Quickstart

#Before you begin

You need:

• A GitHub account that is an owner of the organization that holds your code. Babbit installs a GitHub app on that organization.
• An agent account: a Claude subscription (Pro or Max) or a ChatGPT subscription (Plus or Pro), or an API key from Anthropic or OpenAI. Babbit's agents run on your account; see Connect your agent account for the details.
• A repository with the product you want to work on. If you don't have one yet, Babbit can create one from a sentence. See Start from a sentence.

#What Babbit will write

Before you connect anything, know what each step commits:

Your existing code starts as legacy: Babbit drafts a spec from it, but box-level traces cover only the code your changes write or rewrite. See Legacy code.

#1. Sign in

1. Go to babbit.dev/app.
2. Click Sign in with GitHub and approve the sign-in on GitHub.

Babbit reads who you are from GitHub once. It does not keep your GitHub token.

#2. Connect your agent

Babbit asks for an agent account before anything else, because every agent that works on your product runs on it.

1. On Connect your agent, choose Claude Code or Codex.
2. Keep Subscription selected, or choose API key.
3. Follow the prompt for your choice:
   • Claude subscription: in a terminal, run claude setup-token, then paste the token it prints.
   • Codex subscription: click Connect, then Copy code & open ChatGPT. Paste the code on the ChatGPT page and approve. Babbit updates by itself when you approve.
   • API key: paste the key.
4. Click Continue.

The credential goes straight into Babbit's encrypted vault. See How Babbit handles your credential.

#3. Create a project

A project is one product: one or more code repositories and the people who work on them.

1. Click New project.
2. If Babbit's GitHub app isn't installed on your organization yet, click Install on GitHub. GitHub opens in a new tab.
   1. Choose the organization.
   2. Choose the repositories.
   3. Click Install, then return to the Babbit tab.
3. Select the repositories that make up your product. A web app and its API are one product, so select both.
4. Click Connect repositories.

Babbit starts reading your code right away. You don't configure anything else.

#4. Let Babbit read your code

Babbit's Product agent reads the code in three steps (Fetch, Index and Investigate) and drafts a spec from what it finds. Features appear on screen as the agent saves them.

Reading never changes your code: the agent's access to the source is read-only, and it never runs your application or its tests. Reading takes a few minutes for a small repository and longer for a large one. You can close the tab; the work continues and the screen picks up where it is when you return.

#5. Approve the drafted spec

When reading finishes, Babbit shows the drafted feature tree: each feature with its goals and scenarios.

1. Click a feature to open it in place and read its goals and scenarios.
2. Look for placements marked with a question and a number, such as child? 0.52. These are places where Babbit was unsure.
3. When the tree says what your product does, click Approve tree.

Babbit writes the spec to your repository through a pull request and merges it. The spec is not committed until you approve it. When the merge finishes, Babbit opens Build on your project, with a link to the merged pull request.

Approving commits the tree to your repository. After that, every correction to it is an ordinary change that you review.

#6. Describe your first change

1. Click the bar at the top of the screen that reads Describe a change you'd like to make, or press ⌘ K (Ctrl K on Windows and Linux).
2. Type one sentence about what should change, and why. For example: Show a confirmation before a customer deletes their account, so nobody deletes one by accident.
3. Press Enter.

Babbit opens the change. In a few seconds it expands your sentence into a brief: what you asked for, what done means and how it will be checked. Then the Product agent reads the spec and the code and proposes edits to the spec.

Write it the way you'd say it. The brief fills in what you didn't say.

#7. Review the proposed lines

When the proposals are ready, the change asks for your review.

1. On the Lines tab, read each proposed line. Each one shows the line as it is now and as the change wants it.
2. For a line you don't accept, click Reject and write one sentence about what's wrong. The agent reads it.
3. Click Approve all to approve every line you didn't reject.

You approve what the product should do, not the code. After you approve, the Code Writing agent writes the code and a test for each scenario, without ever seeing your original sentence.

#8. Check the proof

Building and verifying take minutes. The change shows its progress through the steps Asked, Approved, Built, Verified and Live.

When verification finishes, open the Proof tab. For each scenario the change touches, you see whether its test passed and, for anything visible, screenshots of the app before and after the change. A scenario that couldn't be verified says so; it is never counted as done.

#9. Merge and release

When every scenario has its evidence, the change offers Merge & release.

1. Click Merge & release.
2. Confirm.

Babbit merges the spec first, then the code, and releases it: first to preprod, where it runs the smoke scenarios, then to production. The Live step lights when production runs your change.

#Next steps

• See what Babbit checks on every call in What's in the box?.
• See how the spec is structured in Features, goals and scenarios.
• See every step of a change in detail in Describe and review a change.
• Invite the people you build with: Invite your team and set roles.
• Work from your own terminal: Work from Claude Code or Codex.