# Freebookcentre — Wrapped API

> **You are on:** `https://api.beta.paywithlocus.com/api` | [llms.txt](https://beta.paywithlocus.com/llms.txt) | [docs](https://docs.paywithlocus.com)
>
> Locus runs on multiple environments -- make sure every URL you call matches your expected environment.
> | Environment | Landing | API | Docs |
> |---|---|---|---|
> | Production | paywithlocus.com | api.paywithlocus.com | docs.paywithlocus.com |
> | Beta | beta.paywithlocus.com | api.beta.paywithlocus.com | docs.paywithlocus.com |
> | Stage | stage.paywithlocus.com | api.stage.paywithlocus.com | docs.paywithlocus.com |
>
> If the API URL above doesn't match your expected environment, re-fetch this file from the correct domain.

> Browse free technical books across multiple categories, view detailed book information, and search for specific titles in the FreeBookCentre.net library. Discover learning resources organized by subject with quick access to book details and listings.

**Category:** Education | **Website:** [www.freebookcentre.net/](https://www.freebookcentre.net/) | **Docs:** [parse.bot/marketplace/cc6a6c32-d5a5-47e1-a04c-8db70ceb000d/freebookcentre-net-api](https://parse.bot/marketplace/cc6a6c32-d5a5-47e1-a04c-8db70ceb000d/freebookcentre-net-api)

Pay-per-use API proxy for Locus Pro. Each call burns credits from your workspace balance.

## Access

**Base URL:** `https://api.beta.paywithlocus.com/api/wrapped/credits/freebookcentre/`
**Auth:** `Authorization: Bearer <LOCUS_CREDITS_SECRET_KEY>` (an `lcr_` secret key or a scoped `lcac_` agent credential)
**Required header:** `Idempotency-Key: <fresh UUID per call>`. A retry with the same key replays the stored result without a new charge.
**Response:** the provider response after any endpoint-specific normalization. `X-Locus-Credits-Charged` carries the charge and `X-Locus-Credits-Balance` the remaining balance. Insufficient credits return `402` before the provider is called.
**Pricing:** estimated costs below are USD. Locus debits the credit equivalent at your workspace rate.

Full call contract: https://docs.paywithlocus.com/api-reference/introduction

> Using a Pay With Locus wallet key (`claw_` prefix)? Wallet routes are documented separately: https://docs.paywithlocus.com/wrapped-apis/for-agents

## Endpoints

### Get book details

Get detailed information about a specific book including title, author, full description, page count, breadcrumb navigation showing category hierarchy, and the page URL. The book_path is obtained from the detail_path field in list_books responses.

**Estimated cost:** Metered

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `book_path` | string | Yes | URL path to a book detail page, obtained from detail_path in list_books response (e.g. /ComputerScience-Books-Download/Concurrent-Programming-in-ERLANG.html). |

```bash
curl -X POST https://api.beta.paywithlocus.com/api/wrapped/credits/freebookcentre/get-book-details \
  -H "Authorization: Bearer $LOCUS_CREDITS_SECRET_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{"book_path":"<string>"}'
```

### List books

List books from a specific category or subcategory page. Returns book titles, authors, descriptions, page counts, and detail paths. Also returns subcategories if present on the page. The category_path is obtained from list_categories or from the subcategories array in a previous list_books response.

**Estimated cost:** Metered

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `category_path` | string | Yes | URL path to a category or subcategory page, obtained from list_categories or from subcategories in a previous list_books response (e.g. /CompuScience/free-computer-algorithm-books.html). |

```bash
curl -X POST https://api.beta.paywithlocus.com/api/wrapped/credits/freebookcentre/list-books \
  -H "Authorization: Bearer $LOCUS_CREDITS_SECRET_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{"category_path":"<string>"}'
```

### List categories

List all main book categories available on the site. Returns category names and their URL paths for use with the list_books endpoint. Each category path can be passed to list_books to retrieve its book listings and subcategories.

**Estimated cost:** Metered

_No parameters required._

```bash
curl -X POST https://api.beta.paywithlocus.com/api/wrapped/credits/freebookcentre/list-categories \
  -H "Authorization: Bearer $LOCUS_CREDITS_SECRET_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{}'
```

### Search books

Search for books and categories by keyword. Searches the homepage content for matching category names and book titles. Returns matching categories (with paths usable in list_books) and any matching books found on the homepage. The search is case-insensitive and matches against both category/link names and book title/description text.

**Estimated cost:** Metered

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `query` | string | Yes | Search keyword to match against category names and book titles (e.g. 'python', 'algorithms', 'physics'). |

```bash
curl -X POST https://api.beta.paywithlocus.com/api/wrapped/credits/freebookcentre/search-books \
  -H "Authorization: Bearer $LOCUS_CREDITS_SECRET_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{"query":"<string>"}'
```

## Next steps

- [All wrapped API providers](https://beta.paywithlocus.com/wapi/index.md): pick another provider.
- [Find and call tools](https://beta.paywithlocus.com/agent/tools.md): price ceilings, async results, and errors.
- [Credits and billing](https://beta.paywithlocus.com/agent/billing.md): what a call costs and how to add credits.
- [Agent docs index](https://beta.paywithlocus.com/agent/index.md): every Locus agent page.