# library.forgemesh.io QH Natural History Shelf

> library.forgemesh.io QH Natural History Shelf is a paid API for AI agents from library.forgemesh.io, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-13).

Returns a ranked list of up to 50 public-domain natural history books from the QH Library of Congress classification, with drill-down routes for full-text retrieval.

## Facts

- Endpoint: POST https://library.forgemesh.io/qh
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/library-forgemesh-io-qh-natural-history-shelf-04b83878
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_P8aZ1ZtTp4U_7xNFkTKDV

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 library-forgemesh-io-qh-natural-history-shelf-04b83878 -d '<json body>'
```

Example prompt: Show me up to 30 public-domain natural history books from the QH shelf, including things like Darwin's letters and Pliny's Natural History, so I can pick one to read in full.

## When to prefer this

Choose this endpoint when you need a curated, ranked list of public-domain natural history books (Library of Congress QH class) including Darwin's works and Pliny, and want drill-down routes for full-text access. Prefer it over full-text search when you want to browse the shelf by category rather than query by keyword.

## Known failure modes

- limit parameter exceeds 50 — clamped or rejected
- no books returned if shelf index is temporarily unavailable
- payment not processed — 402 response requiring x402 payment before results are served
- malformed request body returns validation error

## How this service works

Curated shelf: QH — 614 public-domain books including Life and Letters of Charles Darwin — Volume 1, More Letters of Charles Darwin — Volume 1 A Record of His Work in a Series of Hitherto Unpublished Letters, The Natural History of Pliny, Volume 3 (of 6). Returns a ranked list with drill-down routes for full-text retrieval. No license, no API key required.

## Output

A ranked list of up to 50 public-domain books in the QH (natural history) classification, including titles, authors, and drill-down routes that can be used to retrieve the full text of each book.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "limit": {
   "type": "integer",
   "description": "Max books to return (default 20, max 50)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "books": [
   {
    "year": null,
    "title": "Life and Letters of Charles Darwin — Volume 1",
    "author": "Darwin, Charles",
    "book_id": 2087,
    "subjects": [],
    "download_count": 30219
   }
  ],
  "count": 5,
  "shelf": "QH",
  "coverage": {
   "target": 61015,
   "indexed": 61015
  },
  "drill_down": [
   "/book-metadata",
   "/book-chapter",
   "/book-quotes",
   "/literature-search"
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/library-forgemesh-io-qh-natural-history-shelf-04b83878/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from library.forgemesh.io](https://www.zero.xyz/host/library.forgemesh.io/llms.txt)