Trilium sends nothing to an AI provider until you send a message. Enabling the integration, adding a provider or opening a chat transmits nothing on its own, the one exception is that listing a provider's models sends your API key to that provider, so the list can be fetched.

Once you send a message, what leaves your machine depends on the provider you chose and on which context options are enabled.

## Where your notes go

Provider type | Destination
--- | ---
Cloud providers | The provider's servers (Anthropic, OpenAI, Google, DeepSeek)
Subscription-based | The provider's servers, via Claude Code running locally
Local / self-hosted | Nothing leaves the machine running the model
Custom endpoint | Wherever you pointed it — which may be your own hardware or a hosted service

This is the reason the provider list is grouped this way, and why Trilium pre-selects nothing: the choice of where your notes travel is made explicitly, by you, before anything is sent.

## What is actually sent

- Always, with every message
  - The conversation itself: your messages and the assistant's replies, including earlier turns
  - Trilium's system prompt describing how to format answers and use tools.
- The current note, only when note context is enabled.
  - In the sidebar chat this is the file icon at the bottom; the dedicated chat note type never sends a current note.
  - What travels is a metadata block: the note's ID, title, type, creation and modification dates, its parent IDs, the titles of up to 20 children, up to 20 attributes, and a preview of the content.
  - Notes above a size threshold send a size hint instead of the text, and the model must call a tool to read further.
- Any note the model asks for, when note access is enabled.
  - Tools let the model search your tree and read notes, attributes and attachments beyond the current one.
  - It decides what to fetch; there is no per-note permission system, so the reachable scope is your whole tree.
- Attachments and mentions, when you add them: images, PDFs and text files are sent to the provider, and an `@` mention makes that note fetchable.
- Your search query, when web search is enabled, the model's search terms reach the provider's own search infrastructure.

## Protected notes

While your protected session is locked, protected notes send neither title nor content. While it is unlocked they are treated like any other note — a note the model reads through a tool is sent to the provider in full. If you keep sensitive material in protected notes, be aware that unlocking them removes that boundary for the duration of the session.

## What you control

- Which provider: the single decision that determines whether anything leaves your machine at all.
- Note access: turn tools off from the model selector at the bottom of the chat, and the model can read nothing beyond what you type.
- The current note: the file icon in the sidebar chat.
- Web search: also in the model selector.

With note access and note context both off, the provider receives only the words you typed.

## Keeping everything local

Adding an Ollama or LM Studio provider keeps every message on the machine running the model, and Trilium marks their models as free because no metered API is involved. The trade-off is quality and hardware: a small local model may fail at tool calls that a cloud model handles, so a local setup that misbehaves is worth benchmarking against a cloud provider before reporting it as a bug.

## Telemetry & security

Trilium itself collects no telemetry from the AI integration.

Your API key is stored in your database, sent only to the provider it belongs to, and is write-only through the options API so that a malevolent Scripting cannot access it. If you have backend or SQL console access enabled, a malevolent script could potentially exfiltrate your API keys.

The built-in MCP server has no authentication and exposes the same note tools to any application on your machine that can reach it. It is off by default and bound to `localhost`.