# Agent Result Freshness Check

> Agent Result Freshness Check is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).

Validates whether an agent-delivered result is within an acceptable age window by comparing observation timestamp against current time and a caller-supplied maximum age budget.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/agent-result-freshness-check
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-result-freshness-check-05f785e6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TSQyV7CKH2hBldhKdRf-2

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 agent-result-freshness-check-05f785e6 -d '<json body>'
```

Example prompt: Before I accept and pay for this agent result, check if it's still fresh — the result was observed at epoch 1718000000, current time is epoch 1718000250, and my maximum allowed age is 300 seconds.

## When to prefer this

Use this endpoint when you need a lightweight, stateless, in-memory freshness gate before accepting or paying for an agent-delivered result — especially in x402 payment flows where stale results should be rejected before funds are committed. Prefer this over custom logic when you need normalized evidence and explicit accept/reject status without external dependencies or data retention.

## Known failure modes

- Missing required fields (now_epoch, observed_at_epoch, maximum_age_seconds) result in validation errors
- Negative or zero maximum_age_seconds may produce undefined or always-reject behavior
- now_epoch earlier than observed_at_epoch (clock skew or bad input) may yield rejection with mismatch reason
- Non-integer epoch values cause schema validation failure
- Payment failure via x402 protocol blocks the call

## How this service works

Agent Result Freshness Check: Agent Result Freshness Check checks result observation age against a caller freshness budget from bounded caller-supplied values without an external provider. Call Agent Result Freshness Check before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for Agent Result Freshness Check as v…

## Output

Returns a structured response containing an explicit acceptance or rejection status, contract-specific check results, normalized evidence of the age calculation, and mismatch reasons if the result falls outside the freshness budget. All computation is performed in-memory without data retention.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "now_epoch": {
   "type": "integer",
   "description": "Now Epoch supplied to Agent Result Freshness Check; used only for this bounded calculation and processed in memory without retention."
  },
  "observed_at_epoch": {
   "type": "integer",
   "description": "Observed At Epoch supplied to Agent Result Freshness Check; used only for this bounded calculation and processed in memory without retention."
  },
  "maximum_age_seconds": {
   "type": "integer",
   "description": "Maximum Age Seconds supplied to Agent Result Freshness Check; 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-agent-result-freshness-check/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "988059b2da4170c5bfc7e047394f4e4a26cb307ee840337c2c752ffa3e5af0e3",
   "external_calls": 0
  },
  "operation": "delivery_contract:agent_result_freshness_check"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-result-freshness-check-05f785e6/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)