[release] v9.0.0

[siriwatknp]

wait for #22002

---

Release version v9.0.0

Prepare the release of the packages

• Compare the last tag with the branch upon which you want to release
• Clean the generated changelog
• Update the root package.json's version
• Update the versions of the other package.json files
• Open PR with changes and wait for review and green CI
• Once CI is green and you have enough approvals, send a message on the team-x slack channel announcing a merge freeze
• Merge PR

Release the packages

• Go to the publish action.
• Choose "Run workflow" dropdown

  Branch: master
  Commit SHA to release from: the commit that contains the merged release on master. This commit is linked to the GitHub release.

• Click "Run workflow"

Publish the documentation

• Run `pnpm docs:deploy`

Publish GitHub release

• Go to the new release on GitHub releases page and publish the draft.

Announce

• Follow the instructions in https://mui-org.notion.site/Releases-7490ef9581b4447ebdbf86b13164272d

[mui-bot]

Deploy preview: https://deploy-preview-22020--material-ui-x.netlify.app/

Bundle size report

Bundle	Parsed size	Gzip size
@mui/x-data-grid	0B(0.00%)	0B(0.00%)
@mui/x-data-grid-pro	▼-5B(0.00%)	▼-4B(0.00%)
@mui/x-data-grid-premium	▼-5B(0.00%)	▼-4B(0.00%)
@mui/x-charts	0B(0.00%)	0B(0.00%)
@mui/x-charts-pro	▼-5B(0.00%)	▼-4B(0.00%)
@mui/x-charts-premium	▼-10B(0.00%)	▼-8B(-0.01%)
@mui/x-date-pickers	0B(0.00%)	0B(0.00%)
@mui/x-date-pickers-pro	▼-20B(-0.01%)	▼-4B(-0.01%)
@mui/x-tree-view	0B(0.00%)	0B(0.00%)
@mui/x-tree-view-pro	▼-5B(0.00%)	▼-4B(-0.01%)

Details of bundle changes

Generated by 🚫 dangerJS against f6cb4df

[mnajdova]

@mui/x-telemetry needs to be updated to 9.0.0.

[mnajdova]

Versions look good 👌

[michelengelen]

Shouldn't this include all contributors for the stable release?

[siriwatknp]

it comes with the release script. I guess we can update it in the GH release.

[michelengelen]

I know ... was just saying that this CHANGELOG entry mentions the stable release and all its benefits and new features, but then goes back to just the 5 contributors that added anything to this specific release cycle ... I'm fine with adding this to the GH release only, but its strange either way

[LukasTy]

Review of #22020 - [release] v9.0.0

Context

Thorough review of the v9.0.0 stable release PR (head f6cb4df83c, base master) to catch missed version bumps or other issues before publishing. Verified:

• Every published package gets a proper version bump
• Dependencies between packages are semantically correct after the bump
• CHANGELOG covers all commits since v9.0.0-rc.0 and names packages correctly
• The release script tag switch (next -> latest) is in place

Checked commits compared: v9.0.0-rc.0 (62e258a585) vs PR head (f6cb4df83c). 8 non-release commits since rc.0.

---

Blocking issue - Scheduler packages not bumped

All four scheduler packages are left at 9.0.0-alpha.0 in the PR:

• packages/x-scheduler/package.json
• packages/x-scheduler-premium/package.json
• packages/x-scheduler-headless/package.json
• packages/x-scheduler-headless-premium/package.json

9.0.0-alpha.0 is already published on npm for every one of them (verified via npm view). The packages are not marked private, so pnpm publish --recursive --tag latest will attempt to publish them and fail with "version already exists".

Worse, these packages actually have changes since the last publish. In #22006 [code-infra] Optimize dependency definition (already merged to master, so it rides along in v9.0.0), their runtime dependencies were modified:

• x-scheduler, x-scheduler-premium, x-scheduler-headless-premium: @base-ui/react changed from ^1.3.0 to catalog:
• x-scheduler-headless: same @base-ui/react change, plus @atlaskit/pragmatic-drag-and-drop changed from ^1.7.7 to catalog:

These are shipped in the published package.json manifests, so the published artifacts differ from what is on npm. The version must be bumped.

Suggested fix: bump all four scheduler packages to 9.0.0-alpha.1 (or whatever the team's convention is for alpha increments). Update the CHANGELOG Scheduler headings to match.

---

CHANGELOG issues

1. Typo - package that does not exist

CHANGELOG.md line ~96 (Scheduler section) reads:

#### `@mui/x-scheduler-premium@9.0.0-alpha.0` [![premium](...)]

Same changes as in `@mui/x-scheduler-pro@9.0.0-alpha.0`.

There is no @mui/x-scheduler-pro package - the community package is @mui/x-scheduler. The "Same changes as in" reference should point to @mui/x-scheduler@... (matching the pattern used by data-grid-pro / tree-view-pro elsewhere in the same changelog).

2. Headless scheduler packages missing from the CHANGELOG

The Scheduler section lists only @mui/x-scheduler and @mui/x-scheduler-premium. The shipped headless packages are omitted:

• @mui/x-scheduler-headless
• @mui/x-scheduler-headless-premium

They exist in packages/, are not private, and (see above) have actual dependency changes to ship. They should be listed - at minimum as "Internal changes." - so consumers know they were rev'd.

---

Verified correct

• Root package.json: 9.0.0-rc.0 -> 9.0.0. OK.
• All 18 other touched package.jsons bumped 9.0.0-rc.0 -> 9.0.0:
  x-charts, x-charts-pro, x-charts-premium, x-charts-vendor, x-codemod, x-data-grid, x-data-grid-pro, x-data-grid-premium, x-data-grid-generator, x-date-pickers, x-date-pickers-pro, x-internal-gestures, x-internals, x-license, x-telemetry, x-tree-view, x-tree-view-pro. OK.
• x-virtualizer: 1.0.0-rc.0 -> 9.0.0-alpha.0 - deliberate version alignment, still pre-release, semver-monotonic. OK.
• @mui/x-virtualizer dep in x-data-grid and x-tree-view-pro changed workspace:^ -> workspace:*. Correct: workspace:^ resolves to ^9.0.0-alpha.0 on publish, which would not match future alpha/beta/rc bumps per semver pre-release rules. workspace:* resolves to the exact version and is the right choice for a pre-release workspace dep. Matching changes are also reflected in pnpm-lock.yaml. OK.
• release:publish tag switched from next to latest (from the already-merged #22018). OK.
• All 8 commits since v9.0.0-rc.0 are represented in the 9.0.0 changelog entry:
  #21132, #21717, #22004, #21989, #22006, #22010, #22002, #22018. OK.
• Contributor count matches (5): @DanailH, @LukasTy, @MBilalShafi, @oliviertassinari, @siriwatknp. OK.

---

Recommended actions (in priority order)

1. Bump scheduler packages to 9.0.0-alpha.1 (files: packages/x-scheduler/package.json, packages/x-scheduler-premium/package.json, packages/x-scheduler-headless/package.json, packages/x-scheduler-headless-premium/package.json), then re-run pnpm install to update pnpm-lock.yaml. Update the Scheduler section of CHANGELOG.md version headers to match.
2. Fix the typo in CHANGELOG.md: @mui/x-scheduler-pro -> @mui/x-scheduler.
3. Add the two headless scheduler packages to the Scheduler section of CHANGELOG.md.

Verification plan

• Run pnpm install after version bumps to refresh the lockfile with link: entries.
• Grep for any lingering 9.0.0-rc.0 or 9.0.0-alpha.0 in packages/*/package.json to confirm only x-virtualizer (at 9.0.0-alpha.0) and the bumped scheduler packages (at 9.0.0-alpha.1) remain as non-9.0.0.
• Dry-run publish against a local registry: pnpm release:publish:dry-run (starts Verdaccio at localhost:4873) - this will surface any "version already exists" errors before the real publish.
• Re-run gh api repos/mui/mui-x/pulls/22020/files style check: every file ending in package.json should contain a version bump line in its patch.