# ChainVerdict Pulse Attestation

> ChainVerdict Pulse Attestation is a paid API for AI agents from pulse.chainverdict.xyz, paid per call via x402, $0.12/call, status unknown (last checked 2026-10-21).

Probes an x402 endpoint and returns an Ed25519-signed quality attestation (compact JWS, 24h TTL) suitable for embedding in 402 payment responses to increase buyer conversion.

## Facts

- Endpoint: GET https://pulse.chainverdict.xyz/v1/attest?utm_source=zero.xyz
- Price: $0.12/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/chainverdict-pulse-attestation-7beded27
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TrD1LmEtYi8J-CP8siXwZ

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 chainverdict-pulse-attestation-7beded27
```

Example prompt: Probe my x402 endpoint at https://api.myservice.com/v1/data and give me a fresh Ed25519-signed quality attestation I can embed in my 402 responses to help buyers trust it.

## When to prefer this

Choose this endpoint when you need a cryptographically signed, third-party quality attestation to embed in your HTTP 402 responses — specifically to increase buyer trust and conversion for x402-gated APIs. It combines a live endpoint probe with an Ed25519 signature in a single call, unlike raw monitoring tools that only return metrics without a verifiable credential. Prefer it over generic uptime monitors when your use case is the x402 payment ecosystem and you need a portable JWS token buyers can verify independently.

## Known failure modes

- Target endpoint unreachable — attestation cannot be issued if the probed URL is offline
- Invalid or non-x402 endpoint URL — returns error if the target doesn't present a valid 402 payment offer
- Malformed URL input — query parameter 'url' missing or not a valid HTTP URL
- Attestation service unavailable — upstream signing service downtime prevents JWS generation
- Rate limit or payment failure — $0.12 USDC call fee not settled, request rejected

## How this service works

Fresh probe of your endpoint plus an Ed25519-signed quality attestation (compact JWS, 24h TTL) you can embed in your 402 responses to raise buyer conversion.

## Output

Returns a compact JWS (JSON Web Signature) containing an Ed25519-signed quality attestation for the probed endpoint. The attestation includes a freshness probe result, quality verdict, and a 24-hour TTL, making it embeddable in HTTP 402 payment responses to signal trustworthiness to potential API buyers.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "url"
 ],
 "properties": {
  "url": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "kid": {
   "type": "string"
  },
  "url": {
   "type": "string"
  },
  "payload": {
   "type": "object"
  },
  "attestation": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/chainverdict-pulse-attestation-7beded27/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from pulse.chainverdict.xyz](https://www.zero.xyz/host/pulse.chainverdict.xyz/llms.txt)