Where your data goes

What leaves your machine, and to whom

1. The model you chose

   Each time TypeBack writes a question or grades a free-text answer.

   • The hunk (its added and removed lines), a few lines of surrounding context, the file's path relative to its workspace folder (only its name for a file outside every folder), the generated question and reference, and your free-text answers go to the model you chose: through the VS Code Language Model API (Copilot or a provider extension), or to the fallback provider you configured. Multiple-choice answers are graded on this machine.
   • With the mentor on, question prompts also carry short snippets of the code that calls or is called by the hunk with their relative paths (only the name for a file outside every folder), excerpts of matching skills (skills come from the repository's own skill folders, .agents/skills, .claude/skills and .github/skills, your user-settings roots in typeback.context.skills, and TypeBack's bundled Next.js, React and Node guidance; a repository cannot point TypeBack at other folders), your level, your learning goal, and your weakest and strongest topics.

2. Your doc-review model

   When you review a Markdown document, and when the mentor writes a digest.

   • For a Markdown document (ADR, spec, agent instructions), the document or a window of it around the change, its relative path, earlier rounds and your replies go to the doc-review model.
   • The digest sends workspace-relative file paths (only the name for a file outside every folder), one-line hunk purposes, question kinds, the key points you missed, and topic tags to the doc-review model, with your level, your learning goal, your weakest and strongest topics, and up to three mentor notes. Purposes and key points are the model's own sentences about the code. It never sends the code, your answers, or the grader's feedback, which can restate an answer.

3. TypeSafe

   Only with typeback.grader set to jev.

   • With typeback.grader set to jev, TypeSafe receives, to grade a free-text answer: the added code, its language, the surrounding context, the generated reference (purpose, key points, pitfalls) and your answer. To check that each generated question is answerable: the added code, its language, the surrounding context, the question, its options and the reference's purpose. No file path.

4. Polar

   Only with a Pro license: when you activate, and about once a week after.

   • With a Pro license, the key, a label for this machine, and Polar's ids for TypeBack go to Polar when you activate. About once a week after, the key, Polar's ids and the activation's id go to Polar to validate it; the label is sent only at activation. The label is the editor's name and the first 8 characters of a random id TypeBack makes once and keeps in globalState; not the editor's machine id, a host name or a user name. An activation made before this label existed keeps its old label at Polar, which came from the editor's machine id, until you activate again. Nothing about your code does.

5. A docs site, in your browser

   Only when you click Read more.

   • A Read more link after I don't know or Explain opens a docs search in your browser, with the question's topic (such as "async await") as the search term. Nothing is sent until you click one.

6. GitHub, from your CI

   Only if you add the pull request check.

   • The pull request check runs in your CI, not on this machine, and sends nothing to TypeBack. With the workflow's token it asks GitHub whether GitHub verified the head commit's signature.

What stays on your machine

• The queue, results, the per-branch review history and the latest digest are in VS Code workspaceState.
• The learner profile (level, goal, topic counts, streak, stats and milestones, mentor notes) and the license status are in VS Code globalState.
• API keys and the license key are in VS Code SecretStorage.
• To reset: TypeBack: Clear Review Queue deletes the queue and its results, TypeBack: Reset Learner Profile empties the profile and can also forget the history and digest, TypeBack: Remove License from This Machine forgets the license, and TypeBack: Set Fallback API Key or Set TypeSafe API Key with an empty value clears that key.
• The hook receiver listens on 127.0.0.1 on a random port with a per-session bearer token, announced in ~/.typeback/receivers/ (mode 0600 on macOS and Linux; on Windows it relies on your user profile's permissions; removed on shutdown). Hook payloads never leave the machine.
• An edit that no TypeBack window was open to take waits in ~/.typeback/inbox/ (owner-only on macOS and Linux; on Windows it relies on your user profile's permissions), as the agent reported it: the file path and the changed text. It is deleted when a window takes it. One older than 30 days is deleted unread the next time an editor takes from the inbox (start, focus, a folder change) or the hook writes to it (at most 100 per write). There is no timer, so with neither happening it stays. Turn starts and ends are never stored.
• No telemetry.