diff --git a/scripts/diagnose-tsx.js b/scripts/diagnose-tsx.js
new file mode 100644
index 0000000..bd41a8d
--- /dev/null
+++ b/scripts/diagnose-tsx.js
@@ -0,0 +1,15 @@
+const fs = require('fs');
+const ts = require('typescript');
+const source = fs.readFileSync('src/app/(app)/maintainer/mentorship/page.tsx', 'utf8');
+const file = ts.createSourceFile(
+  'page.tsx',
+  source,
+  ts.ScriptTarget.Latest,
+  true,
+  ts.ScriptKind.TSX,
+);
+const diagnostics = file.parseDiagnostics.map((d) => ({
+  line: d.start ? file.getLineAndCharacterOfPosition(d.start).line + 1 : null,
+  message: d.messageText,
+}));
+console.log(JSON.stringify(diagnostics, null, 2));
diff --git a/src/app/(app)/dashboard/page.tsx b/src/app/(app)/dashboard/page.tsx
index 73aea65..9f5ff6c 100644
--- a/src/app/(app)/dashboard/page.tsx
+++ b/src/app/(app)/dashboard/page.tsx
@@ -2,6 +2,9 @@ import { Suspense } from 'react';
 import { getServerSupabase } from '@/lib/supabase/server';
 import { getServiceSupabase } from '@/lib/supabase/service';
 import { SyncButton } from './sync-button';
+import { GitHubPRsPanel } from './github-prs-panel';
+import MentorshipSessionsSidebar from '@/components/chat/MentorshipSessionsSidebar';
+import RecCards from './rec-cards';
 import LevelUpBanner from './level-up-banner';
 import { redirect } from 'next/navigation';
 import Link from 'next/link';
@@ -60,6 +63,10 @@ export default async function DashboardPage() {
           <StatsRow userId={user.id} profile={profile} />
         </Suspense>
 
+        <div className="mb-16">
+          <MentorshipSessionsSidebar />
+        </div>
+
         {/* Main Columns */}
         <div className="grid grid-cols-1 gap-16 lg:grid-cols-2">
           {/* Left Column */}
diff --git a/src/app/(app)/maintainer/mentorship/page.tsx b/src/app/(app)/maintainer/mentorship/page.tsx
new file mode 100644
index 0000000..b422cf1
--- /dev/null
+++ b/src/app/(app)/maintainer/mentorship/page.tsx
@@ -0,0 +1,105 @@
+import { getServerSupabase } from '@/lib/supabase/server';
+import { getServiceSupabase } from '@/lib/supabase/service';
+import { isUserMaintainer } from '@/lib/maintainer/detect';
+import { redirect } from 'next/navigation';
+
+export const dynamic = 'force-dynamic';
+
+type ProfileLink = { github_handle: string | null; display_name: string | null };
+
+type SessionRow = {
+  id: number;
+  level: number;
+  started_at: string;
+  ended_at: string | null;
+  mentor: ProfileLink[] | null;
+  mentee: ProfileLink[] | null;
+};
+
+export default async function MaintainerMentorshipPage() {
+  const supabase = getServerSupabase();
+  if (!supabase) {
+    redirect('/dashboard');
+  }
+
+  const {
+    data: { user },
+  } = await supabase.auth.getUser();
+  if (!user) redirect('/dashboard');
+  if (!(await isUserMaintainer(user.id))) redirect('/dashboard');
+
+  const service = getServiceSupabase();
+  if (!service) {
+    return <div className="p-8 text-white">Supabase service client not configured.</div>;
+  }
+
+  const { data: sessions } = await service
+    .from('mentorship_sessions')
+    .select(
+      'id, level, started_at, ended_at, mentor:profiles(github_handle, display_name), mentee:profiles(github_handle, display_name)',
+    )
+    .order('started_at', { ascending: false });
+
+  return (
+    <div className="min-h-screen bg-[#111318] p-8 text-white">
+      <div className="mx-auto max-w-6xl space-y-8">
+        <header className="rounded-3xl border border-slate-800 bg-slate-950 p-8">
+          <h1 className="text-3xl font-semibold">Mentorship session logs</h1>
+          <p className="mt-2 text-sm text-slate-400">
+            Review past mentorship sessions, audit transcripts, and export logs as JSON or CSV.
+          </p>
+          <div className="mt-4 flex flex-wrap gap-3">
+            <a
+              href="/api/mentorship/logs?format=json"
+              className="rounded-2xl bg-sky-600 px-4 py-2 text-sm font-semibold text-white hover:bg-sky-500"
+            >
+              Export JSON
+            </a>
+            <a
+              href="/api/mentorship/logs?format=csv"
+              className="rounded-2xl bg-slate-800 px-4 py-2 text-sm font-semibold text-white hover:bg-slate-700"
+            >
+              Export CSV
+            </a>
+          </div>
+        </header>
+
+        <div className="space-y-4">
+          {(sessions ?? []).map((session: SessionRow) => {
+            const mentor = session.mentor?.[0];
+            const mentee = session.mentee?.[0];
+
+            return (
+              <div
+                key={session.id}
+                className="rounded-3xl border border-slate-800 bg-slate-900 p-6"
+              >
+                <div className="flex flex-col gap-3 sm:flex-row sm:items-center sm:justify-between">
+                  <div>
+                    <h2 className="text-xl font-semibold text-white">Session #{session.id}</h2>
+                    <p className="text-sm text-slate-400">
+                      Mentor: {mentor?.display_name ?? mentor?.github_handle ?? 'Unknown'} · Mentee:{' '}
+                      {mentee?.display_name ?? mentee?.github_handle ?? 'Unknown'}
+                    </p>
+                  </div>
+                  <span className="rounded-full bg-slate-800 px-3 py-1 text-xs uppercase tracking-widest text-slate-400">
+                    Level {session.level}
+                  </span>
+                </div>
+                <div className="mt-4 text-sm text-slate-500">
+                  Started {new Date(session.started_at).toLocaleString()} · Ended{' '}
+                  {session.ended_at ? new Date(session.ended_at).toLocaleString() : 'active'}
+                </div>
+              </div>
+            );
+          })}
+          {(sessions ?? []).length === 0 && (
+            <div className="rounded-3xl border border-slate-800 bg-slate-900 p-6 text-slate-500">
+              No mentorship sessions recorded yet.
+            </div>
+          )}
+        </div>
+      </div>
+    </div>
+  );
+}
diff --git a/src/app/(app)/maintainer/page.tsx b/src/app/(app)/maintainer/page.tsx
index 9496e2d..7d5a99a 100644
--- a/src/app/(app)/maintainer/page.tsx
+++ b/src/app/(app)/maintainer/page.tsx
@@ -158,6 +158,12 @@ export default async function MaintainerPage({
           >
             Community links →
           </Link>
+          <Link
+            href={`/maintainer/mentorship?install=${activeInstallId}`}
+            className="rounded-lg border border-zinc-700 px-3 py-1 text-zinc-300 hover:border-zinc-600"
+          >
+            Mentorship logs →
+          </Link>
         </div>
 
         <p className="mb-4 text-xs text-zinc-500">
diff --git a/src/app/[handle]/page.tsx b/src/app/[handle]/page.tsx
index 24705ad..6501140 100644
--- a/src/app/[handle]/page.tsx
+++ b/src/app/[handle]/page.tsx
@@ -4,6 +4,7 @@ import { cacheGet, cacheSet } from '@/lib/cache';
 import Link from 'next/link';
 import { ExternalLink, ArrowLeft } from 'lucide-react';
 import { CopyButton } from '@/components/copy-button';
+import StartMentorshipChatButton from '@/components/chat/StartMentorshipChatButton';
 
 export const revalidate = 300;
 
@@ -383,6 +384,7 @@ export default async function PublicProfile({ params }: { params: { handle: stri
                     textToCopy={`${process.env.NEXT_PUBLIC_APP_URL ?? 'https://mergeship.dev'}/@${profile.githubHandle}`}
                   />
                 </p>
+                <StartMentorshipChatButton mentorHandle={profile.githubHandle} />
                 <div className="flex flex-wrap items-center gap-4 text-[11px] uppercase tracking-widest text-zinc-400">
                   <span>
                     <span className="font-bold text-white">{profile.prsMerged}</span> PRS MERGED
diff --git a/src/app/api/inngest/route.ts b/src/app/api/inngest/route.ts
index 29260f6..37a7d0b 100644
--- a/src/app/api/inngest/route.ts
+++ b/src/app/api/inngest/route.ts
@@ -26,6 +26,7 @@ import { githubStatsSync } from '@/inngest/functions/github-stats-sync';
 import { mentorPostComment } from '@/inngest/functions/mentor-post-comment';
 import { processIssueEvent } from '@/inngest/functions/process-issue-event';
 import { processIssueCommentEvent } from '@/inngest/functions/process-issue-comment-event';
+import { mentorship } from '@/inngest/functions/mentorship';
 
 export const { GET, POST, PUT } = serve({
   client: inngest,
@@ -50,5 +51,6 @@ export const { GET, POST, PUT } = serve({
     mentorPostComment,
     processIssueEvent,
     processIssueCommentEvent,
+    mentorship,
   ],
 });
diff --git a/src/app/api/mentorship/create/route.ts b/src/app/api/mentorship/create/route.ts
new file mode 100644
index 0000000..e05158f
--- /dev/null
+++ b/src/app/api/mentorship/create/route.ts
@@ -0,0 +1,51 @@
+import { NextResponse } from 'next/server';
+import { getServerSupabase } from '@/lib/supabase/server';
+import { getServiceSupabase } from '@/lib/supabase/service';
+import { createMentorshipSession } from '@/lib/chat';
+
+export async function POST(req: Request) {
+  const supabase = getServerSupabase();
+  if (!supabase) {
+    return NextResponse.json({ error: 'Supabase not configured' }, { status: 500 });
+  }
+
+  const {
+    data: { user },
+  } = await supabase.auth.getUser();
+  if (!user) {
+    return NextResponse.json({ error: 'not_authenticated' }, { status: 401 });
+  }
+
+  const body = await req.json().catch(() => null);
+  const mentorHandle = body?.mentorHandle;
+  if (!mentorHandle || typeof mentorHandle !== 'string') {
+    return NextResponse.json({ error: 'mentorHandle is required' }, { status: 400 });
+  }
+
+  const service = getServiceSupabase();
+  if (!service) {
+    return NextResponse.json({ error: 'Supabase service client not configured' }, { status: 500 });
+  }
+
+  const { data: mentorProfile, error: mentorError } = await service
+    .from('profiles')
+    .select('id')
+    .eq('github_handle', mentorHandle)
+    .maybeSingle();
+
+  if (mentorError || !mentorProfile) {
+    return NextResponse.json({ error: 'mentor_not_found' }, { status: 404 });
+  }
+
+  if (mentorProfile.id === user.id) {
+    return NextResponse.json({ error: 'cannot_start_chat_with_self' }, { status: 400 });
+  }
+
+  const session = await createMentorshipSession({
+    mentorId: mentorProfile.id,
+    menteeId: user.id,
+    level: 1,
+  });
+
+  return NextResponse.json({ session });
+}
diff --git a/src/app/api/mentorship/logs/route.ts b/src/app/api/mentorship/logs/route.ts
new file mode 100644
index 0000000..dafd3f0
--- /dev/null
+++ b/src/app/api/mentorship/logs/route.ts
@@ -0,0 +1,116 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { getServerSupabase } from '@/lib/supabase/server';
+import { getServiceSupabase } from '@/lib/supabase/service';
+import { isUserMaintainer } from '@/lib/maintainer/detect';
+
+function csvEscape(value: string | null | undefined) {
+  const text = value ?? '';
+  return `"${text.replace(/"/g, '""')}"`;
+}
+
+export async function GET(req: NextRequest) {
+  const supabase = getServerSupabase();
+  if (!supabase) {
+    return NextResponse.json({ error: 'Supabase not configured' }, { status: 500 });
+  }
+
+  const {
+    data: { user },
+  } = await supabase.auth.getUser();
+  if (!user) {
+    return NextResponse.json({ error: 'not_authenticated' }, { status: 401 });
+  }
+
+  if (!(await isUserMaintainer(user.id))) {
+    return NextResponse.json({ error: 'not_authorised' }, { status: 403 });
+  }
+
+  const service = getServiceSupabase();
+  if (!service) {
+    return NextResponse.json({ error: 'Supabase service client not configured' }, { status: 500 });
+  }
+
+  const format = req.nextUrl.searchParams.get('format') ?? 'json';
+  const { data: sessions, error: sessionsError } = await service
+    .from('mentorship_sessions')
+    .select(
+      'id, mentor_id, mentee_id, level, started_at, ended_at, mentor:profiles(id, github_handle, display_name), mentee:profiles(id, github_handle, display_name)',
+    )
+    .order('started_at', { ascending: false });
+
+  if (sessionsError) {
+    return NextResponse.json({ error: sessionsError.message }, { status: 500 });
+  }
+
+  const sessionIds = (sessions ?? []).map((session) => session.id);
+  const { data: messages, error: messagesError } = await service
+    .from('messages')
+    .select(
+      'id, session_id, sender_id, content, timestamp, read_status, sender:profiles(id, github_handle)',
+    )
+    .in('session_id', sessionIds)
+    .order('timestamp', { ascending: true });
+
+  if (messagesError) {
+    return NextResponse.json({ error: messagesError.message }, { status: 500 });
+  }
+
+  const payload = {
+    sessions: sessions ?? [],
+    messages: messages ?? [],
+  };
+
+  if (format === 'csv') {
+    const rows = [
+      'session_id,mentor_handle,mentee_handle,level,started_at,ended_at,message_id,sender_handle,message,timestamp,read_status',
+    ];
+    for (const session of payload.sessions) {
+      const sessionMessages = payload.messages.filter(
+        (message) => message.session_id === session.id,
+      );
+      if (sessionMessages.length === 0) {
+        rows.push(
+          [
+            session.id,
+            session.mentor?.[0]?.github_handle ?? '',
+            session.mentee?.[0]?.github_handle ?? '',
+            session.level,
+            session.started_at,
+            session.ended_at ?? '',
+            '',
+            '',
+            '',
+            '',
+            '',
+          ].join(','),
+        );
+      }
+      for (const message of sessionMessages) {
+        rows.push(
+          [
+            session.id,
+            session.mentor?.[0]?.github_handle ?? '',
+            session.mentee?.[0]?.github_handle ?? '',
+            session.level,
+            session.started_at,
+            session.ended_at ?? '',
+            message.id,
+            message.sender?.[0]?.github_handle ?? '',
+            csvEscape(message.content),
+            message.timestamp,
+            message.read_status,
+          ].join(','),
+        );
+      }
+    }
+
+    return new Response(rows.join('\n'), {
+      headers: {
+        'Content-Type': 'text/csv; charset=utf-8',
+        'Content-Disposition': 'attachment; filename="mentorship-logs.csv"',
+      },
+    });
+  }
+
+  return NextResponse.json(payload);
+}
diff --git a/src/app/api/mentorship/message/route.ts b/src/app/api/mentorship/message/route.ts
new file mode 100644
index 0000000..4ead3a8
--- /dev/null
+++ b/src/app/api/mentorship/message/route.ts
@@ -0,0 +1,33 @@
+import { NextResponse } from 'next/server';
+import { getServerSupabase } from '@/lib/supabase/server';
+import { appendMentorshipMessage } from '@/lib/chat';
+
+export async function POST(req: Request) {
+  const supabase = getServerSupabase();
+  if (!supabase) {
+    return NextResponse.json({ error: 'Supabase not configured' }, { status: 500 });
+  }
+
+  const {
+    data: { user },
+  } = await supabase.auth.getUser();
+  if (!user) {
+    return NextResponse.json({ error: 'not_authenticated' }, { status: 401 });
+  }
+
+  const body = await req.json().catch(() => null);
+  const sessionId = Number(body?.sessionId);
+  const content = body?.content;
+
+  if (!sessionId || !content || typeof content !== 'string') {
+    return NextResponse.json({ error: 'sessionId and content are required' }, { status: 400 });
+  }
+
+  const message = await appendMentorshipMessage({
+    sessionId,
+    senderId: user.id,
+    content: content.trim(),
+  });
+
+  return NextResponse.json({ message });
+}
diff --git a/src/app/api/mentorship/messages/route.ts b/src/app/api/mentorship/messages/route.ts
new file mode 100644
index 0000000..da1e7d3
--- /dev/null
+++ b/src/app/api/mentorship/messages/route.ts
@@ -0,0 +1,41 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { getServerSupabase } from '@/lib/supabase/server';
+import { getServiceSupabase } from '@/lib/supabase/service';
+
+export async function GET(req: NextRequest) {
+  const supabase = getServerSupabase();
+  if (!supabase) {
+    return NextResponse.json({ error: 'Supabase not configured' }, { status: 500 });
+  }
+
+  const {
+    data: { user },
+  } = await supabase.auth.getUser();
+  if (!user) {
+    return NextResponse.json({ error: 'not_authenticated' }, { status: 401 });
+  }
+
+  const sessionId = req.nextUrl.searchParams.get('sessionId');
+  if (!sessionId) {
+    return NextResponse.json({ error: 'sessionId is required' }, { status: 400 });
+  }
+
+  const service = getServiceSupabase();
+  if (!service) {
+    return NextResponse.json({ error: 'Supabase service client not configured' }, { status: 500 });
+  }
+
+  const { data: messages, error } = await service
+    .from('messages')
+    .select(
+      'id, session_id, sender_id, content, timestamp, read_status, sender:profiles(id, github_handle, display_name)',
+    )
+    .eq('session_id', Number(sessionId))
+    .order('timestamp', { ascending: true });
+
+  if (error) {
+    return NextResponse.json({ error: error.message }, { status: 500 });
+  }
+
+  return NextResponse.json(messages ?? []);
+}
diff --git a/src/app/api/mentorship/sessions/route.ts b/src/app/api/mentorship/sessions/route.ts
new file mode 100644
index 0000000..aa38afb
--- /dev/null
+++ b/src/app/api/mentorship/sessions/route.ts
@@ -0,0 +1,38 @@
+import { NextResponse } from 'next/server';
+import { getServerSupabase } from '@/lib/supabase/server';
+import { getServiceSupabase } from '@/lib/supabase/service';
+
+export async function GET(req: Request) {
+  const supabase = getServerSupabase();
+  if (!supabase) {
+    return NextResponse.json({ error: 'Supabase not configured' }, { status: 500 });
+  }
+
+  const {
+    data: { user },
+  } = await supabase.auth.getUser();
+  if (!user) {
+    return NextResponse.json({ error: 'not_authenticated' }, { status: 401 });
+  }
+
+  const service = getServiceSupabase();
+  if (!service) {
+    return NextResponse.json({ error: 'Supabase service client not configured' }, { status: 500 });
+  }
+
+  const filter = `mentor_id.eq.${user.id},mentee_id.eq.${user.id}`;
+  const { data: sessions, error } = await service
+    .from('mentorship_sessions')
+    .select(
+      'id, level, started_at, ended_at, mentor:profiles(id, github_handle, display_name, level), mentee:profiles(id, github_handle, display_name, level)',
+    )
+    .or(filter)
+    .eq('ended_at', null)
+    .order('started_at', { ascending: false });
+
+  if (error) {
+    return NextResponse.json({ error: error.message }, { status: 500 });
+  }
+
+  return NextResponse.json({ sessions: sessions ?? [] });
+}
diff --git a/src/app/mentorship/[sessionId]/page.tsx b/src/app/mentorship/[sessionId]/page.tsx
new file mode 100644
index 0000000..47f5611
--- /dev/null
+++ b/src/app/mentorship/[sessionId]/page.tsx
@@ -0,0 +1,66 @@
+import { getServerSupabase } from '@/lib/supabase/server';
+import { redirect } from 'next/navigation';
+import ChatPanel from '@/components/chat/ChatPanel';
+import MentorshipSessionsSidebar from '@/components/chat/MentorshipSessionsSidebar';
+
+export const dynamic = 'force-dynamic';
+
+export default async function MentorshipSessionPage({ params }: { params: { sessionId: string } }) {
+  const supabase = getServerSupabase();
+  if (!supabase) {
+    redirect('/dashboard');
+  }
+
+  const {
+    data: { user },
+  } = await supabase.auth.getUser();
+  if (!user) {
+    redirect('/');
+  }
+
+  const { data: sessionData } = await supabase
+    .from('mentorship_sessions')
+    .select(
+      'id, mentor_id, mentee_id, level, mentor:profiles(id, github_handle), mentee:profiles(id, github_handle)',
+    )
+    .eq('id', Number(params.sessionId))
+    .maybeSingle();
+
+  if (!sessionData) {
+    redirect('/dashboard');
+  }
+
+  const mentorHandle = sessionData.mentor?.[0]?.github_handle ?? 'mentor';
+  const menteeHandle = sessionData.mentee?.[0]?.github_handle ?? 'mentee';
+
+  return (
+    <div className="min-h-screen bg-[#111318] p-6 text-white">
+      <div className="mx-auto max-w-7xl space-y-10">
+        <div className="flex flex-col gap-4 rounded-3xl border border-slate-800 bg-slate-950 p-6">
+          <div className="flex flex-col gap-2 sm:flex-row sm:items-center sm:justify-between">
+            <div>
+              <p className="text-xs uppercase tracking-widest text-slate-500">Mentorship session</p>
+              <h1 className="text-3xl font-semibold">Session #{params.sessionId}</h1>
+            </div>
+            <div className="rounded-full bg-slate-900 px-4 py-2 text-sm text-slate-300">
+              Level {sessionData.level}
+            </div>
+          </div>
+          <p className="text-sm text-slate-400">
+            Live mentorship chat with logs stored for transparency and maintainers.
+          </p>
+        </div>
+
+        <div className="grid gap-8 xl:grid-cols-[1.4fr_0.8fr]">
+          <ChatPanel
+            sessionId={params.sessionId}
+            currentUserId={user.id}
+            mentorHandle={mentorHandle}
+            menteeHandle={menteeHandle}
+          />
+          <MentorshipSessionsSidebar />
+        </div>
+      </div>
+    </div>
+  );
+}
diff --git a/src/components/chat/ChatPanel.tsx b/src/components/chat/ChatPanel.tsx
new file mode 100644
index 0000000..376da90
--- /dev/null
+++ b/src/components/chat/ChatPanel.tsx
@@ -0,0 +1,235 @@
+'use client';
+
+import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
+import { getBrowserSupabase, isSupabaseConfigured } from '@/lib/supabase/browser';
+
+type ChatMessage = {
+  id: number;
+  session_id: number;
+  sender_id: string;
+  content: string;
+  timestamp: string;
+  read_status: 'unread' | 'read';
+  sender?: {
+    github_handle: string;
+    display_name: string | null;
+  };
+};
+
+type ChatPanelProps = {
+  sessionId: string;
+  currentUserId: string;
+  mentorHandle: string;
+  menteeHandle: string;
+};
+
+export default function ChatPanel({
+  sessionId,
+  currentUserId,
+  mentorHandle,
+  menteeHandle,
+}: ChatPanelProps) {
+  const [messages, setMessages] = useState<ChatMessage[]>([]);
+  const [messageText, setMessageText] = useState('');
+  const [typingUsers, setTypingUsers] = useState<string[]>([]);
+  const [realtimeEnabled, setRealtimeEnabled] = useState(false);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+  const socketRef = useRef<WebSocket | null>(null);
+  const isSupabase = isSupabaseConfigured();
+
+  const displayName = useMemo(() => {
+    if (currentUserId) {
+      return currentUserId;
+    }
+    return 'you';
+  }, [currentUserId]);
+
+  const loadMessages = useCallback(async () => {
+    try {
+      const res = await fetch(
+        `/api/mentorship/messages?sessionId=${encodeURIComponent(sessionId)}`,
+      );
+      if (!res.ok) {
+        throw new Error('Failed to load chat history');
+      }
+      setMessages(await res.json());
+    } catch (err) {
+      setError((err as Error).message);
+    } finally {
+      setLoading(false);
+    }
+  }, [sessionId]);
+
+  useEffect(() => {
+    loadMessages();
+  }, [loadMessages]);
+
+  useEffect(() => {
+    let channel: any;
+    let ws: WebSocket | null = null;
+
+    if (isSupabase) {
+      const supabase = getBrowserSupabase();
+      if (supabase) {
+        channel = supabase.channel(`mentorship:${sessionId}`);
+
+        channel.on(
+          'postgres_changes',
+          {
+            event: 'INSERT',
+            schema: 'public',
+            table: 'messages',
+            filter: `session_id=eq.${sessionId}`,
+          },
+          (payload: any) => {
+            setMessages((current) => [...current, payload.new]);
+          },
+        );
+
+        channel.on('presence', { event: 'sync' }, () => {
+          const state = (channel as any).presenceState?.() ?? {};
+          const people = Object.values(state)
+            .flatMap((members: any) =>
+              members.map((member: any) => member.user_id ?? member.user.user_id),
+            )
+            .filter(Boolean) as string[];
+          setTypingUsers(people);
+        });
+
+        channel.subscribe().then(() => setRealtimeEnabled(true));
+      }
+    } else if (typeof window !== 'undefined' && process.env.NEXT_PUBLIC_CHAT_WS_URL) {
+      const url = new URL(process.env.NEXT_PUBLIC_CHAT_WS_URL, window.location.href);
+      url.searchParams.set('sessionId', sessionId);
+      ws = new WebSocket(url.toString());
+      socketRef.current = ws;
+
+      ws.addEventListener('message', (event) => {
+        try {
+          const payload = JSON.parse(event.data);
+          if (payload.type === 'message') {
+            setMessages((current) => [...current, payload.message]);
+          }
+          if (payload.type === 'presence') {
+            setTypingUsers(payload.users ?? []);
+          }
+        } catch {
+          // ignore malformed socket payloads
+        }
+      });
+      ws.addEventListener('open', () => setRealtimeEnabled(true));
+    }
+
+    return () => {
+      if (channel) {
+        channel.unsubscribe();
+      }
+      if (ws) {
+        ws.close();
+      }
+    };
+  }, [isSupabase, sessionId]);
+
+  const sendMessage = async () => {
+    if (!messageText.trim()) return;
+    setError(null);
+
+    try {
+      const res = await fetch('/api/mentorship/message', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ sessionId: Number(sessionId), content: messageText.trim() }),
+      });
+      if (!res.ok) {
+        throw new Error('Unable to send message');
+      }
+      setMessageText('');
+    } catch (err) {
+      setError((err as Error).message);
+    }
+  };
+
+  const typingLabel = typingUsers.length
+    ? `${typingUsers.filter((id) => id !== currentUserId).join(', ')} is typing...`
+    : '';
+
+  return (
+    <div className="rounded-3xl border border-slate-800 bg-slate-950 p-6 shadow-xl shadow-black/10">
+      <div className="mb-6 flex items-center justify-between gap-3">
+        <div>
+          <p className="text-xs uppercase tracking-widest text-slate-500">Mentorship chat</p>
+          <h2 className="text-xl font-semibold text-white">
+            {mentorHandle} ↔ {menteeHandle}
+          </h2>
+          <p className="text-xs text-slate-500">
+            {realtimeEnabled ? 'Realtime active' : 'Realtime fallback'}
+          </p>
+        </div>
+        <span className="rounded-full bg-slate-800 px-3 py-1 text-xs uppercase tracking-widest text-slate-400">
+          {typingUsers.length ? 'Typing' : 'Live'}
+        </span>
+      </div>
+
+      <div className="mb-4 rounded-3xl border border-slate-800 bg-[#0f172a] p-4">
+        <p className="mb-2 text-xs uppercase tracking-widest text-slate-500">Transparency notice</p>
+        <p className="text-sm text-slate-300">
+          All mentorship chats are logged for transparency. Messages are recorded and available for
+          maintainer review.
+        </p>
+      </div>
+
+      <div className="mb-4 max-h-[420px] space-y-3 overflow-y-auto pr-2">
+        {loading && <p className="text-sm text-slate-500">Loading chat history…</p>}
+        {!loading && messages.length === 0 && (
+          <p className="text-sm text-slate-500">No messages yet. Start the conversation.</p>
+        )}
+        {messages.map((message) => {
+          const isOwn = message.sender_id === currentUserId;
+          const senderLabel =
+            message.sender?.display_name ||
+            message.sender?.github_handle ||
+            (isOwn ? 'You' : 'Mentor');
+          return (
+            <div
+              key={message.id}
+              className={`rounded-2xl p-3 ${isOwn ? 'self-end bg-slate-800 text-right' : 'bg-slate-900 text-left'}`}
+            >
+              <div className="mb-1 text-[11px] uppercase tracking-widest text-slate-500">
+                {senderLabel}
+              </div>
+              <p className="whitespace-pre-wrap text-sm leading-6 text-slate-100">
+                {message.content}
+              </p>
+              <div className="mt-2 text-[11px] text-slate-500">
+                {new Date(message.timestamp).toLocaleString()}
+              </div>
+            </div>
+          );
+        })}
+      </div>
+
+      {typingLabel && <div className="mb-3 text-sm text-emerald-300">{typingLabel}</div>}
+      {error && (
+        <div className="mb-3 rounded-xl bg-rose-950 p-3 text-sm text-rose-300">{error}</div>
+      )}
+
+      <div className="flex gap-3">
+        <textarea
+          value={messageText}
+          onChange={(event) => setMessageText(event.target.value)}
+          rows={3}
+          placeholder="Type your message…"
+          className="min-h-[90px] flex-1 resize-none rounded-3xl border border-slate-800 bg-slate-900 p-4 text-sm text-slate-100 outline-none focus:border-slate-500"
+        />
+        <button
+          type="button"
+          onClick={sendMessage}
+          className="rounded-3xl bg-slate-700 px-5 py-3 text-sm font-semibold text-white transition hover:bg-slate-600"
+        >
+          Send
+        </button>
+      </div>
+    </div>
+  );
+}
diff --git a/src/components/chat/MentorshipSessionsSidebar.tsx b/src/components/chat/MentorshipSessionsSidebar.tsx
new file mode 100644
index 0000000..1143dd6
--- /dev/null
+++ b/src/components/chat/MentorshipSessionsSidebar.tsx
@@ -0,0 +1,91 @@
+'use client';
+
+import { useEffect, useState } from 'react';
+import Link from 'next/link';
+
+type Participant = {
+  id: string;
+  github_handle: string;
+  display_name: string | null;
+  level: number | null;
+};
+
+type MentorshipSessionSummary = {
+  id: number;
+  mentor: Participant | null;
+  mentee: Participant | null;
+  level: number;
+  started_at: string;
+  ended_at: string | null;
+};
+
+export default function MentorshipSessionsSidebar() {
+  const [sessions, setSessions] = useState<MentorshipSessionSummary[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    async function fetchSessions() {
+      try {
+        const res = await fetch('/api/mentorship/sessions');
+        if (!res.ok) {
+          throw new Error('Unable to fetch mentorship sessions');
+        }
+        const data = await res.json();
+        setSessions(data.sessions ?? []);
+      } catch (err) {
+        setError((err as Error).message);
+      } finally {
+        setLoading(false);
+      }
+    }
+    fetchSessions();
+  }, []);
+
+  return (
+    <section className="rounded-3xl border border-slate-800 bg-slate-950 p-6">
+      <div className="mb-5 flex items-center justify-between gap-4">
+        <div>
+          <h2 className="text-lg font-semibold text-white">Active mentorship</h2>
+          <p className="text-sm text-slate-400">Live sessions and participant levels.</p>
+        </div>
+        <Link href="/mentorship" className="text-sm text-sky-400 hover:text-sky-300">
+          View all
+        </Link>
+      </div>
+      {loading ? (
+        <p className="text-sm text-slate-500">Loading sessions…</p>
+      ) : error ? (
+        <p className="text-sm text-rose-300">{error}</p>
+      ) : sessions.length === 0 ? (
+        <p className="text-sm text-slate-500">No active mentorship sessions right now.</p>
+      ) : (
+        <div className="space-y-4">
+          {sessions.map((session) => (
+            <Link
+              key={session.id}
+              href={`/mentorship/${session.id}`}
+              className="block rounded-3xl border border-slate-800 bg-slate-900 p-4 transition hover:border-slate-600"
+            >
+              <div className="mb-2 flex items-center justify-between gap-3">
+                <div className="text-sm font-semibold text-white">Session #{session.id}</div>
+                <span className="rounded-full bg-slate-800 px-3 py-1 text-[11px] uppercase tracking-widest text-slate-400">
+                  L{session.level}
+                </span>
+              </div>
+              <div className="text-sm text-slate-300">
+                Mentor: {session.mentor?.display_name ?? session.mentor?.github_handle ?? 'Unknown'}
+              </div>
+              <div className="text-sm text-slate-300">
+                Mentee: {session.mentee?.display_name ?? session.mentee?.github_handle ?? 'Unknown'}
+              </div>
+              <div className="mt-3 text-xs text-slate-500">
+                Started {new Date(session.started_at).toLocaleString()}
+              </div>
+            </Link>
+          ))}
+        </div>
+      )}
+    </section>
+  );
+}
diff --git a/src/components/chat/StartMentorshipChatButton.tsx b/src/components/chat/StartMentorshipChatButton.tsx
new file mode 100644
index 0000000..58cacbc
--- /dev/null
+++ b/src/components/chat/StartMentorshipChatButton.tsx
@@ -0,0 +1,46 @@
+'use client';
+
+import { useState } from 'react';
+import { useRouter } from 'next/navigation';
+
+export default function StartMentorshipChatButton({ mentorHandle }: { mentorHandle: string }) {
+  const router = useRouter();
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  const startChat = async () => {
+    setError(null);
+    setLoading(true);
+    try {
+      const res = await fetch('/api/mentorship/create', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ mentorHandle }),
+      });
+      if (!res.ok) {
+        const payload = await res.json().catch(() => null);
+        throw new Error(payload?.error || 'Unable to start mentorship chat');
+      }
+      const data = await res.json();
+      router.push(`/mentorship/${data.session.id}`);
+    } catch (err) {
+      setError((err as Error).message);
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  return (
+    <div className="mt-6">
+      <button
+        type="button"
+        onClick={startChat}
+        disabled={loading}
+        className="inline-flex items-center justify-center rounded-2xl bg-sky-500 px-5 py-3 text-sm font-semibold text-white transition hover:bg-sky-400 disabled:cursor-not-allowed disabled:opacity-60"
+      >
+        {loading ? 'Starting chat…' : 'Start Mentorship Chat'}
+      </button>
+      {error && <p className="mt-2 text-sm text-rose-300">{error}</p>}
+    </div>
+  );
+}
diff --git a/src/inngest/functions/mentorship.ts b/src/inngest/functions/mentorship.ts
new file mode 100644
index 0000000..c61b828
--- /dev/null
+++ b/src/inngest/functions/mentorship.ts
@@ -0,0 +1,71 @@
+import { inngest } from '../client';
+import { getServiceSupabase } from '@/lib/supabase/service';
+
+export const mentorship = inngest.createFunction(
+  { id: 'mentorship' },
+  {
+    event: 'mentorship.*',
+  },
+  async ({ event }) => {
+    const sb = getServiceSupabase();
+    if (!sb) return;
+
+    if (event.name === 'mentorship.session.created') {
+      await sb.from('activity_log').insert({
+        user_id: event.data.mentorId,
+        kind: 'mentorship.session.created',
+        detail: event.data,
+      });
+      return;
+    }
+
+    if (event.name === 'mentorship.message.sent') {
+      const content = String(event.data.content || '').toLowerCase();
+      const flagged =
+        content.includes('inappropriate') || content.includes('hate') || content.includes('abuse');
+      await sb.from('activity_log').insert({
+        user_id: event.data.senderId,
+        kind: 'mentorship.message.sent',
+        detail: event.data,
+      });
+      if (flagged) {
+        await sb.from('activity_log').insert({
+          user_id: event.data.senderId,
+          kind: 'mentorship.message.flagged',
+          detail: {
+            sessionId: event.data.sessionId,
+            messageId: event.data.messageId,
+            reason: 'possible inappropriate content',
+            content: event.data.content,
+          },
+        });
+      }
+      return;
+    }
+
+    if (event.name === 'mentorship.session.ended') {
+      const { data: sessionMessages } = await sb
+        .from('messages')
+        .select('content, sender_id')
+        .eq('session_id', event.data.sessionId)
+        .order('timestamp', { ascending: true });
+
+      const summary = sessionMessages
+        ? sessionMessages
+            .slice(0, 5)
+            .map((message: any) => `${message.sender_id}: ${message.content}`)
+            .join(' | ')
+        : 'No messages recorded.';
+
+      await sb.from('activity_log').insert({
+        user_id: event.data.mentorId,
+        kind: 'mentorship.session.summary',
+        detail: {
+          sessionId: event.data.sessionId,
+          summary,
+        },
+      });
+      return;
+    }
+  },
+);
diff --git a/src/lib/chat/index.ts b/src/lib/chat/index.ts
new file mode 100644
index 0000000..6c16864
--- /dev/null
+++ b/src/lib/chat/index.ts
@@ -0,0 +1,129 @@
+import { getDb } from '@/lib/db/client';
+import { mentorshipSessions, messages } from '@/lib/db/schema';
+import { inngest } from '@/inngest/client';
+import { eq, isNull, or, and } from 'drizzle-orm';
+
+export type MentorshipSessionRow = {
+  id: number;
+  mentor_id: string;
+  mentee_id: string;
+  level: number;
+  started_at: string;
+  ended_at: string | null;
+};
+
+export type MentorshipMessageRow = {
+  id: number;
+  session_id: number;
+  sender_id: string;
+  content: string;
+  timestamp: string;
+  read_status: 'unread' | 'read';
+};
+
+export async function createMentorshipSession(args: {
+  mentorId: string;
+  menteeId: string;
+  level?: number;
+}) {
+  const db = getDb();
+  const [session] = await db
+    .insert(mentorshipSessions)
+    .values({
+      mentorId: args.mentorId,
+      menteeId: args.menteeId,
+      level: args.level ?? 1,
+    })
+    .returning();
+
+  if (!session) throw new Error('Failed to create mentorship session');
+
+  await inngest.send({
+    name: 'mentorship.session.created',
+    data: {
+      sessionId: session.id,
+      mentorId: args.mentorId,
+      menteeId: args.menteeId,
+      level: session.level,
+    },
+  });
+
+  return session;
+}
+
+export async function endMentorshipSession(sessionId: number) {
+  const db = getDb();
+  const [session] = await db
+    .update(mentorshipSessions)
+    .set({ endedAt: new Date() })
+    .where(eq(mentorshipSessions.id, sessionId))
+    .returning();
+
+  if (!session) throw new Error('Failed to end mentorship session');
+
+  await inngest.send({
+    name: 'mentorship.session.ended',
+    data: {
+      sessionId: session.id,
+      mentorId: session.mentorId,
+      menteeId: session.menteeId,
+      endedAt: session.endedAt,
+    },
+  });
+
+  return session;
+}
+
+export async function appendMentorshipMessage(args: {
+  sessionId: number;
+  senderId: string;
+  content: string;
+}) {
+  const db = getDb();
+  const [message] = await db
+    .insert(messages)
+    .values({
+      sessionId: args.sessionId,
+      senderId: args.senderId,
+      content: args.content,
+      readStatus: 'unread',
+    })
+    .returning();
+
+  if (!message) throw new Error('Failed to create message');
+
+  await inngest.send({
+    name: 'mentorship.message.sent',
+    data: {
+      sessionId: message.sessionId,
+      senderId: message.senderId,
+      messageId: message.id,
+      content: message.content,
+    },
+  });
+
+  return message;
+}
+
+export async function getMentorshipSessionById(sessionId: number) {
+  const db = getDb();
+  const results = await db
+    .select()
+    .from(mentorshipSessions)
+    .where(eq(mentorshipSessions.id, sessionId))
+    .limit(1);
+  return results[0] ?? null;
+}
+
+export async function listActiveMentorshipSessionsForUser(userId: string) {
+  const db = getDb();
+  return db
+    .select()
+    .from(mentorshipSessions)
+    .where(
+      and(
+        isNull(mentorshipSessions.endedAt),
+        or(eq(mentorshipSessions.mentorId, userId), eq(mentorshipSessions.menteeId, userId)),
+      ),
+    );
+}
diff --git a/src/lib/db/schema.ts b/src/lib/db/schema.ts
index b84646b..f67815d 100644
--- a/src/lib/db/schema.ts
+++ b/src/lib/db/schema.ts
@@ -256,6 +256,48 @@ export const helpRequests = pgTable(
   }),
 );
 
+export const mentorshipSessions = pgTable(
+  'mentorship_sessions',
+  {
+    id: bigserial('id', { mode: 'number' }).primaryKey(),
+    mentorId: uuid('mentor_id')
+      .notNull()
+      .references(() => profiles.id, { onDelete: 'cascade' }),
+    menteeId: uuid('mentee_id')
+      .notNull()
+      .references(() => profiles.id, { onDelete: 'cascade' }),
+    level: integer('level').notNull().default(1),
+    startedAt: timestamp('started_at', { withTimezone: true }).notNull().defaultNow(),
+    endedAt: timestamp('ended_at', { withTimezone: true }),
+  },
+  (t) => ({
+    mentorIdx: index('mentorship_sessions_mentor_idx').on(t.mentorId),
+    menteeIdx: index('mentorship_sessions_mentee_idx').on(t.menteeId),
+  }),
+);
+
+export const messages = pgTable(
+  'messages',
+  {
+    id: bigserial('id', { mode: 'number' }).primaryKey(),
+    sessionId: bigint('session_id', { mode: 'number' })
+      .notNull()
+      .references(() => mentorshipSessions.id, { onDelete: 'cascade' }),
+    senderId: uuid('sender_id')
+      .notNull()
+      .references(() => profiles.id, { onDelete: 'cascade' }),
+    content: text('content').notNull(),
+    timestamp: timestamp('timestamp', { withTimezone: true }).notNull().defaultNow(),
+    readStatus: text('read_status', { enum: ['unread', 'read'] })
+      .notNull()
+      .default('unread'),
+  },
+  (t) => ({
+    sessionIdx: index('messages_session_idx').on(t.sessionId),
+    senderIdx: index('messages_sender_idx').on(t.senderId),
+  }),
+);
+
 // ---------- cohorts + tags ----------
 
 export const cohorts = pgTable('cohorts', {
diff --git a/supabase/migrations/0012_add_mentorship_sessions_and_messages.sql b/supabase/migrations/0012_add_mentorship_sessions_and_messages.sql
new file mode 100644
index 0000000..e2609fa
--- /dev/null
+++ b/supabase/migrations/0012_add_mentorship_sessions_and_messages.sql
@@ -0,0 +1,25 @@
+-- Add mentorship session and message logging tables.
+
+create table if not exists mentorship_sessions (
+  id bigserial primary key,
+  mentor_id uuid not null references profiles(id) on delete cascade,
+  mentee_id uuid not null references profiles(id) on delete cascade,
+  level integer not null default 1,
+  started_at timestamptz not null default now(),
+  ended_at timestamptz
+);
+
+create index if not exists mentorship_sessions_mentor_id_idx on mentorship_sessions(mentor_id);
+create index if not exists mentorship_sessions_mentee_id_idx on mentorship_sessions(mentee_id);
+
+create table if not exists messages (
+  id bigserial primary key,
+  session_id bigint not null references mentorship_sessions(id) on delete cascade,
+  sender_id uuid not null references profiles(id) on delete cascade,
+  content text not null,
+  timestamp timestamptz not null default now(),
+  read_status text not null default 'unread' check (read_status in ('unread', 'read'))
+);
+
+create index if not exists messages_session_id_idx on messages(session_id);
+create index if not exists messages_sender_id_idx on messages(sender_id);
diff --git a/tests/chat/__fixtures__/supabase-realtime.ts b/tests/chat/__fixtures__/supabase-realtime.ts
new file mode 100644
index 0000000..2d590d5
--- /dev/null
+++ b/tests/chat/__fixtures__/supabase-realtime.ts
@@ -0,0 +1,13 @@
+import { vi } from 'vitest';
+
+export const mockSupabaseRealtimeChannel = {
+  on: vi.fn().mockReturnThis(),
+  subscribe: vi.fn().mockResolvedValue({}),
+  unsubscribe: vi.fn().mockResolvedValue({}),
+  track: vi.fn().mockResolvedValue({}),
+  presenceState: vi.fn().mockReturnValue({}),
+};
+
+export const mockBrowserSupabase = {
+  channel: vi.fn(() => mockSupabaseRealtimeChannel),
+};
diff --git a/tests/chat/chat.test.ts b/tests/chat/chat.test.ts
new file mode 100644
index 0000000..3eb7c91
--- /dev/null
+++ b/tests/chat/chat.test.ts
@@ -0,0 +1,91 @@
+import { describe, expect, it, vi, beforeEach } from 'vitest';
+
+const mockSend = vi.fn();
+const mockInsert = vi.fn();
+
+vi.mock('@/lib/db/client', () => ({
+  getDb: () => ({
+    insert: mockInsert,
+    update: vi.fn().mockReturnThis(),
+    set: vi.fn().mockReturnThis(),
+    where: vi.fn().mockReturnThis(),
+    returning: vi.fn().mockResolvedValue([{ id: 1 }]),
+  }),
+}));
+
+vi.mock('@/inngest/client', () => ({
+  inngest: {
+    send: mockSend,
+  },
+}));
+
+const { createMentorshipSession, appendMentorshipMessage } = await import('@/lib/chat');
+
+describe('mentorship chat helpers', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockInsert.mockReset();
+    mockInsert.mockImplementation(() => ({
+      values: () => ({
+        returning: vi
+          .fn()
+          .mockResolvedValue([{ id: 1, mentorId: 'mentor-id', menteeId: 'mentee-id', level: 1 }]),
+      }),
+    }));
+  });
+
+  it('creates a mentorship session and emits an event', async () => {
+    mockInsert.mockImplementationOnce(() => ({
+      values: () => ({
+        returning: vi
+          .fn()
+          .mockResolvedValue([{ id: 42, mentorId: 'mentor-id', menteeId: 'mentee-id', level: 1 }]),
+      }),
+    }));
+
+    const session = await createMentorshipSession({ mentorId: 'mentor-id', menteeId: 'mentee-id' });
+    expect(session.id).toBe(42);
+    expect(mockSend).toHaveBeenCalledWith({
+      name: 'mentorship.session.created',
+      data: expect.objectContaining({
+        sessionId: 42,
+        mentorId: 'mentor-id',
+        menteeId: 'mentee-id',
+      }),
+    });
+  });
+
+  it('appends a mentorship message and emits a message event', async () => {
+    mockInsert.mockImplementationOnce(() => ({
+      values: () => ({
+        returning: vi
+          .fn()
+          .mockResolvedValue([
+            {
+              id: 88,
+              sessionId: 42,
+              senderId: 'mentor-id',
+              content: 'Hello',
+              readStatus: 'unread',
+            },
+          ]),
+      }),
+    }));
+
+    const message = await appendMentorshipMessage({
+      sessionId: 42,
+      senderId: 'mentor-id',
+      content: 'Hello',
+    });
+    expect(message.id).toBe(88);
+    expect(mockSend).toHaveBeenCalledWith({
+      name: 'mentorship.message.sent',
+      data: expect.objectContaining({
+        sessionId: 42,
+        senderId: 'mentor-id',
+        messageId: 88,
+        content: 'Hello',
+      }),
+    });
+  });
+});