# Webcat Hkpl — Wrapped API

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>
> 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.

> Search and discover books across Hong Kong's public library system while checking real-time availability, and retrieve detailed book metadata including titles, authors, descriptions, and current stock status. Find exactly what you're looking for and know instantly whether your local library has it in stock.

**Category:** Education | **Website:** [webcat.hkpl.gov.hk/](https://webcat.hkpl.gov.hk/) | **Docs:** [parse.bot/marketplace/031924dc-5520-4ece-9805-001075e3d887/webcat-hkpl-gov-hk-api](https://parse.bot/marketplace/031924dc-5520-4ece-9805-001075e3d887/webcat-hkpl-gov-hk-api)

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

## Access

**Base URL:** `https://api.paywithlocus.com/api/wrapped/credits/webcat-hkpl/`
**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 bibliographic information and all holding copies for a specific book by its chamo_id. Returns the full title, author, call number, a details object with Chinese-keyed bibliographic fields (publisher, year, subject, ISBN, language, etc.), and a holdings array listing every branch copy with its location, call number, availability status (on-shelf, due-date, reserved), and collection type.

**Estimated cost:** Metered

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `chamo_id` | string | Yes | Internal library ID in the format chamo:<numeric_id> (e.g. chamo:3460423). Obtain from search_books results. |

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

### Search books

Search the HKPL catalog by keyword. Returns paginated results (10 per page) with basic metadata per book: title, author, call number, publisher, and a Chinese-language availability summary showing which branches hold copies on-shelf. Pagination advances via the page parameter. The total_results count reflects the full hit set.

**Estimated cost:** Metered

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `page` | integer | No | Page number of search results (1-based) |
| `query` | string | Yes | Search keyword to find books in the catalog |

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

## Next steps

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