Developers often decide whether to use a module within a few minutes of landing on its repository or registry page. In that short time, they want to know what the module does, whether it fits their project and how hard it will be to start. Documentation answers those questions, and it is frequently the deciding factor between two otherwise similar packages.
This guide covers the documentation pieces that matter most and how to write them well.
The README: your front page
The README is usually the first thing people read. A good one is short at the top and detailed further down. Aim to include:
- A one-sentence description of what the module does and for whom.
- Installation instructions using the standard package manager for the ecosystem.
- A minimal working example that someone can copy and run.
- Supported versions of the language, runtime or framework.
- Links to full documentation, the changelog and the licence.
Badges for build status or version can be helpful, but keep them few. A wall of badges pushes the important content down the page.
Examples that actually run
Examples are often more valuable than prose. The most useful examples are complete enough to run, focused on one task and kept up to date. Consider keeping examples in a dedicated folder and running them as part of your test suite so they cannot silently break.
Cover common tasks first
Think about the three or four things most users will want to do and document those first. Edge cases and advanced configuration can live in separate pages.
API reference
An API reference lists every public function, class, component or option, with parameters, return values, defaults and errors. Many ecosystems can generate reference documentation from comments in the source code, which helps keep it accurate. Generated reference material works best alongside hand-written guides, not instead of them.
Guides and explanations
Reference documentation tells people what exists; guides tell them how to accomplish something. A useful structure separates tutorials for beginners, task-focused how-to guides, reference material and conceptual explanations. You do not need all four on day one, but keeping the distinction in mind helps you write each page with a clear purpose.
The changelog
A changelog shows that the module is maintained and tells users what each release changes. Keep entries short and grouped by version, with breaking changes clearly marked and migration notes where needed. A changelog written for humans is more useful than a raw list of commit messages.
Licence and contribution information
Include a licence file so potential users know whether they can use the module in their project. If you welcome contributions, a contributing guide should explain how to set up the project, run tests and submit changes. A code of conduct and an issue template can also help set expectations.
Writing style tips
- Use plain language and short sentences.
- Show code before explaining it in detail.
- Explain why as well as how when a design choice is unusual.
- Keep terminology consistent across pages.
- Date or version-stamp pages that describe behaviour that may change.
Keeping documentation current
Documentation decays when it is treated as a separate task. Make documentation updates part of the definition of done for every change that affects behaviour. Reviewers can check that the README, examples and changelog have been updated alongside the code.
Checking your documentation
A simple test is to ask someone unfamiliar with the module to install it and complete a basic task using only the documentation. Note where they get stuck. Those friction points are the most valuable places to improve.
Bottom line
Clear documentation is one of the most effective ways to encourage adoption of a module. A focused README, runnable examples, accurate reference material and an honest changelog help developers trust your code and get started quickly.