# SperaxOS ERC-8004 Agent Identity Validation

> SperaxOS ERC-8004 Agent Identity Validation is a paid API for AI agents from chat.sperax.io, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-22).

Validates whether a given agent ID has a registered ERC-8004 identity on the SperaxOS agentcash platform via a lightweight HEAD request

## Facts

- Endpoint: HEAD https://chat.sperax.io/api/x402/v1/erc8004/validation/%7BagentId%7D?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/speraxos-erc-8004-agent-identity-validation-8c15619c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8BBZlwEyERSuCHf2i1DoI

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 speraxos-erc-8004-agent-identity-validation-8c15619c -d '<json body>'
```

Example prompt: Check whether agent ID 0xabc123 has a valid ERC-8004 identity registered on SperaxOS agentcash before I try to use the DeFi intelligence APIs.

## When to prefer this

Choose this endpoint when you need a zero-cost, lightweight check of whether a specific agent ID holds a registered ERC-8004 / agentcash identity on SperaxOS before committing to paid DeFi intelligence API calls. It is a HEAD request, so it is fast and incurs no response body overhead. Prefer this over full GET requests when you only need a boolean existence check, not full identity data.

## Known failure modes

- agentId not found in the ERC-8004 registry — returns 404 or equivalent not-found status
- malformed agentId path parameter — returns 400 bad request
- identity exists but lacks sufficient permissions — returns 403
- network or server error on chat.sperax.io — returns 5xx
- payment required for non-SIWX endpoint variant — returns 402 with x402 payment details

## How this service works

AI-powered DeFi intelligence APIs payable via the x402 HTTP payment protocol. No API key required — pay per request with USDC on Base. Identity-only (SIWX) endpoints are free for wallets with an agentcash identity.

## Output

A HEAD response indicating the existence and validity of the ERC-8004 agent identity: HTTP 200 means the agentId is registered and valid on SperaxOS agentcash; HTTP 402 or 404 indicates the identity is absent, unrecognized, or payment is required for further access.

## Request schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/speraxos-erc-8004-agent-identity-validation-8c15619c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from chat.sperax.io](https://www.zero.xyz/host/chat.sperax.io/llms.txt)