API Reference Template for Product Managers

Use a docs-as-code workflow where API documentation lives in the same repository as the API code. Tools like OpenAPI (Swagger) let you generate reference docs from a spec file that is updated alongside code changes. CI checks can flag when endpoints change without a corresponding doc update. For teams using [release management](/glossary/release-management) workflows, treat doc updates as part of the definition of done.

Both. Generate the mechanical reference (endpoint list, parameter types, response schemas) from an OpenAPI spec. Write the guides, examples, authentication walkthroughs, and error handling advice manually. Auto-generated docs are accurate but sterile. Handwritten docs are readable but drift. Combine them.

Detailed enough for a developer to fix the problem without contacting support. Include the specific field that failed validation, the expected format, and a suggestion for resolution. Never return a generic "Bad Request" with no further context. See the [glossary entry on developer experience](/glossary/product-development) for more on reducing friction in API integrations.

Cursor-based pagination is more reliable for large, frequently updated datasets because it avoids the "shifting window" problem of offset pagination (where items get skipped or duplicated as new records are inserted). Offset pagination is simpler to implement and works fine for datasets under 10,000 records that do not change frequently. Choose based on your data characteristics.

Treat webhooks as a separate section after your REST endpoints. For each event type, document: the event name, when it fires, the payload schema, a full JSON example, the retry policy for failed deliveries, and how to verify the webhook signature. Include a testing section that explains how developers can trigger test events. ---