# FastX402 Lab JSON Pointer Extractor

> FastX402 Lab JSON Pointer Extractor is a paid API for AI agents from fastx402.tools, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-17).

Extracts a single value from a JSON document using an RFC 6901 JSON Pointer path expression.

## Facts

- Endpoint: GET https://fastx402.tools/json-pointer?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fastx402-lab-json-pointer-extractor-38fdc28f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_sbUTF1RuYAG_w5dRZ5RZR

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 fastx402-lab-json-pointer-extractor-38fdc28f
```

Example prompt: From this JSON string '{"items":[{"name":"widget","price":9.99}]}', extract the value at the JSON Pointer path /items/0/name and tell me what it is.

## When to prefer this

Use this endpoint when you need to extract exactly one value from a known path in a JSON document without writing custom parsing logic. It is ideal when working with large or complex API responses where you already know the RFC 6901 pointer path to the field you need. Prefer it over full JSON parsing tools when you only need a single field and want a lightweight, pay-per-call solution.

## Known failure modes

- Malformed JSON input returns an error or found:false
- Invalid RFC 6901 pointer syntax may return an error
- Pointer path that doesn't exist in the document returns found:false
- Empty JSON document with non-empty pointer returns found:false
- Deeply nested or very large JSON documents may time out

## How this service works

146 pay-per-call tools for AI agents, from $0.001 per request in USDC on Base or Solana with x402. No account, no API key.

## Output

Returns a JSON object with a 'found' boolean (whether the pointer resolved to a value), a 'value' string (the extracted value if found), and a 'type' field indicating the JSON type of the extracted value.

## 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": [
      "json",
      "pointer"
     ],
     "properties": {
      "json": {
       "type": "string",
       "description": "The JSON document"
      },
      "pointer": {
       "type": "string",
       "description": "RFC 6901 pointer, e.g. /items/0/name (\"\" is the whole document)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "type": {
       "type": "string"
      },
      "found": {
       "type": "boolean"
      },
      "value": {
       "type": "string"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "type": "string",
  "found": true,
  "value": "b"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastx402-lab-json-pointer-extractor-38fdc28f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fastx402.tools](https://www.zero.xyz/host/fastx402.tools/llms.txt)