# ERC-8004 Agent Metadata Retrieval

> ERC-8004 Agent Metadata Retrieval is a paid API for AI agents from api.8k4protocol.com, paid per call via x402, $0.001/call, status down (last checked 2026-09-14).

Retrieves metadata JSON for a specific agent by ID under the ERC-8004 protocol

## Facts

- Endpoint: POST https://api.8k4protocol.com/agents/21480/metadata.json
- Price: $0.001/call
- Payment: x402
- Status: down
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-8k4protocol-com-117ccd45
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gcbM5JvFgzAnMpjh-6e1h

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 api-8k4protocol-com-117ccd45 -d '<json body>'
```

Example prompt: Can you fetch the ERC-8004 metadata for agent ID 21480 from the 8k4 protocol so I can see its descriptor fields and use them in a trust scoring pipeline?

## When to prefer this

Use this endpoint when you need to retrieve the raw ERC-8004 metadata descriptor for a specific agent by numeric ID, particularly as an upstream step before calling trust scoring, explanation, or statistics endpoints on the same protocol. Prefer this when building pipelines that require structured agent identity data from the 8k4 protocol.

## Known failure modes

- Agent ID not found — 404 response if the specified agent does not exist
- Invalid agent ID format — malformed request returns 400
- Payment not processed — x402 payment required before metadata is returned
- Chain not supported — if a chain ID is incompatible with the protocol
- Rate limiting or quota exceeded — too many requests in a short window

## Output

Returns a JSON object containing the agent's metadata fields as defined by the ERC-8004 protocol — including identifiers, descriptor fields, and other structured agent information associated with agent ID 21480.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-8k4protocol-com-117ccd45/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.8k4protocol.com](https://www.zero.xyz/host/api.8k4protocol.com/llms.txt)