feat!: support TypeScript 7 in plugin-kit, require typescript 6.x || 7.x

[stipsan]

Applies the same fix to @sanity/plugin-kit as sanity-io/pkg-utils#2978: the TypeScript baseline moves to 6/7, and the JS compiler API is loaded from @typescript/typescript6 instead of typescript.

Why

TypeScript 7 (the Go-native compiler) no longer ships the JS compiler API — its npm entry point only exports version/versionMajorMinor. plugin-kit's readTSConfig (used by verify-package/verify-studio to parse tsconfig.json via ts.readConfigFile/ts.parseJsonConfigFileContent/ts.sys) breaks at runtime when a consumer installs typescript@7, which is now latest on npm.

Changes

• Peer range (breaking): typescript peer moves from 5.8.x || 5.9.x || 6.0.x to 6.x || 7.x. TypeScript 5.x is no longer supported; 7 is not required.
• Compiler API via @typescript/typescript6: src/util/ts.ts and the ParsedCommandLine type imports in verify-common.ts/validations.ts now use the official @typescript/typescript6 compat package, added as a regular dependency (statically imported, same as pkg-utils@11). The installed typescript peer no longer affects tsconfig parsing and is only used to run tsc --build. @sanity/pkg-utils@11 already ships the same dependency, so it dedupes in consumer trees.
• plugin-kit init scaffolds typescript at ^6 instead of latest: discovered while smoke-testing — with typescript@7 as latest, freshly scaffolded plugins failed npm install with an ERESOLVE conflict because the scaffolded @typescript-eslint@8 toolchain declares peer typescript ">=4.8.4 <6.1.0". Locked with a comment to unlock once typescript-eslint supports TS 7.
• Changeset: major for @sanity/plugin-kit.

Verification

• pnpm format, pnpm lint, pnpm knip, pnpm build, pnpm test run (167 files, 893 tests) all pass, including plugin-kit's init -> verify-package -> tsc -> pkg-utils build integration test.
• Packed-tarball consumer smoke tests:
  • pnpm consumer with typescript@7.0.2: verify-package parses tsconfig via @typescript/typescript6 and its spawned tsc --build runs the Go-native TS7 compiler; full npm run build passes.
  • npm consumer with typescript@7.0.2: TS7 tsc --build compiles the scaffold directly; verify-package and the full build pass (npm's hoisted .bin/tsc collision with @typescript/old pre-exists for every pkg-utils@11 consumer).
  • Default plugin-kit init scaffold: installs cleanly again with typescript ^6.0.3 (previously failed with ERESOLVE against latest = 7.0.2).

Smoke test log

=== 1) pnpm consumer with typescript 7.0.2 ===
plugin-kit peer typescript: 6.x || 7.x
plugin-kit dependency @typescript/typescript6: ^6.0.2
node_modules/.bin/tsc --version: Version 7.0.2   <-- the Go-native TS7 compiler

--- npx plugin-kit verify-package (tsconfig parsed via @typescript/typescript6; spawned 'tsc --build' is TypeScript 7) ---
[info] All checks ok, running TypeScript compiler.
[info] Running command: tsc --build
[success] No outstanding upgrade issues detected.

--- npm run build (plugin-kit verify-package --silent && pkg-utils build --strict --check --clean) ---
sanity-plugin-ts7-smoke@1.0.0
├─ type: module
└─ exports
   └─ sanity-plugin-ts7-smoke
      ├─ source: ./src/index.ts 573 B
      ├─ import: ./dist/index.js 236 B
      └─ default: ./dist/index.js 236 B

[success] 35ms

=== 2) npm consumer with typescript 7.0.2 ===
direct devDependency typescript: 7.0.2
TS7 native tsc builds the project directly:
Version 7.0.2
tsc --build (7.0.2): OK

--- npx plugin-kit verify-package ---
[info] All checks ok, running TypeScript compiler.
[info] Running command: tsc --build
[success] No outstanding upgrade issues detected.

=== 3) default 'plugin-kit init' scaffold now locks typescript to ^6 ===
scaffolded devDependencies.typescript: ^6.0.3
installed typescript: 6.0.3
(before: init scaffolded 'latest' = 7.0.2 and npm install failed with ERESOLVE, because
 @typescript-eslint/parser@8 declares peer typescript '>=4.8.4 <6.1.0')

--- npm run build ---
[success] 34ms

  

[changeset-bot]

🦋 Changeset detected

Latest commit: 56c5673

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

This PR includes changesets to release 1 package

Name	Type
@sanity/plugin-kit	Major

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Project	Deployment	Actions	Updated (UTC)
plugins-studio	Ready	Preview, Comment	Jul 13, 2026 10:56am

[Copilot]

Pull request overview

This PR updates @sanity/plugin-kit to work when consumers install typescript@7 by switching tsconfig parsing to the classic JS compiler API provided by @typescript/typescript6, while also updating the peer dependency baseline to TypeScript 6/7 and adjusting plugin-kit init scaffolding away from typescript@latest.

Changes:

• Switch tsconfig parsing (readTSConfig) from typescript to @typescript/typescript6 to avoid runtime breakage under typescript@7.
• Update @sanity/plugin-kit peer dependency range from TypeScript 5.x/6.0 to 6.x || 7.x, and add @typescript/typescript6 as a dependency.
• Lock plugin-kit init scaffolding to TypeScript 6 (instead of latest) to avoid installation conflicts when TS7 is latest.

Reviewed changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pnpm-lock.yaml	Adds lockfile entries for the new @typescript/typescript6 dependency.
packages/@sanity/plugin-kit/src/util/ts.ts	Loads the JS compiler API from @typescript/typescript6 for tsconfig parsing.
packages/@sanity/plugin-kit/src/npm/resolveLatestVersions.ts	Locks scaffolded TypeScript version away from latest to avoid TS7 incompatibilities.
packages/@sanity/plugin-kit/src/actions/verify/verify-common.ts	Updates ParsedCommandLine type import to match @typescript/typescript6.
packages/@sanity/plugin-kit/src/actions/verify/validations.ts	Updates ParsedCommandLine type import to match @typescript/typescript6.
packages/@sanity/plugin-kit/package.json	Adds @typescript/typescript6 dependency and updates typescript peer range to `6.x
.changeset/plugin-kit-typescript-7-support.md	Adds a major changeset documenting the breaking peer range update and TS7 support rationale.

Files not reviewed (1)

• pnpm-lock.yaml: Generated file

Comments suppressed due to low confidence (1)

packages/@sanity/plugin-kit/src/npm/resolveLatestVersions.ts:15

• lockedDependencies.typescript is set to ^6, but the scaffolded ESLint toolchain currently has a TypeScript peer of >=4.8.4 <6.1.0 (see pnpm-lock.yaml entry for @typescript-eslint/parser@8.63.0). Also, rangeify() always emits a caret range, which would allow upgrading to 6.1+ and reintroduce peer conflicts. Constrain the selection to 6.0.x and emit a ~6.0.z range for the scaffolded TypeScript version.

  'typescript': '^6',
}

export function resolveLatestVersions(packages: string[]) {
  const versions: Record<string, string> = {}

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