Major Version Mode

Only use when explicitly invoked by the user (e.g. via '/major-version-mode'). Do NOT trigger autonomously based on task content.

Context

This task is part of the next AI SDK major release. Breaking changes are acceptable.

Breaking Change Guidelines

While breaking changes are acceptable, it is still encouraged to minimize unnecessary disruption for 3P consumers of the AI SDK. Providing deprecated aliases and automated migration logic can help ease the transition.

Renamed/changed exports

If renaming or modifying an exported function or type, provide a deprecated alias as a package-level export where feasible:

/** @deprecated Use `newFunctionName` instead. */
export { newFunctionName as oldFunctionName } from './new-module';

Only do this if it doesn't introduce meaningful technical debt. If it does, skip the alias — but check with the user first before making a clean break.

Modified message types (e.g. in @ai-sdk/provider-utils)

If modifying model message shapes:

1. Deprecate in @ai-sdk/provider-utils rather than removing immediately. Mark deprecated types/members with a @deprecated JSDoc comment and a TODO note to remove in the following major version.
2. Keep deprecated equivalents in packages/ai/src/prompt/content-part.ts — this is the consumer-facing layer and should retain old shapes in Zod schemas so existing consumer code continues to compile with a deprecation warning.
3. If clean deprecation isn't feasible without meaningful technical debt, a hard removal may be preferred — but check with the user first.

Provider spec changes (@ai-sdk/provider)

The provider package defines the spec that provider implementers code against. Breaking changes without backward compatibility are more acceptable here because the audience is smaller.

Rules:

• Only modify the latest spec version. Older versioned spec interfaces must remain completely untouched.
• Deprecated aliases are not required — a clean break is preferred to preserve spec clarity.
• If it's unclear which spec version to operate on, ask the user before proceeding.

Documentation

After implementing changes, update relevant documentation in content/docs/.

If the change requires consumers to update their code or migrate stored data, add a section to the latest migration guide:

• Find the migration guide with the highest version number in content/docs/08-migration-guides/
• Add a concise section explaining what changed and how to migrate

Mirrored from https://github.com/vercel/ai — original author: vercel, license: Apache-2.0. This is an unclaimed mirror. Content and ownership transfer to the author when they claim this account.