feat(backend): Add support for User locale

[tmilewski]

Description

Adds support for CRUD operations on the User locale field.

FIXES USER-3626

Checklist

• pnpm test runs as expected.
• pnpm build runs as expected.
• (If applicable) JSDoc comments have been added or updated for any package exports
• (If applicable) Documentation has been updated

Type of change

• 🐛 Bug fix
• 🌟 New feature
• 🔨 Breaking change
• 📖 Refactoring / dependency upgrade / documentation
• other:

Summary by CodeRabbit

• New Features

  • Added support for a user locale (BCP‑47). You can set a locale when creating or updating a user, and read it from user data. If not provided, it may be null.
  • Enables localized experiences by storing a user’s preferred language/region.

• Chores

  • Added changeset and prepared a minor release for the backend package.

[changeset-bot]

🦋 Changeset detected

Latest commit: 1c91373

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 11 packages

Name	Type
@clerk/backend	Minor
@clerk/agent-toolkit	Patch
@clerk/astro	Patch
@clerk/express	Patch
@clerk/fastify	Patch
@clerk/nextjs	Patch
@clerk/nuxt	Patch
@clerk/react-router	Patch
@clerk/remix	Patch
@clerk/tanstack-react-start	Patch
@clerk/testing	Patch

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Project	Deployment	Preview	Comments	Updated (UTC)
clerk-js-sandbox	Ready	Preview	Comment	Oct 7, 2025 6:36pm

[coderabbitai]

Walkthrough

Adds optional BCP‑47 locale support across backend user types: creation/update params, public User model, and JSON shape. Populates User.locale from JSON and includes a changeset entry for a minor release of @clerk/backend.

Changes

Cohort / File(s)	Summary
User API params packages/backend/src/api/endpoints/UserApi.ts	Added optional locale?: string to CreateUserParams and UpdateUserParams with BCP‑47 description.
User resource + JSON shape packages/backend/src/api/resources/JSON.ts, packages/backend/src/api/resources/User.ts	Introduced `locale: string
Release metadata .changeset/calm-brooms-grab.md	Added changeset entry for a minor release documenting User locale support.

Sequence Diagram(s)

sequenceDiagram
  autonumber
  actor Dev as Client Code
  participant API as UserApi (Create/Update)
  participant Model as User (fromJSON)
  participant Store as Backend Service

  Dev->>API: createUser({ ..., locale? })
  API->>Store: POST /users { ..., locale? }
  Store-->>API: 200 OK { ..., locale }
  API->>Model: User.fromJSON({ ..., locale })
  Model-->>Dev: User { ..., locale }

  Dev->>API: updateUser({ ..., locale? })
  API->>Store: PATCH /users/:id { ..., locale? }
  Store-->>API: 200 OK { ..., locale }
  API->>Model: User.fromJSON({ ..., locale })
  Model-->>Dev: User { ..., locale }

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Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Poem

A nibble of code, a hop through fields,
I taught our Users how locale yields—
BCP‑47 tucked in a neat little fold,
Whispered in JSON, carried in gold.
Minor release, a carrot for cheer—tail up, I steer. 🥕🐇

Pre-merge checks and finishing touches

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title Check	✅ Passed	The title succinctly highlights that this PR adds support for the User locale in the backend, matching the code changes. It uses the conventional feat(backend) prefix and avoids extraneous detail, making it clear and specific. This aligns with best practices for PR titles.
Linked Issues Check	✅ Passed	The implemented code adds locale support across CreateUserParams, UpdateUserParams, the UserJSON interface, and the User resource, fully addressing the requirements of USER-3626 to support locale in CRUD operations. It covers both request parameter definitions and response mappings without leaving gaps. This satisfies the primary coding objective of the linked issue.
Out of Scope Changes Check	✅ Passed	All modifications in this PR are directly related to introducing the locale field, including parameter definitions, JSON interfaces, and resource mappings. No unrelated files or features have been touched, and only changes relevant to USER-3626 are present. This confirms that there are no out-of-scope alterations.
Docstring Coverage	✅ Passed	No functions found in the changes. Docstring coverage check skipped.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch tom/user-3626-update-js-backend-sdk-to-support-locale

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Review profile: CHILL

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📥 Commits

Reviewing files that changed from the base of the PR and between 1596486 and 1c91373.

📒 Files selected for processing (2)

• packages/backend/src/api/resources/JSON.ts (1 hunks)
• packages/backend/src/api/resources/User.ts (2 hunks)

🚧 Files skipped from review as they are similar to previous changes (2)

• packages/backend/src/api/resources/JSON.ts
• packages/backend/src/api/resources/User.ts

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (5)

• GitHub Check: Formatting | Dedupe | Changeset
• GitHub Check: Build Packages
• GitHub Check: Analyze (javascript-typescript)
• GitHub Check: semgrep-cloud-platform/scan
• GitHub Check: semgrep-cloud-platform/scan

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[wobsoriano]

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commit: 1c91373