# HTTP Status Code Reference

> HTTP Status Code Reference is a paid API for AI agents from intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Look up HTTP status codes by class (4xx), specific code (404), or keyword (teapot, redirect, auth) to get reason phrases and usage explanations

## Facts

- Endpoint: GET https://intel.rallylive.ca/dev/status-codes
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/http-status-code-reference-f9481825
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mYVf1e-4NKR7fj2MyGNIG

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 http-status-code-reference-f9481825
```

Example prompt: Can you look up all the 4xx HTTP status codes and list each one with its reason phrase and what it's typically used for?

## When to prefer this

Choose this endpoint when you need structured, machine-readable HTTP status code data covering the full IANA registry including edge cases like 418 (teapot) and 402 (Payment Required / x402). It supports flexible input — class ranges, specific codes, or natural language keywords — making it ideal for developer tools, API documentation assistants, and debugging agents that need to programmatically enumerate or explain HTTP codes rather than retrieve a single hard-coded explanation.

## Known failure modes

- Invalid or non-existent status code number returns no results or an error
- Keyword with no matching codes returns an empty result set
- Malformed class format (e.g. '4X' instead of '4xx') may not match
- Non-HTTP numeric codes (e.g. 999) return no results since only IANA-registered 100-511 are covered
- Payment failure via x402 prevents the lookup from executing

## How this service works

HTTP status code reference: give a class like 4xx to list every code in it with its reason phrase, a specific code for its meaning and typical use, or a word (e.g. 'teapot', 'redirect', 'auth') to search. Covers all IANA-registered codes 100-511 including 402 Payment Required (used by x402). $0.01 per lookup.

## Output

Returns a list of matching HTTP status codes, each with its numeric code, official IANA reason phrase, meaning, and typical use case. For class queries (e.g. 4xx), returns all codes in that class. For specific codes, returns the single entry. For keyword searches, returns all codes whose names or descriptions match.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/http-status-code-reference-f9481825/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from intel.rallylive.ca](https://www.zero.xyz/host/intel.rallylive.ca/llms.txt)