free-pro-contract-check - SKILL.md Agent Skill

name: "free-pro-contract-check" description: "Verify a change to the Free plugin does not break the window.PM contract that Pro depends on. Diffs window.PM exports, slot/filter/route registrations, externalized libs, and the shape of Free thunks/actions Pro consumes. TRIGGER when the diff touches views/assets/src/index.jsx, views/assets/src/hooks/useSlot.js, store/index.js, router/routeRegistry.js, or any file under @components/common that is re-exported via window.PM. Also TRIGGER when the user mentions Pro, asks 'will this break Pro', or invokes /free-pro-contract-check."

Free → Pro Contract Check

The Free plugin is the host; Pro (../pm-pro/) attaches at runtime via window.PM. Any change to that surface can break Pro.

Workflow

Identify touched contract surfaces. Read these files in the diff:
- views/assets/src/index.jsx — window.PM object literal
- views/assets/src/hooks/useSlot.js — registerSlot/registerFilter/applyFilters/doAction/addAction/Slot/useFilter/useSlotFills
- views/assets/src/store/index.js — store, injectReducer, resetProjectState
- views/assets/src/router/routeRegistry.js — registerRoute, useRegisteredRoutes
- views/assets/src/hooks/useNavRegistry.js — registerNavItem, useRegisteredNavItems
- Any file in views/assets/src/components/common/ listed under window.PM.components
- Any file in views/assets/src/components/ui/ listed under window.PM.ui
- Any file in views/assets/src/lib/ listed under window.PM.utils
Diff the window.PM shape.
```
git diff HEAD~1..HEAD -- views/assets/src/index.jsx | sed -n '/window\.PM/,/^}$/p'
```
Classify each delta:
- Add a new key — safe (additive).
- Remove a key — BREAKING; flag and require Pro coordination.
- Rename a key — BREAKING.
- Change a function signature — BREAKING unless backward-compatible (new optional arg only).
- Change a re-export source (e.g., shadcn primitive moved/renamed) — verify the same component is still exported under the same key.
Verify the Pro webpack externals still resolve. Read ../pm-pro/webpack.config.js:
- react, react-dom, react/jsx-runtime → React/ReactDOM/['PM', 'libs', 'ReactJsxRuntime']
- react-redux, react-router-dom, @reduxjs/toolkit, sonner → ['PM', 'libs', '*']
- Every @radix-ui/react-* Pro uses → ['PM', 'radix', '*']
- The function external maps @components/common/*, @components/ui/*, @lib/* resolved paths to ['PM', '...', '...']. If Free adds a new common/ui/lib re-export, Pro's map may need updating.
Check slot/filter names.
```
grep -rn "registerSlot\|registerFilter\|Slot name" views/assets/src/
```
- Slot names that Pro fills (search Pro repo): if Free removes a <Slot name="X" />, Pro's registerSlot('X', ...) becomes dead code.
- Filter names: same logic for useFilter('Y', ...) vs Pro's registerFilter('Y', ...).
- Both sides must agree on the string literal — typos break silently.
Check route registry shape. registerRoute(path, element):
- If signature changes, Pro breaks.
- If a previously-registered route is now declared statically in Free (the dynamicRoutes.some(r => r.path === ...) guards in index.jsx), confirm Pro's still-installed Pro-specific route doesn't clash.
Check Redux contract.
- injectReducer(key, reducer) shape unchanged.
- store.dispatch({ type: 'global/resetProjectState' }) — if the action type changes, Pro's listeners break.
- Any new Free thunk/action exposed under window.PM.thunks / .actions — additive only.
Output.

## Free → Pro contract diff

### Additive (safe)
- window.PM.foo — new field, no Pro impact.

### Breaking (requires Pro coordination)
- window.PM.bar — REMOVED. Pro repo `pm-pro/views/assets/src/.../X.jsx:Y` consumes it.

### Inspect manually
- Slot "task.detail.subtasks" body changed — Pro fill component may need to update props.

### Pro webpack externals
- All current externals still resolve.

Hard rules

Never rename or remove a window.PM.* key without coordinating with Pro.
Never change a slot/filter/route NAME — add a new one if shape changes.
Never stop externalizing a shared lib (React, Redux, Sonner, Radix) — duplicate instances break contexts.
Always add to .claude/rules/free-pro-bridge.md when introducing a new public surface.