[DennisSmolek]

Foundation workstream for 3.0. It moves the tooling and dependency stack, so the other 3.0 branches (bug fixes, docs, character controller, soft bodies, core stepping) can build on it. Library src changes are kept to what the new stack needs to compile and test.

What changed

Package manager

• Yarn 4.18.1 through Corepack (packageManager), with nodeLinker: node-modules.
• Root tooling moved from dependencies to devDependencies. @manypkg/cli, preconstruct and babel are removed.
• The demo and addons depend on the workspace packages through workspace:*.
• engines.node >=22. .nvmrc is v22.22.2 because jsdom 30 needs at least 22.22.2.

Stack

• @react-three/fiber and @react-three/test-renderer 10.0.0-canary.a056612 (scheduler 0.3, fixed step)
• three / @types/three 0.186
• react / react-dom 19.2.8
• drei 11.0.0-alpha.7 (demo only)
• vitest 5 with jsdom 30, TypeScript 5.9
• Peer dependencies: fiber >=10.0.0-0, react >=19.0 <19.3, three >=0.185.0. The addons package peers on @react-three/rapier ^3.0.0-0.
• three-stdlib is bumped to ^2.36.1, because 2.35 imports LuminanceFormat, which three has removed. It is removed entirely in the bug-fix workstream.

Build

• rollup + esbuild + rollup-plugin-dts replace preconstruct, mirroring react-three-jolt.
• Output is dual ESM/CJS (dist/index.{mjs,cjs}, .d.{ts,mts,cts}). Each package gets an exports map, sideEffects: false, engines, a narrowed files list and repository metadata.
• The config is shared in scripts/rollup-library.mjs, and entry points are derived from the exports map. Adding @react-three/rapier/soft-bodies therefore only needs src/soft-bodies/index.ts plus an exports, files and typesVersions entry.
• Relative imports of another entry are rewritten to the package specifier, so core is never bundled twice.
• yarn check:packages runs publint --strict and attw --pack on each package.
• vitest, the root tsc and the demo resolve the workspace packages from src (aliases and tsconfig paths), so none of them needs a build first.

Minimal source and test changes

• utils.ts: type-only narrowing for v10's readonly-tuple math types.
• Tests:
  • They now await create() instead of racing it against mount callbacks. On v10, the overlapping act() scopes left updates unflushed.
  • They expect the extra zero-delta priming frame from advanceFrames.
  • The physics snapshot was re-baselined.

Demo (minimal)

• state.clock became state.elapsed.
• <Canvas shadows> became gl={{ shadows: true }}, which keeps the WebGL renderer.
• drei Text now comes from @react-three/drei/legacy.
• OrbitControls types come from three/addons.
• The deep imports of library internals were removed.
• r3f-perf was replaced by drei <Stats>. r3f-perf pins drei 9 and an old three-stdlib, which breaks the build on three 0.186.

Lint and format

• ESLint 9 flat config and Prettier 3 (.prettierrc keeps the repo's existing style options), with lint, format and format:check scripts.
• The codebase is not reformatted or lint-fixed. Current baseline: 29 lint errors, 126 warnings, and 4 files that differ under Prettier.
• The pre-commit hook now runs yarn typecheck instead of the full CI.

CI and release

• ci.yml replaces test.yml and runs typecheck, test, build with publint/attw, and the demo build. Lint/format is a non-blocking job for now.
• Runs on PRs and pushes to main and next, with concurrency and permissions blocks.
• A shared .github/actions/setup action enables Corepack, sets up the yarn cache and installs.
• Actions are on their current majors (checkout/setup-node v7, configure-pages v6, upload-pages-artifact v5, deploy-pages v5). This supersedes chore(.github/workflows): update actions version #733.
• The release workflow mirrors jolt and runs on main and next.
• @changesets/cli 3, and changeset pre enter alpha has been run (.changeset/pre.json).
• Added a major changeset for core and addons.
• Dependabot now covers the root workspace and github-actions.
• Added DEVELOPMENT.md.

Decided differently from the plan

• Prettier style: I kept the repo's style (2 spaces, double quotes) rather than jolt's (4 spaces, single quotes). This keeps the deferred reformat at 4 files instead of every line. Switching is a one-line change.
• changesets/action: stays on @v1, as in jolt. v2 drops the NPM_TOKEN/.npmrc handling, which would change the npm auth setup.

Risks

• Snapshot re-baseline: the values changed by about 1e-14. The test renderer's advanceFrames now drives the scheduler with millisecond timestamps, so per-frame deltas are not exactly 1/60. The accumulator therefore carries a tiny residual, and the interpolated positions differ in the last digits.
• useFrame call counts: advanceFrames(n) now runs n+1 frames because of a priming step(0) frame. useFrame callbacks see n+1 calls, while physics still steps n times.
• Canary pin: r3f is pinned to a canary until alpha.6 ships.
• Demo not run: the demo builds, but I did not test it in a browser (shadows via gl, <Stats>, drei 11).
• Release workflow on next: it can only be verified once this merges.

Verification (fresh yarn install --immutable)

• yarn build ✅
• yarn typecheck ✅
• yarn workspace demo typecheck ✅
• yarn test: 38/38 ✅
• yarn check:packages (publint + attw, all resolution modes green) ✅
• yarn demo:build ✅
• yarn changeset version dry run gives @react-three/rapier 3.0.0-alpha.0 (reverted)
• yarn lint and yarn format:check fail on the existing baseline, as expected

🤖 Generated with Claude Code

[changeset-bot]

🦋 Changeset detected

Latest commit: a4a0c34

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

This PR includes changesets to release 2 packages

Name	Type
@react-three/rapier	Major
@react-three/rapier-addons	Major

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