# Agent Card Discovery Decision

> Agent Card Discovery Decision is a paid API for AI agents from agentreadiness.halowerk.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-16).

Fetches public evidence from a target URL and evaluates whether it exposes a valid agent card, returning a verdict, evidence source, threshold, and recommended action.

## Facts

- Endpoint: POST https://agentreadiness.halowerk.com/v1/agent-card-decision?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-card-discovery-decision-490cb404
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lviNkheeTrfkpAPn9HOj7

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 agent-card-discovery-decision-490cb404 -d '<json body>'
```

Example prompt: Check if https://api.example.com has a valid agent card — I need to know if it's discoverable by AI agents, what evidence was found, and what I should do next.

## When to prefer this

Choose this endpoint when you need a passive, read-only check specifically for agent card presence and validity on a public URL. Prefer it over general crawling or manual inspection when you need a structured verdict with evidence sourcing and actionable guidance. Use it as a pre-integration step before connecting to a third-party service, or as part of an automated AI readiness audit pipeline. It complements sibling endpoints for OpenAPI discovery, llms.txt, and header semantics.

## Known failure modes

- Target URL is unreachable or returns non-200 status — verdict may be inconclusive
- Agent card path exists but is malformed — observation notes the issue but verdict may still fail
- Domain normalization fails for non-standard URLs — request rejected with validation error
- Rate limits or network timeouts during passive fetch — partial or no evidence returned
- Target blocks crawlers — evidence source unavailable, limitations noted in response

## How this service works

Agent card discovery decision fetches current public evidence from the supplied target and evaluates the documented criterion. It returns the observation, threshold, verdict, exact evidence source, limitations and a mode-specific action. The check is passive: no login attempt, payload injection, exploit, purchase, form submission or load test is performed.

## Output

Returns an observation describing what was found at the target, the evaluation threshold, a pass/fail verdict, the exact evidence source URL, any limitations of the passive check, and a mode-specific recommended action. No login, form submission, or active probing is performed.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "target": {
   "type": "string",
   "maxLength": 2048,
   "minLength": 3,
   "description": "Public HTTP(S) URL or domain to inspect. A bare domain is normalized to HTTPS."
  },
  "context": {
   "type": "object",
   "description": "Optional non-secret correlation labels returned unchanged only in the request lifecycle.",
   "maxProperties": 12,
   "additionalProperties": {
    "type": [
     "string",
     "number",
     "boolean",
     "null"
    ]
   }
  },
  "baseline": {
   "type": [
    "object",
    "null"
   ],
   "description": "Optional baseline returned by a previous snapshot call.",
   "additionalProperties": true
  },
  "compare_url": {
   "type": "string",
   "maxLength": 2048,
   "minLength": 3,
   "description": "Optional public comparison URL. Used by change and monitoring services."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-card-discovery-decision-490cb404/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentreadiness.halowerk.com](https://www.zero.xyz/host/agentreadiness.halowerk.com/llms.txt)