# Dev Reference: HTTP Method Lookup

> Dev Reference: HTTP Method Lookup is a paid API for AI agents from dev-reference.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Returns whether an HTTP method is safe and idempotent per IANA registry, its purpose, and request-body semantics.

## Facts

- Endpoint: GET https://dev-reference.x402tookit.com/http-method?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/dev-reference-http-method-lookup-0daa6a8c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_C4YBoRLhtbuSMVzJWKndI

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-method-lookup-0daa6a8c
```

Example prompt: Is the PATCH HTTP method safe and idempotent, and can it include a request body? I want to know what IANA says about it.

## When to prefer this

Use this endpoint when an agent or developer needs authoritative, IANA-grounded information about an HTTP method's safety, idempotency, or body semantics — especially for non-standard methods like PROPFIND, REPORT, or LOCK. Prefer it over general LLM knowledge when accuracy and a citable reference are important.

## Known failure modes

- Unknown or unregistered HTTP method returns registered=false with null safety/idempotency fields
- Misspelled method name returns no match or degraded result
- IANA registry temporarily unavailable may return degraded=true with stale data
- Missing required 'method' query parameter results in an error response

## How this service works

Whether an HTTP method is safe and idempotent (IANA registry), what it is for, and request-body semantics.

## Output

Returns a structured object containing: whether the method is registered with IANA, whether it is safe, whether it is idempotent, whether responses are cacheable by default, the method's purpose, body semantics (allowed/forbidden/meaningful), a summary explanation, reasons for the verdict, a reference URL, and a disclaimer about degraded data if applicable.

## 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": [
      "method"
     ],
     "properties": {
      "method": {
       "type": "string",
       "description": "Method name such as GET, PATCH or PROPFIND"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "safe": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "method": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "purpose": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "reference": {
       "type": [
        "null",
        "string"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "idempotent": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "registered": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "bodySemantics": {
       "type": [
        "null",
        "string"
       ]
      },
      "cacheableByDefault": {
       "type": [
        "boolean",
        "null"
       ]
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/dev-reference-http-method-lookup-0daa6a8c/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)