# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Project Context

Multica is an AI-native task management platform — like Linear, but with AI agents as first-class citizens.

- Agents can be assigned issues, create issues, comment, and change status
- Supports local (daemon) and cloud agent runtimes
- Built for 2-10 person AI-native teams

## Architecture

**Go backend + monorepo frontend (pnpm workspaces + Turborepo) with shared packages.**

- `server/` — Go backend (Chi router, sqlc for DB, gorilla/websocket for real-time)
- `apps/web/` — Next.js frontend (App Router)
- `apps/desktop/` — Electron desktop app (electron-vite)
- `packages/core/` — Headless business logic (zero react-dom, all-platform reuse)
- `packages/ui/` — Atomic UI components (zero business logic)
- `packages/views/` — Shared business pages/components (zero next/* imports, zero react-router imports)
- `packages/tsconfig/` — Shared TypeScript configuration

### Key Architectural Decisions

**Internal Packages pattern** — all shared packages export raw `.ts`/`.tsx` files (no pre-compilation). The consuming app's bundler compiles them directly. This gives zero-config HMR and instant go-to-definition.

**Dependency direction:** `views/ → core/ + ui/`. Core and UI are independent of each other. No package imports from `next/*`, `react-router-dom`, or app-specific code.

**Platform bridge:** `packages/core/platform/` provides `CoreProvider` — initializes API client, auth/workspace stores, WS connection, and QueryClient. Each app wraps its root with `<CoreProvider>` and provides its own `NavigationAdapter` for routing.

**pnpm catalog** — `pnpm-workspace.yaml` defines `catalog:` for version pinning. All shared deps use `catalog:` references to guarantee a single version across all packages. When adding new shared deps (including test deps), add to catalog first.

### State Management

The architecture relies on a strict split between server state and client state. Mixing them is the most common way to break it.

- **TanStack Query owns all server state.** Issues, users, workspaces, inbox — anything fetched from the API lives in the Query cache. WS events keep it fresh via invalidation; no polling, no `staleTime` workarounds.
- **Zustand owns all client state.** UI selections, filters, drafts, modal state, navigation history. Stores live in `packages/core/` (never in `packages/views/`) so both apps share them.
- **React Context** is reserved for cross-cutting platform plumbing — `WorkspaceIdProvider`, `NavigationProvider`. Don't reach for it for general state.
- **Auth and workspace stores are the only stores allowed to call `api.*` directly**, because they manage critical state that must exist before queries can run. They're created via factory + injected dependencies, registered by the platform layer.

**Hard rules — these are how the architecture stays coherent:**

- **Never duplicate server data into Zustand.** If it came from the API, it belongs in the Query cache. Copying it into a store creates two sources of truth and they will drift.
- **Workspace-scoped queries must key on `wsId`.** This is what makes workspace switching automatic — the cache key changes, the right data appears, no manual invalidation needed.
- **Mutations are optimistic by default.** Apply the change locally, send the request, roll back on failure, invalidate on settle. The user shouldn't wait for the server.
- **WS events invalidate queries — they never write to stores directly.** This keeps the cache as the single source of truth and avoids race conditions.
- **Persist what's worth preserving across restarts** (user preferences, drafts, tab layout). **Don't persist ephemeral UI state** (modal open/close, transient selections) or server data.

**Common Zustand footguns to avoid:**

- Selectors must return stable references. Returning a freshly built object or array on every call (e.g. `s => ({ a: s.a, b: s.b })` or `s => s.items.map(...)`) triggers infinite re-renders. Either select primitives separately or use shallow comparison.
- Hooks that need workspace context should accept `wsId` as a parameter, not call `useWorkspaceId()` internally — this lets them work outside the `WorkspaceIdProvider` (e.g. in a sidebar that renders before workspace is loaded).

## Commands

```bash
# One-command dev (auto-setup + start everything)
make dev              # Auto-creates env, installs deps, starts DB, migrates, launches app

# Explicit setup & run (if you prefer separate steps)
make setup            # First-time: ensure shared DB, create app DB, migrate
make start            # Start backend + frontend together
make stop             # Stop app processes for the current checkout
make db-down          # Stop the shared PostgreSQL container

# Frontend (all commands go through Turborepo)
pnpm install
pnpm dev:web          # Next.js dev server (port 3000)
pnpm dev:desktop      # Electron dev (electron-vite, HMR)
pnpm build            # Build all frontend apps
pnpm typecheck        # TypeScript check (all packages + apps via turbo)
pnpm lint             # ESLint
pnpm test             # TS tests (Vitest, all packages + apps via turbo)

# Backend (Go)
make server           # Run Go server only (port 8080)
make daemon           # Run local daemon
make build            # Build server + CLI binaries to server/bin/
make cli ARGS="..."   # Run multica CLI (e.g. make cli ARGS="config")
make test             # Go tests
make sqlc             # Regenerate sqlc code after editing SQL in server/pkg/db/queries/
make migrate-up       # Run database migrations
make migrate-down     # Rollback migrations

# Run a single TS test (works for any package with a test script)
pnpm --filter @multica/views exec vitest run auth/login-page.test.tsx
pnpm --filter @multica/core exec vitest run runtimes/version.test.ts
pnpm --filter @multica/web exec vitest run app/\(auth\)/login/page.test.tsx

# Run a single Go test
cd server && go test ./internal/handler/ -run TestName

# Run a single E2E test (requires backend + frontend running)
pnpm exec playwright test e2e/tests/specific-test.spec.ts

# Desktop build & package
pnpm --filter @multica/desktop build      # Compile TS → JS (reads .env.production)
pnpm --filter @multica/desktop package    # Package into .app/.dmg/.exe (current platform only)

# shadcn — config lives in packages/ui/components.json (Base UI variant, base-nova style)
pnpm ui:add badge                # Adds component to packages/ui/components/ui/

# Infrastructure
make db-up            # Start shared PostgreSQL (pgvector/pg17 image)
make db-down          # Stop shared PostgreSQL
make db-reset         # Drop + recreate current env's DB, then re-run migrations (local only; stop backend first)
```

### CI Requirements

CI runs on Node 22 and Go 1.26.1 with a `pgvector/pgvector:pg17` PostgreSQL service. See `.github/workflows/ci.yml`.

### Worktree Support

All checkouts share one PostgreSQL container. Isolation is at the database level — each worktree gets its own DB name and unique ports via `.env.worktree`. Main checkouts use `.env`.

`make dev` auto-detects worktrees and handles everything. For explicit control:

```bash
make worktree-env       # Generate .env.worktree with unique DB/ports
make setup-worktree     # Setup using .env.worktree
make start-worktree     # Start using .env.worktree
```

## Coding Rules

- TypeScript strict mode is enabled; keep types explicit.
- Go code follows standard Go conventions (gofmt, go vet).
- Keep comments in code **English only**.
- Prefer existing patterns/components over introducing parallel abstractions.
- Unless the user explicitly asks for backwards compatibility, do **not** add compatibility layers, fallback paths, dual-write logic, legacy adapters, or temporary shims.
- If a flow or API is being replaced and the product is not yet live, prefer removing the old path instead of preserving both old and new behavior.
- Avoid broad refactors unless required by the task.
- New global (pre-workspace) routes MUST use a single word (`/login`, `/inbox`) or a `/{noun}/{verb}` pair (`/workspaces/new`). NEVER add hyphenated word-group root routes (`/new-workspace`, `/create-team`) — they collide with common user workspace names and force endless reserved-slug audits. Reserving the noun (`workspaces`) automatically protects the entire `/workspaces/*` subtree.

### Backend Handler UUID Parsing Convention

Every Go handler in `server/internal/handler/` follows these rules. The convention exists because `util.ParseUUID` used to silently return a zero UUID on invalid input, which caused #1661 — a `DELETE` returning 204 success while the SQL `DELETE` matched zero rows.

- **Resource path params that accept either a UUID or a human-readable identifier** (e.g. `chi.URLParam(r, "id")` for an issue, which accepts both `MUL-123` and a UUID) MUST be resolved through the dedicated loader (`loadIssueForUser` / `loadSkillForUser` / `loadAgentForUser` / `requireDaemonRuntimeAccess`). After resolution, all subsequent DB calls — especially `Queries.Delete*` / `Queries.Update*` — MUST use `entity.ID` from the resolved object. Never round-trip the raw URL string through `parseUUID` for a write query.
- **Pure-UUID inputs from request boundaries** (URL params that are always UUIDs, request body fields, query params, headers) MUST be validated with `parseUUIDOrBadRequest(w, s, fieldName)`. On invalid input it writes a 400 and returns `ok=false` — return immediately.
- **Trusted UUID round-trips** (sqlc-returned UUIDs being passed back into queries, test fixtures) use `parseUUID(s)` which calls `util.MustParseUUID` and panics on invalid input. A panic here means an unguarded user-input string slipped in — that is a real bug. `chi`'s `middleware.Recoverer` translates the panic into a 500 so the process keeps running.
- **`util.ParseUUID(s) (pgtype.UUID, error)`** is the only safe variant outside the handler package. Always check the error.

When adding a `Queries.Delete*` or `Queries.Update*` call, ask: "Where did this UUID come from?" If the answer is "raw user input that hasn't been validated," route it through `parseUUIDOrBadRequest` or a loader first.

### Package Boundary Rules

These are hard constraints. Violating them breaks the cross-platform architecture:

- `packages/core/` — zero react-dom, zero localStorage (use StorageAdapter), zero process.env, zero UI libraries. **All shared Zustand stores live here**, even view-related ones (filters, view modes) — stores are pure state, not UI.
- `packages/ui/` — zero `@multica/core` imports (pure UI, no business logic).
- `packages/views/` — zero `next/*` imports, zero `react-router-dom` imports, zero stores. Use `NavigationAdapter` for all routing.
- `apps/web/platform/` — the only place for Next.js APIs (`next/navigation`).
- `apps/desktop/src/renderer/src/platform/` — the only place for react-router-dom navigation wiring.

### The No-Duplication Rule

**If the same logic exists in both apps, it must be extracted to a shared package.**

This applies to everything: components, hooks, guards, providers, utility functions. The decision process:

1. Does this code depend on Next.js or Electron APIs? → Keep in the respective app.
2. Does it depend on `react-router-dom` or `next/navigation`? → Keep in app's `platform/` layer.
3. Everything else → belongs in `packages/core/` (headless logic) or `packages/views/` (UI components).

When the two apps need different behavior for the same concept (e.g., different loading UI), extract the shared logic into a component with props/slots for the differences. Don't duplicate the logic.

### Cross-Platform Development Rules

When adding a new page or feature:

1. **New page component** → add to `packages/views/<domain>/`. Never import from `next/*` or `react-router-dom`.
2. **Wire it in both apps** → add a route in `apps/web/app/` (Next.js page file) AND in the desktop router. **Exception**: pre-workspace transition flows (create workspace, accept invite) are NOT routes on desktop — they're `WindowOverlay` state. See *Desktop-specific Rules → Route categories*.
3. **Navigation** → use `useNavigation().push()` or `<AppLink>`. Never use framework-specific link/router APIs in shared code.
4. **Shared guards/providers** → use `DashboardGuard` from `packages/views/layout/`. Don't create separate guard logic per app.
5. **Platform-specific UI** → if a feature is web-only or desktop-only, keep it in the respective app. Use props slots (`extra`, `topSlot`) on shared layout components to inject platform-specific UI.
6. **New hooks that need workspace context** → accept `wsId` as parameter instead of reading from `useWorkspaceId()` Context, so they work both inside and outside `WorkspaceIdProvider`.

### CSS Architecture

Both apps share the same CSS foundation from `packages/ui/styles/`.

- **Design tokens** → use semantic tokens (`bg-background`, `text-muted-foreground`). Never use hardcoded Tailwind colors (`text-red-500`, `bg-gray-100`).
- **Shared styles** → `packages/ui/styles/`. Never duplicate scrollbar styling, keyframes, or base layer rules in app CSS.
- **`@source` directives** → both apps scan shared packages so Tailwind sees all class names.

## Desktop-specific Rules

These rules apply to `apps/desktop/` only. Web has different constraints (URL bar, SSR, no tabs) and doesn't share these concerns. Every rule in this section was added after a concrete bug — treat them as enforced, not suggestions.

### Route categories

Every path in the desktop app falls into exactly one category. Choosing the wrong one reproduces bugs we've already fixed.

- **Session routes** — workspace-scoped pages (`/:slug/issues`, `/:slug/settings`). Rendered by the per-tab memory router under `WorkspaceRouteLayout`. These are legitimate tab destinations.
- **Transition flows** — pre-workspace / one-shot actions (create workspace, accept invite). **NOT routes.** They live as `WindowOverlay` state, dispatched when the navigation adapter sees `push('/workspaces/new')` or `push('/invite/<id>')`. The shared view (`NewWorkspacePage`, `InvitePage`) is the content; the overlay wrapper supplies platform chrome.
- **Error / stale states** — "workspace not available", tabs pointing at a revoked workspace. **NOT pages.** `WorkspaceRouteLayout` auto-heals by dropping the stale tab group from the store; the user never lands on an explicit error screen. Web keeps `NoAccessPage` (shareable URL makes the error state meaningful); desktop has no URL bar so stale = heal silently.

**Adding a new pre-workspace flow on desktop**: register a new `WindowOverlay` type in `stores/window-overlay-store.ts`. Do NOT add it to `routes.tsx`. If a shared view needs the flow on both platforms, add the route on web (`apps/web/app/(auth)/...`) AND the overlay type on desktop — the shared view component is identical.

### Workspace context

`setCurrentWorkspace(slug, uuid)` from `@multica/core/platform` is the single source of truth for the active workspace. `WorkspaceRouteLayout` sets it on mount; unmount does NOT clear it. Code that leaves workspace context (leave/delete workspace, force-navigate to overlay) must call `setCurrentWorkspace(null, null)` explicitly.

### Workspace destructive operations

Leave / Delete workspace flows must follow this order, otherwise concurrent refetches race and the renderer hard-reloads:

1. Read destination from cached workspace list.
2. `setCurrentWorkspace(null, null)`.
3. `navigation.push(destination)`.
4. THEN `await mutation.mutateAsync(workspaceId)`.

### Tab isolation

Tabs are grouped per workspace in `stores/tab-store.ts`. The TabBar shows only the active workspace's tabs; cross-workspace tab leakage is impossible by construction (no flat global tabs array).

Cross-workspace `push(path)` is detected by the navigation adapter (`platform/navigation.tsx`) and translated into `switchWorkspace(slug, targetPath)` — NOT a navigation within the current tab's router. Don't bypass the adapter; always go through `useNavigation()` from shared code.

### Drag region (macOS)

Every full-window desktop view (anything outside the dashboard shell) must mount `<DragStrip />` from `@multica/views/platform` as the first flex child of the page root, otherwise users can't drag the window. Interactive UI inside the top 48px needs `WebkitAppRegion: "no-drag"` to stay clickable.

## UI/UX Rules

- Prefer shadcn components over custom implementations. Install via `pnpm ui:add <component>` from project root — adds to `packages/ui/components/ui/`. All components use Base UI primitives (`@base-ui/react`), not Radix.
- Use shadcn design tokens for styling. Avoid hardcoded color values.
- Do not introduce extra state (useState, context, reducers) unless explicitly required by the design.
- Pay close attention to **overflow** (truncate long text, scrollable containers), **alignment**, and **spacing** consistency.
- **If a component is identical between web and desktop, it belongs in a shared package.** Do not copy-paste between apps.

## Testing Rules

### Where to write tests

Tests follow the code, not the app. This is the most important testing principle in this monorepo:

| What you're testing | Where the test lives | Why |
|---|---|---|
| Shared business logic (stores, queries, hooks) | `packages/core/*.test.ts` | No DOM needed, pure logic |
| Shared UI components (pages, forms, modals) | `packages/views/*.test.tsx` | jsdom, no framework mocks |
| Platform-specific wiring (cookies, redirects, searchParams) | `apps/web/*.test.tsx` or `apps/desktop/` | Needs framework-specific mocks |
| End-to-end user flows | `e2e/*.spec.ts` | Real browser, real backend |

**Never test shared component behavior in an app's test file.** If a test requires mocking `next/navigation` or `react-router-dom` to test a component from `@multica/views`, the test is in the wrong place — move it to `packages/views/` and mock `@multica/core` instead.

### Test infrastructure

- `packages/core/` — Vitest, Node environment (no DOM)
- `packages/views/` — Vitest, jsdom environment, `@testing-library/react`
- `apps/web/` — Vitest, jsdom environment, framework-specific mocks
- `e2e/` — Playwright
- `server/` — Go standard `go test`

All test deps are in the pnpm catalog for unified versioning.

### Mocking conventions

- Mock `@multica/core` stores with `vi.hoisted()` + `Object.assign(selectorFn, { getState })` pattern (Zustand stores are both callable and have `.getState()`).
- Mock `@multica/core/api` for API calls.
- In `packages/views/` tests: never mock `next/*` or `react-router-dom` — those don't exist here.
- In `apps/web/` tests: mock framework-specific APIs only for platform-specific behavior.

### TDD workflow

1. Write failing test in the **correct package** first.
2. Write implementation.
3. Run `pnpm test` (Turborepo discovers all packages).
4. Green → done.

### Go tests

Standard `go test`. Tests should create their own fixture data in a test database.

### E2E tests

E2E tests should be self-contained. Use the `TestApiClient` fixture for data setup/teardown:

```typescript
import { loginAsDefault, createTestApi } from "./helpers";
import type { TestApiClient } from "./fixtures";

let api: TestApiClient;

test.beforeEach(async ({ page }) => {
  api = await createTestApi();
  await loginAsDefault(page);
});

test.afterEach(async () => {
  await api.cleanup();
});

test("example", async ({ page }) => {
  const issue = await api.createIssue("Test Issue");
  await page.goto(`/issues/${issue.id}`);
});
```

## Commit Rules

- Use atomic commits grouped by logical intent.
- Conventional format: `feat(scope)`, `fix(scope)`, `refactor(scope)`, `docs`, `test(scope)`, `chore(scope)`.

## Minimum Pre-Push Checks

```bash
make check    # Runs all checks: typecheck, unit tests, Go tests, E2E
```

Run verification only when the user explicitly asks for it.

For targeted checks when requested:
```bash
pnpm typecheck        # TypeScript type errors only
pnpm test             # TS unit tests only (Vitest, all packages)
make test             # Go tests only
pnpm exec playwright test   # E2E only (requires backend + frontend running)
```

## AI Agent Verification Loop

After writing or modifying code, always run the full verification pipeline:

```bash
make check
```

**Workflow:**
- Write code to satisfy the requirement
- Run `make check`
- If any step fails, read the error output, fix the code, and re-run
- Repeat until all checks pass
- Only then consider the task complete

**Quick iteration:** If you know only TypeScript or Go is affected, run individual checks first for faster feedback, then finish with a full `make check` before marking work complete.

## CLI Release

**Prerequisite:** A CLI release must accompany every Production deployment.

1. Create a tag on the `main` branch: `git tag v0.x.x`
2. Push the tag: `git push origin v0.x.x`
3. GitHub Actions automatically triggers `release.yml`: runs Go tests → GoReleaser builds multi-platform binaries → publishes to GitHub Releases + Homebrew tap

By default, bump the patch version each release (e.g. `v0.1.12` → `v0.1.13`), unless the user specifies a specific version.

## Multi-tenancy

All queries filter by `workspace_id`. Membership checks gate access. `X-Workspace-ID` header routes requests to the correct workspace.

## Agent Assignees

Assignees are polymorphic — can be a member or an agent. `assignee_type` + `assignee_id` on issues. Agents render with distinct styling (purple background, robot icon).
