flag, and any notes flagging issues — all in one JSON object.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "feed": "0x71041dddad3595f9ced3dccfbe3d1f4b0a16bb70",
  "chain": "base",
  "notes": [],
  "decimals": 8,
  "description": "ETH / USD",
  "answer_scaled": 3120.45,
  "updated_at_ts": 1715000000,
  "is_safe_to_use": true,
  "staleness_seconds": 120
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/preflight-oracle-freshness-check-f7301cdf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from meryol-agenticmarket-x402.hf.space](https://www.zero.xyz/host/meryol-agenticmarket-x402.hf.space/llms.txt)