# SperaxOS ERC-8004 Agent Registration API

> SperaxOS ERC-8004 Agent Registration API is a paid API for AI agents from chat.sperax.io, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).

Registers an AI agent on-chain using the ERC-8004 standard, storing its identity, services, trust mechanisms, and optional IPFS service manifest on a target blockchain.

## Facts

- Endpoint: POST https://chat.sperax.io/api/x402/tools/erc8004/registerAgent?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/speraxos-erc-8004-agent-registration-api-25811a7b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0mD-8ObSTzCM6FqffFsA7

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-registration-api-25811a7b -d '<json body>'
```

Example prompt: Register my AI agent called 'ArbitrageBot' on Base mainnet with a description of 'automated DeFi arbitrage agent', trust mechanisms of reputation and crypto-economic, an A2A service endpoint at https://myagent.example.com/a2a, and store my IPFS service manifest CID bafybeiabc123 in the on-chain metadata.

## When to prefer this

Choose this endpoint when you need to anchor an AI agent's identity and service endpoints on-chain in a standards-compliant way (ERC-8004), especially when you want peer agents to discover your agent's paid capabilities via an IPFS service manifest without relying on a centralized database. It is preferable over off-chain registries when trustless discoverability and verifiability across blockchain networks are required.

## Known failure modes

- Invalid or unsupported chain identifier returns an error listing valid options
- Malformed IPFS CID for serviceRegistryHash causes rejection
- Missing required 'name' field results in validation error
- Payment failure via x402 protocol (insufficient USDC balance) causes 402 response
- Service endpoint URLs that are malformed or unreachable may cause registration to fail
- Duplicate agent registrations on the same chain may conflict depending on registry logic

## 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

Returns confirmation that the agent has been registered on-chain, including the transaction hash or on-chain record reference, along with any stored metadata fields such as the service registry IPFS hash anchored under 'a2a.serviceRegistry'.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "name": {
   "type": "string",
   "description": "The name of the agent to register"
  },
  "chain": {
   "type": "string",
   "default": "bsc-testnet",
   "description": "Blockchain to register on. Accepts full names (bsc-mainnet, ethereum, arbitrum) or shortcuts (bsc, eth, arb, base, op, polygon, matic). Options: bsc-testnet, bsc-mainnet, ethereum, sepolia, arbitrum, base, optimism, polygon, arbitrum-sepolia, base-sepolia, optimism-sepolia, polygon-amoy"
  },
  "trust": {
   "type": "array",
   "items": {
    "type": "string"
   },
   "description": "Trust mechanisms (e.g., reputation, crypto-economic, institutional)"
  },
  "imageUrl": {
   "type": "string",
   "description": "Optional URL to an avatar/image for the agent"
  },
  "services": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "name",
     "endpoint"
    ],
    "properties": {
     "name": {
      "type": "string",
      "description": "Service name (e.g., A2A, MCP, inference)"
     },
     "endpoint": {
      "type": "string",
      "description": "Service endpoint URL"
     }
    }
   },
   "description": "Array of service endpoints the agent provides (A2A, MCP, etc.)"
  },
  "description": {
   "type": "string",
   "description": "A description of the agent and its purpose"
  },
  "serviceRegistryHash": {
   "type": "string",
   "description": "IPFS CID (CIDv1 or CIDv0) of the agent's commerce service manifest. When provided, the hash is stored in on-chain metadata under the key \"a2a.serviceRegistry\" so that peer agents can discover and verify paid capabilities without trusting a centralised database."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/speraxos-erc-8004-agent-registration-api-25811a7b/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)