# SperaxOS ERC-8004 Agent Metadata Lookup

> SperaxOS ERC-8004 Agent Metadata Lookup 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).

Retrieves a specific metadata key for an ERC-8004 on-chain agent by token ID from a specified blockchain network

## Facts

- Endpoint: POST https://chat.sperax.io/api/x402/tools/erc8004/getMetadata?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-metadata-lookup-aa6ee626
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_SACF9Qdz-xyg-bpFSeOMx

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-metadata-lookup-aa6ee626 -d '<json body>'
```

Example prompt: Look up the 'a2a.endpoint' metadata key for agent token ID 42 on the BSC mainnet using SperaxOS.

## When to prefer this

Use this endpoint when you need to look up specific ERC-8004 on-chain agent metadata by token ID and key, especially when querying BSC, Ethereum, or Sepolia networks. Prefer this over generic blockchain RPC calls when you want a structured, pay-per-use API without managing API keys, and when the metadata standard is ERC-8004.

## Known failure modes

- Agent token ID does not exist on the specified chain — returns an error or null value
- Invalid or unrecognized metadata key — returns empty or null result
- Unsupported chain specified — returns validation error
- Payment failure via x402 protocol — request blocked before execution
- Network or RPC timeout when querying the blockchain

## 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 the value associated with the requested metadata key for the specified ERC-8004 agent token on the given blockchain. Typically a string value such as a URL, version string, or descriptive text stored on-chain for that agent.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "key": {
   "type": "string",
   "description": "Metadata key to look up (e.g., \"version\", \"a2a.endpoint\")"
  },
  "chain": {
   "type": "string",
   "default": "bsc-testnet",
   "description": "Blockchain to query. Options: bsc-testnet, bsc-mainnet, ethereum, sepolia"
  },
  "agentId": {
   "type": "number",
   "description": "The token ID of the agent"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/speraxos-erc-8004-agent-metadata-lookup-aa6ee626/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)