# CSP First-Directive Fallback Binding Resolver

> CSP First-Directive Fallback Binding Resolver is a paid API for AI agents from detect.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-20).

Resolves Content Security Policy first-wins directives and ordered twelve-destination fallback bindings from measured response headers, counting duplicate conflicts without issuing browser or safety verdicts.

## Facts

- Endpoint: POST https://detect.halowerk.com/u/csp-first-directive-fallback-binding?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/csp-first-directive-fallback-binding-resolver-6ebfe9e5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zk-x3Bjw_q4SM9qKJq6_D

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 csp-first-directive-fallback-binding-resolver-6ebfe9e5 -d '<json body>'
```

Example prompt: Can you fetch the CSP headers for https://example.com and resolve which first-wins directives apply, list the ordered twelve fallback bindings, and count any duplicate directive conflicts?

## When to prefer this

Use this endpoint when you need to programmatically resolve which CSP directives take precedence under first-wins rules and enumerate the ordered fallback source bindings, especially when duplicate conflict counting is needed. Prefer it over generic CSP validators when you need structured binding data rather than a pass/fail safety verdict.

## Known failure modes

- URL is unreachable or returns non-2xx — no headers to parse
- URL has no Content-Security-Policy header — empty or null result
- Malformed URL input fails schema validation
- URL times out during header measurement

## How this service works

Resolve first-wins Content Security Policy directives and the ordered twelve-destination fallback bindings from measured response headers, with duplicate conflicts counted and no browser or safety verdict.

## Output

Returns the resolved first-wins CSP directives from the URL's measured response headers, the ordered twelve-destination fallback binding list per directive, and a count of duplicate directive conflicts. No browser safety verdict or pass/fail judgment is included.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "format": "uri",
   "maxLength": 2048
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/csp-first-directive-fallback-binding-resolver-6ebfe9e5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from detect.halowerk.com](https://www.zero.xyz/host/detect.halowerk.com/llms.txt)