# ERC-8004 Agent Identity Registry - Register Agent

> ERC-8004 Agent Identity Registry - Register Agent is a paid API for AI agents from theloopbreaker.com, paid per call via x402, $0.100000/call, status unknown (last checked 2026-09-15).

Registers an AI agent on the ERC-8004 Identity Registry by returning a fully-encoded unsigned transaction (calldata, gas estimate, chain ID) ready for local wallet signing, in exchange for $0.50 USDC via x402 payment.

## Facts

- Endpoint: POST https://theloopbreaker.com/api/x402/actions/register-agent
- Price: $0.100000/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/theloopbreaker-com-4dbcb57f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_onBL9ZImdxJlq35NrqXlu

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 theloopbreaker-com-4dbcb57f -d '<json body>'
```

Example prompt: Register my AI agent named 'NexusBot' with wallet address 0x1234567890123456789012345678901234567890 on the ERC-8004 Identity Registry on Base — give me the unsigned transaction I can sign locally.

## When to prefer this

Use this endpoint when you need to register a new AI agent on the ERC-8004 on-chain identity registry and want a fully-prepared unsigned transaction without ever exposing private keys to a third party. Prefer this over manual contract interaction when you want a gas-estimated, calldata-encoded transaction ready for signing, and when you are operating on Base mainnet within the Vaultfire/theloopbreaker ecosystem.

## Known failure modes

- Missing or invalid X-PAYMENT header — returns 402 with accepted payment schemes and asset details
- Invalid or malformed wallet address — returns 400 validation error
- Missing required fields (name or walletAddress) — returns 400 schema validation error
- Insufficient USDC payment amount — returns 402 payment required
- Chain ID not supported — returns 400 or 422 error

## How this service works

Register an AI agent on the ERC-8004 Identity Registry. Pay $0.10 in USDC and receive a fully-encoded unsigned transaction (calldata + gas estimate + chain ID) — sign locally in your wallet to become the registered agent. No private keys ever touch our servers.

## Output

Returns a fully-encoded unsigned transaction object including calldata, gas estimate, and chain ID (Base, chain ID 8453) that the caller can sign locally with their own wallet to complete ERC-8004 agent registration. Private keys never leave the client.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object"
  },
  "output": {
   "type": "object"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/theloopbreaker-com-4dbcb57f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from theloopbreaker.com](https://www.zero.xyz/host/theloopbreaker.com/llms.txt)