# 8k4 Protocol — ERC-8004 Agent Trust Score

> 8k4 Protocol — ERC-8004 Agent Trust Score is a paid API for AI agents from api.8k4protocol.com, paid per call via x402, $0.001/call, status down (last checked 2026-10-07).

Returns an ERC-8004 trust score, risk band, and confidence tier for a specific on-chain agent by agent ID and chain

## Facts

- Endpoint: GET https://api.8k4protocol.com/agents/%7Bagent_id%7D/score?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: down
- Last checked: 2026-10-07
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/8k4-protocol-erc-8004-agent-trust-score-34538355
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gkfrzCU4g0oZFfVc-Dsyn

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 8k4-protocol-erc-8004-agent-trust-score-34538355
```

Example prompt: What's the ERC-8004 trust score and risk band for agent ID 21480 on the Base chain — I want to know if it's safe to interact with before delegating anything.

## When to prefer this

Use this endpoint when you need a quick, single-agent trust score and risk classification for a specific ERC-8004 agent on a known chain, especially before delegating tasks or interacting with an unknown agent. Prefer this over the score explanation endpoint when you need only the numeric verdict, not the reasoning behind it.

## Known failure modes

- Unknown agent_id returns 404 not found
- Unsupported chain name returns 400 bad request
- Agent has insufficient validator data, returning low confidence tier
- API key or x402 payment missing returns 402 payment required
- Rate limit exceeded returns 429 too many requests

## How this service works

Get an ERC-8004 trust score for a specific agent and chain

## Output

A JSON object containing the agent's numeric trust score (0-100), risk band (e.g. MEDIUM), confidence tier, validator count bucket, global EIP-155 identifier, chain name, and the timestamp the score was last computed.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "as_of": "2026-03-03T00:00:00+00:00",
  "chain": "base",
  "score": 78.4,
  "agent_id": 21480,
  "global_id": "eip155:8453:0x8004...:21480",
  "risk_band": "MEDIUM",
  "confidence_tier": "MEDIUM",
  "validator_count_bucket": "10+"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/8k4-protocol-erc-8004-agent-trust-score-34538355/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)