Release Notes Template for API Products

API release notes are high-stakes

When you ship a change to a consumer SaaS, users might notice something looks different. When you ship a change to an API, developers' integrations can break at 3am. The stakes are different.

API release notes need to be precise, version-aware, and actionable. Here's the template and the standard.

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Core API release notes template

## API v[X.Y.Z] — [Release date]

### ⚠️ Breaking Changes
> **Action required before [date if applicable]**
- `[endpoint or parameter]`: [What changed, what it used to do, what it does now]
- Migration path: [Exact steps to update, with code example if possible]

### ✨ New Endpoints / Parameters
- `POST /[endpoint]` — [What it does, link to docs]
- Added `[parameter]` to `GET /[endpoint]` — [Use case and behavior]

### ⚡ Improvements
- `[endpoint]`: [Performance or behavior improvement with measurable delta]
- Rate limits on `[endpoint]` increased from X to Y req/min

### 🐛 Bug Fixes
- Fixed: `[endpoint]` returning `[error code]` when `[condition]` — [workaround if any was needed]

### 🗑️ Deprecations
- `[endpoint or parameter]` is deprecated as of this release. It will be removed in v[X+1]. Use `[replacement]` instead.
  
### 📘 Docs Updated
- [Link to updated documentation pages]

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3 real API release note examples

Example 1 — Breaking change (Stripe style)

[Breaking] The invoice.payment_succeeded event now fires after the invoice is marked paid, not when the charge succeeds. This affects integrations that use this event to trigger fulfillment. See migration guide →

Example 2 — New endpoint (Twilio style)

New: GET /v2/conversations/{sid}/messages now supports cursor-based pagination via the PageToken parameter. This replaces the previous page-number approach and handles high-volume conversations significantly better.

Example 3 — Deprecation (Shopify style)

The variant_ids parameter on POST /orders is deprecated. Use line_items[].variant_id instead. The deprecated parameter will stop working on June 1, 2026.

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API-specific best practices

Breaking changes deserve their own section — always. Never bury a breaking change in "Improvements." Developers need to see it immediately and assess impact.

Include the migration path inline. Don't just say "this changed." Show the before/after in code:

# Before
GET /users?page=2

# After  
GET /users?cursor=eyJpZCI6MX0

Give deprecations a hard sunset date. "Will be removed eventually" means developers will ignore it. "Will be removed on June 1" means they'll schedule the work.

Version everything. Your release notes should reference a specific API version. Developers need to know exactly which version introduced what.

Link to full API reference for every new endpoint. One sentence in release notes, full spec in docs.

Send proactive notifications for breaking changes. Email + in-dashboard banner + release notes. Don't rely on developers checking your changelog.

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What good looks like

Stripe, Twilio, Shopify, and GitHub have set the standard for API changelogs. What they all do:

1. Separate breaking from non-breaking changes visually
2. Include code snippets for anything requiring developer action
3. Provide generous migration windows (90+ days for breaking changes)
4. Maintain a versioned changelog that's searchable and linkable

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