Versioning

The Mercel API is versioned. Today the only supported version prefix is /v1 and there are no breaking releases yet.

When we introduce versioned changes, we'll publish them under date-stamped release notes and let clients pin a version per request via a Mercel-Version header. Until then, clients should treat /v1 as stable and watch the changelog for backward-incompatible notices.

Backward-compatible changes

The following changes are considered backward-compatible and may ship without a version bump:

• Adding new endpoints, fields, or response properties.
• Adding new optional request parameters.
• Adding new error code values within an existing error shape.
• Reordering JSON object keys.

Clients should ignore unknown fields and tolerate added enum values.