# URL Redirect Target Check

> URL Redirect Target Check is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Validates a URL redirect target against caller-supplied allowed schemes and hosts, returning a deterministic pass/advisory finding as versioned JSON.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/url-redirect-target-check
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/url-redirect-target-check-0dde555f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_OKYgwTdmxyWJr4Db4rETJ

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 url-redirect-target-check-0dde555f -d '<json body>'
```

Example prompt: Before following this redirect to 'https://evil.example.com/landing', check whether the target is allowed — my permitted hosts are ['myapp.com','cdn.myapp.com'] and allowed schemes are ['https'], with a base URL of 'https://myapp.com'.

## When to prefer this

Choose this endpoint when you need a fast, stateless, deterministic check of a redirect target URL against a caller-controlled allowlist of hosts and schemes — especially before accepting, following, caching, or retrying a redirect in an automated agent workflow. Prefer this over building custom redirect validation logic when you want consistent, versioned, auditable results without storing data. Ideal for open-redirect vulnerability prevention in agentic pipelines, OAuth callback validation, and any scenario where redirect targets are user- or third-party-supplied.

## Known failure modes

- Target URL malformed or missing — validation cannot proceed
- Allowed hosts or schemes list is empty or omitted — may default to restrictive policy
- Target URL uses a scheme not in allowed_schemes — returns advisory/fail status
- Target host does not match any entry in allowed_hosts — returns advisory/fail status
- Redirect target is a relative URL that cannot be resolved without a valid base_url — error or advisory returned
- Input exceeds maxLength of 8192 characters — request rejected
- Payment not provided or insufficient — x402 payment required error

## How this service works

URL Redirect Target Check: URL Redirect Target Check checks a redirect target against allowed schemes and hosts from bounded caller-supplied values without an external provider. Call URL Redirect Target Check before accepting, caching, redirecting, or retrying a caller-supplied web response. Returns normalized web evidence, the computed finding, and an explicit pass or advisory status for URL Redirect Target Check as versioned deterministic JSON. Price: $0.001 USDC via x402 on Base. First-party…

## Output

Returns versioned deterministic JSON containing: normalized evidence of the evaluated URL, the computed finding (e.g. whether the target matches allowed hosts and schemes), and an explicit pass or advisory status indicating whether the redirect target should be accepted.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "target": {
   "type": "string",
   "maxLength": 8192,
   "description": "Target supplied to URL Redirect Target Check; used only for this bounded calculation and processed in memory without retention."
  },
  "base_url": {
   "type": "string",
   "maxLength": 8192,
   "description": "Base URL supplied to URL Redirect Target Check; used only for this bounded calculation and processed in memory without retention."
  },
  "allowed_hosts": {
   "type": "array",
   "items": {
    "type": "string",
    "maxLength": 8192
   },
   "maxItems": 256,
   "description": "Allowed Hosts supplied to URL Redirect Target Check; used only for this bounded calculation and processed in memory without retention."
  },
  "allowed_schemes": {
   "type": "array",
   "items": {
    "type": "string",
    "maxLength": 8192
   },
   "maxItems": 256,
   "description": "Allowed Schemes supplied to URL Redirect Target Check; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "host": "example.com",
   "scheme": "https",
   "allowed": true,
   "resolved_url": "https://example.com/account"
  },
  "schema": "delx/util-url-redirect-target-check/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "6a1d59c98f30fc06ce9df9cfcba2c305b66be8e5eb56388a33bf40e364792c0c",
   "external_calls": 0
  },
  "operation": "web_reliability:url_redirect_target_check"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/url-redirect-target-check-0dde555f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)