# Dev Reference – HTTP Status Codes by Class

> Dev Reference – HTTP Status Codes by Class is a paid API for AI agents from dev-reference.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-31).

Returns all registered HTTP status codes in a given class (1xx–5xx) with their names and one-line meanings.

## Facts

- Endpoint: GET https://dev-reference.x402tookit.com/http-status-class?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/dev-reference-http-status-codes-by-class-065b552c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_H2SH9fukAkDOfR5jZH9ah

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 dev-reference-http-status-codes-by-class-065b552c
```

Example prompt: Give me a full list of all HTTP 4xx status codes with their names and what each one means — I want to see every code registered in the client-error class.

## When to prefer this

Choose this endpoint when you need a comprehensive enumeration of all HTTP status codes within a specific class (1xx–5xx), rather than looking up a single known status code. Prefer it over a single-code lookup endpoint when you want to build reference tables, populate dropdowns, validate ranges, or present a complete class overview to a user or documentation system.

## Known failure modes

- Missing or invalid `class` query parameter (not 1–5) — likely returns an error or empty result
- Non-integer value passed as class digit — schema validation failure
- Network or upstream registry unavailability — degraded flag may be set in response
- Class digit outside valid range (e.g. 6 or 0) — no matching codes returned

## How this service works

All registered HTTP status codes in a class (1xx to 5xx) with names and one-line meanings.

## Output

A structured response containing the class label, a description of the class, the total count of codes, a list of objects each with a numeric status code, its official IANA name, and a one-line meaning, plus metadata like source and the date the registry was retrieved.

## 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",
     "required": [
      "class"
     ],
     "properties": {
      "class": {
       "type": "integer",
       "description": "First digit of the code: 1, 2, 3, 4 or 5"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "class": {
       "type": [
        "null",
        "string"
       ]
      },
      "codes": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "object",
        "properties": {
         "code": {
          "type": [
           "null",
           "number"
          ]
         },
         "name": {
          "type": [
           "null",
           "string"
          ]
         },
         "meaning": {
          "type": [
           "null",
           "string"
          ]
         }
        }
       }
      },
      "count": {
       "type": [
        "null",
        "number"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "classDigit": {
       "type": [
        "null",
        "number"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "description": {
       "type": [
        "null",
        "string"
       ]
      },
      "registryRetrie
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/dev-reference-http-status-codes-by-class-065b552c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from dev-reference.x402tookit.com](https://www.zero.xyz/host/dev-reference.x402tookit.com/llms.txt)