Next.js TypeScript plugin diagnostics not reported by CLI / CI type checking with `tsc` or `next` subcommand

Link to the code that reproduces this issue

https://github.com/karlhorky/repro-next-js-typescript-plugin-diagnostics-no-cli

To Reproduce

1. Open the reproduction sandbox at https://codesandbox.io/p/devbox/recursing-lamarr-3ypq8k?file=%2Fapp%2Fpage.tsx%3A3%2C18
2. Use the Next.js TypeScript language service plugin: cmd/ctrl-shift-P -> TypeScript: Select TypeScript Version... -> Use Workspace Version
3. Observe the The Next.js "metadata" export should be type of "Metadata" from "next". ts(71008) warning-level diagnostic in app/page.tsx
4. Run pnpm tsc and observe no diagnostics reported 💥
5. Run pnpm next check and pnpm next tsc and observe that these are not valid subcommands 💥

Terminal output:

➜  workspace git:(main) ✗ pnpm tsc
➜  workspace git:(main) ✗ echo $?
0
➜  workspace git:(main) ✗ pnpm next check
Invalid project directory provided, no such directory: /project/workspace/check
➜  workspace git:(main) ✗ pnpm next tsc
Invalid project directory provided, no such directory: /project/workspace/tsc

Current vs. Expected behavior

The next TypeScript plugin reports Next.js-specific diagnostics through the editor TypeScript language service, but there is no command-line check that reports the same diagnostics.

I am aware that the TypeScript team have up until now (August 2026) rejected the feature request that tsc execute TypeScript language-service plugins:

• https://github.com/microsoft/TypeScript/issues/16607

I expected Next.js to provide a framework-aware CLI type check that includes its own plugin diagnostics, similar to the following prior art:

• astro check
• vue-tsc
• mdx-tsc
• effect-language-service diagnostics

For Next.js this command could be something like next check or next tsc.

Provide environment information

Operating System:
  Platform: linux
  Arch: x64
  Version: microsoft/typescript-go#1 SMP PREEMPT_DYNAMIC Sun Aug  6 20:05:33 UTC 2023
  Available memory (MB): 8198
  Available CPU cores: 4
Binaries:
  Node: 20.12.1
  npm: 10.5.0
  Yarn: 1.22.19
  pnpm: 8.15.6
Relevant Packages:
  next: 16.3.1-canary.13 // Latest available version is detected (16.3.1-canary.13).
  eslint-config-next: N/A
  react: 19.2.8
  react-dom: 19.2.8
  typescript: 5.9.3
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

TypeScript

Which stage(s) are affected? (Select all that apply)

next build (local)

Additional context

Next.js's own TypeScript plugin tests already create a TypeScript LanguageService, wrap it with the next plugin, and call getSemanticDiagnostics():

https://github.com/vercel/next.js/blob/26824378a648f57c4595d5edd7fcfa20c96b71ba/test/development/typescript-plugin/test-utils.ts#L69-L100

Start with the reproduction and compare pnpm tsc with the editor diagnostic for app/page.tsx. Read test/development/typescript-plugin/test-utils.ts, especially its LanguageService setup and getSemanticDiagnostics() call, then review the existing CLI entry points. Done means a documented framework-aware command reports the same Next.js plugin diagnostics during local and CI type checking.