clerk-monorepo

Working in the clerk/javascript monorepo

This is Clerk's JavaScript SDK monorepo: 24 packages (22 published @clerk/* plus the private @clerk/msw and @clerk/swingset) managed with pnpm workspaces and Turborepo. Read this before building, testing, committing, or touching anything under packages/.

AGENTS.md (repo root) is the canonical source of truth for the hard rules. This skill restates those rules in actionable form and links back to it. If a rule here ever disagrees with AGENTS.md, AGENTS.md wins, and the discrepancy should be fixed here.

Fast setup (happy path)

The order matters more than the commands. Do them in sequence:

1. Node >=24.15.0 (pinned in .nvmrc). nvm use if you have nvm. Wrong Node version is the single most common cause of cryptic "cannot find module @clerk/..." build errors.
2. corepack enable before installing. The preinstall hook runs only-allow pnpm; npm/yarn are hard-blocked. Corepack pins the right pnpm (>=10.33.0).
3. pnpm install from the repo root (never a subdirectory). It is a workspace; installing from a package dir leaves cross-package links broken.
4. pnpm build before anything else. Packages depend on each other's built dist/ + .d.ts. Skipping this makes dev, tests, and the editor's types all report phantom errors.
5. pnpm dev to start watch mode.

Full sequence, the 11 footguns, and the internal integration-test / 1Password setup live in references/setup-and-footguns.md.

Package map: where does X live?

The ~10 packages people touch most. Full 25-package table, the dependency pyramid, and the complete "change X, touch Y" routing are in references/package-map.md.

Heads-up: packages/ may contain stale leftover dirs (types, remix, themes, elements, ...) with only build artifacts and no package.json. Those are removed packages, not active ones. The authoritative list is the git-tracked packages/*/package.json files.

Dev-loop recipes

# Build one package (and its deps, via turbo ^build)
pnpm turbo build --filter=@clerk/nextjs

# Watch subsets instead of everything
pnpm dev:fe-libs      # clerk-js + ui + shared
pnpm dev:js           # clerk-js only
pnpm dev:sandbox      # rspack sandbox for previewing UI components

# Run one package's unit tests (builds the package and its deps first)
pnpm turbo test --filter=@clerk/backend
# Faster, after a full build, for tight iteration:
pnpm --filter @clerk/backend test

# Run a single test file (vitest matches by filename substring). No `--` before the path:
# pnpm forwards a literal `--` into the script and vitest then ignores the filter.
pnpm --filter @clerk/shared test path/to/file.test.ts
# @clerk/backend runs a multi-runtime suite (run-s), so target one runtime for a single file:
pnpm --filter @clerk/backend test:node path/to/file.test.ts

# Quality gates (run before pushing; CI runs equivalent checks)
pnpm lint
pnpm format            # workspace packages plus root files, docs/, integration/, scripts/
pnpm prettier --write '.claude/**/*.md'   # pnpm format does not cover .claude/; format skill files this way

# Changesets — write the file, don't run the CLI (both scripts are interactive prompts)
pnpm changeset status --since=origin/main   # what CI checks; run this to verify

Write .changeset/<descriptive-name>.md directly, in the repo root .changeset/ (never packages/<pkg>/.changeset/). Package change:

---
'@clerk/nextjs': patch
---

Remove the redundant `https://*.client.protect.clerk.com` source from CSP headers generated by `clerkMiddleware()`.

Repo/tooling-only or private-package-only change — the file is exactly two delimiters, nothing else:

---
---

@clerk/swingset and @clerk/msw are private and never appear in a changeset; every other packages/* entry publishes, including @clerk/ui and @clerk/clerk-js. Bump selection, which packages to list, body-writing rules, and the major-version gate are in references/changesets.md.

Test runner differs by package (shared, clerk-js, most adapters use vitest; backend runs a multi-runtime suite), but the pnpm --filter <name> test invocation is uniform.

If the bundlewatch CI job fails, a built file in @clerk/clerk-js or @clerk/ui exceeds its maxSize in that package's bundlewatch.config.json (often after a rebase on main). If the growth is expected, raise the limits; if it is larger than the change explains, investigate instead:

pnpm turbo build --filter=@clerk/clerk-js       # measures dist/, so build first
pnpm --filter @clerk/clerk-js bundlewatch:fix   # failing maxSize -> current size + 1KB, rounded up

Same commands with @clerk/ui for the UI package. Commit the updated bundlewatch.config.json and call out the bump in the PR description; never raise limits silently.

Check the printed diff: if any file's maxSize goes up by more than 10KB, stop before committing and flag it to the user, listing each file with its old and new limit. Only commit the bump once they confirm the growth is expected.

If the editor or a build reports stale types from @clerk/shared, rebuild the foundations: pnpm turbo build --filter=@clerk/shared.

Integration-test variants (pnpm test:integration:*) and canary/snapshot releases are the long tail: see references/setup-and-footguns.md and docs/CONTRIBUTING.md.

The hard rules

Each rule below restates AGENTS.md; the parenthetical is how it is enforced.

• pnpm only, Node >=24.15, pnpm >=10.33. (preinstall blocks npm/yarn; engines in package.json.)
• Every PR needs a changeset. Write the file directly; the pnpm changeset / pnpm changeset:empty scripts are interactive prompts an agent cannot drive. A changeset is a changelog entry for users upgrading, not a summary of the diff. See references/changesets.md. (CI runs pnpm changeset status --since=origin/main and fails PRs missing one.)
• Conventional commit type(scope):, scope is mandatory. Enforced on the PR title (.github/workflows/pr-title-linter.yml), not on individual commits. There is no local commit-msg hook. Valid scope = any packages/* short name and its clerk--stripped form (so clerk-js accepts clerk-js or js), plus repo, release, e2e, ci, *. docs is a valid type, not a scope. Source of truth: commitlint.config.ts.
• clerk-js and ui must stay backwards-compatible across non-major releases. A new clerk-js runtime loads into apps still pinned to an older framework SDK (@clerk/nextjs, etc.), so removing or renaming anything an older SDK calls breaks those apps in production. (break-check flags API-surface changes in api-changes.yml, but that check is informational; shipping such a change means a major, gated by major-version-check.yml.)
• Changes to the core Clerk class API (packages/clerk-js/src/core/clerk.ts) require a major version and !allow-major approval. (.github/workflows/major-version-check.yml.) APIs prefixed __internal_ or exported from an /experimental subpath are exempt from SemVer guarantees.

PR / changeset / commit flow

1. Branch off main.
2. Make the change in the right package(s); add/update unit tests next to the code.
3. Write .changeset/<name>.md (see above, and references/changesets.md), then git add it. An unstaged changeset fails CI the same as a missing one.
4. Verify locally: pnpm build, pnpm test (or the filtered forms above), pnpm lint, pnpm format:check.
5. Open the PR; the title must be a valid conventional commit (it becomes the squash commit). Fill in the PR template and add nothing beyond its sections — in particular, never write a "Testing" / "Test plan" / "How to test" section listing the tests added or the checks run. The Checklist covers that and reviewers read the diff. Describe the change, not the work done on it.

Release policy (when/how things ship, canary, snapshot, backports) is in docs/PUBLISH.md. This skill stops at opening the PR.

Breaking-change quick check

If you are editing clerk-js or ui, answer these. Any "yes" means it is breaking, needs a major + !allow-major, and break-check will flag it:

1. Removing or renaming a public export, method, or property?
2. Changing a public function/method signature (new required arg, changed return type)?
3. Changing the Clerk class public surface in core/clerk.ts?
4. Renaming/removing something an older SDK version still calls at runtime?

If the symbol is __internal_/__experimental_-prefixed or under /experimental, it is exempt. Full decision matrix: references/breaking-changes.md.

Deeper references

• AGENTS.md: the canonical hard rules (authority for this skill).
• docs/CONTRIBUTING.md: full setup, testing, JSDoc/Typedoc, changeset writing.
• docs/PUBLISH.md: release process (stable, canary, snapshot, backport, !allow-major).
• docs/CICD.md: CI/CD pipeline and automated releases.
• docs/SECURITY.md: vulnerability reporting (do not open public issues).
• references/theming-architecture.md (repo root, not this skill's references/): deep dive on the @clerk/ui appearance/theming system.
• Bundled: setup-and-footguns.md, package-map.md, breaking-changes.md, changesets.md.

Analyzing or coordinating a release PR (the "Version packages" PR) is out of scope for this skill; the release process lives in docs/PUBLISH.md and docs/CICD.md. Clerk employees may also have dedicated analyze-javascript-release / coordinate-clerk-release skills installed globally, but those are not shipped in this repo.