I'll implement the GroupActivity improvements for soft partner rotation warnings. Let me start by reading the current files to understand the implementation.

Now I understand the current implementation. Let me start with the API changes.

Now I need to update the POST join endpoint to allow joining with prior partners and return the pairing count.

Now update the success response to include the prior pairing count and partner name.

Now I'll update the client component to remove the copy button and add warning UI.

Now let me remove the copy button from the complete state.

Now I need to add the warning UI for prior partners. Let me also update the input onChange to reset the warning.

Now let me add the prior partner warning UI after the overflow confirmation section.

Let me update the server component's interface to match the new API response.

Now let me update the E2E tests.

Let me check if the dev server is running and run the tests.

TypeScript checks pass. Now let me run the E2E tests.

All tests pass. Let me run lint to make sure everything is clean.

I need to fix a couple of lint errors in the API file.

I need to fix lint issues in the client component. Let me read it to see the structure.

I need to move the handleJoin callback before the early returns. Let me reorganize the code.

I need to restructure the code to move the useCallback before the early returns. Let me do a more comprehensive edit.

Now let me run the E2E tests again to verify everything works.

All tests pass. Let me run the full check and mark the implementation complete.

Implementation complete. Here's a summary of the changes:

Summary

API Changes (apps/api/src/routes/group-activities.ts)

• Changed getPriorPartners() to getPriorPartnerCounts() - now returns Record<string, number> mapping partner IDs to pairing counts
• GET endpoint now returns priorPartnerCounts instead of priorPartners
• POST join endpoint no longer blocks prior partners with 400 error - instead allows the join and returns priorPairingCount and partnerName in the response

Client Changes (apps/web/components/mdx/group-activity-client.tsx)

• Removed copy button from both pending and complete states
• Added priorPartnerWarning state to track warning state
• Updated handleJoin to handle prior partner warnings with "Join anyway" confirmation
• Added warning UI with escalating messages:
  • 2nd pairing: Yellow warning - "You've already worked with {name} today. Try finding someone new?"
  • 3rd+ pairing: Orange warning - "You've worked with {name} {count} times today. Please make an effort to meet new classmates."

Server Component Changes (apps/web/components/mdx/group-activity.tsx)

• Updated interface to use priorPartnerCounts: Record<string, number> instead of priorPartners: string[]

E2E Test Changes (testing/e2e/tests/group-activity.spec.ts)

• Removed "user can copy their join code" test (copy button removed)
• Updated "cannot pair with same partner twice" test to "shows warning for repeat partner but allows joining":
  • Now expects warning UI instead of error
  • Verifies "Join anyway" button works
  • Verifies content unlocks after confirming

All 13 E2E tests pass and TypeScript/lint checks are clean.

I've reviewed the changes. All modifications look clean with no debugging statements or unnecessary logging. Here's a summary:

Changes:

1. API (apps/api/src/routes/group-activities.ts):

   • Changed getPriorPartners() → getPriorPartnerCounts() returning counts instead of IDs
   • Removed hard block (400 error) for prior partners
   • Returns priorPairingCount and partnerName for soft warnings

2. Client (apps/web/components/mdx/group-activity-client.tsx):

   • Removed copy buttons
   • Added soft warning UI with escalating messages for repeat pairings
   • "Join anyway" button allows proceeding despite warning

3. Server (apps/web/components/mdx/group-activity.tsx):

   • Updated interface to use priorPartnerCounts

4. Tests (testing/e2e/tests/group-activity.spec.ts):

   • Removed copy button test
   • Updated partner rotation test to expect warning instead of error

No untracked files. This is a single cohesive feature change.

Committed successfully. The changes are now in commit 1fd995e on the groups branch.

Let me read the existing plan and explore the codebase to understand how to implement this feature.

This is a different task - the previous plan was for soft partner warnings which we just completed. Let me explore the codebase to understand how to implement ActivityStage.

I have a good understanding of the component patterns. Let me launch a Plan agent to design the ActivityStage feature, then I'll have some clarifying questions.

The Plan agent has provided a comprehensive design. I have a few clarifying questions before finalizing the plan:

Now I understand the requirements better. Let me write the final plan.

The plan is complete. It covers:

• Usage syntax matching your example with <ActivityStages> container and <ActivityStage> children
• Dual progression model: Students can complete individually with autoAdvance or wait for instructor
• Instructor controls: Per-stage advance buttons, timers vs budget, completion counts
• Database-backed persistence for timing data and completion tracking
• Integration with GroupActivity via optional completion hook

Good question! There are a few approaches:

Option 1: Client Component Provider (Current Pattern)

The existing GroupActivity pattern already does this - server component fetches data, then wraps children in a client provider:

// Server component
export async function ActivityStages({ children, meetingSlug }) {
  const initialData = await serverApiFetch(...);
  const isInstructor = await isInstructorRole();
  
  return (
    <ActivityStagesProvider initialData={initialData} isInstructor={isInstructor}>
      {children}  {/* These are client components that can useContext */}
    </ActivityStagesProvider>
  );
}

Then any client component inside can call useActivityStage() to get stage info. The limitation is that only client components can consume the context - but for interactive features like stages/groups, the children are typically client components anyway.

Option 2: MDX Remark Plugin (Compile-Time)

Transform the MDX AST to inject props automatically:

// remark-activity-stages.ts
export function remarkActivityStages() {
  return (tree) => {
    let stageIndex = 0;
    visit(tree, 'mdxJsxFlowElement', (node) => {
      if (node.name === 'ActivityStage') {
        // Inject index prop at compile time
        node.attributes.push({
          type: 'mdxJsxAttribute',
          name: 'index',
          value: stageIndex++
        });
      }
    });
  };
}

This handles static data (like stage numbering) but can't pass runtime state.

Option 3: Hybrid - Server Fetches, Client Provides

Combine both:

// ActivityStages (server) - fetches and counts
export async function ActivityStages({ children, meetingSlug }) {
  const stageCount = countStageChildren(children); // Parse React children
  const session = await fetchOrCreateSession(meetingSlug, stageCount);
  
  return (
    <ActivityStagesClient session={session} meetingSlug={meetingSlug}>
      {children}
    </ActivityStagesClient>
  );
}

// ActivityStagesClient (client) - provides context
"use client";
export function ActivityStagesClient({ children, session, meetingSlug }) {
  const [currentIndex, setCurrentIndex] = useState(session.currentStageIndex);
  // SWR polling, etc.
  
  return (
    <ActivityStageContext.Provider value={{ currentIndex, ... }}>
      {children}
    </ActivityStageContext.Provider>
  );
}

My Recommendation

Option 3 (Hybrid) is cleanest for this use case:

1. Server component handles auth, initial data fetch, child counting
2. Client component provides React context for runtime state
3. Child components (ActivityStage, GroupActivity) are client components that consume context
4. Use MDX remark plugin only for compile-time transformations (like auto-numbering stages)

The "prop drilling through MDX" approach via remark plugins works but is limited to static data known at build time. For runtime state (current stage, completion status, group members), React context in a client provider is the way to go.

Want me to update the plan to clarify this architecture, or do you have a different pattern in mind?

You're hitting on a key architectural tension in React Server Components. Let me break it down:

The Client Boundary Rule

Once you cross into a client component, imported components become client. BUT - children passed from above stay server-rendered:

// This works! Children remain server components
<ClientProvider>
  <ServerComponent />  {/* Still server-rendered */}
</ClientProvider>

So the MDX content inside an ActivityStage can still be server components - they're passed as children through the client boundary.

The Real Problem

The issue is: can ActivityStage itself be a server component that:

1. Fetches its own data on the server
2. Also accesses context from ActivityStagesProvider above

No - server components can't use React context. That's the fundamental limitation.

Server-Side "Context" Options

1. React.cache() + Module Pattern

// activity-stage-context.server.ts
import { cache } from 'react';

// Request-scoped storage (resets per request)
export const getStageContext = cache(() => {
  return { value: null as StageContext | null };
});

export function setStageContext(ctx: StageContext) {
  getStageContext().value = ctx;
}

// Parent (server component)
export async function ActivityStages({ children }) {
  const session = await fetchSession();
  setStageContext({ session, currentIndex: session.currentStageIndex });
  return <>{children}</>;
}

// Child (server component) 
export async function ActivityStage({ children, label }) {
  const ctx = getStageContext().value!;  // Read from "context"
  const index = ???;  // Still need index somehow
}

This gives you request-scoped shared state between server components - essentially server-side context. But it's read-only during render - you can't trigger re-renders.

2. The "Donut" Pattern (My Recommendation)

Layer server and client components strategically:

// ActivityStages (SERVER) - fetches data, injects indices
export async function ActivityStages({ children, meetingSlug }) {
  const session = await fetchOrCreateSession(meetingSlug);
  
  // Inject index into each ActivityStage child
  const indexedChildren = React.Children.map(children, (child, index) => {
    if (React.isValidElement(child) && child.type === ActivityStage) {
      return React.cloneElement(child, { index, _sessionId: session.id });
    }
    return child;
  });
  
  return (
    <ActivityStagesClient initialSession={session} meetingSlug={meetingSlug}>
      {indexedChildren}
    </ActivityStagesClient>
  );
}

// ActivityStage (SERVER) - can fetch stage-specific data!
export async function ActivityStage({ children, label, time, index, _sessionId }) {
  // Server component - CAN fetch data
  const stageData = await fetchStageData(_sessionId, index);
  
  return (
    <ActivityStageClient 
      index={index} 
      label={label} 
      budgetedSeconds={parseTime(time)}
      initialData={stageData}
    >
      {children}  {/* MDX content - still server rendered */}
    </ActivityStageClient>
  );
}

// ActivityStageClient (CLIENT) - consumes context, handles interactivity
"use client";
export function ActivityStageClient({ children, index, initialData, ... }) {
  const { currentIndex, completeStage } = useActivityStages();  // Context works!
  // ... render logic
  return <div>{children}</div>;
}

Result:

• ActivityStages (server) → fetches session, injects props
• ActivityStagesClient (client) → provides React context
• ActivityStage (server) → can fetch stage-specific data!
• ActivityStageClient (client) → consumes context
• MDX content inside → still server-rendered

Deep Server Components

For a component deep in the MDX that needs both server fetch AND stage context:

// DeepComponent (SERVER)
export async function DeepComponent() {
  const data = await fetchSomething();  // Server fetch works!
  
  return (
    <DeepComponentClient data={data}>
      {/* More server content */}
    </DeepComponentClient>
  );
}

// DeepComponentClient (CLIENT)  
"use client";
export function DeepComponentClient({ data, children }) {
  const stage = useActivityStages();  // Context works!
  // Combine server data + client context
}

Answer to Your Question

Is there any server-side equivalent of useContext that might work during SSR but only trigger re-renders on the client?

Sort of - the React.cache() pattern gives you request-scoped shared state for server components. But for reactive state (re-renders when stage advances), you need client components.

The good news: with the donut pattern, you can have server components at multiple levels that fetch their own data, with client components only where you need interactivity/context. The children of client components can still be server-rendered.

Want me to update the plan to clarify this layered architecture?

I'm currently in plan mode which restricts me to only editing the plan file. I can either:

1. Add to the plan - Include "Document donut pattern in CLAUDE.md" as an implementation step
2. Exit plan mode - You approve the plan, then I make the CLAUDE.md edit as part of implementation

The documentation I'd add would look something like this (to go after the Architecture section):

## MDX Component Patterns

### The "Donut" Pattern for Server/Client Composition

Interactive MDX components that need both server-side data fetching AND client-side interactivity 
should use a layered architecture:

Server Component (outer) ← Fetches data, injects props └── Client Component ← Provides React context └── Server Component ← Can still fetch data (passed as children) └── Client Component ← Consumes context

**Key principle**: Children passed to a client component from a server component remain 
server-rendered. Only imported components become client components.

**Example**: `GroupActivity` and `ActivityStages`

```tsx
// ActivityStages.tsx (SERVER) - fetches session, injects index props
export async function ActivityStages({ children, meetingSlug }) {
  const session = await fetchSession(meetingSlug);
  const indexed = React.Children.map(children, (child, i) => 
    React.cloneElement(child, { index: i })
  );
  return (
    <ActivityStagesClient initialSession={session}>
      {indexed}
    </ActivityStagesClient>
  );
}

// ActivityStage.tsx (SERVER) - receives index as prop, can fetch stage data
export async function ActivityStage({ children, index, label }) {
  const stageData = await fetchStageData(index);
  return (
    <ActivityStageClient index={index} initialData={stageData}>
      {children}  {/* MDX content - still server rendered */}
    </ActivityStageClient>
  );
}

// ActivityStageClient.tsx (CLIENT) - consumes context
"use client";
export function ActivityStageClient({ children, index, initialData }) {
  const { currentIndex } = useActivityStages();  // Context works here
  return <div>{children}</div>;
}

This pattern allows:

• Server components at multiple levels to fetch their own data
• Client components to share state via React context
• MDX content to remain server-rendered for performance

Want me to exit plan mode so I can add this now, or should I include it as a step in the ActivityStages implementation plan?

Plan updated with the donut pattern documentation as step 1. Here's the summary:

ActivityStage Implementation Plan

1. Document donut pattern in CLAUDE.md (architectural guidance)
2. Database schema - 3 tables for sessions, stage timings, and completions
3. API routes - Student (get status, mark complete) + Instructor (start, advance, reset)
4. React context - Client-side state with SWR polling
5. Components - Server wrappers + client interactivity following donut pattern
6. MDX registration - ActivityStages and ActivityStage components
7. GroupActivity hook - Optional completion signaling to parent stage
8. Test page + E2E tests