Click on "Install Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type
@followed by the MCP server name and your instructions, e.g., "@Calibre MCP ServerFind all books about machine learning and summarize the first chapter of the top result."
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
Calibre MCP Server
This MCP server bridges the gap between AI agents and your Calibre. It enables agents to interact with your collection as a dynamic knowledge base, allowing them to search, manage, and read your digital libraries. Unlike other MCP servers it can also allow an AI agent to update library metadata and contents if a library's permissions are set to allow it.
Key Features
Advanced Search: Query libraries using book metadata or perform full-text content searches.
Metadata Management: View and update metadata (titles, authors, tags, ratings, etc.) for any book.
Library Maintenance: Add new titles to your collection or remove existing ones.
Format Conversion: Leverage Calibre’s powerful conversion engine to switch between ebook formats (e.g., PDF to EPUB) on the fly.
Direct Reading: Search and read the text content of a book directly into the agent's context window for analysis, summarization, or Q&A.
Granular Permissions: Define strict access controls per library, including read-only modes and field-level write restrictions.
Prerequisites
Calibre: Must be installed on the host system. This server utilizes
calibre-debugto execute worker processes.Concurrency Note: Calibre does not support concurrent access to a single library. Do not point an agent to a library currently being used by the Calibre desktop application or other processes to avoid database corruption.
Configuration
The server is configured via a JSON file. Since JSON does not support comments, use the structure below as a template.
Example Configuration (config.json)
JSON
Configuration Schema Reference
Each library is identified by a unique text key and can have its own separate configuration values:
Key | Description |
| Absolute path to the Calibre library (where |
| Free-form context provided to the agent explaining what this library contains or what its purpose is. |
| If |
| Set to |
| List of metadata fields the agent is allowed to modify, |
| Boolean. If |
| Boolean. Allows the agent to add new formats to a book record by converting existing ones. If |
| A whitelist of directories from which the agent can import new files. |
| If |
| A whitelist of directories the agent can export book files to. |
| If |
There are also several top-level configuration settings that apply to the MCP server as a whole:
Key | Description |
| The port the server is exposed on. |
| Each Calibre library has its own |
| Sets what minimum level of logging message will be recorded in |
| Some older MCP clients don't understand the "resources" type that this server exposes, for example to allow the agent to read the contents of the |
Example MCP Configuration
Point to the above configuration file with the CALIBREMCP_CONFIGPATH environment variable in your MCP configuration. For example:
JSON
This should allow you to easily switch library configurations as needed for different agents by selecting which configuration to point CALIBREMCP_CONFIGPATH at.
Pro-Tips for Better Performance
1. Optimize Field Access
Calibre libraries often contain internal metadata that can clutter an agent's context window. It is highly recommended to use a specific list for read permissions. Only expose fields the agent actually needs (e.g., title, author, tags, comments).
2. Custom Fields & Series
Custom Fields: If you use custom columns in Calibre, you must include the
#prefix (e.g.,#my_custom_field).Series: Every
seriesfield has a correspondingseries_index. Ensure both are included in your permissions list if you want the agent to see or manage book order within a series.Descriptions: The server passes custom field "descriptions" to the agent. Use these in Calibre to give the agent hints on how to use specific custom columns. For example if you create a custom field for a book's "age rating"" you could use the description to explain what the values of that field represent.
3. Resource Exposure
If your agent does not yet support the @mcp.resources standard, set expose_resources_via_tools to true. This will expose dedicated tools that allow the agent to fetch files via standard tool calls.
Architecture
For a deep dive into how this server manages worker processes and interacts with the Calibre database, please refer to the Architecture Documentation.