# Header Semantics Repair Plan

> Header Semantics Repair Plan is a paid API for AI agents from agentreadiness.halowerk.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-14).

Passively fetches public evidence from a target URL and evaluates its HTTP header semantics, returning an observation, threshold, verdict, evidence source, limitations, and a concrete repair action.

## Facts

- Endpoint: POST https://agentreadiness.halowerk.com/v1/header-semantics-repair?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/header-semantics-repair-plan-e9310955
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XXwZNl612gzddrxF3auWU

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 header-semantics-repair-plan-e9310955 -d '<json body>'
```

Example prompt: Can you check the header semantics on https://example.com and give me a repair plan — I need to know what's wrong and exactly what to fix to make the site readable by AI agents?

## When to prefer this

Choose this endpoint when you need a passive, read-only audit of HTTP header semantics for a public URL specifically to assess and improve AI agent readiness. It is especially useful when you want actionable repair guidance rather than just a raw header dump, and when you need a structured verdict with evidence citations. Prefer it over generic HTTP inspection tools when the goal is agent/crawler compatibility rather than general security or performance auditing.

## Known failure modes

- Target URL is unreachable or returns a non-public response, preventing evidence collection
- Target domain is malformed or fails normalization, resulting in a validation error
- Rate limits or firewall rules on the target block passive inspection
- Baseline object is malformed or incompatible, causing comparison to fail
- Target redirects in a loop or returns ambiguous headers, leading to inconclusive verdict

## How this service works

Header semantics repair plan 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 a structured report containing the observed header semantics evidence gathered passively from the target URL, the threshold criterion being evaluated, a pass/fail verdict, the exact evidence source, identified limitations of the check, and a mode-specific repair action the site owner can take to remediate issues.

## 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/header-semantics-repair-plan-e9310955/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)