# Free Public-Domain Books by Subject: Sisters

> Free Public-Domain Books by Subject: Sisters is a paid API for AI agents from intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Returns a ranked, paginated catalogue of free public-domain books tagged with the Library of Congress subject 'Sisters' from Project Gutenberg and Internet Archive, with direct download links.

## Facts

- Endpoint: GET https://intel.rallylive.ca/library/subject/sisters
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/free-public-domain-books-by-subject-sisters-d0410a58
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Uyf2AOCoJt06SFh7jUhDU

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 free-public-domain-books-by-subject-sisters-d0410a58
```

Example prompt: Can you pull up the first page of free public-domain ebooks tagged with the 'Sisters' subject — I want epub or txt download links for the most popular ones, ideally novels by classic authors like Louisa May Alcott or Jane Austen?

## When to prefer this

Use this endpoint when you need a ready-made, daily-verified catalogue of public-domain books specifically tagged with the Library of Congress 'Sisters' subject, with direct download links — rather than scraping Project Gutenberg or Internet Archive yourself. Best when you want ranked results combining both sources in one call at low cost.

## Known failure modes

- No results returned if keyword filter is too restrictive or misspelled
- Stale or broken download links if a source removes content between daily re-verification cycles
- Rate limiting or payment failure if the $0.01 USDC per-call fee is not satisfied
- Empty catalogue page if page number exceeds total available results

## How this service works

Free public-domain books on "Sisters": browse the catalogue's works tagged with that Library of Congress subject (207 in Project Gutenberg alone, plus Internet Archive scans), ranked by relevance and popularity, with direct epub/txt/html download links. Add words to narrow by title or author. Re-verified daily. $0.01 per page of 20.

## Output

A paginated list of up to 20 public-domain book records per page, each including title, author, relevance and popularity ranking, and direct download links in epub, txt, and/or html formats. Results are sourced from Project Gutenberg (207+ works) and Internet Archive scans, re-verified daily.

## 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",
     "properties": {}
    }
   },
   "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/free-public-domain-books-by-subject-sisters-d0410a58/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from intel.rallylive.ca](https://www.zero.xyz/host/intel.rallylive.ca/llms.txt)