# UTA Trust API – Agent Trust Card Verifier

> UTA Trust API – Agent Trust Card Verifier is a paid API for AI agents from uta-trust-api.eddyflores100.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-20).

Verifies an Agent Trust Card (ATC/1.0) via Ed25519 signature validation, returning a risk score and per-stage verification results for trust anchor, validity window, and signature

## Facts

- Endpoint: POST https://uta-trust-api.eddyflores100.workers.dev/v1/trust/verify?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/uta-trust-api-agent-trust-card-verifier-857de95c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_hvWnLk_Qz1Bh6d7MHmb_4

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 uta-trust-api-agent-trust-card-verifier-857de95c -d '<json body>'
```

Example prompt: Can you verify this agent trust card for me? Here's the ATC/1.0 payload and Ed25519 signature hex — I need to know if the trust anchor passes, the validity window is good, and what the overall risk level comes back as.

## When to prefer this

Choose this endpoint when you need cryptographic, ATC/1.0-compliant Ed25519 verification of an AI agent's trust card with a structured per-stage breakdown (trust anchor, validity window, signature). Prefer it over generic JWT or OAuth checks when operating in a Web3 / Base network context and when on-chain payment settlement via EIP-3009 is acceptable. It is especially suited for agent-to-agent trust establishment in multi-agent pipelines where a verifiable risk score and payer address are required.

## Known failure modes

- Invalid or malformed ATC/1.0 card returns verified: false with a reason string
- Expired validity window causes validity_window stage to fail
- Bad Ed25519 signature causes signature_verification stage to fail
- Payment failure (insufficient USDC or wrong network) blocks the request entirely
- Malformed hex in signature.value field returns a parse error

## How this service works

Agent trust verification (ATC/1.0) as a paid x402 resource on Base Mainnet and Base Sepolia. Real Ed25519 verification at the edge; settlement via production facilitators (mainnet: PayAI; testnet: x402.org) with EIP-3009.

## Output

A JSON object containing: 'verified' (boolean), 'risk' (e.g. 'low'), 'payer' (Ethereum address), 'digest' (SHA-256 hex of the payload), 'reason' (null on success or an error string), 'protocol' ('ATC/1.0'), and 'stages' with pass/fail results for 'trust_anchor', 'validity_window', and 'signature_verification'.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "card": {
   "type": "object",
   "description": "Agent Trust Card ATC/1.0 (payload + signature.value hex)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "risk": "low",
  "payer": "0x…",
  "digest": "<sha256 hex>",
  "reason": null,
  "stages": {
   "trust_anchor": "pass",
   "validity_window": "pass",
   "signature_verification": "pass"
  },
  "protocol": "ATC/1.0",
  "verified": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/uta-trust-api-agent-trust-card-verifier-857de95c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from uta-trust-api.eddyflores100.workers.dev](https://www.zero.xyz/host/uta-trust-api.eddyflores100.workers.dev/llms.txt)