# Quartermaster Structured JSON Extraction

> Quartermaster Structured JSON Extraction is a paid API for AI agents from quartermaster.surewhynot.app, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13).

Extracts structured JSON from a URL or raw text using a caller-supplied JSON Schema to define the output shape.

## Facts

- Endpoint: GET https://quartermaster.surewhynot.app/v1/extract-json
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quartermaster-structured-json-extraction-03b348f8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XjPeTooMPV976SCRW3JvJ

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 quartermaster-structured-json-extraction-03b348f8
```

Example prompt: Fetch the Wikipedia page for Elon Musk at https://en.wikipedia.org/wiki/Elon_Musk and extract just his birthdate, nationality, and list of companies he founded — return it as JSON matching this schema: {"type":"object","properties":{"birthdate":{"type":"string"},"nationality":{"type":"string"},"companies":{"type":"array","items":{"type":"string"}}}}

## When to prefer this

Choose this endpoint when you need to transform unstructured web pages or raw text into typed, schema-defined JSON objects. Ideal when you already know the exact output shape you want and want extraction guided by your schema. Prefer this over generic scrapers when field-level structure matters, and over LLM prompting alone when you need reliable, validated JSON output conforming to a specific contract.

## Known failure modes

- URL is inaccessible or returns non-200 — extraction cannot proceed
- Supplied JSON Schema is malformed or invalid — returns schema parse error
- Requested fields are not present in the source content — returns null or missing fields
- Source content is too large or complex for extraction — may return partial results
- Both url and text omitted — missing required input error
- Schema describes a shape incompatible with source content — best-effort or empty result

## How this service works

Structured extraction: give a JSON Schema plus a URL or raw text, get back JSON matching the schema.

## Output

A JSON object conforming to the caller-supplied JSON Schema, populated with values extracted from the provided URL or raw text. The response is structured data ready for downstream use, with fields mapped according to the schema definitions.

## 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": [
      "schema"
     ],
     "properties": {
      "url": {
       "type": "string",
       "format": "uri",
       "description": "Page to extract from (or pass text instead)"
      },
      "text": {
       "type": "string",
       "description": "Raw text to extract from (alternative to url)"
      },
      "schema": {
       "type": "string",
       "description": "JSON Schema (as a JSON string) describing the desired output"
      }
     }
    }
   },
   "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/quartermaster-structured-json-extraction-03b348f8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from quartermaster.surewhynot.app](https://www.zero.xyz/host/quartermaster.surewhynot.app/llms.txt)