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Pre-Release Cycle

contributing/pre-release-cycle.md

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Pre-Release Cycle

This guide explains how to start and end a pre-release (beta) cycle for a new major version of the AI SDK.

Overview

Every major release of the AI SDK introduces a new provider specification version (e.g. V3 to V4). Evolving the spec is the reason we do major releases — it lets us make breaking changes to the provider interface while giving provider authors a clear migration target.

A pre-release cycle lets us develop the next major version on main while keeping the current stable version available for patches. During the cycle:

  • main publishes beta releases (e.g. [email protected])
  • A maintenance branch (e.g. release-v6.0) receives backported patches and publishes stable releases

Starting a Pre-Release Cycle

1. Create a maintenance branch

Create a branch from the current main HEAD so the current stable version can continue receiving patches:

bash
git checkout main
git pull origin main
git checkout -b release-v<current-major>.0   # e.g. release-v6.0
git push origin release-v<current-major>.0

The release workflow already runs on release-v* branches, so no workflow changes are needed.

2. Set the npm dist-tag on the maintenance branch

On the new maintenance branch, update the ci:release script in the root package.json to publish with a version-specific npm dist-tag. This prevents maintenance releases from taking over the latest tag on npm:

diff
-    "ci:release": "turbo clean && turbo build && changeset publish",
+    "ci:release": "turbo clean && turbo build && changeset publish --tag ai-v<current-major>",

For example, for release-v6.0 use --tag ai-v6. Commit and push the change directly to the maintenance branch.

3. Enter pre-release mode on main

Switch back to main and enter changeset pre-release mode:

bash
git checkout main
pnpm changeset pre enter beta

This modifies .changeset/pre.json. The initialVersions field should only contain packages from packages/*/package.json files — remove any other entries (e.g. @example/*, tools/*, or nested test packages). Commit and push the change (or open a PR).

4. Create a major changeset

Create a changeset that bumps every published package to the next major version:

bash
pnpm changeset

Select all packages from packages/*/package.json (skip @example/*, tools/*, and any other non-packages/ entries — they are private and not published) and choose major for each. Write a summary like:

Start v7 pre-release

Commit the generated .changeset/*.md file.

5. Seed the new spec version

Every major release introduces a new provider specification version (e.g. V3 to V4). You must create a new version directory for every spec directory under packages/provider/src/ that contains a versioned subdirectory. To find them, run:

bash
ls -d packages/provider/src/*/v3

As of writing, the directories are: embedding-model, embedding-model-middleware, image-model, image-model-middleware, language-model, language-model-middleware, provider, reranking-model, shared, speech-model, transcription-model, video-model.

For each directory:

  1. Copy the current spec directory (e.g. v3/) to a new version directory (e.g. v4/).
  2. Rename all files from the old version to the new (e.g. language-model-v3.ts → language-model-v4.ts).
  3. Inside each file, replace all occurrences of the old version with the new (e.g. V3 → V4, v3 → v4 in type names, imports, and the specificationVersion literal).
  4. Add export * from './v4/index'; to the parent index.ts (before the v3 export).
  5. Update cross-references: if the provider v4 spec imports other model types, ensure it imports from the new v4 paths (not v3).

Verify by running pnpm build in packages/provider — all new types should appear in the built .d.ts output.

6. Create mock test utilities

Create V4 counterparts for every mock file in packages/ai/src/test/ (e.g. mock-language-model-v3.ts → mock-language-model-v4.ts). Update packages/ai/test/index.ts to export the new V4 mocks.

7. Update packages/ai for the new spec version

The core packages/ai package needs adapter functions, updated public APIs, and test updates to support the new spec version alongside older ones.

Adapter functions

Create V4 adapter files in packages/ai/src/model/ for each model type. These use a Proxy to convert V3 models to V4 by overriding specificationVersion:

  • as-language-model-v4.ts
  • as-embedding-model-v4.ts
  • as-image-model-v4.ts
  • as-speech-model-v4.ts
  • as-transcription-model-v4.ts
  • as-reranking-model-v4.ts
  • as-video-model-v4.ts
  • as-provider-v4.ts (converts a V3 provider to V4 by wrapping all model factory methods)

Each adapter checks specificationVersion and returns the model as-is if already V4, or wraps it in a Proxy otherwise.

Each adapter should have a corresponding test file (e.g. as-language-model-v4.test.ts) that verifies:

  • V4 input is returned as-is (identity check with .toBe())
  • V3 input is proxied with specificationVersion changed to 'v4'
  • V2 input (where applicable) is converted through V3 then to V4
  • Properties and methods are preserved through the proxy

Public API updates

Update the following files to accept V2 | V3 | V4 models at their public boundaries, converting to V4 internally using the adapters:

  • packages/ai/src/middleware/wrap-language-model.ts — accept LanguageModelV2 | V3 | V4
  • packages/ai/src/middleware/wrap-image-model.ts — accept ImageModelV2 | V3 | V4
  • packages/ai/src/middleware/wrap-embedding-model.ts — accept EmbeddingModelV3 | V4 (V2 is generic, not included; V3 kept for backward compatibility)
  • packages/ai/src/registry/custom-provider.ts — accept V2/V3/V4 models in all model maps
  • packages/ai/src/registry/provider-registry.ts — accept ProviderV2 | V3 | V4, convert with asProviderV4
  • packages/ai/src/types/language-model-middleware.ts — relax to accept both V3 and V4 middleware

Test updates

  • Create test files for each V4 adapter (e.g. as-language-model-v4.test.ts), verifying identity pass-through, V3→V4 conversion, and V2→V4 conversion.
  • Update resolve-model.test.ts to test both V3→V4 conversion (using V3 mocks) and V4 pass-through (using V4 mocks) as separate test blocks.
  • Update other test files to use V4 mocks where the code now returns V4 models (e.g. custom-provider.test.ts, provider-registry.test.ts, middleware tests). Use V4 mocks for any test that checks reference equality (.toBe()) on returned models.

Run pnpm test in packages/ai and pnpm type-check:full from the workspace root to verify.

8. Set up the documentation site (ai-sdk.dev)

The documentation site lives in the ai-studio repository and uses a Git submodule pointing at this repository. During the pre-release cycle the site needs versioned branches and Vercel deployments for both stable and beta docs.

In the vercel/ai repository:

  1. Update .github/workflows/update-sdk-submodule-v6.yml to track the release-v6.0 branch instead of main.
  2. Create .github/workflows/update-sdk-submodule-v7.yml — this workflow fetches main, checks out the sdk/v7 branch in ai-studio, and pushes to origin sdk/v7.

In the ai-studio repository:

  1. Create a sdk/v7 branch (the default branch stays sdk/v6 for now so the production site continues serving stable docs).
  2. In Vercel, create a v7 preview deployment connected to the sdk/v7 branch (e.g. v7.ai-sdk.dev).

9. Merge to main

Open a PR with all the changes from steps 3-7. Once merged, the first beta release (e.g. [email protected]) will be published automatically.

During the Pre-Release Cycle

Day-to-day development

  • All feature PRs continue to target main.
  • Every PR still needs a changeset (use patch by default).
  • Beta versions are published automatically when the Version Packages PR is merged.

Backporting fixes to stable

To backport a fix from main to the maintenance branch, add the backport label to the merged PR. This creates a new PR targeting the maintenance branch automatically.

Publishing stable patches

Patches merged into the maintenance branch trigger the release workflow and publish stable patch releases.

Ending the Pre-Release Cycle

When the new major version is ready for stable release:

1. Exit pre-release mode

bash
git checkout main
pnpm changeset pre exit

This removes .changeset/pre.json. Commit and push (or open a PR).

2. Publish the stable release

Once the exit-PR is merged, the next Version Packages PR will produce stable versions (e.g. [email protected]). Merge it to publish.

3. Switch the documentation site

In the ai-studio repository, change the default branch from sdk/v6 to sdk/v7 so the production site serves the new major version. Update the Vercel production deployment accordingly.

4. Archive the maintenance branch

The maintenance branch (e.g. release-v6.0) can remain for emergency patches but will no longer receive regular backports.