# JSON Keys Extractor – GPT-5.5 x402 Gateway

> JSON Keys Extractor – GPT-5.5 x402 Gateway is a paid API for AI agents from gpt55.558686.xyz, paid per call via x402, $0.0001/call, status unknown (last checked 2026-09-15).

Returns a list of all key paths found in a given JSON object or JSON string, paid per-call via x402 USDC on Base.

## Facts

- Endpoint: POST https://gpt55.558686.xyz/v1/tools/json-keys
- Price: $0.0001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/json-keys-extractor-gpt-5-5-x402-gateway-a4d6e967
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_vvfVf0l-5XU5vlgEDkSnN

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 json-keys-extractor-gpt-5-5-x402-gateway-a4d6e967 -d '<json body>'
```

Example prompt: Can you list all the key paths in this JSON object for me: {"user":{"id":123,"profile":{"name":"Alice","age":30}},"active":true}? Limit to depth 4 and return up to 50 keys.

## When to prefer this

Use this endpoint when you need a quick, cheap ($0.0001 USDC) programmatic enumeration of all key paths in a JSON blob without setting up any local tooling. Ideal for agents that need to introspect unknown API responses, map JSON schemas on the fly, or prepare downstream data transformations. Prefer it over manual parsing when the JSON depth is unknown and a flat key-path list is the desired output.

## Known failure modes

- Missing or invalid 'json' query parameter returns an error response
- JSON parse failure if input string is malformed JSON
- Depth or limit parameters out of allowed range (depth 1-8, limit 1-500) may return validation error
- x402 payment failure if USDC balance is insufficient or Base network tx fails
- Non-GET HTTP method returns 405
- Empty JSON object or array returns empty key list with ok:true

## How this service works

Low-price OpenAI-compatible GPT-5.5 chat completions and text tools over x402 USDC on Base: $0.0001 compact requests, $0.066667 true max-output requests, no subscription.

## Output

Returns a JSON response with a boolean 'ok' field, the tool name ('jsonKeys'), a 'fetchedAt' timestamp, and a summary or array of all dot-notation or path-style key paths found in the provided JSON input, up to the specified depth and limit.

## Example request

```json
{
 "input": {
  "type": "http",
  "method": "GET",
  "queryParams": {
   "json": {
    "user": {
     "id": 123,
     "profile": {
      "age": 30,
      "name": "Alice"
     }
    },
    "active": true
   },
   "limit": 50,
   "max_depth": 4
  }
 }
}
```

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "properties": {
      "json": {
       "oneOf": [
        {
         "type": "string"
        },
        {
         "type": "object",
         "additionalProperties": true
        },
        {
         "type": "array"
        }
       ]
      },
      "text": {
       "type": "string"
      },
      "limit": {
       "type": "integer",
       "maximum": 500,
       "minimum": 1
      },
      "max_depth": {
       "type": "integer",
       "maximum": 8,
       "minimum": 1
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "ok": {
       "type": "boolean"
      },
      "tool": {
       "type": "string"
      },
      "fetchedAt": {
       "type": "string"
      }
     },
     "additionalProperties": true
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "tool": "jsonKeys",
  "summary": "List JSON key paths using x402 USDC payment"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/json-keys-extractor-gpt-5-5-x402-gateway-a4d6e967/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from gpt55.558686.xyz](https://www.zero.xyz/host/gpt55.558686.xyz/llms.txt)