TanStack/router

Never create UI/router reactivity on the server, including development/tests. Branch before reactive setup; use direct reads and core non-reactive stores. Required transport listeners are allowed only with request-scoped lifetimes and cleanup.

Keep isServer ?? router.isServer directly in each branch condition for dead-code elimination; negate the whole expression for client branches. Never extract it into a variable (e.g. const serverRendering = isServer ?? router.isServer) or helper. Without a router, inline isServer ?? typeof window === 'undefined' (or the existing document check). Keep the constant first and use ??, never ||.

Never manually edit pnpm-lock.yaml or any routeTree.gen.ts. Regenerate the lockfile with pnpm install --no-frozen-lockfile after intentional dependency changes; regenerate route trees through app builds/dev servers or the generator fixture harness.

For suspected dependency issues, verify the upstream root cause, then propose an upstream fix to the user, including for other @tanstack/* packages. Never implement a workaround in this repository unless the user explicitly authorizes it.

Do not mass-submit unrelated or low-quality AI-generated pull requests. We treat that behavior as spam and may close the pull requests, block the contributor, and report the GitHub account.

Every change that affects a published package must include a changeset. Create it with pnpm changeset; documentation, CI, examples, and development-only changes do not require one.

Do not paste LLM output verbatim into the codebase or a contribution. Treat generated text and code as a draft: check its claims, adapt it to the repository, and remove anything you cannot justify. Issues or pull requests that appear to contain unreviewed LLM output may be closed without further review.

Run one Nx command at a time. For a ~20-second startup/graph stall, stop, run pnpm nx reset, and retry once, then escalate. Do not apply that timeout to running tests.

For sandbox-blocked registry/store access, escalate the same command; report the blocker if unavailable. Do not change stores, delete dependencies/lockfiles, use --force/--ignore-scripts, or weaken workspace trust/build policies to bypass it.

Start bug fixes with a failing regression test that uses only public APIs to reproduce and assert user- or developer-visible behavior. Do not manufacture bugs by mutating internals. Establish whether real usage can reach the failing state before adding runtime handling; simplify handling of states proven unreachable.