Library of Congress API
Public Library of Congress JSON/YAML API for searching collections and retrieving structured bibliographic and cultural-heritage item metadata, including books.
Connect this API to an AI agent Browse all specs
What you can do with Library of Congress API via MCP
Every endpoint below becomes a governed tool your AI agent (Claude, ChatGPT, or a customer-facing VX agent) can call — with scoped permissions, sandbox testing, and audit logs.
| Method | Path | Operation | Description |
|---|---|---|---|
| GET | / |
SearchLibraryOfCongress | Search Library of Congress Method: GET Path: / IMPORTANT: This function has 0 REQUIRED parameter(s) and 6 OPTIONAL parameter(s) REQUIRED parameters MUST be provided OPTIONAL parameters can be omitted if not needed Parameters: Query Parameters: OPTIONAL: - q: Search expression. - fo: Response format. - c: Page size. - sp: Page number. - at: API field selection. - sb: Sort field. |
| GET | /item/{id}/ |
GetItem | Get item Method: GET Path: /item/{id}/ IMPORTANT: This function has 1 REQUIRED parameter(s) and 1 OPTIONAL parameter(s) REQUIRED parameters MUST be provided OPTIONAL parameters can be omitted if not needed Parameters: Path Parameters: REQUIRED: - id: Library of Congress item identifier. Query Parameters: OPTIONAL: - fo: Response format. |
Usage guide
## Authentication The Library of Congress JSON/YAML API is publicly accessible and does not require an API key or bearer token for the documented search and item-read endpoints. Use a descriptive `User-Agent`, cache results, respect rate and paging limits, and follow the Library of Congress API terms and usage guidance. Use `fo=json` for JSON responses or `fo=yaml` where supported. ## Coverage Includes public collection/catalog search and item metadata retrieval. The API covers books and many other library and cultural-heritage materials.
How to use this spec
- Create a free VX Agents account (sandbox tools included).
- Open the marketplace and connect “Library of Congress API” to an agent.
- Expose it as an MCP server for Claude/ChatGPT, or chat with it directly.