diff --git a/codeframe/core/tasks.py b/codeframe/core/tasks.py
index cc0b389c..6834f011 100644
--- a/codeframe/core/tasks.py
+++ b/codeframe/core/tasks.py
@@ -60,6 +60,7 @@ class Task:
     lineage: list[str] = field(default_factory=list)
     is_leaf: bool = True
     hierarchical_id: Optional[str] = None
+    requirement_ids: list[str] = field(default_factory=list)
 
 
 def create(
@@ -77,6 +78,7 @@ def create(
     lineage: Optional[list[str]] = None,
     is_leaf: bool = True,
     hierarchical_id: Optional[str] = None,
+    requirement_ids: Optional[list[str]] = None,
 ) -> Task:
     """Create a new task.
 
@@ -95,6 +97,7 @@ def create(
         lineage: Optional list of ancestor descriptions
         is_leaf: Whether this is a leaf/executable task (default True)
         hierarchical_id: Optional display ID like "1.2.3"
+        requirement_ids: Optional list of PROOF9 requirement IDs this task implements
 
     Returns:
         Created Task
@@ -103,16 +106,17 @@ def create(
     now = _utc_now().isoformat()
     depends_on_list = depends_on or []
     lineage_list = lineage or []
+    requirement_ids_list = requirement_ids or []
 
     conn = get_db_connection(workspace)
     try:
         cursor = conn.cursor()
         cursor.execute(
             """
-            INSERT INTO tasks (id, workspace_id, prd_id, title, description, status, priority, depends_on, estimated_hours, complexity_score, uncertainty_level, parent_id, lineage, is_leaf, hierarchical_id, created_at, updated_at)
-            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+            INSERT INTO tasks (id, workspace_id, prd_id, title, description, status, priority, depends_on, estimated_hours, complexity_score, uncertainty_level, parent_id, lineage, is_leaf, hierarchical_id, created_at, updated_at, requirement_ids)
+            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
             """,
-            (task_id, workspace.id, prd_id, title, description, status.value, priority, json.dumps(depends_on_list), estimated_hours, complexity_score, uncertainty_level, parent_id, json.dumps(lineage_list), 1 if is_leaf else 0, hierarchical_id, now, now),
+            (task_id, workspace.id, prd_id, title, description, status.value, priority, json.dumps(depends_on_list), estimated_hours, complexity_score, uncertainty_level, parent_id, json.dumps(lineage_list), 1 if is_leaf else 0, hierarchical_id, now, now, json.dumps(requirement_ids_list)),
         )
         conn.commit()
     finally:
@@ -134,6 +138,7 @@ def create(
         lineage=lineage_list,
         is_leaf=is_leaf,
         hierarchical_id=hierarchical_id,
+        requirement_ids=requirement_ids_list,
         created_at=datetime.fromisoformat(now),
         updated_at=datetime.fromisoformat(now),
     )
@@ -154,7 +159,7 @@ def get(workspace: Workspace, task_id: str) -> Optional[Task]:
 
     cursor.execute(
         """
-        SELECT id, workspace_id, prd_id, title, description, status, priority, depends_on, estimated_hours, complexity_score, uncertainty_level, created_at, updated_at, github_issue_number, parent_id, lineage, is_leaf, hierarchical_id
+        SELECT id, workspace_id, prd_id, title, description, status, priority, depends_on, estimated_hours, complexity_score, uncertainty_level, created_at, updated_at, github_issue_number, parent_id, lineage, is_leaf, hierarchical_id, requirement_ids
         FROM tasks
         WHERE workspace_id = ? AND id = ?
         """,
@@ -190,7 +195,7 @@ def list_tasks(
     if status:
         cursor.execute(
             """
-            SELECT id, workspace_id, prd_id, title, description, status, priority, depends_on, estimated_hours, complexity_score, uncertainty_level, created_at, updated_at, github_issue_number, parent_id, lineage, is_leaf, hierarchical_id
+            SELECT id, workspace_id, prd_id, title, description, status, priority, depends_on, estimated_hours, complexity_score, uncertainty_level, created_at, updated_at, github_issue_number, parent_id, lineage, is_leaf, hierarchical_id, requirement_ids
             FROM tasks
             WHERE workspace_id = ? AND status = ?
             ORDER BY priority ASC, created_at ASC
@@ -201,7 +206,7 @@ def list_tasks(
     else:
         cursor.execute(
             """
-            SELECT id, workspace_id, prd_id, title, description, status, priority, depends_on, estimated_hours, complexity_score, uncertainty_level, created_at, updated_at, github_issue_number, parent_id, lineage, is_leaf, hierarchical_id
+            SELECT id, workspace_id, prd_id, title, description, status, priority, depends_on, estimated_hours, complexity_score, uncertainty_level, created_at, updated_at, github_issue_number, parent_id, lineage, is_leaf, hierarchical_id, requirement_ids
             FROM tasks
             WHERE workspace_id = ?
             ORDER BY priority ASC, created_at ASC
@@ -415,6 +420,49 @@ def update_depends_on(
     return task
 
 
+def update_requirement_ids(
+    workspace: Workspace,
+    task_id: str,
+    requirement_ids: list[str],
+) -> Task:
+    """Update a task's linked PROOF9 requirement IDs.
+
+    Args:
+        workspace: Target workspace
+        task_id: Task to update
+        requirement_ids: List of PROOF9 requirement IDs this task implements
+
+    Returns:
+        Updated Task
+
+    Raises:
+        ValueError: If task not found
+    """
+    task = get(workspace, task_id)
+    if not task:
+        raise ValueError(f"Task not found: {task_id}")
+
+    now = _utc_now().isoformat()
+
+    conn = get_db_connection(workspace)
+    cursor = conn.cursor()
+    cursor.execute(
+        """
+        UPDATE tasks
+        SET requirement_ids = ?, updated_at = ?
+        WHERE workspace_id = ? AND id = ?
+        """,
+        (json.dumps(requirement_ids), now, workspace.id, task_id),
+    )
+    conn.commit()
+    conn.close()
+
+    task.requirement_ids = requirement_ids
+    task.updated_at = datetime.fromisoformat(now)
+
+    return task
+
+
 def get_dependents(workspace: Workspace, task_id: str) -> list[Task]:
     """Get all tasks that depend on the given task.
 
@@ -705,7 +753,7 @@ def _row_to_task(row: tuple) -> Task:
     Row columns: id, workspace_id, prd_id, title, description, status, priority,
                  depends_on, estimated_hours, complexity_score, uncertainty_level,
                  created_at, updated_at, github_issue_number, parent_id, lineage,
-                 is_leaf, hierarchical_id
+                 is_leaf, hierarchical_id, requirement_ids
     """
     # Parse depends_on from JSON string (default to empty list if null)
     depends_on_raw = row[7]
@@ -719,6 +767,10 @@ def _row_to_task(row: tuple) -> Task:
     is_leaf_raw = row[16] if len(row) > 16 else 1
     is_leaf = bool(is_leaf_raw) if is_leaf_raw is not None else True
 
+    # Parse requirement_ids from JSON string (default to empty list if null)
+    requirement_ids_raw = row[18] if len(row) > 18 else None
+    requirement_ids = json.loads(requirement_ids_raw) if requirement_ids_raw else []
+
     return Task(
         id=row[0],
         workspace_id=row[1],
@@ -738,4 +790,5 @@ def _row_to_task(row: tuple) -> Task:
         lineage=lineage,
         is_leaf=is_leaf,
         hierarchical_id=row[17] if len(row) > 17 else None,
+        requirement_ids=requirement_ids,
     )
diff --git a/codeframe/core/workspace.py b/codeframe/core/workspace.py
index aef3de01..465c6280 100644
--- a/codeframe/core/workspace.py
+++ b/codeframe/core/workspace.py
@@ -147,6 +147,8 @@ def _init_database(db_path: Path) -> None:
         cursor.execute("ALTER TABLE tasks ADD COLUMN is_leaf INTEGER DEFAULT 1")
     if "hierarchical_id" not in columns:
         cursor.execute("ALTER TABLE tasks ADD COLUMN hierarchical_id TEXT")
+    if "requirement_ids" not in columns:
+        cursor.execute("ALTER TABLE tasks ADD COLUMN requirement_ids TEXT DEFAULT '[]'")
 
     # Append-only event log
     cursor.execute("""
@@ -489,6 +491,9 @@ def _ensure_schema_upgrades(db_path: Path) -> None:
         if "hierarchical_id" not in task_columns:
             cursor.execute("ALTER TABLE tasks ADD COLUMN hierarchical_id TEXT")
             conn.commit()
+        if "requirement_ids" not in task_columns:
+            cursor.execute("ALTER TABLE tasks ADD COLUMN requirement_ids TEXT DEFAULT '[]'")
+            conn.commit()
         if "github_issue_number" not in task_columns:
             cursor.execute("ALTER TABLE tasks ADD COLUMN github_issue_number INTEGER")
             conn.commit()
diff --git a/codeframe/ui/routers/tasks_v2.py b/codeframe/ui/routers/tasks_v2.py
index da20f243..de97e41b 100644
--- a/codeframe/ui/routers/tasks_v2.py
+++ b/codeframe/ui/routers/tasks_v2.py
@@ -141,6 +141,7 @@ class TaskResponse(BaseModel):
     status: str
     priority: int
     depends_on: list[str] = []
+    requirement_ids: list[str] = []
     estimated_hours: Optional[float] = None
     created_at: Optional[str] = None
     updated_at: Optional[str] = None
@@ -216,6 +217,7 @@ async def list_tasks(
                 status=t.status.value,
                 priority=t.priority,
                 depends_on=t.depends_on,
+                requirement_ids=t.requirement_ids,
                 estimated_hours=t.estimated_hours,
                 created_at=t.created_at.isoformat() if t.created_at else None,
                 updated_at=t.updated_at.isoformat() if t.updated_at else None,
@@ -260,6 +262,7 @@ async def get_task(
         status=task.status.value,
         priority=task.priority,
         depends_on=task.depends_on,
+        requirement_ids=task.requirement_ids,
         estimated_hours=task.estimated_hours,
         created_at=task.created_at.isoformat() if task.created_at else None,
         updated_at=task.updated_at.isoformat() if task.updated_at else None,
@@ -330,6 +333,7 @@ async def update_task(
             status=task.status.value,
             priority=task.priority,
             depends_on=task.depends_on,
+            requirement_ids=task.requirement_ids,
             estimated_hours=task.estimated_hours,
             created_at=task.created_at.isoformat() if task.created_at else None,
             updated_at=task.updated_at.isoformat() if task.updated_at else None,
diff --git a/tests/core/test_task_requirement_ids.py b/tests/core/test_task_requirement_ids.py
new file mode 100644
index 00000000..1bf446df
--- /dev/null
+++ b/tests/core/test_task_requirement_ids.py
@@ -0,0 +1,139 @@
+"""Tests for task requirement_ids field (issue #468).
+
+Tests that tasks can be linked to PROOF9 requirement IDs for traceability.
+"""
+
+import sqlite3
+
+import pytest
+
+from codeframe.core import tasks
+from codeframe.core.workspace import create_or_load_workspace
+
+pytestmark = pytest.mark.v2
+
+
+@pytest.fixture
+def workspace(tmp_path):
+    """Create a test workspace."""
+    return create_or_load_workspace(tmp_path)
+
+
+class TestTaskRequirementIdsField:
+    """Test the requirement_ids field on Task model."""
+
+    def test_task_has_empty_requirement_ids_by_default(self, workspace):
+        """New tasks should have empty requirement_ids list."""
+        task = tasks.create(workspace, title="Test task")
+        assert task.requirement_ids == []
+
+    def test_task_created_with_requirement_ids(self, workspace):
+        """Tasks can be created with requirement_ids."""
+        req_ids = ["REQ-001", "REQ-002"]
+        task = tasks.create(workspace, title="Task with reqs", requirement_ids=req_ids)
+        assert task.requirement_ids == req_ids
+
+    def test_task_get_includes_requirement_ids(self, workspace):
+        """Getting a task should include its requirement_ids."""
+        req_ids = ["REQ-042"]
+        task = tasks.create(workspace, title="Task", requirement_ids=req_ids)
+        retrieved = tasks.get(workspace, task.id)
+        assert retrieved.requirement_ids == req_ids
+
+    def test_task_list_includes_requirement_ids(self, workspace):
+        """Listing tasks should include requirement_ids."""
+        t1 = tasks.create(workspace, title="No reqs")
+        t2 = tasks.create(workspace, title="With reqs", requirement_ids=["REQ-007"])
+
+        all_tasks = tasks.list_tasks(workspace)
+        task_map = {t.id: t for t in all_tasks}
+
+        assert task_map[t1.id].requirement_ids == []
+        assert task_map[t2.id].requirement_ids == ["REQ-007"]
+
+    def test_task_requirement_ids_persisted_across_get(self, workspace):
+        """requirement_ids should survive a round-trip to the database."""
+        req_ids = ["REQ-001", "REQ-002", "REQ-003"]
+        task = tasks.create(workspace, title="Multi-req task", requirement_ids=req_ids)
+        fetched = tasks.get(workspace, task.id)
+        assert fetched.requirement_ids == req_ids
+
+    def test_update_requirement_ids(self, workspace):
+        """requirement_ids can be updated on an existing task."""
+        task = tasks.create(workspace, title="Task")
+        assert task.requirement_ids == []
+
+        updated = tasks.update_requirement_ids(workspace, task.id, ["REQ-099"])
+        assert updated.requirement_ids == ["REQ-099"]
+
+        fetched = tasks.get(workspace, task.id)
+        assert fetched.requirement_ids == ["REQ-099"]
+
+    def test_update_requirement_ids_to_empty(self, workspace):
+        """requirement_ids can be cleared."""
+        task = tasks.create(workspace, title="Task", requirement_ids=["REQ-001"])
+        updated = tasks.update_requirement_ids(workspace, task.id, [])
+        assert updated.requirement_ids == []
+
+    def test_task_without_requirement_ids_in_existing_db(self, tmp_path):
+        """Migration guard adds requirement_ids column to pre-migration databases.
+
+        Simulates a workspace that was created before the requirement_ids column
+        was added, then verifies that opening it triggers the migration guard
+        and tasks can be read back with requirement_ids == [].
+        """
+        # Step 1: Create a workspace and inject a "pre-migration" tasks table
+        # by directly dropping the requirement_ids column from the DB.
+        ws = create_or_load_workspace(tmp_path)
+        db_path = ws.db_path
+
+        conn = sqlite3.connect(db_path)
+        # Insert a task using the old schema (without requirement_ids)
+        import uuid
+        from datetime import datetime, timezone
+        task_id = str(uuid.uuid4())
+        now = datetime.now(timezone.utc).isoformat()
+        conn.execute(
+            """
+            INSERT INTO tasks (id, workspace_id, prd_id, title, description, status,
+                               priority, depends_on, created_at, updated_at)
+            VALUES (?, ?, NULL, ?, '', 'BACKLOG', 0, '[]', ?, ?)
+            """,
+            (task_id, ws.id, "Legacy task", now, now),
+        )
+        # Simulate the column not existing by removing it (SQLite workaround)
+        conn.execute("ALTER TABLE tasks RENAME TO tasks_old")
+        conn.execute("""
+            CREATE TABLE tasks (
+                id TEXT PRIMARY KEY,
+                workspace_id TEXT NOT NULL,
+                prd_id TEXT,
+                title TEXT NOT NULL,
+                description TEXT,
+                status TEXT NOT NULL DEFAULT 'BACKLOG',
+                priority INTEGER DEFAULT 0,
+                depends_on TEXT DEFAULT '[]',
+                created_at TEXT NOT NULL,
+                updated_at TEXT NOT NULL
+            )
+        """)
+        conn.execute("""
+            INSERT INTO tasks (id, workspace_id, prd_id, title, description, status,
+                               priority, depends_on, created_at, updated_at)
+            SELECT id, workspace_id, prd_id, title, description, status,
+                   priority, depends_on, created_at, updated_at
+            FROM tasks_old
+        """)
+        conn.execute("DROP TABLE tasks_old")
+        conn.commit()
+        conn.close()
+
+        # Step 2: Re-open workspace — this triggers _ensure_schema_upgrades()
+        # which should add the requirement_ids column.
+        ws2 = create_or_load_workspace(tmp_path)
+
+        # Step 3: Verify the legacy task reads back with requirement_ids == []
+        fetched = tasks.get(ws2, task_id)
+        assert fetched is not None
+        assert hasattr(fetched, "requirement_ids")
+        assert fetched.requirement_ids == []
diff --git a/web-ui/src/components/tasks/TaskBoardContent.tsx b/web-ui/src/components/tasks/TaskBoardContent.tsx
index 666a6f7b..0ea412e0 100644
--- a/web-ui/src/components/tasks/TaskBoardContent.tsx
+++ b/web-ui/src/components/tasks/TaskBoardContent.tsx
@@ -2,7 +2,7 @@
 
 import { useMemo } from 'react';
 import { TaskColumn } from './TaskColumn';
-import type { Task, TaskStatus } from '@/types';
+import type { Task, TaskStatus, ProofRequirement } from '@/types';
 
 /** Column display order matches the task lifecycle. */
 const COLUMN_ORDER: TaskStatus[] = [
@@ -27,6 +27,7 @@ interface TaskBoardContentProps {
   onSelectAll?: (taskIds: string[]) => void;
   onDeselectAll?: (taskIds: string[]) => void;
   loadingTaskIds?: Set<string>;
+  requirementsMap?: Map<string, ProofRequirement>;
 }
 
 export function TaskBoardContent({
@@ -42,6 +43,7 @@ export function TaskBoardContent({
   onSelectAll,
   onDeselectAll,
   loadingTaskIds,
+  requirementsMap,
 }: TaskBoardContentProps) {
   /** Group flat task array into per-status buckets. */
   const tasksByStatus = useMemo(() => {
@@ -75,6 +77,7 @@ export function TaskBoardContent({
           onSelectAll={onSelectAll}
           onDeselectAll={onDeselectAll}
           loadingTaskIds={loadingTaskIds}
+          requirementsMap={requirementsMap}
         />
       ))}
     </div>
diff --git a/web-ui/src/components/tasks/TaskBoardView.tsx b/web-ui/src/components/tasks/TaskBoardView.tsx
index bca56632..7b7a8fd7 100644
--- a/web-ui/src/components/tasks/TaskBoardView.tsx
+++ b/web-ui/src/components/tasks/TaskBoardView.tsx
@@ -10,6 +10,7 @@ import { BatchActionsBar } from './BatchActionsBar';
 import { BulkActionConfirmDialog, type BulkActionType } from './BulkActionConfirmDialog';
 import { Cancel01Icon } from '@hugeicons/react';
 import { tasksApi } from '@/lib/api';
+import { useRequirementsLookup } from '@/hooks/useRequirementsLookup';
 import type {
   TaskStatus,
   TaskListResponse,
@@ -29,6 +30,7 @@ export function TaskBoardView({ workspacePath }: TaskBoardViewProps) {
     `/api/v2/tasks?path=${workspacePath}`,
     () => tasksApi.getAll(workspacePath)
   );
+  const { requirementsMap } = useRequirementsLookup(workspacePath);
 
   // ─── Filter state ──────────────────────────────────────────────
   const [searchQuery, setSearchQuery] = useState('');
@@ -363,6 +365,7 @@ export function TaskBoardView({ workspacePath }: TaskBoardViewProps) {
         onSelectAll={handleSelectAll}
         onDeselectAll={handleDeselectAll}
         loadingTaskIds={loadingTaskIds}
+        requirementsMap={requirementsMap}
       />
 
       {/* Task detail modal */}
diff --git a/web-ui/src/components/tasks/TaskCard.tsx b/web-ui/src/components/tasks/TaskCard.tsx
index 9bd017b6..9b46f26b 100644
--- a/web-ui/src/components/tasks/TaskCard.tsx
+++ b/web-ui/src/components/tasks/TaskCard.tsx
@@ -1,11 +1,12 @@
 'use client';
 
-import { PlayCircleIcon, CheckmarkCircle01Icon, LinkCircleIcon, Cancel01Icon, ArrowTurnBackwardIcon, Loading03Icon } from '@hugeicons/react';
+import Link from 'next/link';
+import { PlayCircleIcon, CheckmarkCircle01Icon, LinkCircleIcon, Cancel01Icon, ArrowTurnBackwardIcon, Loading03Icon, BookOpen01Icon } from '@hugeicons/react';
 import { Card, CardContent } from '@/components/ui/card';
 import { Badge } from '@/components/ui/badge';
 import { Button } from '@/components/ui/button';
 import { Checkbox } from '@/components/ui/checkbox';
-import type { Task, TaskStatus } from '@/types';
+import type { Task, TaskStatus, ProofRequirement } from '@/types';
 
 /** Map backend TaskStatus to badge variant name. */
 const STATUS_BADGE_VARIANT: Record<TaskStatus, string> = {
@@ -42,6 +43,8 @@ interface TaskCardProps {
   /** Optional — when omitted, FAILED cards silently hide the Reset button. TaskBoardView always provides this. */
   onReset?: (taskId: string) => void;
   isLoading?: boolean;
+  /** Map of requirement ID → ProofRequirement for badge lookup (shared SWR cache from parent). */
+  requirementsMap?: Map<string, ProofRequirement>;
 }
 
 export function TaskCard({
@@ -55,12 +58,17 @@ export function TaskCard({
   onStop,
   onReset,
   isLoading = false,
+  requirementsMap,
 }: TaskCardProps) {
+  const reqIds = task.requirement_ids ?? [];
+  const firstReq = reqIds.length > 0 ? requirementsMap?.get(reqIds[0]) : undefined;
+  const overflowCount = reqIds.length > 1 ? reqIds.length - 1 : 0;
   return (
     <Card
       className="cursor-pointer transition-colors hover:border-primary/50 focus-visible:outline-none focus-visible:ring-[3px] focus-visible:ring-ring"
       onClick={() => onClick(task.id)}
       onKeyDown={(e) => {
+        if (e.target !== e.currentTarget) return;
         if (e.key === 'Enter' || e.key === ' ') {
           e.preventDefault();
           onClick(task.id);
@@ -106,6 +114,28 @@ export function TaskCard({
           </p>
         )}
 
+        {/* Requirement badges */}
+        {reqIds.length > 0 && (
+          <div
+            className="mt-2 flex flex-wrap items-center gap-1"
+            onClick={(e) => e.stopPropagation()}
+            onKeyDown={(e) => e.stopPropagation()}
+          >
+            <BookOpen01Icon className="h-3 w-3 shrink-0 text-muted-foreground" />
+            <Link href={`/proof/${encodeURIComponent(reqIds[0])}`}>
+              <Badge variant="outline" className="h-5 cursor-pointer gap-1 px-1.5 text-[10px] hover:bg-accent">
+                <span className="font-mono">{reqIds[0].slice(0, 10)}</span>
+                {firstReq?.glitch_type && (
+                  <span className="text-muted-foreground">· {firstReq.glitch_type}</span>
+                )}
+              </Badge>
+            </Link>
+            {overflowCount > 0 && (
+              <span className="text-[10px] text-muted-foreground">+{overflowCount}</span>
+            )}
+          </div>
+        )}
+
         {/* Action buttons */}
         {(task.status === 'READY' || task.status === 'BACKLOG' || task.status === 'IN_PROGRESS' || task.status === 'FAILED') && (
           <div className="mt-2 flex gap-1">
diff --git a/web-ui/src/components/tasks/TaskColumn.tsx b/web-ui/src/components/tasks/TaskColumn.tsx
index 15f5f8d8..f9a307e3 100644
--- a/web-ui/src/components/tasks/TaskColumn.tsx
+++ b/web-ui/src/components/tasks/TaskColumn.tsx
@@ -3,7 +3,7 @@
 import { Badge } from '@/components/ui/badge';
 import { Checkbox } from '@/components/ui/checkbox';
 import { TaskCard } from './TaskCard';
-import type { Task, TaskStatus } from '@/types';
+import type { Task, TaskStatus, ProofRequirement } from '@/types';
 
 /** Human-readable column headers. */
 const STATUS_LABEL: Record<TaskStatus, string> = {
@@ -30,6 +30,7 @@ interface TaskColumnProps {
   onSelectAll?: (taskIds: string[]) => void;
   onDeselectAll?: (taskIds: string[]) => void;
   loadingTaskIds?: Set<string>;
+  requirementsMap?: Map<string, ProofRequirement>;
 }
 
 export function TaskColumn({
@@ -46,6 +47,7 @@ export function TaskColumn({
   onSelectAll,
   onDeselectAll,
   loadingTaskIds = new Set(),
+  requirementsMap,
 }: TaskColumnProps) {
   const taskIds = tasks.map((t) => t.id);
   const selectedCount = tasks.filter((t) => selectedTaskIds.has(t.id)).length;
@@ -99,6 +101,7 @@ export function TaskColumn({
               onStop={onStop}
               onReset={onReset}
               isLoading={loadingTaskIds.has(task.id)}
+              requirementsMap={requirementsMap}
             />
           ))
         )}
diff --git a/web-ui/src/components/tasks/TaskDetailModal.tsx b/web-ui/src/components/tasks/TaskDetailModal.tsx
index 526159b5..566b0762 100644
--- a/web-ui/src/components/tasks/TaskDetailModal.tsx
+++ b/web-ui/src/components/tasks/TaskDetailModal.tsx
@@ -1,5 +1,6 @@
 'use client';
 
+import Link from 'next/link';
 import { useEffect, useState } from 'react';
 import { useRouter } from 'next/navigation';
 import {
@@ -9,6 +10,7 @@ import {
   Loading03Icon,
   Time01Icon,
   ViewIcon,
+  BookOpen01Icon,
 } from '@hugeicons/react';
 import {
   Dialog,
@@ -21,6 +23,7 @@ import {
 import { Badge } from '@/components/ui/badge';
 import { Button } from '@/components/ui/button';
 import { tasksApi } from '@/lib/api';
+import { useRequirementsLookup } from '@/hooks/useRequirementsLookup';
 import type { Task, TaskStatus, ApiError } from '@/types';
 
 const STATUS_BADGE_VARIANT: Record<TaskStatus, string> = {
@@ -65,6 +68,7 @@ export function TaskDetailModal({
   const [isLoading, setIsLoading] = useState(false);
   const [error, setError] = useState<string | null>(null);
   const [isUpdating, setIsUpdating] = useState(false);
+  const { requirementsMap, isLoading: reqsLoading } = useRequirementsLookup(workspacePath);
 
   useEffect(() => {
     if (!open || !taskId) {
@@ -181,6 +185,42 @@ export function TaskDetailModal({
               )}
             </div>
 
+            {/* Requirements */}
+            {(task.requirement_ids ?? []).length > 0 && (
+              <div className="space-y-1.5">
+                <div className="flex items-center gap-1.5 text-xs font-medium text-muted-foreground">
+                  <BookOpen01Icon className="h-3.5 w-3.5" />
+                  Requirements
+                </div>
+                {reqsLoading ? (
+                  <Loading03Icon className="h-3.5 w-3.5 animate-spin text-muted-foreground" />
+                ) : (
+                  <ul className="space-y-1">
+                    {(task.requirement_ids ?? []).map((reqId) => {
+                      const req = requirementsMap.get(reqId);
+                      return (
+                        <li key={reqId} className="flex items-start gap-2 text-xs">
+                          <Link
+                            href={`/proof/${encodeURIComponent(reqId)}`}
+                            className="font-mono text-primary hover:underline"
+                            onClick={(e) => e.stopPropagation()}
+                          >
+                            {reqId}
+                          </Link>
+                          {req && (
+                            <span className="text-foreground">{req.title}</span>
+                          )}
+                          {req?.glitch_type && (
+                            <span className="ml-auto text-muted-foreground">{req.glitch_type}</span>
+                          )}
+                        </li>
+                      );
+                    })}
+                  </ul>
+                )}
+              </div>
+            )}
+
             <DialogFooter>
               {task.status === 'BACKLOG' && (
                 <Button
diff --git a/web-ui/src/hooks/index.ts b/web-ui/src/hooks/index.ts
index 1568df1b..779f8a04 100644
--- a/web-ui/src/hooks/index.ts
+++ b/web-ui/src/hooks/index.ts
@@ -1,4 +1,5 @@
 export { useEventSource, type SSEStatus, type UseEventSourceOptions } from './useEventSource';
+export { useRequirementsLookup } from './useRequirementsLookup';
 export {
   useTaskStream,
   type UseTaskStreamOptions,
diff --git a/web-ui/src/hooks/useRequirementsLookup.ts b/web-ui/src/hooks/useRequirementsLookup.ts
new file mode 100644
index 00000000..f761fd12
--- /dev/null
+++ b/web-ui/src/hooks/useRequirementsLookup.ts
@@ -0,0 +1,27 @@
+'use client';
+
+import { useMemo } from 'react';
+import useSWR from 'swr';
+import { proofApi } from '@/lib/api';
+import type { ProofRequirement } from '@/types';
+
+/**
+ * Fetches all PROOF9 requirements for a workspace and returns a Map for O(1) lookup by ID.
+ * Uses SWR so the fetch is deduplicated across all consumers (TaskCard, TaskDetailModal, etc.)
+ * The Map is memoized so identity only changes when the underlying requirements data changes.
+ */
+export function useRequirementsLookup(workspacePath: string | null | undefined) {
+  const { data, isLoading, error } = useSWR(
+    workspacePath ? ['/proof/requirements', workspacePath] : null,
+    ([, path]: [string, string]) => proofApi.listRequirements(path),
+  );
+
+  const requirementsMap = useMemo(
+    () => new Map<string, ProofRequirement>(
+      (data?.requirements ?? []).map((r) => [r.id, r]),
+    ),
+    [data?.requirements],
+  );
+
+  return { requirementsMap, isLoading, error };
+}
diff --git a/web-ui/src/types/index.ts b/web-ui/src/types/index.ts
index 6b28dad7..a66928e5 100644
--- a/web-ui/src/types/index.ts
+++ b/web-ui/src/types/index.ts
@@ -61,6 +61,7 @@ export interface Task {
   status: TaskStatus;
   priority: number;
   depends_on: string[];
+  requirement_ids?: string[];
   estimated_hours?: number;
   created_at?: string;
   updated_at?: string;