# Data Freshness Certificate

> Data Freshness Certificate is a paid API for AI agents from phion.systems, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Calculate data age against an explicit freshness policy and return a certificate indicating whether the data meets freshness requirements

## Facts

- Endpoint: POST https://phion.systems/v1/paid/trust/data-freshness-certificate
- 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/data-freshness-certificate-cfc7f68e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_USuycksw-w4GDr2JNKMlk

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 data-freshness-certificate-cfc7f68e -d '<json body>'
```

Example prompt: Check whether this dataset is still fresh enough to use — it was last updated at 2024-06-01T10:00:00Z and our policy requires data to be no older than 24 hours; give me a freshness certificate I can attach to the workflow.

## When to prefer this

Choose this endpoint when you need a tamper-evident, policy-aware certificate of data freshness rather than a simple age calculation. It is ideal for agent workflows that must prove compliance with data recency SLAs, audit pipelines that require attestation receipts, or multi-agent handoffs where the receiving agent needs verifiable assurance that upstream data was fresh at the time of use. Prefer over ad-hoc timestamp comparisons when auditability or downstream verification is required.

## Known failure modes

- Missing or unparseable timestamp in input — returns validation error
- No freshness policy provided — returns schema error
- Timestamp in future relative to current time — may return error or zero-age result
- Malformed policy thresholds — returns policy parse error
- Network or service timeout — HTTP 5xx response

## How this service works

Calculate data age against an explicit freshness policy

## Output

Returns a structured certificate indicating the calculated age of the data, whether it satisfies the provided freshness policy, the degree of staleness or remaining freshness window, and an attestation receipt that can be logged or forwarded as trust evidence.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/data-freshness-certificate-cfc7f68e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from phion.systems](https://www.zero.xyz/host/phion.systems/llms.txt)