diff --git a/__tests__/components/ui/coaching-session-selector.test.tsx b/__tests__/components/ui/coaching-session-selector.test.tsx
index 5f3e2ae2..76c9bce5 100644
--- a/__tests__/components/ui/coaching-session-selector.test.tsx
+++ b/__tests__/components/ui/coaching-session-selector.test.tsx
@@ -28,7 +28,7 @@ vi.mock('@/lib/hooks/use-current-coaching-session', () => ({
 }))
 
 vi.mock('@/lib/api/goals', () => ({
-  useGoalBySession: vi.fn(() => ({
+  useGoalByRelationship: vi.fn(() => ({
     goal: { title: 'Test Goal' },
     isLoading: false,
     isError: false,
diff --git a/__tests__/lib/api/goals.test.ts b/__tests__/lib/api/goals.test.ts
new file mode 100644
index 00000000..8753e56d
--- /dev/null
+++ b/__tests__/lib/api/goals.test.ts
@@ -0,0 +1,198 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { GoalApi, useGoalList, useGoalsBySession } from '@/lib/api/goals'
+import { EntityApi } from '@/lib/api/entity-api'
+import { renderHook } from '@testing-library/react'
+import { TestProviders } from '@/test-utils/providers'
+
+// Mock EntityApi
+vi.mock('@/lib/api/entity-api', () => ({
+  EntityApi: {
+    listFn: vi.fn(),
+    listNestedFn: vi.fn(),
+    getFn: vi.fn(),
+    createFn: vi.fn(),
+    updateFn: vi.fn(),
+    deleteFn: vi.fn(),
+    useEntityList: vi.fn(),
+    useEntityMutation: vi.fn(),
+  },
+}))
+
+// Mock site config to provide a proper base URL
+vi.mock('@/site.config', () => ({
+  siteConfig: {
+    env: {
+      backendServiceURL: 'http://localhost:3000',
+    },
+  },
+}))
+
+describe('GoalApi.list', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('sends coaching_relationship_id as query param', async () => {
+    vi.mocked(EntityApi.listFn).mockResolvedValue([])
+
+    await GoalApi.list('rel-123')
+
+    expect(EntityApi.listFn).toHaveBeenCalledWith('http://localhost:3000/goals', {
+      params: {
+        coaching_relationship_id: 'rel-123',
+      },
+    })
+  })
+
+  it('does not send coaching_session_id', async () => {
+    vi.mocked(EntityApi.listFn).mockResolvedValue([])
+
+    await GoalApi.list('rel-123')
+
+    const callArgs = vi.mocked(EntityApi.listFn).mock.calls[0]
+    expect(callArgs[1].params).not.toHaveProperty('coaching_session_id')
+  })
+
+  it('includes sort params when provided', async () => {
+    vi.mocked(EntityApi.listFn).mockResolvedValue([])
+
+    await GoalApi.list('rel-123', 'title', 'asc')
+
+    expect(EntityApi.listFn).toHaveBeenCalledWith('http://localhost:3000/goals', {
+      params: {
+        coaching_relationship_id: 'rel-123',
+        sort_by: 'title',
+        sort_order: 'asc',
+      },
+    })
+  })
+
+  it('omits sort params when not provided', async () => {
+    vi.mocked(EntityApi.listFn).mockResolvedValue([])
+
+    await GoalApi.list('rel-123')
+
+    const callArgs = vi.mocked(EntityApi.listFn).mock.calls[0]
+    expect(callArgs[1].params).not.toHaveProperty('sort_by')
+    expect(callArgs[1].params).not.toHaveProperty('sort_order')
+  })
+})
+
+describe('useGoalList hook', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('passes coaching_relationship_id to EntityApi.useEntityList', () => {
+    const mockReturn = {
+      entities: [],
+      isLoading: false,
+      isError: false,
+      refresh: vi.fn(),
+    }
+
+    vi.mocked(EntityApi.useEntityList).mockReturnValue(mockReturn)
+
+    renderHook(
+      () => useGoalList('rel-456'),
+      { wrapper: TestProviders }
+    )
+
+    expect(EntityApi.useEntityList).toHaveBeenCalledWith(
+      'http://localhost:3000/goals',
+      expect.any(Function),
+      'rel-456'
+    )
+  })
+
+  it('passes null to EntityApi.useEntityList when relationship ID is null', () => {
+    const mockReturn = {
+      entities: [],
+      isLoading: false,
+      isError: false,
+      refresh: vi.fn(),
+    }
+
+    vi.mocked(EntityApi.useEntityList).mockReturnValue(mockReturn)
+
+    renderHook(
+      () => useGoalList(null),
+      { wrapper: TestProviders }
+    )
+
+    expect(EntityApi.useEntityList).toHaveBeenCalledWith(
+      'http://localhost:3000/goals',
+      expect.any(Function),
+      null
+    )
+  })
+})
+
+describe('GoalApi.listNested', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('fetches goals nested under the coaching session endpoint', async () => {
+    vi.mocked(EntityApi.listNestedFn).mockResolvedValue([])
+
+    await GoalApi.listNested('session-123')
+
+    expect(EntityApi.listNestedFn).toHaveBeenCalledWith(
+      'http://localhost:3000/coaching_sessions',
+      'session-123',
+      'goals',
+      {}
+    )
+  })
+})
+
+describe('useGoalsBySession hook', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('passes session-scoped URL to EntityApi.useEntityList', () => {
+    const mockReturn = {
+      entities: [],
+      isLoading: false,
+      isError: false,
+      refresh: vi.fn(),
+    }
+
+    vi.mocked(EntityApi.useEntityList).mockReturnValue(mockReturn)
+
+    renderHook(
+      () => useGoalsBySession('session-789'),
+      { wrapper: TestProviders }
+    )
+
+    expect(EntityApi.useEntityList).toHaveBeenCalledWith(
+      'http://localhost:3000/coaching_sessions/session-789/goals',
+      expect.any(Function),
+      'session-789'
+    )
+  })
+
+  it('returns goals array from entities', () => {
+    const mockGoals = [
+      { id: 'goal-1', title: 'Test Goal' },
+      { id: 'goal-2', title: 'Another Goal' },
+    ]
+
+    vi.mocked(EntityApi.useEntityList).mockReturnValue({
+      entities: mockGoals as any,
+      isLoading: false,
+      isError: false,
+      refresh: vi.fn(),
+    })
+
+    const { result } = renderHook(
+      () => useGoalsBySession('session-789'),
+      { wrapper: TestProviders }
+    )
+
+    expect(result.current.goals).toEqual(mockGoals)
+    expect(result.current.isLoading).toBe(false)
+  })
+})
diff --git a/__tests__/test-utils.ts b/__tests__/test-utils.ts
index 980e94d0..f432c7c7 100644
--- a/__tests__/test-utils.ts
+++ b/__tests__/test-utils.ts
@@ -1,6 +1,8 @@
 import { DateTime } from "ts-luxon";
 import { CoachingSession } from "@/types/coaching-session";
 import { CoachingRelationshipWithUserNames } from "@/types/coaching_relationship";
+import { Goal } from "@/types/goal";
+import { ItemStatus } from "@/types/general";
 import { Organization } from "@/types/organization";
 import { User } from "@/types/user";
 import { OAuthConnection } from "@/types/oauth-connection";
@@ -84,6 +86,25 @@ export function createSessionAt(minutesFromNow: number): CoachingSession {
   });
 }
 
+export function createMockGoal(overrides?: Partial<Goal>): Goal {
+  const now = DateTime.now();
+  return {
+    id: "goal-1",
+    coaching_relationship_id: "rel-1",
+    created_in_session_id: "session-1",
+    user_id: "user-1",
+    title: "Improve communication",
+    body: "Work on active listening",
+    status: ItemStatus.NotStarted,
+    status_changed_at: now,
+    completed_at: now,
+    target_date: null,
+    created_at: now,
+    updated_at: now,
+    ...overrides,
+  };
+}
+
 export function createMockGoogleOAuthConnectionState(
   overrides?: Partial<OAuthConnection>
 ): OAuthConnection {
diff --git a/__tests__/types/goal.test.ts b/__tests__/types/goal.test.ts
new file mode 100644
index 00000000..98720cbe
--- /dev/null
+++ b/__tests__/types/goal.test.ts
@@ -0,0 +1,199 @@
+import { describe, it, expect } from 'vitest'
+import { DateTime } from 'ts-luxon'
+import { ItemStatus } from '@/types/general'
+import {
+  isGoal,
+  isGoalArray,
+  parseGoal,
+  defaultGoal,
+  defaultGoals,
+  getGoalById,
+  goalToString,
+  goalsToString,
+} from '@/types/goal'
+import type { Goal } from '@/types/goal'
+
+/** Factory for creating test Goal data matching the PR2 schema */
+function makeGoalData(overrides?: Partial<Record<string, unknown>>): Record<string, unknown> {
+  return {
+    id: 'goal-1',
+    coaching_relationship_id: 'rel-1',
+    created_in_session_id: 'session-1',
+    user_id: 'user-1',
+    title: 'Improve communication',
+    body: 'Work on active listening',
+    status: 'NotStarted',
+    status_changed_at: '2026-03-01T00:00:00Z',
+    completed_at: '2026-03-10T00:00:00Z',
+    target_date: '2026-06-15',
+    created_at: '2026-03-01T00:00:00Z',
+    updated_at: '2026-03-01T00:00:00Z',
+    ...overrides,
+  }
+}
+
+describe('isGoal', () => {
+  it('returns true for a valid goal with all required fields', () => {
+    expect(isGoal(makeGoalData())).toBe(true)
+  })
+
+  it('returns true when created_in_session_id is null', () => {
+    expect(isGoal(makeGoalData({ created_in_session_id: null }))).toBe(true)
+  })
+
+  it('returns true when target_date is null', () => {
+    expect(isGoal(makeGoalData({ target_date: null }))).toBe(true)
+  })
+
+  it('returns false for null', () => {
+    expect(isGoal(null)).toBe(false)
+  })
+
+  it('returns false for undefined', () => {
+    expect(isGoal(undefined)).toBe(false)
+  })
+
+  it('returns false for a non-object', () => {
+    expect(isGoal('not a goal')).toBe(false)
+  })
+
+  it('returns false when id is missing', () => {
+    const { id: _, ...rest } = makeGoalData()
+    expect(isGoal(rest)).toBe(false)
+  })
+
+  it('returns false when coaching_relationship_id is missing', () => {
+    const { coaching_relationship_id: _, ...rest } = makeGoalData()
+    expect(isGoal(rest)).toBe(false)
+  })
+
+  it('returns false when user_id is missing', () => {
+    const { user_id: _, ...rest } = makeGoalData()
+    expect(isGoal(rest)).toBe(false)
+  })
+
+  it('does not require the old coaching_session_id field', () => {
+    // PR2 removed coaching_session_id — goals should validate without it
+    const data = makeGoalData()
+    expect(data).not.toHaveProperty('coaching_session_id')
+    expect(isGoal(data)).toBe(true)
+  })
+})
+
+describe('isGoalArray', () => {
+  it('returns true for an array of valid goals', () => {
+    expect(isGoalArray([makeGoalData(), makeGoalData({ id: 'goal-2' })])).toBe(true)
+  })
+
+  it('returns true for an empty array', () => {
+    expect(isGoalArray([])).toBe(true)
+  })
+
+  it('returns false for a non-array', () => {
+    expect(isGoalArray(makeGoalData())).toBe(false)
+  })
+})
+
+describe('parseGoal', () => {
+  it('parses valid goal data into a Goal object', () => {
+    const data = makeGoalData()
+    const goal = parseGoal(data)
+
+    expect(goal.id).toBe('goal-1')
+    expect(goal.coaching_relationship_id).toBe('rel-1')
+    expect(goal.created_in_session_id).toBe('session-1')
+    expect(goal.user_id).toBe('user-1')
+    expect(goal.title).toBe('Improve communication')
+    expect(goal.body).toBe('Work on active listening')
+    expect(goal.status).toBe('NotStarted')
+    expect(goal.target_date).toBe('2026-06-15')
+  })
+
+  it('parses goal with null created_in_session_id', () => {
+    const goal = parseGoal(makeGoalData({ created_in_session_id: null }))
+    expect(goal.created_in_session_id).toBeNull()
+  })
+
+  it('parses goal with null target_date', () => {
+    const goal = parseGoal(makeGoalData({ target_date: null }))
+    expect(goal.target_date).toBeNull()
+  })
+
+  it('throws on invalid data', () => {
+    expect(() => parseGoal({ id: 123 })).toThrow()
+  })
+})
+
+describe('defaultGoal', () => {
+  it('returns a goal with the PR2 field shape', () => {
+    const goal = defaultGoal()
+
+    expect(goal).toHaveProperty('id')
+    expect(goal).toHaveProperty('coaching_relationship_id')
+    expect(goal).toHaveProperty('created_in_session_id')
+    expect(goal).toHaveProperty('target_date')
+    expect(goal).toHaveProperty('user_id')
+    expect(goal).toHaveProperty('title')
+    expect(goal).toHaveProperty('body')
+    expect(goal).toHaveProperty('status')
+  })
+
+  it('does not have the old coaching_session_id field', () => {
+    const goal = defaultGoal()
+    expect(goal).not.toHaveProperty('coaching_session_id')
+  })
+
+  it('has null for nullable fields', () => {
+    const goal = defaultGoal()
+    expect(goal.created_in_session_id).toBeNull()
+    expect(goal.target_date).toBeNull()
+  })
+
+  it('has NotStarted status', () => {
+    const goal = defaultGoal()
+    expect(goal.status).toBe(ItemStatus.NotStarted)
+  })
+})
+
+describe('defaultGoals', () => {
+  it('returns an array with one default goal', () => {
+    const goals = defaultGoals()
+    expect(goals).toHaveLength(1)
+    expect(goals[0]).toHaveProperty('coaching_relationship_id')
+  })
+})
+
+describe('getGoalById', () => {
+  it('returns the matching goal', () => {
+    const now = DateTime.now()
+    const goals: Goal[] = [
+      { ...defaultGoal(), id: 'a', coaching_relationship_id: 'rel-1', created_at: now, updated_at: now },
+      { ...defaultGoal(), id: 'b', coaching_relationship_id: 'rel-1', created_at: now, updated_at: now },
+    ]
+    expect(getGoalById('b', goals).id).toBe('b')
+  })
+
+  it('returns a default goal when not found', () => {
+    const goal = getGoalById('nonexistent', [])
+    expect(goal.id).toBe('')
+    expect(goal).toHaveProperty('coaching_relationship_id')
+  })
+})
+
+describe('goalToString / goalsToString', () => {
+  it('serializes a goal to JSON', () => {
+    const goal = defaultGoal()
+    const json = goalToString(goal)
+    expect(json).toContain('coaching_relationship_id')
+    expect(json).not.toContain('coaching_session_id')
+  })
+
+  it('serializes undefined to "undefined"', () => {
+    expect(goalToString(undefined)).toBe(undefined)
+  })
+
+  it('serializes a goal array to JSON', () => {
+    const json = goalsToString([defaultGoal()])
+    expect(json).toContain('coaching_relationship_id')
+  })
+})
diff --git a/src/components/ui/coaching-session-selector.tsx b/src/components/ui/coaching-session-selector.tsx
index 12fb8170..ed7d644d 100644
--- a/src/components/ui/coaching-session-selector.tsx
+++ b/src/components/ui/coaching-session-selector.tsx
@@ -17,7 +17,8 @@ import {
   useEnrichedCoachingSessionsForUser,
   CoachingSessionInclude,
 } from "@/lib/api/coaching-sessions";
-import { useGoalBySession } from "@/lib/api/goals";
+import { useGoalByRelationship } from "@/lib/api/goals";
+import { DEFAULT_GOAL_TITLE, goalTitle } from "@/types/goal";
 import { useCurrentCoachingSession } from "@/lib/hooks/use-current-coaching-session";
 import { DateTime } from "ts-luxon";
 import type { EnrichedCoachingSession } from "@/types/coaching-session";
@@ -143,7 +144,7 @@ function SessionItem({
       <div className="flex min-w-0 ml-4">
         <div className="min-w-0 w-full">
           <p className="truncate text-sm font-medium">
-            {session.goal?.title || "No goal set"}
+            {session.goal ? goalTitle(session.goal) : DEFAULT_GOAL_TITLE}
           </p>
           <p className="truncate text-sm text-gray-400">
             {formatDateInUserTimezone(
@@ -172,7 +173,7 @@ export default function CoachingSessionSelector({
   const { userSession } = useAuthStore((state) => state);
 
   const { goal, isLoading: isLoadingGoal } =
-    useGoalBySession(currentCoachingSessionId || "");
+    useGoalByRelationship(relationshipId);
 
   const handleSetCoachingSession = (coachingSessionId: Id) => {
     // Navigate to the coaching session page
@@ -199,7 +200,7 @@ export default function CoachingSessionSelector({
             <span>Loading goal...</span>
           </span>
         ) : (
-          goal?.title || "No goal set"
+          goalTitle(goal)
         )}
       </span>
       <span className="text-sm text-gray-500 text-left truncate">
diff --git a/src/components/ui/coaching-session.tsx b/src/components/ui/coaching-session.tsx
index 0a1dc8f2..05e8fcc5 100644
--- a/src/components/ui/coaching-session.tsx
+++ b/src/components/ui/coaching-session.tsx
@@ -4,7 +4,8 @@ import React from "react";
 import { Card, CardHeader } from "@/components/ui/card";
 import { Button } from "@/components/ui/button";
 import Link from "next/link";
-import { useGoalBySession } from "@/lib/api/goals";
+import { useGoalsBySession } from "@/lib/api/goals";
+import { DEFAULT_GOAL_TITLE, goalTitle } from "@/types/goal";
 import { Id } from "@/types/general";
 import {
   DropdownMenu,
@@ -101,19 +102,21 @@ const SessionGoal: React.FC<SessionGoalProps> = ({
   coachingSessionId,
 }) => {
   const {
-    goal,
-    isLoading: isLoadingGoal,
-    isError: isErrorGoal,
-  } = useGoalBySession(coachingSessionId);
+    goals,
+    isLoading: isLoadingGoals,
+    isError: isErrorGoals,
+  } = useGoalsBySession(coachingSessionId);
 
   let titleText: string;
 
-  if (isLoadingGoal) {
+  if (isLoadingGoals) {
     titleText = "Loading...";
-  } else if (isErrorGoal) {
+  } else if (isErrorGoals) {
     titleText = "Error loading goal";
   } else {
-    titleText = goal?.title || "No goal set";
+    titleText = goals.length > 0
+      ? goalTitle(goals[0])
+      : DEFAULT_GOAL_TITLE;
   }
 
   return <div>{titleText}</div>;
diff --git a/src/components/ui/coaching-sessions/goal-container.tsx b/src/components/ui/coaching-sessions/goal-container.tsx
index 51609d36..ab1faf6b 100644
--- a/src/components/ui/coaching-sessions/goal-container.tsx
+++ b/src/components/ui/coaching-sessions/goal-container.tsx
@@ -6,46 +6,60 @@ import { Collapsible, CollapsibleContent } from "@/components/ui/collapsible";
 import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
 import { GoalComponent } from "./goal";
 import {
-  useGoalBySession,
+  useGoalsBySession,
   useGoalMutation,
 } from "@/lib/api/goals";
-import { Goal } from "@/types/goal";
+import {
+  defaultGoal,
+  Goal,
+  extractActiveGoalLimitError,
+} from "@/types/goal";
+import { Id } from "@/types/general";
 import { useCurrentCoachingSession } from "@/lib/hooks/use-current-coaching-session";
+import { useCurrentCoachingRelationship } from "@/lib/hooks/use-current-coaching-relationship";
+import { toast } from "@/components/ui/use-toast";
 
-const GoalContainer: React.FC = () => {
-  const [isOpen, setIsOpen] = useState(false);
+interface GoalContainerInnerProps {
+  coachingSessionId: Id;
+  coachingRelationshipId: Id;
+}
 
-  // Get coaching session ID from URL
-  const { currentCoachingSessionId } = useCurrentCoachingSession();
+const GoalContainerInner: React.FC<GoalContainerInnerProps> = ({
+  coachingSessionId,
+  coachingRelationshipId,
+}) => {
+  const [isOpen, setIsOpen] = useState(false);
 
-  const { goal, refresh } =
-    useGoalBySession(currentCoachingSessionId || "");
+  const { goals, refresh } =
+    useGoalsBySession(coachingSessionId);
+  const goal = goals.length > 0 ? goals[0] : defaultGoal();
   const { create: createGoal, update: updateGoal } =
     useGoalMutation();
 
-  const handleGoalChange = async (newGoal: Goal) => {
+  const handleGoalChange = async (currentGoal: Goal, newGoal: Goal) => {
     try {
-      if (currentCoachingSessionId) {
-        if (goal.id) {
-          await updateGoal(
-            goal.id,
-            newGoal
-          );
-        } else if (!goal.id) {
-          newGoal.coaching_session_id = currentCoachingSessionId;
-          await createGoal(newGoal);
-
-          // Manually trigger a local refresh of the cached Goal data such that
-          // any other local code using the KeyedMutator will also update with this new data.
-          refresh();
-        }
+      if (currentGoal.id) {
+        await updateGoal(currentGoal.id, newGoal);
       } else {
-        console.error(
-          "Could not update or create a Goal since coachingSessionId or userId are not set."
-        );
+        newGoal.coaching_relationship_id = coachingRelationshipId;
+        newGoal.created_in_session_id = coachingSessionId;
+        await createGoal(newGoal);
+
+        // Manually trigger a local refresh of the cached Goal data such that
+        // any other local code using the KeyedMutator will also update with this new data.
+        refresh();
       }
     } catch (err) {
-      console.error("Failed to update or create Goal: " + err);
+      const limitInfo = extractActiveGoalLimitError(err);
+      if (limitInfo) {
+        toast({
+          variant: "destructive",
+          title: "Goal limit reached",
+          description: `You already have ${limitInfo.maxActiveGoals} goals in progress for this coaching relationship. Please complete or change the status of one before starting another.`,
+        });
+      } else {
+        console.error("Failed to update or create Goal: " + err);
+      }
     }
   };
 
@@ -60,7 +74,7 @@ const GoalContainer: React.FC = () => {
           <GoalComponent
             initialValue={goal}
             onOpenChange={(open: boolean) => setIsOpen(open)}
-            onGoalChange={(g: Goal) => handleGoalChange(g)}
+            onGoalChange={(g: Goal) => handleGoalChange(goal, g)}
           ></GoalComponent>
           <CollapsibleContent className="px-4">
             <div className="flex-col space-y-4 sm:flex">
@@ -89,4 +103,21 @@ const GoalContainer: React.FC = () => {
   );
 };
 
+const GoalContainer: React.FC = () => {
+  const { currentCoachingSessionId } = useCurrentCoachingSession();
+  const { currentCoachingRelationshipId } = useCurrentCoachingRelationship();
+
+  // Guard: only render when both session and relationship IDs are available
+  if (!currentCoachingSessionId || !currentCoachingRelationshipId) {
+    return null;
+  }
+
+  return (
+    <GoalContainerInner
+      coachingSessionId={currentCoachingSessionId}
+      coachingRelationshipId={currentCoachingRelationshipId}
+    />
+  );
+};
+
 export { GoalContainer };
diff --git a/src/components/ui/coaching-sessions/goal.tsx b/src/components/ui/coaching-sessions/goal.tsx
index 53e64374..113d93f6 100644
--- a/src/components/ui/coaching-sessions/goal.tsx
+++ b/src/components/ui/coaching-sessions/goal.tsx
@@ -14,6 +14,7 @@ import { cn } from "@/components/lib/utils";
 import {
   defaultGoal,
   Goal,
+  goalTitle,
 } from "@/types/goal";
 
 const GoalComponent: React.FC<{
@@ -77,7 +78,7 @@ const GoalComponent: React.FC<{
                   onClick={(e) => e.stopPropagation()}
                 >
                   <span className="mr-1 text-foreground hidden md:inline">Goal:</span>
-                  {goal.title}
+                  {goalTitle(goal)}
                 </div>
               </div>
             )}
diff --git a/src/components/ui/dashboard/today-session-card.tsx b/src/components/ui/dashboard/today-session-card.tsx
index df924853..def4d4bb 100644
--- a/src/components/ui/dashboard/today-session-card.tsx
+++ b/src/components/ui/dashboard/today-session-card.tsx
@@ -13,6 +13,7 @@ import { copyCoachingSessionLinkWithToast } from "@/components/ui/share-session-
 import { cn } from "@/components/lib/utils";
 import { PulsingDot } from "@/components/ui/pulsing-dot";
 import { SessionUrgency } from "@/types/session-display";
+import { DEFAULT_GOAL_TITLE, goalTitle } from "@/types/goal";
 import { RelationshipRole } from "@/types/relationship-role";
 import type { AssignedActionWithContext } from "@/types/assigned-actions";
 import { useAuthStore } from "@/lib/providers/auth-store-provider";
@@ -209,7 +210,7 @@ export function TodaySessionCard({
     timezone
   );
 
-  const goalText = session.goal?.title || "No goal set";
+  const goalText = session.goal ? goalTitle(session.goal) : DEFAULT_GOAL_TITLE;
   const organizationName = session.organization?.name || "Unknown organization";
 
   /**
diff --git a/src/components/ui/join-session-popover.tsx b/src/components/ui/join-session-popover.tsx
index 0d287f29..5b9854ee 100644
--- a/src/components/ui/join-session-popover.tsx
+++ b/src/components/ui/join-session-popover.tsx
@@ -17,6 +17,7 @@ import {
   CollapsibleContent,
   CollapsibleTrigger,
 } from "@/components/ui/collapsible";
+import { DEFAULT_GOAL_TITLE, goalTitle } from "@/types/goal";
 import {
   Select,
   SelectContent,
@@ -364,7 +365,7 @@ function SessionGroup({
           className="flex flex-col items-start w-full rounded-md px-2 py-1.5 text-left text-sm transition-colors hover:bg-accent hover:text-accent-foreground"
         >
           <span className="w-full truncate font-medium">
-            {session.goal?.title || "No goal set"}
+            {session.goal ? goalTitle(session.goal) : DEFAULT_GOAL_TITLE}
           </span>
           <span className="text-xs text-muted-foreground truncate">
             {formatDateInUserTimezone(session.date, timezone)}
diff --git a/src/lib/api/goals.ts b/src/lib/api/goals.ts
index a9367453..2eda5bf0 100644
--- a/src/lib/api/goals.ts
+++ b/src/lib/api/goals.ts
@@ -10,6 +10,7 @@ import { ApiSortOrder, GoalSortField } from "@/types/sorting";
 import { EntityApi } from "./entity-api";
 
 const GOALS_BASEURL: string = `${siteConfig.env.backendServiceURL}/goals`;
+const COACHING_SESSIONS_BASEURL: string = `${siteConfig.env.backendServiceURL}/coaching_sessions`;
 
 /**
  * API client for goal-related operations.
@@ -19,20 +20,20 @@ const GOALS_BASEURL: string = `${siteConfig.env.backendServiceURL}/goals`;
  */
 export const GoalApi = {
   /*
-   * Fetches a list of goals associated with a specific coaching session.
+   * Fetches a list of goals associated with a specific coaching relationship.
    *
-   * @param coachingSessionId The ID of the coaching session whose goals should be retrieved
+   * @param coachingRelationshipId The ID of the coaching relationship whose goals should be retrieved
    * @param sortBy Optional field to sort by.
    * @param sortOrder Optional sort order.
    * @returns Promise resolving to an array of Goal objects
    */
   list: async (
-    coachingSessionId: Id,
+    coachingRelationshipId: Id,
     sortBy?: GoalSortField,
     sortOrder?: ApiSortOrder
   ): Promise<Goal[]> => {
     const params: Record<string, string> = {
-      coaching_session_id: coachingSessionId,
+      coaching_relationship_id: coachingRelationshipId,
     };
 
     if (sortBy) {
@@ -45,6 +46,22 @@ export const GoalApi = {
     return EntityApi.listFn<Goal>(GOALS_BASEURL, { params });
   },
 
+  /**
+   * Fetches goals nested under a coaching session via the join table.
+   * Uses GET /coaching_sessions/{session_id}/goals which returns full Goal models.
+   *
+   * @param coachingSessionId The ID of the parent coaching session
+   * @returns Promise resolving to an array of Goal objects linked to the session
+   */
+  listNested: async (coachingSessionId: Id): Promise<Goal[]> => {
+    return EntityApi.listNestedFn<Goal>(
+      COACHING_SESSIONS_BASEURL,
+      coachingSessionId,
+      'goals',
+      {}
+    );
+  },
+
   /**
    * Fetches a single goal by its ID.
    *
@@ -116,12 +133,12 @@ export const GoalApi = {
 };
 
 /**
- * A custom React hook that fetches a list of goals for a specific coaching session.
+ * A custom React hook that fetches a list of goals for a specific coaching relationship.
  *
  * This hook uses SWR to efficiently fetch, cache, and revalidate goal data.
  * It automatically refreshes data when the component mounts.
  *
- * @param coachingSessionId The ID of the coaching session whose goals should be fetched
+ * @param coachingRelationshipId The ID of the coaching relationship whose goals should be fetched
  * @returns An object containing:
  *
  * * goals: Array of Goal objects (empty array if data is not yet loaded)
@@ -129,12 +146,13 @@ export const GoalApi = {
  * * isError: Error object if the fetch operation failed, undefined otherwise
  * * refresh: Function to manually trigger a refresh of the data
  */
-export const useGoalList = (coachingSessionId: Id) => {
+export const useGoalList = (coachingRelationshipId: Id | null) => {
   const { entities, isLoading, isError, refresh } =
     EntityApi.useEntityList<Goal>(
       GOALS_BASEURL,
-      () => GoalApi.list(coachingSessionId),
-      coachingSessionId
+      // SWR skips this fetcher when params are falsy (null key = no fetch)
+      () => GoalApi.list(coachingRelationshipId!),
+      coachingRelationshipId
     );
 
   return {
@@ -177,10 +195,10 @@ export const useGoal = (id: Id) => {
 };
 
 /**
- * A custom React hook that fetches a single goal by coaching session ID.
+ * A custom React hook that fetches the first goal for a coaching relationship.
  * This hook uses SWR to efficiently fetch and cache goal data.
  *
- * @param coachingSessionId The coaching session ID of the goal to fetch.
+ * @param coachingRelationshipId The coaching relationship ID whose first goal should be fetched.
  * @returns An object containing:
  *
  * * goal: The fetched Goal object, or a default goal if not yet loaded
@@ -188,9 +206,9 @@ export const useGoal = (id: Id) => {
  * * isError: Error object if the fetch operation failed, undefined otherwise
  * * refresh: Function to manually trigger a refresh of the data
  */
-export const useGoalBySession = (coachingSessionId: Id) => {
+export const useGoalByRelationship = (coachingRelationshipId: Id | null) => {
   const { goals, isLoading, isError, refresh } =
-    useGoalList(coachingSessionId);
+    useGoalList(coachingRelationshipId);
 
   return {
     goal: goals.length
@@ -202,6 +220,41 @@ export const useGoalBySession = (coachingSessionId: Id) => {
   };
 };
 
+/**
+ * A custom React hook that fetches goals linked to a specific coaching session
+ * via the coaching_sessions_goals join table.
+ *
+ * Uses GET /coaching_sessions/{session_id}/goals which returns full Goal models.
+ *
+ * @param coachingSessionId The coaching session ID whose linked goals should be fetched.
+ * @returns An object containing:
+ *
+ * * goals: Array of Goal objects linked to the session (empty array if not loaded)
+ * * isLoading: Boolean indicating if the data is currently being fetched
+ * * isError: Error object if the fetch operation failed, undefined otherwise
+ * * refresh: Function to manually trigger a refresh of the data
+ */
+export const useGoalsBySession = (coachingSessionId: Id | null) => {
+  const url = coachingSessionId
+    ? `${COACHING_SESSIONS_BASEURL}/${coachingSessionId}/goals`
+    : COACHING_SESSIONS_BASEURL;
+
+  const { entities, isLoading, isError, refresh } =
+    EntityApi.useEntityList<Goal>(
+      url,
+      // SWR skips this fetcher when params are falsy (null key = no fetch)
+      () => GoalApi.listNested(coachingSessionId!),
+      coachingSessionId
+    );
+
+  return {
+    goals: entities,
+    isLoading,
+    isError,
+    refresh,
+  };
+};
+
 /**
  * Hook for goal mutations.
  * Provides methods to create, update, and delete goals.
diff --git a/src/lib/hooks/use-sse-cache-invalidation.ts b/src/lib/hooks/use-sse-cache-invalidation.ts
index 466ae42d..c10a4e8c 100644
--- a/src/lib/hooks/use-sse-cache-invalidation.ts
+++ b/src/lib/hooks/use-sse-cache-invalidation.ts
@@ -36,6 +36,23 @@ export function useSSECacheInvalidation(eventSource: EventSource | null) {
     console.log(`[SSE] Revalidated ${endpointPath} cache after ${eventName}`);
   }, [mutate, baseUrl]);
 
+  /**
+   * Invalidates only the session-scoped goal caches (e.g. /coaching_sessions/{id}/goals)
+   * without touching other coaching_sessions caches (session list, enriched sessions, etc.).
+   */
+  const invalidateSessionGoals = useCallback((eventName: string) => {
+    const sessionGoalsPattern = `${baseUrl}/coaching_sessions/`;
+    mutate(
+      (key) => {
+        const url = typeof key === 'string' ? key : Array.isArray(key) ? key[0] : null;
+        return typeof url === 'string' && url.startsWith(sessionGoalsPattern) && url.endsWith('/goals');
+      },
+      undefined,
+      { revalidate: true }
+    );
+    console.log(`[SSE] Revalidated session-scoped goal caches after ${eventName}`);
+  }, [mutate, baseUrl]);
+
   // ACTION EVENTS - Invalidate only /actions endpoint
   useSSEEventHandler(eventSource, 'action_created', () => {
     invalidateEndpoint('/actions', 'action_created');
@@ -62,16 +79,19 @@ export function useSSECacheInvalidation(eventSource: EventSource | null) {
     invalidateEndpoint('/agreements', 'agreement_deleted');
   });
 
-  // GOAL EVENTS - Invalidate only /goals endpoint
+  // GOAL EVENTS - Invalidate /goals and session-scoped goal caches (join table)
   useSSEEventHandler(eventSource, 'goal_created', () => {
     invalidateEndpoint('/goals', 'goal_created');
+    invalidateSessionGoals('goal_created');
   });
 
   useSSEEventHandler(eventSource, 'goal_updated', () => {
     invalidateEndpoint('/goals', 'goal_updated');
+    invalidateSessionGoals('goal_updated');
   });
 
   useSSEEventHandler(eventSource, 'goal_deleted', () => {
     invalidateEndpoint('/goals', 'goal_deleted');
+    invalidateSessionGoals('goal_deleted');
   });
 }
diff --git a/src/lib/utils/session.ts b/src/lib/utils/session.ts
index 1fe5567c..6f5534fe 100644
--- a/src/lib/utils/session.ts
+++ b/src/lib/utils/session.ts
@@ -12,6 +12,7 @@ import {
   getUserRoleInRelationship,
 } from "@/lib/utils/relationship";
 import { getBrowserTimezone } from "@/lib/timezone-utils";
+import { goalTitle } from "@/types/goal";
 
 /**
  * Session Utility Functions
@@ -224,7 +225,7 @@ export function enrichSessionForDisplay(
 
   return {
     id: session.id,
-    goalTitle: goal?.title || "Coaching Session",
+    goalTitle: goal ? goalTitle(goal, "Coaching Session") : "Coaching Session",
     participantName: getOtherParticipantName(relationship, user),
     userRole: getUserRoleInRelationship(relationship, user),
     dateTime: formatSessionDateTime(session.date, timezone),
diff --git a/src/types/goal.ts b/src/types/goal.ts
index b6de1cc0..21be9082 100644
--- a/src/types/goal.ts
+++ b/src/types/goal.ts
@@ -1,34 +1,100 @@
 import { DateTime } from "ts-luxon";
-import { Id, ItemStatus } from "@/types/general";
+import { Id, ItemStatus, EntityApiError } from "@/types/general";
+
+// ─── Active Goal Limit (409 Conflict) ───────────────────────────────
+// "Active" means InProgress ONLY — NotStarted does not count.
+// See ActiveGoalLimitError contract v4 on the coordination board.
+
+/** Default limit used when no 409 response has been received yet. */
+const DEFAULT_MAX_ACTIVE_GOALS = 3;
+
+/** Summary of an InProgress goal returned in the 409 response body. */
+export interface ActiveGoalSummary {
+  id: Id;
+  title: string;
+}
+
+/** Parsed result from a 409 active-goal-limit error. */
+export interface ActiveGoalLimitInfo {
+  maxActiveGoals: number;
+  activeGoals: ActiveGoalSummary[];
+}
+
+/** Shape of the 409 response body when the active-goal limit is exceeded. */
+export interface ActiveGoalLimitErrorData {
+  status_code: 409;
+  error: "active_goal_limit_reached";
+  message: string;
+  max_active_goals: number;
+  active_goals: ActiveGoalSummary[];
+}
+
+/**
+ * Extracts active-goal-limit info from an EntityApiError if it represents
+ * a 409 active-goal-limit error. Returns the limit and active goals on match,
+ * or null if the error is something else.
+ */
+export function extractActiveGoalLimitError(
+  err: unknown
+): ActiveGoalLimitInfo | null {
+  if (
+    !(err instanceof EntityApiError) ||
+    err.status !== 409
+  ) {
+    return null;
+  }
+
+  const data = err.data;
+  if (
+    data &&
+    typeof data === "object" &&
+    data.error === "active_goal_limit_reached" &&
+    Array.isArray(data.active_goals) &&
+    typeof data.max_active_goals === "number"
+  ) {
+    return {
+      maxActiveGoals: data.max_active_goals,
+      activeGoals: data.active_goals as ActiveGoalSummary[],
+    };
+  }
+
+  return null;
+}
+
+export { DEFAULT_MAX_ACTIVE_GOALS };
 
 // This must always reflect the Rust struct on the backend
 // entity::goals::Model
 export interface Goal {
   id: Id;
-  coaching_session_id: Id;
+  coaching_relationship_id: Id;
+  created_in_session_id: Id | null;
   user_id: Id;
   title: string;
   body: string;
   status: ItemStatus;
   status_changed_at: DateTime;
   completed_at: DateTime;
+  target_date: string | null;
   created_at: DateTime;
   updated_at: DateTime;
 }
 
 export function parseGoal(data: any): Goal {
   if (!isGoal(data)) {
-    throw new Error("Invalid CoachingSession data");
+    throw new Error("Invalid Goal data");
   }
   return {
     id: data.id,
-    coaching_session_id: data.coaching_session_id,
+    coaching_relationship_id: data.coaching_relationship_id,
+    created_in_session_id: data.created_in_session_id ?? null,
     user_id: data.user_id,
     title: data.title,
     body: data.body,
     status: data.status,
     status_changed_at: data.status_changed_at,
     completed_at: data.completed_at,
+    target_date: data.target_date ?? null,
     created_at: data.created_at,
     updated_at: data.updated_at,
   };
@@ -41,16 +107,18 @@ export function isGoal(value: unknown): value is Goal {
   const object = value as Record<string, unknown>;
 
   return (
-    (typeof object.id === "string" &&
-      typeof object.coaching_session_id === "string" &&
-      typeof object.user_id === "string" &&
-      typeof object.status === "string" &&
-      typeof object.created_at === "string" &&
-      typeof object.updated_at === "string") ||
-    typeof object.title === "string" ||
-    typeof object.body === "string" ||
-    typeof object.status_changed_at === "string" ||
-    typeof object.completed_at === "string"
+    typeof object.id === "string" &&
+    typeof object.coaching_relationship_id === "string" &&
+    (object.created_in_session_id === null || typeof object.created_in_session_id === "string") &&
+    typeof object.user_id === "string" &&
+    typeof object.title === "string" &&
+    typeof object.body === "string" &&
+    typeof object.status === "string" &&
+    (object.target_date === null || typeof object.target_date === "string") &&
+    typeof object.status_changed_at === "string" &&
+    typeof object.completed_at === "string" &&
+    typeof object.created_at === "string" &&
+    typeof object.updated_at === "string"
   );
 }
 
@@ -72,13 +140,15 @@ export function defaultGoal(): Goal {
   const now = DateTime.now();
   return {
     id: "",
-    coaching_session_id: "",
+    coaching_relationship_id: "",
+    created_in_session_id: null,
     user_id: "",
     title: "",
     body: "",
     status: ItemStatus.NotStarted,
     status_changed_at: now,
     completed_at: now,
+    target_date: null,
     created_at: now,
     updated_at: now,
   };
@@ -88,6 +158,19 @@ export function defaultGoals(): Goal[] {
   return [defaultGoal()];
 }
 
+export const DEFAULT_GOAL_TITLE = "No goal set";
+
+/**
+ * Returns the goal's title if non-empty, otherwise a default fallback.
+ * Handles empty string titles consistently across the UI.
+ */
+export function goalTitle(
+  goal: Pick<Goal, "title">,
+  fallback: string = DEFAULT_GOAL_TITLE
+): string {
+  return goal.title || fallback;
+}
+
 export function goalToString(
   goal: Goal | undefined
 ): string {