This is BuildGist's own blog, written by the people who make BuildGist. Everything below comes from our live privacy page, pricing page and docs. We drafted it with AI help and checked it line by line against buildgist.com/privacy.

If a tool reads your coding agent's runs, the first question is what leaves your machine, what stays on someone's server, and for how long. Summary quality comes second.

We make BuildGist, a Mac app that writes a plain-English explanation after each meaningful Claude Code, Cursor or Codex run, and carries the task over when you switch agents. This post is our full account of what it sends, keeps and throws away, including the parts we'd rather were better. Even if you never use BuildGist, it's the list we think any tool like it should show you.

What leaves your Mac to write an explanation

Only what that one run needs:

• what you asked your coding agent, plus your Current task's instructions if one is open
• the changes the run made, and the code around them in the files it changed
• the names of the files it changed, by how many lines, and the messages of commits made during the run
• selected test commands your agent ran during the run, and their results
• project details: folder name, branch, which agent made the run, and the names of the top-level files and folders

Your Mac masks secrets in all of this before it leaves. Masking is best-effort. It catches common credential shapes, and pattern matching can miss a secret in an unusual shape.

Nothing is sent before you sign in and connect your Mac, and the app asks before it sends anything.

What never leaves

• your whole repository
• files the run didn't change
• files named like secrets, such as .env files and keys

This choice shaped the product more than any other. A whole-repo explainer could sometimes write a better explanation, because it could see how a change interacts with code the run never touched. It would also mean shipping your codebase to a server on every run. We send the run's changes plus the surrounding code in the changed files instead. The cost is real: an explanation can miss an effect on a file the run didn't open.

What we throw away

The material your Mac sends to write an explanation is used once and discarded. It isn't kept in BuildGist's database, logs or backups.

The explanation is written by a model from Anthropic, which we pay for. You don't need an account with Anthropic or any other AI provider. Anthropic processes the material for us under its commercial terms, doesn't use it to train its models, and deletes it within 30 days. There are two exceptions: it may keep content it flags as breaking its usage policies for up to 2 years, and it keeps what the law requires it to keep.

What we keep

For each run: what you asked, which files changed and by how many lines, which test commands ran and what each reported (not their output), the short IDs and messages of commits, the project's folder name and branch, and your Current task's instructions if one is open.

For explained runs: the explanation, and short cited excerpts of changed code, at most 12 lines each. The excerpts let an explanation point at the exact line it's talking about. Twelve lines is the cap per excerpt, and a very short file can fit inside one. We also keep when each explanation was made, whether it worked and how much processing it used.

For your account: your GitHub user ID, username and display name. GitHub is only used to sign you in. We don't get your GitHub email, repositories, organizations or access token.

For your computers: each one's short host name, its BuildGist version, which coding agents it has set up and how far setup got. Nothing about your projects or files.

Product activity: which days you signed in or opened the Inbox, which explanations you opened, how far you got in setup, and steps like starting a trial. We use this to learn whether BuildGist is useful and easy to set up.

Analytics, and where PostHog fits

We added PostHog, an analytics service, to see where setup stops between downloading the app and the first explanation. Here is exactly how it works.

There is no PostHog script or cookie in your browser. Our server forwards a small set of facts to PostHog:

• anonymous counts of visits and downloads, with the word for the site that linked to us and the kind of device (a Mac, another computer, or a phone or tablet), and nothing that links two of them together
• your account's product activity listed above, under a one-way pseudonym of your account ID

PostHog never gets your name, email, GitHub details, IP address, prompts, code or file paths.

On the website itself, BuildGist runs no third-party analytics, advertising or tracking scripts, and doesn't track you across other sites. Visits and downloads are counted as daily numbers by the site that linked to us. If you'd rather not be counted at all, open buildgist.com/count-me-out in your browser. It sets one cookie that is used for nothing else, and it also keeps your visits and downloads out of what goes to PostHog.

One more place your data can appear: our server logs record requests with your account ID and in some cases your IP address. They never contain your prompts or code.

When you switch agents

When you start a new chat in another coding agent in the same project, BuildGist offers the earlier agent's task. Choose Continue and the new agent receives that task's context, under your own account with that agent and its provider's terms. Choose Start fresh and nothing is handed over.

Your controls

• In the Mac app, "What BuildGist can send" shows exactly what is sent, including what's sent to write explanations.
• Pause a project and nothing in it is recorded, sent or explained.
• "Disconnect this Mac" stops all sending. "Uninstall…" removes the app. Neither touches your projects.
• Settings → Download my BuildGist data gives you your data as JSON.
• Settings → Delete my account deletes your account and its synced data right away. Backups are kept for 7 days, so deleted data can sit in a backup for up to 7 days. One thing stays until the next day begins (00:00 UTC): what your explanations cost that day, under a keyed hash of your GitHub user ID, so deleting and recreating an account doesn't reset the daily limit.

What's still imperfect

Two items are on the known-limits list in our docs:

1. If you edit a file by hand between two agent turns, the next explanation can include your edit.
2. Secret masking is best-effort. A secret in an unusual shape, in code a run changed, could be sent to us and Anthropic, and could show up in a cited excerpt. If a project holds something that must never leave the machine, check "What BuildGist can send" or pause the project.

And one that applies to every tool like this: explanations are written by AI and can be wrong. Check important behavior against the code and tests.

Questions to ask any tool that reads your agent runs

• Does it send the whole repo, or only what changed? Can you see the exact payload?
• What does it keep, in what form, and for how long?
• Who is the model provider, and do they train on your code?
• Can you leave one project out without uninstalling?
• Does its website track you while it asks you to trust it with code?

Those are the questions we tried to answer above.

BuildGist runs on Macs with Apple silicon and macOS 12 or later, for people in the US who are 18 or older. Every account gets 7 days free with no card, starting at your first explanation or Continue handoff, and nobody is charged when the trial ends. After that it's $12 a month plus any tax shown at checkout. The full privacy page is at buildgist.com/privacy.

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