# free-books-mars-planet

> free-books-mars-planet 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).

Browse and download free public-domain books tagged with the Library of Congress subject 'Mars (Planet)' from Project Gutenberg and Internet Archive, ranked by relevance and popularity.

## Facts

- Endpoint: GET https://intel.rallylive.ca/library/subject/mars-planet
- 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-books-mars-planet-74313e5a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nDBJIFJpfjgpPtfN61u1j

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-books-mars-planet-74313e5a
```

Example prompt: Can you pull up a list of free public-domain books about Mars the planet — I want to browse what's available with download links, maybe filtered to Edgar Rice Burroughs if possible?

## When to prefer this

Choose this endpoint when you need a curated, daily-verified catalogue of free public-domain books specifically about Mars the planet, with direct download links across multiple formats. It is ideal over general web search when you want structured bibliographic data with epub/txt/html links ready to use, filtered by the authoritative Library of Congress subject heading rather than keyword guessing.

## Known failure modes

- No results returned if query keywords don't match any titles or authors in the catalogue
- Pagination out of range returns empty result set
- Occasional stale links if a source removes content between daily re-verification cycles
- Rate or payment failure if USDC payment for the $0.01 per call is not processed

## How this service works

Free public-domain books on "Mars (Planet)": browse the catalogue's works tagged with that Library of Congress subject (185 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 (20 items per page) of public-domain books tagged with the Library of Congress subject 'Mars (Planet)', including title, author, relevance/popularity ranking, and direct download links in epub, txt, and/or html formats. Data is re-verified daily and draws from Project Gutenberg (185+ titles) and Internet Archive scans.

## 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-books-mars-planet-74313e5a/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)