Changelog

The role of changelogs in API governance

A well-kept changelog is extremely important for managing APIs effectively. It helps in several key ways:

Improving communication & trust

A good changelog makes things clear and open by showing exactly what has changed in an API, when it changed, and why. This openness builds trust with people who use the API, as they can easily see new features and also know when older features will be removed. This makes connecting to the API and planning for future changes much smoother.

Supporting rules & version control

API governance rules often define whether changes are “major,” “minor,” or “patch” updates. Changelogs act as the official history of these changes, matching how versions are controlled (like using numbers such as 1.0.0, 1.0.1). They help enforce rules about whether new updates will still work with old code and when old features will stop being supported. This keeps both the API creators and users on the same page.

Driving security, compliance & lifecycle management

Beyond just tracking features, changelogs are strategic for following rules and managing risks. Companies that must follow regulations like GDPR or HIPAA need complete records of changes, especially for security fixes or policy changes to show they are responsible and to meet audit requirements.

Changelogs also work hand-in-hand with managing the entire life of an API: every step, from designing and launching to monitoring, removing, and retiring an API, benefits from having a recorded history of what was done and why.

Fostering collaboration & accountability

In today’s companies, managing APIs often involves many teams: product managers, developers, quality assurance, compliance, and even outside partners. Changelogs provide a single, reliable source of information for everyone, breaking down barriers between teams and allowing for better coordination. They support teamwork and ensure that everyone involved stays informed about changes across the API.

Additionally, when changelog updates include details like who made the change, when, and what type of change it was (Added, Changed, Deprecated, Fixed), they add transparency and make it easier to track who is responsible, which are key parts of accountable governance.

What belongs in an API changelog

An effective API changelog isn’t just a list of every little change. It’s a clear, organised record that helps users quickly understand what changed, when it happened, and how it affects them.

Version & release date

Every entry in the changelog should start with a version number (like 1.2.0) or a date-based version (like 2025-07-22), along with the release date. This gives users clear context and aligns with how you manage your API versions.

Categorised changes

Organise updates into easy-to-scan categories. This helps users quickly find what’s relevant to them:

– Added: For brand new features, endpoints, or capabilities.
– Changed: For modifications to existing behaviors or how responses are formatted.
– Deprecated: For features that are still available but will be removed in the future.
– Removed: For features that have been completely taken out.
– Fixed: For corrections to bugs or errors.
– Security: For patches or updates that address security vulnerabilities.

Many well-known API providers, like GitHub and Substack, use this structured approach.

Clear, user-friendly descriptions

The descriptions for each entry should:

– Focus on the user: Explain how the change impacts the user, not just internal code details.
– Be concise but informative: Be brief, but provide enough detail. If a change is complex, include a short example or a link to more detailed guides.

Context & migration guidance

For changes that have a big impact (like breaking changes, deprecated features, or changes to how data is structured):

– Explain “Why”: Tell users why the change happened.
– Suggest “What to do”: Advise users on how they should adapt their code.
– Provide links: Include links to migration guides, more detailed documentation, or discussions about the issue (this is common with Facebook’s Graph API changelog).

Security-aware entries

Security updates need special attention.

– Label clearly: Mark them clearly under a “Security” category.
– Highlight actions needed: Explain any specific steps API consumers need to take (e.g., “Update your SDK immediately”).

Metadata & traceability

Include additional details for better tracking:

– Author/team: Who was responsible for this update.
– Planned dates: For deprecated features, include dates when they are planned for removal.
– Internal IDs: Any internal tracking IDs or references that can help with deeper investigations.

Note: Always place the latest version at the top, so users immediately find the newest changes without scrolling through outdated entries.

Communicating API changes

When your API changes, whether you’re adding features, fixing bugs, or making big changes that might break existing code, how you tell users about these updates is crucial. It can really affect how easy or difficult developers find it to work with your API.

Update API metadata & changelog

– Update API specs: Always update the info.version in your OpenAPI/Swagger specification whenever you make any change to your documentation, even small ones. This helps clarify the version of your documentation separately from the actual API version.
– Maintain a public changelog: Keep a public changelog alongside your API documentation. It’s best to publish it in an easy-to-read format like Markdown or directly within your API docs. You should also link directly to your changelog from your API specification.

Choose & customise communication channels

Don’t rely on just one way to tell people about changes. Use different channels to reach your audience effectively:

– Changelog feed (RSS/Atom): Offer feeds that developers can subscribe to, allowing them to get automatic notifications of updates.
– Email or newsletter alerts: Set up mailing lists where developers can opt-in to receive important information like migration tips, dates when old features will stop working, and details about the impact of changes.
– Portal widgets & developer dashboard notices: Display important announcements directly on your developer portal or within your documentation hub.
– Social media & forums: Tailor your messages for different platforms. For example, send quick alerts to general users on X (formerly Twitter), and more detailed information to dedicated community members on Slack or in forums.

Proactive vs. passive communication

– Be proactive: Just updating a changelog quietly (passive) might not reach many users. It’s better to be proactive by sending targeted notices, offering feeds, and sending emails to make sure updates are seen.
– Tailor messages: Adjust your messages for different groups of users, like API integrators, business partners, or internal teams. The message should be relevant to their role and the changes that affect them.

Structure your messages

For important updates, especially those that might break existing code:

– Clear summary: Start with a simple explanation of “What changed and why.”
– Impact details: Explain “Which parts of the API or behaviors are affected?”
– Migration guidance: Offer clear instructions on how users should update their code. Include code snippets, links to more detailed guides, and step-by-step instructions.
– Timelines: Provide clear timelines, such as dates when features will be removed or when support for older versions will end.

Use automation & templates

– Automate changelog: Use tools like GitHub releases or special “changelog bots” to automatically generate and distribute your changelog updates.
– Prepare templates: Create ready-to-use message templates for emails, website banners, and newsletter posts. This standardises your communication when you release new versions.

Monitor & iterate

– Track metrics: After releasing an update, keep an eye on things like how long it takes for users to migrate, the number of support tickets you receive, and any spikes in errors. This helps you understand how effective your communication was.
– Get feedback: Ask developers for their thoughts on how clear, useful, and timely your notices are.
– Improve over time: Use the data and feedback you collect to fine-tune your timing, choose better communication channels, and refine your messaging style for future updates.

Common pitfalls & how to avoid them

API changelogs can often disappoint users and damage trust if important details are missed. Here are the most common mistakes and how to prevent them:

Dumping raw commit logs

– Mistake: Just publishing the full list of every code change (Git logs) as your changelog makes it messy and hard to read for users.
– How to avoid: Always carefully select and organise the entries. Group changes by category, use simple language, and only include updates that are important or relevant to the user.

Omitting breaking changes or deprecations

– Mistake: Not including notices about features that will be removed or plans for their removal leaves users unprepared and can break their applications.
– How to avoid: Clearly label entries as “Deprecated” (meaning it will be removed soon) or “Removed.” Always include specific “sunset dates” (when the feature will be fully removed) and provide guides on how to update their code (migration guidance).

Inconsistent formatting

– Mistake: Mixing different styles of formatting or version numbering makes the changelog difficult to follow and understand.
– How to avoid: Stick to a standard template for every entry: include the version, date, categories of changes, and who made the update. Apply this style consistently throughout the entire changelog.

Poor or technical language

– Mistake: Using internal jargon or overly technical terms that outside users don’t understand.
– How to avoid: Use clear, simple language. Focus on what the user will experience and what they need to do. Provide concrete examples when explaining complex changes.

Neglecting version & change visibility

– Mistake: Forgetting to update the API’s version number in its main specification (like OpenAPI’s info.version) or not publishing changelogs in easily findable places.
– How to avoid: Always increase the version number in your API specifications, even for minor documentation changes. Publish changelogs in prominent locations, ideally with an RSS feed (so users can subscribe) or directly in your developer portal.

Ignoring developer feedback

– Mistake: Not asking users if they find the changelog useful, clear, or timely.
– How to avoid: Actively ask for feedback through comments, support channels, or surveys. Use this feedback to improve the changelog based on what matters to your users.

Over-versioning or under-versioning

– Mistake: Creating new versions too often (even for tiny changes) or, worse, making big changes that break old code without releasing a new version number.
– How to avoid: Follow “semantic versioning”:
      – Major version (e.g., 2.0.0): For changes that break old code.
      – Minor version (e.g., 1.1.0): For adding new features that don’t break old code.
      – Patch version (e.g., 1.0.1): For bug fixes. Also, implement clear plans for deprecating features and when they will be removed.

Neglecting documentation maintenance

– Mistake: Updating your API’s code but forgetting to update the related documentation and changelogs.
– How to avoid: Treat documentation and changelogs as essential parts of your release process, just as important as writing code and running tests. Include them in your release checklist.

Sportmonks: Changelog best practices in action

Sportmonks, a leading provider of sports-data APIs (football, cricket, F1), follows best practices with changelogs, such as: 

– Clear versioning and migration support: Our switch from API 2.0 to 3.0 of our Football API is documented with transparent migration guidance and encouragement to upgrade
– Linking docs and changelog: Users can find the changelog directly from our docs, making change visibility and discovery straightforward.
– Supporting developer experience: Our use of interactive components and detailed blog posts enhances comprehension and offers context around API updates.

Stay informed and build with confidence

Track every update with clarity using Sportmonks’ detailed changelog. From new features to important fixes, you’ll always know what’s changed and how it affects your app.

Explore Sportmonks’ changelog and start building smarter today.