Working in products/desktop

products/desktop/ is the PostHog desktop app (Electron + agent framework), imported from PostHog/code and kept as a nested standalone workspace: own pnpm-workspace.yaml, own lockfile, own Biome config, Node 22. It is excluded from the root pnpm-workspace.yaml, from ruff/mypy, from root Jest, from oxlint/oxfmt, from stylelint and from pytest.

Read products/desktop/AGENTS.md before writing code in this tree. It is the source of truth for architecture, layer boundaries, DI, and style. This skill only covers the scoping contract around it.

Scope contract

Default: everything you read, edit, run and test lives under products/desktop/. Run all commands with that as cwd. Do not go fishing in frontend/, posthog/, or other products/* for patterns — the desktop tree has its own, and copying monorepo idioms in is a defect.

Step outside only when one of these is true:

1. The user explicitly tells you to.
2. A backend API the app calls needs to change. The client is packages/api-client/; the endpoints it hits live in the Django monorepo (see below).
3. Desktop CI / config that lives at the root by design. The list is fixed — see products/desktop/MIGRATION.md "Root-repo changes (outside products/desktop/)": .github/workflows/desktop-*.yml, .github/actions/desktop-*/, .github/scripts/products/desktop/, and the exclusion entries in pnpm-workspace.yaml, pyproject.toml, pytest.ini, package.json (lint:css), frontend/jest.config.ts, .dockerignore, .oxlintrc.json, .oxfmtrc.json, .config/.markdownlint-cli2.jsonc, .github/workflows/ci-{frontend,storybook,backend}.yml (+ .depot/workflows/ci-backend.yml). Touch these only to keep an exclusion correct; say so when you do.

Anything else outside the tree: stop and ask.

Toolchain — root CLAUDE.md does not apply here

Root monorepo says	In products/desktop use
ruff / mypy / pytest	nothing — no Python app code here
oxlint + Oxfmt, pnpm --filter=@posthog/frontend fix	pnpm lint (Biome check --write), pnpm format
Jest, hogli test	Vitest (pnpm test), Playwright (pnpm test:e2e)
pnpm --filter=@posthog/frontend typescript:check	pnpm typecheck (turbo, all packages)
Kea logics, typegen:write	Zustand stores + InversifyJS services; no kea, no typegen
LemonUI in frontend/ and products/*/frontend/	@posthog/quill + Tailwind + Radix Themes
hogli build:openapi → generated frontend types	packages/api-client/src/generated.ts (hand-maintained here)
4-space / repo Prettier habits	Biome, 2-space, double quotes

Commands (from products/desktop/): pnpm install, pnpm dev, pnpm build, pnpm typecheck, pnpm lint, pnpm test, pnpm test:e2e, pnpm --filter <pkg> <task>, node scripts/check-host-boundaries.mjs.

Never run root-level pnpm install expecting it to cover desktop, and never let a desktop dependency change alter the root lockfile — the root install must stay byte-identical.

What still applies from the root

• Conventional commits and PR titles; scope of desktop (e.g. fix(desktop/$feature): ...).
• .github/pull_request_template.md structure, including the Agent context section.
• Public-repo copy safety: no customer names, internal incidents, or Slack quotes.
• Merging: gh pr merge <number> --squash into master. AGENTS.md "Merging PRs" and products/desktop/.claude/skills/merging-prs/ are stale — they describe the PostHog/code Trunk queue against main, which does not exist here. products/desktop/POST-MIGRATION.md has the correct flow.
• hogli ci:preflight on push (pre-push hook) still runs repo-wide.

Cross-boundary: the Django API

packages/api-client/ calls monorepo endpoints — tasks (/api/projects/:id/tasks/...), signals, agent applications, environments/MCP installations, /api/users/. When a change needs the backend:

• Read the Django side to get the contract right; that is in scope without asking.
• Editing it is a separate, monorepo-side change: root CLAUDE.md rules apply again (/improving-drf-endpoints, /django-migrations, serializer help_text, hogli build:openapi).
• Keep the two sides in one PR only if they must ship together; otherwise land the backend first.
• Wiring the app at a local Django instance (OAuth app, RSA keys, flags) is products/desktop/docs/LOCAL-DEVELOPMENT.md.

Resync hazard

The tree is a verbatim copy of PostHog/code at a pinned SHA. A resync replaces it wholesale, so edits to imported files are lost unless they are upstreamed or listed as intentional drift. Before changing a file, consider whether the fix belongs upstream in PostHog/code. The drift list, the local security patches that must be reapplied, and the monorepo-only files (MIGRATION.md, POST-MIGRATION.md, product.yaml, docs/plan.md) are in products/desktop/MIGRATION.md. Do not delete or "clean up" monorepo-only files.

Desktop-local skills

products/desktop/.claude/skills/ ships its own: test-electron-app (drive the running app over CDP :9222), quill-code, storybook-stories, canvas-templates, merging-prs (stale, see above). Prefer these over monorepo equivalents while in this tree.

Before reporting done

• pnpm typecheck and pnpm lint from products/desktop/, plus pnpm test for touched packages.
• After touching packages/core: biome lint packages/core, zero noRestrictedImports.
• After touching @posthog/platform: rebuild or typecheck its dist/.
• After moving logic out of apps/code: node scripts/check-host-boundaries.mjs --prune.
• Confirm the diff touches nothing outside products/desktop/ — or name what it touches and why.