How to automatically update documentation after a pull request mergesHow to automatically update documentation after a pull request merges

The short answer: a tool that automatically updates documentation after a pull request merges does three jobs. It reads the merged change, works out which documentation pages it made inaccurate, and drafts the fix as a reviewable pull request. Thally Track does this for connected docs, website, and support repositories. You connect the product repositories to watch, and every relevant merge produces an evidence-backed docs PR, or a clear "no change needed." Nothing publishes without a person approving it.

What "automatically update docs" should mean

Plenty of tools say they update docs automatically. The phrase covers very different things:

Approach	What it updates	What it misses
Reference generation	API, SDK, and CLI reference from source	Guides, tutorials, and examples that describe the same behavior
Snippet sync	Code blocks embedded from source files	Prose around the snippet that explains what it does
Docs reminders in CI	Nothing; it asks a person to check	Pages the person does not know about
Impact analysis with drafted PRs	Any connected page the change contradicts	Changes that were never merged or tracked

The first two are worth having no matter which tool you use. The last row is the one that answers "which pages did this merge make wrong?", and it is the one this guide covers.

How it works with Thally Track

1. Connect a docs site and the repositories that change your product

Start with the documentation site: pages, code samples, OpenAPI descriptions, and llms.txt. Then connect the product repositories whose changes customers feel. The best candidates define your public surface: SDK exports, configuration schemas, CLI commands, and API operations.

You can narrow each repository to the paths that matter. A change to internal test helpers should not wake anything up. A change to src/public-api/** or openapi.yaml should.

Other surfaces can join later: your marketing website repository, help center content, or a changelog repository. Track looks at all connected surfaces for each change.

2. A pull request merges

By default Track runs when a pull request merges into a tracked branch. It reads the pull request and its diff, and works out what changed for users. That is a different question from what changed in the code. A renamed internal function matters to nobody outside the team. A renamed configuration key matters to everyone who copied the old one.

3. Track finds what the change contradicts

For each user-facing change, Track searches the connected surfaces for pages that now say something different: the reference entry, the quickstart that uses the old flag, the troubleshooting article that quotes the old error, the blog post with a copyable example.

Each candidate comes with the evidence behind it, a confidence level, and a drafted diff.

4. Your team reviews a pull request

Track opens pull requests in the affected repositories. Each one contains the proposed edits and the reasoning: which merged change caused them, what the page said, and why that is no longer true. Reviewers can edit the PR like any other before merging it.

If the change does not affect any documentation, Track says so and opens nothing. A no-change result is a valid outcome, not a failure.

Other ways to run it

Merge is the default trigger, but not the only one:

• Before merge. Add a docs-preview label to an open pull request, and the docs are drafted while the code is still in review. Reviewers see the code and the docs change side by side, and the draft updates as new commits land.
• On a schedule. Check for changes since the previous run instead of reacting to each merge. This is useful for repositories with many small merges a day.
• On request. Comment @thally document this on a GitHub issue or pull request to ask for a documentation PR about that specific change.

Guardrails that matter

Automated documentation edits are only useful if you can trust them. Whatever tool you pick, look for:

• Human approval before publishing. An automated edit that goes live on its own can put a wrong claim in front of every reader. Track never publishes to any surface without a person merging it.
• Evidence, not just a diff. A reviewer should be able to see why a page changed without reconstructing the reasoning from scratch.
• Scoped access. The tool should read only the repositories you grant and write only through pull requests.
• Quiet when nothing changed. A tool that proposes edits for every merge trains the team to ignore it.

Try it on your own history

The fastest way to judge any tool in this category is to run it against changes you have already shipped. The Track demo connects to GitHub, reads your last five merged pull requests, and shows which pages each one affected. No Thally account is needed, and Thally only reads the repositories you grant.

Track is included with Thally Cloud. If you want to see how it fits alongside your existing CI jobs, the CI guide walks through the full pipeline.

Related reading

• How to keep your docs site in sync when code changes: the manual layers that should sit under any automation.
• Swimm alternatives for automated documentation updates: how code-coupled internal docs compare with product-change tracking.

Sources and verification

Track behavior was checked against the current Thally product repository, documentation, and the Track overview. Checked September 24, 2026. Read our editorial policy for how we write and review guides.