Docs that update when the code does,
drafted by the agent, checked by a human
Documentation drifts from reality the moment a deadline gets tight, because updating a README never feels as urgent as shipping the feature. A documentation agent watches what actually changed in the codebase and drafts the update, README, architecture notes, API reference, onboarding guide, so the gap between code and docs closes before a new engineer hits it. Nothing publishes without a human reading it first.
The role today
A feature ships, the pull request merges, and the README still describes how things worked three versions ago. Nobody updates it on purpose; it is just that writing the doc change never feels as urgent as the feature itself, so it slips, and it keeps slipping until a new engineer hits the gap and loses a day figuring out what the code actually does.
The second cost compounds over time: each undocumented change makes the next engineer’s onboarding slower, and eventually the docs are wrong often enough that people stop trusting them and start asking in chat instead, which puts the burden back on whoever already knows the answer.
The third is architecture notes specifically. They are usually written once, at a point in time, and almost never revisited as the system evolves, so the diagram everyone points new hires to stops matching reality within a few months.
What the agent takes over
The agent watches your repository’s change history and drafts the documentation update that should go with it: a README section, an architecture note, an API reference entry, a line in the onboarding guide. It flags cases where a change looks significant - a new service, a changed API contract, a renamed core concept - but has no matching doc update, so the gap gets noticed instead of quietly growing.
Drafts come as a reviewable diff, written in the tone of your existing docs rather than a generic style, so a human reviewer is checking accuracy and judgment, not rewriting the voice.
Typical scope: READMEs, architecture notes, API documentation, onboarding guides, changelogs. Deciding what is worth documenting at all - some internal detail genuinely does not need a doc - stays a human call the agent defers to.
What stays with humans
Reviewing every draft before it publishes is non-negotiable; nothing goes live unread. Deciding what is worth documenting, and how much detail a given audience needs, is a judgment call your team makes, not the agent. Tone and structure decisions for a documentation overhaul stay human-led.
Guards
No draft publishes without a human review - every update is a diff, not a direct write to the live docs. The agent flags undocumented significant changes rather than silently skipping them. It reads only the repository and existing docs; it has no access to production systems or customer data by default.
Price and timeline
| Option | Price | What it covers | Timeline |
|---|---|---|---|
| Agency runs it | from $1,800 + support plan | Agent built, tuned and supervised by us, monthly doc accuracy check | 1 to 2 weeks |
| Full control, handover-ready | from $3,000 | Same agent on your own repository and docs site, your team reviews and runs it | 2 to 3 weeks |
Running cost is usually $10 to $40 a month in model usage, depending on repository activity.
Related
See the AI agents service page and development for the surrounding build. Within this group: coding agent with review and legacy migration agent are the agents whose work this one documents, and QA and test agent shares the same review-before-publish discipline. For a one-time project version, see automate documentation generation and automate release notes. Real handoff discipline behind this page: the ProBay AI agent team case study, built with documentation a new engineer could pick up without us in the room.
Docs a version behind the actual code? Get in touch and we will look at what has drifted first.
FAQ
How much does a documentation agent cost?
From $1,800 to set it up against one repository, live in 1 to 2 weeks. Multiple repositories or a full documentation site usually runs $2,800 to $4,000.
How long before it is drafting real updates?
1 to 2 weeks: it needs to read your existing docs and recent change history first, then it runs alongside a few real pull requests so your team can check its drafts before trusting it on more.
Which tools does it work with?
Your repository and its commit and pull request history, your docs site or wiki (Markdown, Docusaurus, Notion, or similar), and your ticket tracker for context on why a change happened.
What if the drafted update is wrong or misses the point?
Every draft is a diff for a human to review before it publishes, the same as a pull request. A wrong draft gets corrected, and that correction sharpens the next one, since style and accuracy both improve from real feedback.
Does it need deep access to our systems to write docs?
It reads the repository, its history, and existing docs, nothing beyond what writing accurate documentation requires. It does not need production access, customer data, or infrastructure credentials.