diff --git a/Actions/Brain/ListKnowledge.php b/Actions/Brain/ListKnowledge.php
index e4c0e94..8484e51 100644
--- a/Actions/Brain/ListKnowledge.php
+++ b/Actions/Brain/ListKnowledge.php
@@ -6,7 +6,6 @@ namespace Core\Mod\Agentic\Actions\Brain;
 
 use Core\Actions\Action;
 use Core\Mod\Agentic\Models\BrainMemory;
-use Illuminate\Support\Collection;
 
 /**
  * List memories in the shared OpenBrain knowledge store.
diff --git a/Actions/Phase/AddCheckpoint.php b/Actions/Phase/AddCheckpoint.php
new file mode 100644
index 0000000..fe138c0
--- /dev/null
+++ b/Actions/Phase/AddCheckpoint.php
@@ -0,0 +1,69 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Phase;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentPhase;
+use Core\Mod\Agentic\Models\AgentPlan;
+
+/**
+ * Add a checkpoint note to a phase.
+ *
+ * Checkpoints record milestones, decisions, and progress notes
+ * within a phase's metadata for later review.
+ *
+ * Usage:
+ *   $phase = AddCheckpoint::run('deploy-v2', '1', 'Tests passing', 1);
+ */
+class AddCheckpoint
+{
+    use Action;
+
+    /**
+     * @throws \InvalidArgumentException
+     */
+    public function handle(string $planSlug, string|int $phase, string $note, int $workspaceId, array $context = []): AgentPhase
+    {
+        if ($note === '') {
+            throw new \InvalidArgumentException('note is required');
+        }
+
+        $plan = AgentPlan::forWorkspace($workspaceId)
+            ->where('slug', $planSlug)
+            ->first();
+
+        if (! $plan) {
+            throw new \InvalidArgumentException("Plan not found: {$planSlug}");
+        }
+
+        $resolved = $this->resolvePhase($plan, $phase);
+
+        if (! $resolved) {
+            throw new \InvalidArgumentException("Phase not found: {$phase}");
+        }
+
+        $resolved->addCheckpoint($note, $context);
+
+        return $resolved->fresh();
+    }
+
+    private function resolvePhase(AgentPlan $plan, string|int $identifier): ?AgentPhase
+    {
+        if (is_numeric($identifier)) {
+            return $plan->agentPhases()->where('order', (int) $identifier)->first();
+        }
+
+        return $plan->agentPhases()
+            ->where('name', $identifier)
+            ->first();
+    }
+}
diff --git a/Actions/Phase/GetPhase.php b/Actions/Phase/GetPhase.php
new file mode 100644
index 0000000..3e9647c
--- /dev/null
+++ b/Actions/Phase/GetPhase.php
@@ -0,0 +1,66 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Phase;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentPhase;
+use Core\Mod\Agentic\Models\AgentPlan;
+
+/**
+ * Get details of a specific phase within a plan.
+ *
+ * Resolves the phase by order number or name.
+ *
+ * Usage:
+ *   $phase = GetPhase::run('deploy-v2', '1', 1);
+ *   $phase = GetPhase::run('deploy-v2', 'Build', 1);
+ */
+class GetPhase
+{
+    use Action;
+
+    /**
+     * @throws \InvalidArgumentException
+     */
+    public function handle(string $planSlug, string|int $phase, int $workspaceId): AgentPhase
+    {
+        $plan = AgentPlan::forWorkspace($workspaceId)
+            ->where('slug', $planSlug)
+            ->first();
+
+        if (! $plan) {
+            throw new \InvalidArgumentException("Plan not found: {$planSlug}");
+        }
+
+        $resolved = $this->resolvePhase($plan, $phase);
+
+        if (! $resolved) {
+            throw new \InvalidArgumentException("Phase not found: {$phase}");
+        }
+
+        return $resolved;
+    }
+
+    private function resolvePhase(AgentPlan $plan, string|int $identifier): ?AgentPhase
+    {
+        if (is_numeric($identifier)) {
+            return $plan->agentPhases()->where('order', (int) $identifier)->first();
+        }
+
+        return $plan->agentPhases()
+            ->where(function ($query) use ($identifier) {
+                $query->where('name', $identifier)
+                    ->orWhere('order', $identifier);
+            })
+            ->first();
+    }
+}
diff --git a/Actions/Phase/UpdatePhaseStatus.php b/Actions/Phase/UpdatePhaseStatus.php
new file mode 100644
index 0000000..a01e620
--- /dev/null
+++ b/Actions/Phase/UpdatePhaseStatus.php
@@ -0,0 +1,79 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Phase;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentPhase;
+use Core\Mod\Agentic\Models\AgentPlan;
+
+/**
+ * Update the status of a phase within a plan.
+ *
+ * Optionally adds a checkpoint note when the status changes.
+ *
+ * Usage:
+ *   $phase = UpdatePhaseStatus::run('deploy-v2', '1', 'in_progress', 1);
+ *   $phase = UpdatePhaseStatus::run('deploy-v2', 'Build', 'completed', 1, 'All tests pass');
+ */
+class UpdatePhaseStatus
+{
+    use Action;
+
+    /**
+     * @throws \InvalidArgumentException
+     */
+    public function handle(string $planSlug, string|int $phase, string $status, int $workspaceId, ?string $notes = null): AgentPhase
+    {
+        $valid = ['pending', 'in_progress', 'completed', 'blocked', 'skipped'];
+        if (! in_array($status, $valid, true)) {
+            throw new \InvalidArgumentException(
+                sprintf('status must be one of: %s', implode(', ', $valid))
+            );
+        }
+
+        $plan = AgentPlan::forWorkspace($workspaceId)
+            ->where('slug', $planSlug)
+            ->first();
+
+        if (! $plan) {
+            throw new \InvalidArgumentException("Plan not found: {$planSlug}");
+        }
+
+        $resolved = $this->resolvePhase($plan, $phase);
+
+        if (! $resolved) {
+            throw new \InvalidArgumentException("Phase not found: {$phase}");
+        }
+
+        if ($notes !== null && $notes !== '') {
+            $resolved->addCheckpoint($notes, ['status_change' => $status]);
+        }
+
+        $resolved->update(['status' => $status]);
+
+        return $resolved->fresh();
+    }
+
+    private function resolvePhase(AgentPlan $plan, string|int $identifier): ?AgentPhase
+    {
+        if (is_numeric($identifier)) {
+            return $plan->agentPhases()->where('order', (int) $identifier)->first();
+        }
+
+        return $plan->agentPhases()
+            ->where(function ($query) use ($identifier) {
+                $query->where('name', $identifier)
+                    ->orWhere('order', $identifier);
+            })
+            ->first();
+    }
+}
diff --git a/Actions/Plan/ArchivePlan.php b/Actions/Plan/ArchivePlan.php
new file mode 100644
index 0000000..4ba21fe
--- /dev/null
+++ b/Actions/Plan/ArchivePlan.php
@@ -0,0 +1,51 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Plan;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentPlan;
+
+/**
+ * Archive a completed or abandoned plan.
+ *
+ * Sets the plan status to archived with an optional reason.
+ * Scoped to workspace for tenant isolation.
+ *
+ * Usage:
+ *   $plan = ArchivePlan::run('deploy-v2', 1, 'Superseded by v3');
+ */
+class ArchivePlan
+{
+    use Action;
+
+    /**
+     * @throws \InvalidArgumentException
+     */
+    public function handle(string $slug, int $workspaceId, ?string $reason = null): AgentPlan
+    {
+        if ($slug === '') {
+            throw new \InvalidArgumentException('slug is required');
+        }
+
+        $plan = AgentPlan::forWorkspace($workspaceId)
+            ->where('slug', $slug)
+            ->first();
+
+        if (! $plan) {
+            throw new \InvalidArgumentException("Plan not found: {$slug}");
+        }
+
+        $plan->archive($reason);
+
+        return $plan->fresh();
+    }
+}
diff --git a/Actions/Plan/CreatePlan.php b/Actions/Plan/CreatePlan.php
new file mode 100644
index 0000000..3f1fcfc
--- /dev/null
+++ b/Actions/Plan/CreatePlan.php
@@ -0,0 +1,89 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Plan;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentPhase;
+use Core\Mod\Agentic\Models\AgentPlan;
+use Illuminate\Support\Str;
+
+/**
+ * Create a new work plan with phases and tasks.
+ *
+ * Validates input, generates a unique slug, creates the plan
+ * and any associated phases with their tasks.
+ *
+ * Usage:
+ *   $plan = CreatePlan::run([
+ *       'title' => 'Deploy v2',
+ *       'phases' => [['name' => 'Build', 'tasks' => ['compile', 'test']]],
+ *   ], 1);
+ */
+class CreatePlan
+{
+    use Action;
+
+    /**
+     * @param  array{title: string, slug?: string, description?: string, context?: array, phases?: array}  $data
+     *
+     * @throws \InvalidArgumentException
+     */
+    public function handle(array $data, int $workspaceId): AgentPlan
+    {
+        $title = $data['title'] ?? null;
+        if (! is_string($title) || $title === '' || mb_strlen($title) > 255) {
+            throw new \InvalidArgumentException('title is required and must be a non-empty string (max 255 characters)');
+        }
+
+        $slug = $data['slug'] ?? null;
+        if ($slug !== null) {
+            if (! is_string($slug) || mb_strlen($slug) > 255) {
+                throw new \InvalidArgumentException('slug must be a string (max 255 characters)');
+            }
+        } else {
+            $slug = Str::slug($title).'-'.Str::random(6);
+        }
+
+        if (AgentPlan::where('slug', $slug)->exists()) {
+            throw new \InvalidArgumentException("Plan with slug '{$slug}' already exists");
+        }
+
+        $plan = AgentPlan::create([
+            'slug' => $slug,
+            'title' => $title,
+            'description' => $data['description'] ?? null,
+            'status' => AgentPlan::STATUS_DRAFT,
+            'context' => $data['context'] ?? [],
+            'workspace_id' => $workspaceId,
+        ]);
+
+        if (! empty($data['phases'])) {
+            foreach ($data['phases'] as $order => $phaseData) {
+                $tasks = collect($phaseData['tasks'] ?? [])->map(fn ($task) => [
+                    'name' => $task,
+                    'status' => 'pending',
+                ])->all();
+
+                AgentPhase::create([
+                    'agent_plan_id' => $plan->id,
+                    'name' => $phaseData['name'] ?? 'Phase '.($order + 1),
+                    'description' => $phaseData['description'] ?? null,
+                    'order' => $order + 1,
+                    'status' => AgentPhase::STATUS_PENDING,
+                    'tasks' => $tasks,
+                ]);
+            }
+        }
+
+        return $plan->load('agentPhases');
+    }
+}
diff --git a/Actions/Plan/GetPlan.php b/Actions/Plan/GetPlan.php
new file mode 100644
index 0000000..a050446
--- /dev/null
+++ b/Actions/Plan/GetPlan.php
@@ -0,0 +1,50 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Plan;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentPlan;
+
+/**
+ * Get detailed information about a specific plan.
+ *
+ * Returns the plan with all phases, progress, and context data.
+ * Scoped to workspace for tenant isolation.
+ *
+ * Usage:
+ *   $plan = GetPlan::run('deploy-v2', 1);
+ */
+class GetPlan
+{
+    use Action;
+
+    /**
+     * @throws \InvalidArgumentException
+     */
+    public function handle(string $slug, int $workspaceId): AgentPlan
+    {
+        if ($slug === '') {
+            throw new \InvalidArgumentException('slug is required');
+        }
+
+        $plan = AgentPlan::with('agentPhases')
+            ->forWorkspace($workspaceId)
+            ->where('slug', $slug)
+            ->first();
+
+        if (! $plan) {
+            throw new \InvalidArgumentException("Plan not found: {$slug}");
+        }
+
+        return $plan;
+    }
+}
diff --git a/Actions/Plan/ListPlans.php b/Actions/Plan/ListPlans.php
new file mode 100644
index 0000000..aa00efa
--- /dev/null
+++ b/Actions/Plan/ListPlans.php
@@ -0,0 +1,59 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Plan;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentPlan;
+use Illuminate\Support\Collection;
+
+/**
+ * List work plans for a workspace with optional filtering.
+ *
+ * Returns plans ordered by most recently updated, with progress data.
+ *
+ * Usage:
+ *   $plans = ListPlans::run(1);
+ *   $plans = ListPlans::run(1, 'active');
+ */
+class ListPlans
+{
+    use Action;
+
+    /**
+     * @return Collection<int, AgentPlan>
+     */
+    public function handle(int $workspaceId, ?string $status = null, bool $includeArchived = false): Collection
+    {
+        if ($status !== null) {
+            $valid = ['draft', 'active', 'paused', 'completed', 'archived'];
+            if (! in_array($status, $valid, true)) {
+                throw new \InvalidArgumentException(
+                    sprintf('status must be one of: %s', implode(', ', $valid))
+                );
+            }
+        }
+
+        $query = AgentPlan::with('agentPhases')
+            ->forWorkspace($workspaceId)
+            ->orderBy('updated_at', 'desc');
+
+        if (! $includeArchived && $status !== 'archived') {
+            $query->notArchived();
+        }
+
+        if ($status !== null) {
+            $query->where('status', $status);
+        }
+
+        return $query->get();
+    }
+}
diff --git a/Actions/Plan/UpdatePlanStatus.php b/Actions/Plan/UpdatePlanStatus.php
new file mode 100644
index 0000000..be505a4
--- /dev/null
+++ b/Actions/Plan/UpdatePlanStatus.php
@@ -0,0 +1,54 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Plan;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentPlan;
+
+/**
+ * Update the status of a plan.
+ *
+ * Validates the transition and updates the plan status.
+ * Scoped to workspace for tenant isolation.
+ *
+ * Usage:
+ *   $plan = UpdatePlanStatus::run('deploy-v2', 'active', 1);
+ */
+class UpdatePlanStatus
+{
+    use Action;
+
+    /**
+     * @throws \InvalidArgumentException
+     */
+    public function handle(string $slug, string $status, int $workspaceId): AgentPlan
+    {
+        $valid = ['draft', 'active', 'paused', 'completed'];
+        if (! in_array($status, $valid, true)) {
+            throw new \InvalidArgumentException(
+                sprintf('status must be one of: %s', implode(', ', $valid))
+            );
+        }
+
+        $plan = AgentPlan::forWorkspace($workspaceId)
+            ->where('slug', $slug)
+            ->first();
+
+        if (! $plan) {
+            throw new \InvalidArgumentException("Plan not found: {$slug}");
+        }
+
+        $plan->update(['status' => $status]);
+
+        return $plan->fresh();
+    }
+}
diff --git a/Actions/Session/ContinueSession.php b/Actions/Session/ContinueSession.php
new file mode 100644
index 0000000..eb366e4
--- /dev/null
+++ b/Actions/Session/ContinueSession.php
@@ -0,0 +1,56 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Session;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentSession;
+use Core\Mod\Agentic\Services\AgentSessionService;
+
+/**
+ * Continue from a previous session (multi-agent handoff).
+ *
+ * Creates a new session with context inherited from the previous one
+ * and marks the previous session as handed off.
+ *
+ * Usage:
+ *   $session = ContinueSession::run('ses_abc123', 'opus');
+ */
+class ContinueSession
+{
+    use Action;
+
+    public function __construct(
+        private AgentSessionService $sessionService,
+    ) {}
+
+    /**
+     * @throws \InvalidArgumentException
+     */
+    public function handle(string $previousSessionId, string $agentType): AgentSession
+    {
+        if ($previousSessionId === '') {
+            throw new \InvalidArgumentException('previous_session_id is required');
+        }
+
+        if ($agentType === '') {
+            throw new \InvalidArgumentException('agent_type is required');
+        }
+
+        $session = $this->sessionService->continueFrom($previousSessionId, $agentType);
+
+        if (! $session) {
+            throw new \InvalidArgumentException("Previous session not found: {$previousSessionId}");
+        }
+
+        return $session;
+    }
+}
diff --git a/Actions/Session/EndSession.php b/Actions/Session/EndSession.php
new file mode 100644
index 0000000..d27c8ee
--- /dev/null
+++ b/Actions/Session/EndSession.php
@@ -0,0 +1,56 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Session;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentSession;
+use Core\Mod\Agentic\Services\AgentSessionService;
+
+/**
+ * End an agent session with a final status and optional summary.
+ *
+ * Usage:
+ *   $session = EndSession::run('ses_abc123', 'completed', 'All phases done');
+ */
+class EndSession
+{
+    use Action;
+
+    public function __construct(
+        private AgentSessionService $sessionService,
+    ) {}
+
+    /**
+     * @throws \InvalidArgumentException
+     */
+    public function handle(string $sessionId, string $status, ?string $summary = null): AgentSession
+    {
+        if ($sessionId === '') {
+            throw new \InvalidArgumentException('session_id is required');
+        }
+
+        $valid = ['completed', 'handed_off', 'paused', 'failed'];
+        if (! in_array($status, $valid, true)) {
+            throw new \InvalidArgumentException(
+                sprintf('status must be one of: %s', implode(', ', $valid))
+            );
+        }
+
+        $session = $this->sessionService->end($sessionId, $status, $summary);
+
+        if (! $session) {
+            throw new \InvalidArgumentException("Session not found: {$sessionId}");
+        }
+
+        return $session;
+    }
+}
diff --git a/Actions/Session/GetSession.php b/Actions/Session/GetSession.php
new file mode 100644
index 0000000..c74f1b0
--- /dev/null
+++ b/Actions/Session/GetSession.php
@@ -0,0 +1,49 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Session;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentSession;
+
+/**
+ * Get detailed information about a specific session.
+ *
+ * Returns the session with plan context, scoped to workspace.
+ *
+ * Usage:
+ *   $session = GetSession::run('ses_abc123', 1);
+ */
+class GetSession
+{
+    use Action;
+
+    /**
+     * @throws \InvalidArgumentException
+     */
+    public function handle(string $sessionId, int $workspaceId): AgentSession
+    {
+        if ($sessionId === '') {
+            throw new \InvalidArgumentException('session_id is required');
+        }
+
+        $session = AgentSession::with('plan')
+            ->where('session_id', $sessionId)
+            ->where('workspace_id', $workspaceId)
+            ->first();
+
+        if (! $session) {
+            throw new \InvalidArgumentException("Session not found: {$sessionId}");
+        }
+
+        return $session;
+    }
+}
diff --git a/Actions/Session/ListSessions.php b/Actions/Session/ListSessions.php
new file mode 100644
index 0000000..3987919
--- /dev/null
+++ b/Actions/Session/ListSessions.php
@@ -0,0 +1,68 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Session;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentSession;
+use Core\Mod\Agentic\Services\AgentSessionService;
+use Illuminate\Support\Collection;
+
+/**
+ * List sessions for a workspace, with optional filtering.
+ *
+ * Usage:
+ *   $sessions = ListSessions::run(1);
+ *   $sessions = ListSessions::run(1, 'active', 'deploy-v2', 20);
+ */
+class ListSessions
+{
+    use Action;
+
+    public function __construct(
+        private AgentSessionService $sessionService,
+    ) {}
+
+    /**
+     * @return Collection<int, AgentSession>
+     */
+    public function handle(int $workspaceId, ?string $status = null, ?string $planSlug = null, ?int $limit = null): Collection
+    {
+        if ($status !== null) {
+            $valid = ['active', 'paused', 'completed', 'failed'];
+            if (! in_array($status, $valid, true)) {
+                throw new \InvalidArgumentException(
+                    sprintf('status must be one of: %s', implode(', ', $valid))
+                );
+            }
+        }
+
+        // Active sessions use the optimised service method
+        if ($status === 'active' || $status === null) {
+            return $this->sessionService->getActiveSessions($workspaceId);
+        }
+
+        $query = AgentSession::query()
+            ->where('workspace_id', $workspaceId)
+            ->where('status', $status)
+            ->orderBy('last_active_at', 'desc');
+
+        if ($planSlug !== null) {
+            $query->whereHas('plan', fn ($q) => $q->where('slug', $planSlug));
+        }
+
+        if ($limit !== null && $limit > 0) {
+            $query->limit(min($limit, 1000));
+        }
+
+        return $query->get();
+    }
+}
diff --git a/Actions/Session/StartSession.php b/Actions/Session/StartSession.php
new file mode 100644
index 0000000..cee098b
--- /dev/null
+++ b/Actions/Session/StartSession.php
@@ -0,0 +1,56 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Session;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentPlan;
+use Core\Mod\Agentic\Models\AgentSession;
+use Core\Mod\Agentic\Services\AgentSessionService;
+
+/**
+ * Start a new agent session, optionally linked to a plan.
+ *
+ * Creates an active session and caches it for fast lookup.
+ * Workspace can be provided directly or inferred from the plan.
+ *
+ * Usage:
+ *   $session = StartSession::run('opus', null, 1);
+ *   $session = StartSession::run('sonnet', 'deploy-v2', 1, ['goal' => 'testing']);
+ */
+class StartSession
+{
+    use Action;
+
+    public function __construct(
+        private AgentSessionService $sessionService,
+    ) {}
+
+    /**
+     * @throws \InvalidArgumentException
+     */
+    public function handle(string $agentType, ?string $planSlug, int $workspaceId, array $context = []): AgentSession
+    {
+        if ($agentType === '') {
+            throw new \InvalidArgumentException('agent_type is required');
+        }
+
+        $plan = null;
+        if ($planSlug !== null && $planSlug !== '') {
+            $plan = AgentPlan::where('slug', $planSlug)->first();
+            if (! $plan) {
+                throw new \InvalidArgumentException("Plan not found: {$planSlug}");
+            }
+        }
+
+        return $this->sessionService->start($agentType, $plan, $workspaceId, $context);
+    }
+}
diff --git a/Actions/Task/ToggleTask.php b/Actions/Task/ToggleTask.php
new file mode 100644
index 0000000..0955c60
--- /dev/null
+++ b/Actions/Task/ToggleTask.php
@@ -0,0 +1,90 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Task;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentPhase;
+use Core\Mod\Agentic\Models\AgentPlan;
+
+/**
+ * Toggle a task's completion status (pending <-> completed).
+ *
+ * Quick convenience method for marking tasks done or undone.
+ *
+ * Usage:
+ *   $result = ToggleTask::run('deploy-v2', '1', 0, 1);
+ */
+class ToggleTask
+{
+    use Action;
+
+    /**
+     * @return array{task: array, plan_progress: array}
+     *
+     * @throws \InvalidArgumentException
+     */
+    public function handle(string $planSlug, string|int $phase, int $taskIndex, int $workspaceId): array
+    {
+        $plan = AgentPlan::forWorkspace($workspaceId)
+            ->where('slug', $planSlug)
+            ->first();
+
+        if (! $plan) {
+            throw new \InvalidArgumentException("Plan not found: {$planSlug}");
+        }
+
+        $resolved = $this->resolvePhase($plan, $phase);
+
+        if (! $resolved) {
+            throw new \InvalidArgumentException("Phase not found: {$phase}");
+        }
+
+        $tasks = $resolved->tasks ?? [];
+
+        if (! isset($tasks[$taskIndex])) {
+            throw new \InvalidArgumentException("Task not found at index: {$taskIndex}");
+        }
+
+        $currentStatus = is_string($tasks[$taskIndex])
+            ? 'pending'
+            : ($tasks[$taskIndex]['status'] ?? 'pending');
+
+        $newStatus = $currentStatus === 'completed' ? 'pending' : 'completed';
+
+        if (is_string($tasks[$taskIndex])) {
+            $tasks[$taskIndex] = [
+                'name' => $tasks[$taskIndex],
+                'status' => $newStatus,
+            ];
+        } else {
+            $tasks[$taskIndex]['status'] = $newStatus;
+        }
+
+        $resolved->update(['tasks' => $tasks]);
+
+        return [
+            'task' => $tasks[$taskIndex],
+            'plan_progress' => $plan->fresh()->getProgress(),
+        ];
+    }
+
+    private function resolvePhase(AgentPlan $plan, string|int $identifier): ?AgentPhase
+    {
+        if (is_numeric($identifier)) {
+            return $plan->agentPhases()->where('order', (int) $identifier)->first();
+        }
+
+        return $plan->agentPhases()
+            ->where('name', $identifier)
+            ->first();
+    }
+}
diff --git a/Actions/Task/UpdateTask.php b/Actions/Task/UpdateTask.php
new file mode 100644
index 0000000..4bcde4e
--- /dev/null
+++ b/Actions/Task/UpdateTask.php
@@ -0,0 +1,101 @@
+<?php
+
+/*
+ * Core PHP Framework
+ *
+ * Licensed under the European Union Public Licence (EUPL) v1.2.
+ * See LICENSE file for details.
+ */
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Actions\Task;
+
+use Core\Actions\Action;
+use Core\Mod\Agentic\Models\AgentPhase;
+use Core\Mod\Agentic\Models\AgentPlan;
+
+/**
+ * Update a task's status or notes within a phase.
+ *
+ * Tasks are stored as a JSON array on the phase model.
+ * Handles legacy string-format tasks by normalising to {name, status}.
+ *
+ * Usage:
+ *   $task = UpdateTask::run('deploy-v2', '1', 0, 1, 'in_progress', 'Started build');
+ */
+class UpdateTask
+{
+    use Action;
+
+    /**
+     * @return array{task: array, plan_progress: array}
+     *
+     * @throws \InvalidArgumentException
+     */
+    public function handle(string $planSlug, string|int $phase, int $taskIndex, int $workspaceId, ?string $status = null, ?string $notes = null): array
+    {
+        if ($status !== null) {
+            $valid = ['pending', 'in_progress', 'completed', 'blocked', 'skipped'];
+            if (! in_array($status, $valid, true)) {
+                throw new \InvalidArgumentException(
+                    sprintf('status must be one of: %s', implode(', ', $valid))
+                );
+            }
+        }
+
+        $plan = AgentPlan::forWorkspace($workspaceId)
+            ->where('slug', $planSlug)
+            ->first();
+
+        if (! $plan) {
+            throw new \InvalidArgumentException("Plan not found: {$planSlug}");
+        }
+
+        $resolved = $this->resolvePhase($plan, $phase);
+
+        if (! $resolved) {
+            throw new \InvalidArgumentException("Phase not found: {$phase}");
+        }
+
+        $tasks = $resolved->tasks ?? [];
+
+        if (! isset($tasks[$taskIndex])) {
+            throw new \InvalidArgumentException("Task not found at index: {$taskIndex}");
+        }
+
+        // Normalise legacy string-format tasks
+        if (is_string($tasks[$taskIndex])) {
+            $tasks[$taskIndex] = ['name' => $tasks[$taskIndex], 'status' => 'pending'];
+        }
+
+        if ($status !== null) {
+            $tasks[$taskIndex]['status'] = $status;
+        }
+
+        if ($notes !== null) {
+            $tasks[$taskIndex]['notes'] = $notes;
+        }
+
+        $resolved->update(['tasks' => $tasks]);
+
+        return [
+            'task' => $tasks[$taskIndex],
+            'plan_progress' => $plan->fresh()->getProgress(),
+        ];
+    }
+
+    private function resolvePhase(AgentPlan $plan, string|int $identifier): ?AgentPhase
+    {
+        if (is_numeric($identifier)) {
+            return $plan->agentPhases()->where('order', (int) $identifier)->first();
+        }
+
+        return $plan->agentPhases()
+            ->where(function ($query) use ($identifier) {
+                $query->where('name', $identifier)
+                    ->orWhere('order', $identifier);
+            })
+            ->first();
+    }
+}
diff --git a/Controllers/Api/PhaseController.php b/Controllers/Api/PhaseController.php
new file mode 100644
index 0000000..412f881
--- /dev/null
+++ b/Controllers/Api/PhaseController.php
@@ -0,0 +1,115 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Controllers\Api;
+
+use Core\Front\Controller;
+use Core\Mod\Agentic\Actions\Phase\AddCheckpoint;
+use Core\Mod\Agentic\Actions\Phase\GetPhase;
+use Core\Mod\Agentic\Actions\Phase\UpdatePhaseStatus;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
+
+class PhaseController extends Controller
+{
+    /**
+     * GET /api/plans/{slug}/phases/{phase}
+     */
+    public function show(Request $request, string $slug, string $phase): JsonResponse
+    {
+        $workspace = $request->attributes->get('workspace');
+
+        try {
+            $resolved = GetPhase::run($slug, $phase, $workspace->id);
+
+            return response()->json([
+                'data' => [
+                    'order' => $resolved->order,
+                    'name' => $resolved->name,
+                    'description' => $resolved->description,
+                    'status' => $resolved->status,
+                    'tasks' => $resolved->tasks,
+                    'checkpoints' => $resolved->getCheckpoints(),
+                    'dependencies' => $resolved->dependencies,
+                    'task_progress' => $resolved->getTaskProgress(),
+                ],
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'not_found',
+                'message' => $e->getMessage(),
+            ], 404);
+        }
+    }
+
+    /**
+     * PATCH /api/plans/{slug}/phases/{phase}
+     */
+    public function update(Request $request, string $slug, string $phase): JsonResponse
+    {
+        $validated = $request->validate([
+            'status' => 'required|string|in:pending,in_progress,completed,blocked,skipped',
+            'notes' => 'nullable|string|max:5000',
+        ]);
+
+        $workspace = $request->attributes->get('workspace');
+
+        try {
+            $resolved = UpdatePhaseStatus::run(
+                $slug,
+                $phase,
+                $validated['status'],
+                $workspace->id,
+                $validated['notes'] ?? null,
+            );
+
+            return response()->json([
+                'data' => [
+                    'order' => $resolved->order,
+                    'name' => $resolved->name,
+                    'status' => $resolved->status,
+                ],
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'not_found',
+                'message' => $e->getMessage(),
+            ], 404);
+        }
+    }
+
+    /**
+     * POST /api/plans/{slug}/phases/{phase}/checkpoint
+     */
+    public function checkpoint(Request $request, string $slug, string $phase): JsonResponse
+    {
+        $validated = $request->validate([
+            'note' => 'required|string|max:5000',
+            'context' => 'nullable|array',
+        ]);
+
+        $workspace = $request->attributes->get('workspace');
+
+        try {
+            $resolved = AddCheckpoint::run(
+                $slug,
+                $phase,
+                $validated['note'],
+                $workspace->id,
+                $validated['context'] ?? [],
+            );
+
+            return response()->json([
+                'data' => [
+                    'checkpoints' => $resolved->getCheckpoints(),
+                ],
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'not_found',
+                'message' => $e->getMessage(),
+            ], 404);
+        }
+    }
+}
diff --git a/Controllers/Api/PlanController.php b/Controllers/Api/PlanController.php
new file mode 100644
index 0000000..e71e19c
--- /dev/null
+++ b/Controllers/Api/PlanController.php
@@ -0,0 +1,170 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Controllers\Api;
+
+use Core\Front\Controller;
+use Core\Mod\Agentic\Actions\Plan\ArchivePlan;
+use Core\Mod\Agentic\Actions\Plan\CreatePlan;
+use Core\Mod\Agentic\Actions\Plan\GetPlan;
+use Core\Mod\Agentic\Actions\Plan\ListPlans;
+use Core\Mod\Agentic\Actions\Plan\UpdatePlanStatus;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
+
+class PlanController extends Controller
+{
+    /**
+     * GET /api/plans
+     */
+    public function index(Request $request): JsonResponse
+    {
+        $validated = $request->validate([
+            'status' => 'nullable|string|in:draft,active,paused,completed,archived',
+            'include_archived' => 'nullable|boolean',
+        ]);
+
+        $workspace = $request->attributes->get('workspace');
+
+        try {
+            $plans = ListPlans::run(
+                $workspace->id,
+                $validated['status'] ?? null,
+                (bool) ($validated['include_archived'] ?? false),
+            );
+
+            return response()->json([
+                'data' => $plans->map(fn ($plan) => [
+                    'slug' => $plan->slug,
+                    'title' => $plan->title,
+                    'status' => $plan->status,
+                    'progress' => $plan->getProgress(),
+                    'updated_at' => $plan->updated_at->toIso8601String(),
+                ])->values()->all(),
+                'total' => $plans->count(),
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'validation_error',
+                'message' => $e->getMessage(),
+            ], 422);
+        }
+    }
+
+    /**
+     * GET /api/plans/{slug}
+     */
+    public function show(Request $request, string $slug): JsonResponse
+    {
+        $workspace = $request->attributes->get('workspace');
+
+        try {
+            $plan = GetPlan::run($slug, $workspace->id);
+
+            return response()->json([
+                'data' => $plan->toMcpContext(),
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'not_found',
+                'message' => $e->getMessage(),
+            ], 404);
+        }
+    }
+
+    /**
+     * POST /api/plans
+     */
+    public function store(Request $request): JsonResponse
+    {
+        $validated = $request->validate([
+            'title' => 'required|string|max:255',
+            'slug' => 'nullable|string|max:255',
+            'description' => 'nullable|string|max:10000',
+            'context' => 'nullable|array',
+            'phases' => 'nullable|array',
+            'phases.*.name' => 'required_with:phases|string',
+            'phases.*.description' => 'nullable|string',
+            'phases.*.tasks' => 'nullable|array',
+            'phases.*.tasks.*' => 'string',
+        ]);
+
+        $workspace = $request->attributes->get('workspace');
+
+        try {
+            $plan = CreatePlan::run($validated, $workspace->id);
+
+            return response()->json([
+                'data' => [
+                    'slug' => $plan->slug,
+                    'title' => $plan->title,
+                    'status' => $plan->status,
+                    'phases' => $plan->agentPhases->count(),
+                ],
+            ], 201);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'validation_error',
+                'message' => $e->getMessage(),
+            ], 422);
+        }
+    }
+
+    /**
+     * PATCH /api/plans/{slug}
+     */
+    public function update(Request $request, string $slug): JsonResponse
+    {
+        $validated = $request->validate([
+            'status' => 'required|string|in:draft,active,paused,completed',
+        ]);
+
+        $workspace = $request->attributes->get('workspace');
+
+        try {
+            $plan = UpdatePlanStatus::run($slug, $validated['status'], $workspace->id);
+
+            return response()->json([
+                'data' => [
+                    'slug' => $plan->slug,
+                    'status' => $plan->status,
+                ],
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'not_found',
+                'message' => $e->getMessage(),
+            ], 404);
+        }
+    }
+
+    /**
+     * DELETE /api/plans/{slug}
+     */
+    public function destroy(Request $request, string $slug): JsonResponse
+    {
+        $request->validate([
+            'reason' => 'nullable|string|max:500',
+        ]);
+
+        $workspace = $request->attributes->get('workspace');
+
+        try {
+            $plan = ArchivePlan::run($slug, $workspace->id, $request->input('reason'));
+
+            return response()->json([
+                'data' => [
+                    'slug' => $plan->slug,
+                    'status' => 'archived',
+                    'archived_at' => $plan->archived_at?->toIso8601String(),
+                ],
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'not_found',
+                'message' => $e->getMessage(),
+            ], 404);
+        }
+    }
+}
diff --git a/Controllers/Api/SessionController.php b/Controllers/Api/SessionController.php
new file mode 100644
index 0000000..956beff
--- /dev/null
+++ b/Controllers/Api/SessionController.php
@@ -0,0 +1,173 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Controllers\Api;
+
+use Core\Front\Controller;
+use Core\Mod\Agentic\Actions\Session\ContinueSession;
+use Core\Mod\Agentic\Actions\Session\EndSession;
+use Core\Mod\Agentic\Actions\Session\GetSession;
+use Core\Mod\Agentic\Actions\Session\ListSessions;
+use Core\Mod\Agentic\Actions\Session\StartSession;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
+
+class SessionController extends Controller
+{
+    /**
+     * GET /api/sessions
+     */
+    public function index(Request $request): JsonResponse
+    {
+        $validated = $request->validate([
+            'status' => 'nullable|string|in:active,paused,completed,failed',
+            'plan_slug' => 'nullable|string|max:255',
+            'limit' => 'nullable|integer|min:1|max:1000',
+        ]);
+
+        $workspace = $request->attributes->get('workspace');
+
+        try {
+            $sessions = ListSessions::run(
+                $workspace->id,
+                $validated['status'] ?? null,
+                $validated['plan_slug'] ?? null,
+                $validated['limit'] ?? null,
+            );
+
+            return response()->json([
+                'data' => $sessions->map(fn ($session) => [
+                    'session_id' => $session->session_id,
+                    'agent_type' => $session->agent_type,
+                    'status' => $session->status,
+                    'plan' => $session->plan?->slug,
+                    'duration' => $session->getDurationFormatted(),
+                    'started_at' => $session->started_at->toIso8601String(),
+                    'last_active_at' => $session->last_active_at->toIso8601String(),
+                ])->values()->all(),
+                'total' => $sessions->count(),
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'validation_error',
+                'message' => $e->getMessage(),
+            ], 422);
+        }
+    }
+
+    /**
+     * GET /api/sessions/{id}
+     */
+    public function show(Request $request, string $id): JsonResponse
+    {
+        $workspace = $request->attributes->get('workspace');
+
+        try {
+            $session = GetSession::run($id, $workspace->id);
+
+            return response()->json([
+                'data' => $session->toMcpContext(),
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'not_found',
+                'message' => $e->getMessage(),
+            ], 404);
+        }
+    }
+
+    /**
+     * POST /api/sessions
+     */
+    public function store(Request $request): JsonResponse
+    {
+        $validated = $request->validate([
+            'agent_type' => 'required|string|max:50',
+            'plan_slug' => 'nullable|string|max:255',
+            'context' => 'nullable|array',
+        ]);
+
+        $workspace = $request->attributes->get('workspace');
+
+        try {
+            $session = StartSession::run(
+                $validated['agent_type'],
+                $validated['plan_slug'] ?? null,
+                $workspace->id,
+                $validated['context'] ?? [],
+            );
+
+            return response()->json([
+                'data' => [
+                    'session_id' => $session->session_id,
+                    'agent_type' => $session->agent_type,
+                    'plan' => $session->plan?->slug,
+                    'status' => $session->status,
+                ],
+            ], 201);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'validation_error',
+                'message' => $e->getMessage(),
+            ], 422);
+        }
+    }
+
+    /**
+     * POST /api/sessions/{id}/end
+     */
+    public function end(Request $request, string $id): JsonResponse
+    {
+        $validated = $request->validate([
+            'status' => 'required|string|in:completed,handed_off,paused,failed',
+            'summary' => 'nullable|string|max:10000',
+        ]);
+
+        try {
+            $session = EndSession::run($id, $validated['status'], $validated['summary'] ?? null);
+
+            return response()->json([
+                'data' => [
+                    'session_id' => $session->session_id,
+                    'status' => $session->status,
+                    'duration' => $session->getDurationFormatted(),
+                ],
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'not_found',
+                'message' => $e->getMessage(),
+            ], 404);
+        }
+    }
+
+    /**
+     * POST /api/sessions/{id}/continue
+     */
+    public function continue(Request $request, string $id): JsonResponse
+    {
+        $validated = $request->validate([
+            'agent_type' => 'required|string|max:50',
+        ]);
+
+        try {
+            $session = ContinueSession::run($id, $validated['agent_type']);
+
+            return response()->json([
+                'data' => [
+                    'session_id' => $session->session_id,
+                    'agent_type' => $session->agent_type,
+                    'plan' => $session->plan?->slug,
+                    'status' => $session->status,
+                    'continued_from' => $session->context_summary['continued_from'] ?? null,
+                ],
+            ], 201);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'not_found',
+                'message' => $e->getMessage(),
+            ], 404);
+        }
+    }
+}
diff --git a/Controllers/Api/TaskController.php b/Controllers/Api/TaskController.php
new file mode 100644
index 0000000..38f608a
--- /dev/null
+++ b/Controllers/Api/TaskController.php
@@ -0,0 +1,68 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Core\Mod\Agentic\Controllers\Api;
+
+use Core\Front\Controller;
+use Core\Mod\Agentic\Actions\Task\ToggleTask;
+use Core\Mod\Agentic\Actions\Task\UpdateTask;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
+
+class TaskController extends Controller
+{
+    /**
+     * PATCH /api/plans/{slug}/phases/{phase}/tasks/{index}
+     */
+    public function update(Request $request, string $slug, string $phase, int $index): JsonResponse
+    {
+        $validated = $request->validate([
+            'status' => 'nullable|string|in:pending,in_progress,completed,blocked,skipped',
+            'notes' => 'nullable|string|max:5000',
+        ]);
+
+        $workspace = $request->attributes->get('workspace');
+
+        try {
+            $result = UpdateTask::run(
+                $slug,
+                $phase,
+                $index,
+                $workspace->id,
+                $validated['status'] ?? null,
+                $validated['notes'] ?? null,
+            );
+
+            return response()->json([
+                'data' => $result,
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'not_found',
+                'message' => $e->getMessage(),
+            ], 404);
+        }
+    }
+
+    /**
+     * POST /api/plans/{slug}/phases/{phase}/tasks/{index}/toggle
+     */
+    public function toggle(Request $request, string $slug, string $phase, int $index): JsonResponse
+    {
+        $workspace = $request->attributes->get('workspace');
+
+        try {
+            $result = ToggleTask::run($slug, $phase, $index, $workspace->id);
+
+            return response()->json([
+                'data' => $result,
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return response()->json([
+                'error' => 'not_found',
+                'message' => $e->getMessage(),
+            ], 404);
+        }
+    }
+}
diff --git a/Mcp/Tools/Agent/Phase/PhaseAddCheckpoint.php b/Mcp/Tools/Agent/Phase/PhaseAddCheckpoint.php
index e0d33b1..a2d8e84 100644
--- a/Mcp/Tools/Agent/Phase/PhaseAddCheckpoint.php
+++ b/Mcp/Tools/Agent/Phase/PhaseAddCheckpoint.php
@@ -4,9 +4,8 @@ declare(strict_types=1);
 
 namespace Core\Mod\Agentic\Mcp\Tools\Agent\Phase;
 
+use Core\Mod\Agentic\Actions\Phase\AddCheckpoint;
 use Core\Mod\Agentic\Mcp\Tools\Agent\AgentTool;
-use Core\Mod\Agentic\Models\AgentPhase;
-use Core\Mod\Agentic\Models\AgentPlan;
 
 /**
  * Add a checkpoint note to a phase.
@@ -55,44 +54,25 @@ class PhaseAddCheckpoint extends AgentTool
 
     public function handle(array $args, array $context = []): array
     {
+        $workspaceId = $context['workspace_id'] ?? null;
+        if ($workspaceId === null) {
+            return $this->error('workspace_id is required');
+        }
+
         try {
-            $planSlug = $this->require($args, 'plan_slug');
-            $phaseIdentifier = $this->require($args, 'phase');
-            $note = $this->require($args, 'note');
+            $phase = AddCheckpoint::run(
+                $args['plan_slug'] ?? '',
+                $args['phase'] ?? '',
+                $args['note'] ?? '',
+                (int) $workspaceId,
+                $args['context'] ?? [],
+            );
+
+            return $this->success([
+                'checkpoints' => $phase->getCheckpoints(),
+            ]);
         } catch (\InvalidArgumentException $e) {
             return $this->error($e->getMessage());
         }
-
-        $plan = AgentPlan::where('slug', $planSlug)->first();
-
-        if (! $plan) {
-            return $this->error("Plan not found: {$planSlug}");
-        }
-
-        $phase = $this->findPhase($plan, $phaseIdentifier);
-
-        if (! $phase) {
-            return $this->error("Phase not found: {$phaseIdentifier}");
-        }
-
-        $phase->addCheckpoint($note, $args['context'] ?? []);
-
-        return $this->success([
-            'checkpoints' => $phase->fresh()->checkpoints,
-        ]);
-    }
-
-    /**
-     * Find a phase by order number or name.
-     */
-    protected function findPhase(AgentPlan $plan, string|int $identifier): ?AgentPhase
-    {
-        if (is_numeric($identifier)) {
-            return $plan->agentPhases()->where('order', (int) $identifier)->first();
-        }
-
-        return $plan->agentPhases()
-            ->where('name', $identifier)
-            ->first();
     }
 }
diff --git a/Mcp/Tools/Agent/Phase/PhaseGet.php b/Mcp/Tools/Agent/Phase/PhaseGet.php
index 55f2fd7..1afc535 100644
--- a/Mcp/Tools/Agent/Phase/PhaseGet.php
+++ b/Mcp/Tools/Agent/Phase/PhaseGet.php
@@ -4,9 +4,8 @@ declare(strict_types=1);
 
 namespace Core\Mod\Agentic\Mcp\Tools\Agent\Phase;
 
+use Core\Mod\Agentic\Actions\Phase\GetPhase;
 use Core\Mod\Agentic\Mcp\Tools\Agent\AgentTool;
-use Core\Mod\Agentic\Models\AgentPhase;
-use Core\Mod\Agentic\Models\AgentPlan;
 
 /**
  * Get details of a specific phase within a plan.
@@ -47,52 +46,31 @@ class PhaseGet extends AgentTool
 
     public function handle(array $args, array $context = []): array
     {
+        $workspaceId = $context['workspace_id'] ?? null;
+        if ($workspaceId === null) {
+            return $this->error('workspace_id is required');
+        }
+
         try {
-            $planSlug = $this->require($args, 'plan_slug');
-            $phaseIdentifier = $this->require($args, 'phase');
+            $phase = GetPhase::run(
+                $args['plan_slug'] ?? '',
+                $args['phase'] ?? '',
+                (int) $workspaceId,
+            );
+
+            return $this->success([
+                'phase' => [
+                    'order' => $phase->order,
+                    'name' => $phase->name,
+                    'description' => $phase->description,
+                    'status' => $phase->status,
+                    'tasks' => $phase->tasks,
+                    'checkpoints' => $phase->getCheckpoints(),
+                    'dependencies' => $phase->dependencies,
+                ],
+            ]);
         } catch (\InvalidArgumentException $e) {
             return $this->error($e->getMessage());
         }
-
-        $plan = AgentPlan::where('slug', $planSlug)->first();
-
-        if (! $plan) {
-            return $this->error("Plan not found: {$planSlug}");
-        }
-
-        $phase = $this->findPhase($plan, $phaseIdentifier);
-
-        if (! $phase) {
-            return $this->error("Phase not found: {$phaseIdentifier}");
-        }
-
-        return [
-            'phase' => [
-                'order' => $phase->order,
-                'name' => $phase->name,
-                'description' => $phase->description,
-                'status' => $phase->status,
-                'tasks' => $phase->tasks,
-                'checkpoints' => $phase->checkpoints,
-                'dependencies' => $phase->dependencies,
-            ],
-        ];
-    }
-
-    /**
-     * Find a phase by order number or name.
-     */
-    protected function findPhase(AgentPlan $plan, string|int $identifier): ?AgentPhase
-    {
-        if (is_numeric($identifier)) {
-            return $plan->agentPhases()->where('order', (int) $identifier)->first();
-        }
-
-        return $plan->agentPhases()
-            ->where(function ($query) use ($identifier) {
-                $query->where('name', $identifier)
-                    ->orWhere('order', $identifier);
-            })
-            ->first();
     }
 }
diff --git a/Mcp/Tools/Agent/Phase/PhaseUpdateStatus.php b/Mcp/Tools/Agent/Phase/PhaseUpdateStatus.php
index df4be7c..ef4bff1 100644
--- a/Mcp/Tools/Agent/Phase/PhaseUpdateStatus.php
+++ b/Mcp/Tools/Agent/Phase/PhaseUpdateStatus.php
@@ -5,9 +5,8 @@ declare(strict_types=1);
 namespace Core\Mod\Agentic\Mcp\Tools\Agent\Phase;
 
 use Core\Mcp\Dependencies\ToolDependency;
+use Core\Mod\Agentic\Actions\Phase\UpdatePhaseStatus;
 use Core\Mod\Agentic\Mcp\Tools\Agent\AgentTool;
-use Core\Mod\Agentic\Models\AgentPhase;
-use Core\Mod\Agentic\Models\AgentPlan;
 
 /**
  * Update the status of a phase.
@@ -69,55 +68,29 @@ class PhaseUpdateStatus extends AgentTool
 
     public function handle(array $args, array $context = []): array
     {
+        $workspaceId = $context['workspace_id'] ?? null;
+        if ($workspaceId === null) {
+            return $this->error('workspace_id is required');
+        }
+
         try {
-            $planSlug = $this->require($args, 'plan_slug');
-            $phaseIdentifier = $this->require($args, 'phase');
-            $status = $this->require($args, 'status');
+            $phase = UpdatePhaseStatus::run(
+                $args['plan_slug'] ?? '',
+                $args['phase'] ?? '',
+                $args['status'] ?? '',
+                (int) $workspaceId,
+                $args['notes'] ?? null,
+            );
+
+            return $this->success([
+                'phase' => [
+                    'order' => $phase->order,
+                    'name' => $phase->name,
+                    'status' => $phase->status,
+                ],
+            ]);
         } catch (\InvalidArgumentException $e) {
             return $this->error($e->getMessage());
         }
-
-        $plan = AgentPlan::where('slug', $planSlug)->first();
-
-        if (! $plan) {
-            return $this->error("Plan not found: {$planSlug}");
-        }
-
-        $phase = $this->findPhase($plan, $phaseIdentifier);
-
-        if (! $phase) {
-            return $this->error("Phase not found: {$phaseIdentifier}");
-        }
-
-        if (! empty($args['notes'])) {
-            $phase->addCheckpoint($args['notes'], ['status_change' => $status]);
-        }
-
-        $phase->update(['status' => $status]);
-
-        return $this->success([
-            'phase' => [
-                'order' => $phase->order,
-                'name' => $phase->name,
-                'status' => $phase->fresh()->status,
-            ],
-        ]);
-    }
-
-    /**
-     * Find a phase by order number or name.
-     */
-    protected function findPhase(AgentPlan $plan, string|int $identifier): ?AgentPhase
-    {
-        if (is_numeric($identifier)) {
-            return $plan->agentPhases()->where('order', (int) $identifier)->first();
-        }
-
-        return $plan->agentPhases()
-            ->where(function ($query) use ($identifier) {
-                $query->where('name', $identifier)
-                    ->orWhere('order', $identifier);
-            })
-            ->first();
     }
 }
diff --git a/Mcp/Tools/Agent/Plan/PlanArchive.php b/Mcp/Tools/Agent/Plan/PlanArchive.php
index 2f9c270..3eedd6f 100644
--- a/Mcp/Tools/Agent/Plan/PlanArchive.php
+++ b/Mcp/Tools/Agent/Plan/PlanArchive.php
@@ -4,8 +4,8 @@ declare(strict_types=1);
 
 namespace Core\Mod\Agentic\Mcp\Tools\Agent\Plan;
 
+use Core\Mod\Agentic\Actions\Plan\ArchivePlan;
 use Core\Mod\Agentic\Mcp\Tools\Agent\AgentTool;
-use Core\Mod\Agentic\Models\AgentPlan;
 
 /**
  * Archive a completed or abandoned plan.
@@ -46,26 +46,27 @@ class PlanArchive extends AgentTool
 
     public function handle(array $args, array $context = []): array
     {
+        $workspaceId = $context['workspace_id'] ?? null;
+        if ($workspaceId === null) {
+            return $this->error('workspace_id is required');
+        }
+
         try {
-            $slug = $this->require($args, 'slug');
+            $plan = ArchivePlan::run(
+                $args['slug'] ?? '',
+                (int) $workspaceId,
+                $args['reason'] ?? null,
+            );
+
+            return $this->success([
+                'plan' => [
+                    'slug' => $plan->slug,
+                    'status' => 'archived',
+                    'archived_at' => $plan->archived_at?->toIso8601String(),
+                ],
+            ]);
         } catch (\InvalidArgumentException $e) {
             return $this->error($e->getMessage());
         }
-
-        $plan = AgentPlan::where('slug', $slug)->first();
-
-        if (! $plan) {
-            return $this->error("Plan not found: {$slug}");
-        }
-
-        $plan->archive($args['reason'] ?? null);
-
-        return $this->success([
-            'plan' => [
-                'slug' => $plan->slug,
-                'status' => 'archived',
-                'archived_at' => $plan->archived_at?->toIso8601String(),
-            ],
-        ]);
     }
 }
diff --git a/Mcp/Tools/Agent/Plan/PlanCreate.php b/Mcp/Tools/Agent/Plan/PlanCreate.php
index 3e74189..dfd877a 100644
--- a/Mcp/Tools/Agent/Plan/PlanCreate.php
+++ b/Mcp/Tools/Agent/Plan/PlanCreate.php
@@ -5,10 +5,8 @@ declare(strict_types=1);
 namespace Core\Mod\Agentic\Mcp\Tools\Agent\Plan;
 
 use Core\Mcp\Dependencies\ToolDependency;
+use Core\Mod\Agentic\Actions\Plan\CreatePlan;
 use Core\Mod\Agentic\Mcp\Tools\Agent\AgentTool;
-use Core\Mod\Agentic\Models\AgentPhase;
-use Core\Mod\Agentic\Models\AgentPlan;
-use Illuminate\Support\Str;
 
 /**
  * Create a new work plan with phases and tasks.
@@ -84,61 +82,24 @@ class PlanCreate extends AgentTool
 
     public function handle(array $args, array $context = []): array
     {
-        try {
-            $title = $this->requireString($args, 'title', 255);
-            $slug = $this->optionalString($args, 'slug', null, 255) ?? Str::slug($title).'-'.Str::random(6);
-            $description = $this->optionalString($args, 'description', null, 10000);
-        } catch (\InvalidArgumentException $e) {
-            return $this->error($e->getMessage());
-        }
-
-        if (AgentPlan::where('slug', $slug)->exists()) {
-            return $this->error("Plan with slug '{$slug}' already exists");
-        }
-
-        // Determine workspace_id - never fall back to hardcoded value in multi-tenant environment
         $workspaceId = $context['workspace_id'] ?? null;
         if ($workspaceId === null) {
             return $this->error('workspace_id is required. Ensure you have authenticated with a valid API key and started a session. See: https://host.uk.com/ai');
         }
 
-        $plan = AgentPlan::create([
-            'slug' => $slug,
-            'title' => $title,
-            'description' => $description,
-            'status' => 'draft',
-            'context' => $args['context'] ?? [],
-            'workspace_id' => $workspaceId,
-        ]);
+        try {
+            $plan = CreatePlan::run($args, (int) $workspaceId);
 
-        // Create phases if provided
-        if (! empty($args['phases'])) {
-            foreach ($args['phases'] as $order => $phaseData) {
-                $tasks = collect($phaseData['tasks'] ?? [])->map(fn ($task) => [
-                    'name' => $task,
-                    'status' => 'pending',
-                ])->all();
-
-                AgentPhase::create([
-                    'agent_plan_id' => $plan->id,
-                    'name' => $phaseData['name'],
-                    'description' => $phaseData['description'] ?? null,
-                    'order' => $order + 1,
-                    'status' => 'pending',
-                    'tasks' => $tasks,
-                ]);
-            }
+            return $this->success([
+                'plan' => [
+                    'slug' => $plan->slug,
+                    'title' => $plan->title,
+                    'status' => $plan->status,
+                    'phases' => $plan->agentPhases->count(),
+                ],
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return $this->error($e->getMessage());
         }
-
-        $plan->load('agentPhases');
-
-        return $this->success([
-            'plan' => [
-                'slug' => $plan->slug,
-                'title' => $plan->title,
-                'status' => $plan->status,
-                'phases' => $plan->agentPhases->count(),
-            ],
-        ]);
     }
 }
diff --git a/Mcp/Tools/Agent/Plan/PlanGet.php b/Mcp/Tools/Agent/Plan/PlanGet.php
index 2929bc7..ce1f77c 100644
--- a/Mcp/Tools/Agent/Plan/PlanGet.php
+++ b/Mcp/Tools/Agent/Plan/PlanGet.php
@@ -5,8 +5,8 @@ declare(strict_types=1);
 namespace Core\Mod\Agentic\Mcp\Tools\Agent\Plan;
 
 use Core\Mcp\Dependencies\ToolDependency;
+use Core\Mod\Agentic\Actions\Plan\GetPlan;
 use Core\Mod\Agentic\Mcp\Tools\Agent\AgentTool;
-use Core\Mod\Agentic\Models\AgentPlan;
 
 /**
  * Get detailed information about a specific plan.
@@ -62,56 +62,23 @@ class PlanGet extends AgentTool
 
     public function handle(array $args, array $context = []): array
     {
-        try {
-            $slug = $this->require($args, 'slug');
-        } catch (\InvalidArgumentException $e) {
-            return $this->error($e->getMessage());
-        }
-
-        // Validate workspace context for tenant isolation
         $workspaceId = $context['workspace_id'] ?? null;
         if ($workspaceId === null) {
             return $this->error('workspace_id is required. Ensure you have authenticated with a valid API key and started a session. See: https://host.uk.com/ai');
         }
 
-        $format = $this->optional($args, 'format', 'json');
+        try {
+            $plan = GetPlan::run($args['slug'] ?? '', (int) $workspaceId);
+        } catch (\InvalidArgumentException $e) {
+            return $this->error($e->getMessage());
+        }
 
-        // Use circuit breaker for Agentic module database calls
-        return $this->withCircuitBreaker('agentic', function () use ($slug, $format, $workspaceId) {
-            // Query plan with workspace scope to prevent cross-tenant access
-            $plan = AgentPlan::with('agentPhases')
-                ->forWorkspace($workspaceId)
-                ->where('slug', $slug)
-                ->first();
+        $format = $args['format'] ?? 'json';
 
-            if (! $plan) {
-                return $this->error("Plan not found: {$slug}");
-            }
+        if ($format === 'markdown') {
+            return $this->success(['markdown' => $plan->toMarkdown()]);
+        }
 
-            if ($format === 'markdown') {
-                return $this->success(['markdown' => $plan->toMarkdown()]);
-            }
-
-            return $this->success([
-                'plan' => [
-                    'slug' => $plan->slug,
-                    'title' => $plan->title,
-                    'description' => $plan->description,
-                    'status' => $plan->status,
-                    'context' => $plan->context,
-                    'progress' => $plan->getProgress(),
-                    'phases' => $plan->agentPhases->map(fn ($phase) => [
-                        'order' => $phase->order,
-                        'name' => $phase->name,
-                        'description' => $phase->description,
-                        'status' => $phase->status,
-                        'tasks' => $phase->tasks,
-                        'checkpoints' => $phase->checkpoints,
-                    ])->all(),
-                    'created_at' => $plan->created_at->toIso8601String(),
-                    'updated_at' => $plan->updated_at->toIso8601String(),
-                ],
-            ]);
-        }, fn () => $this->error('Agentic service temporarily unavailable', 'service_unavailable'));
+        return $this->success(['plan' => $plan->toMcpContext()]);
     }
 }
diff --git a/Mcp/Tools/Agent/Plan/PlanList.php b/Mcp/Tools/Agent/Plan/PlanList.php
index 68e0250..c003669 100644
--- a/Mcp/Tools/Agent/Plan/PlanList.php
+++ b/Mcp/Tools/Agent/Plan/PlanList.php
@@ -5,8 +5,8 @@ declare(strict_types=1);
 namespace Core\Mod\Agentic\Mcp\Tools\Agent\Plan;
 
 use Core\Mcp\Dependencies\ToolDependency;
+use Core\Mod\Agentic\Actions\Plan\ListPlans;
 use Core\Mod\Agentic\Mcp\Tools\Agent\AgentTool;
-use Core\Mod\Agentic\Models\AgentPlan;
 
 /**
  * List all work plans with their current status and progress.
@@ -61,43 +61,30 @@ class PlanList extends AgentTool
 
     public function handle(array $args, array $context = []): array
     {
-        try {
-            $status = $this->optionalEnum($args, 'status', ['draft', 'active', 'paused', 'completed', 'archived']);
-            $includeArchived = (bool) ($args['include_archived'] ?? false);
-        } catch (\InvalidArgumentException $e) {
-            return $this->error($e->getMessage());
-        }
-
-        // Validate workspace context for tenant isolation
         $workspaceId = $context['workspace_id'] ?? null;
         if ($workspaceId === null) {
             return $this->error('workspace_id is required. Ensure you have authenticated with a valid API key and started a session. See: https://host.uk.com/ai');
         }
 
-        // Query plans with workspace scope to prevent cross-tenant access
-        $query = AgentPlan::with('agentPhases')
-            ->forWorkspace($workspaceId)
-            ->orderBy('updated_at', 'desc');
+        try {
+            $plans = ListPlans::run(
+                (int) $workspaceId,
+                $args['status'] ?? null,
+                (bool) ($args['include_archived'] ?? false),
+            );
 
-        if (! $includeArchived && $status !== 'archived') {
-            $query->notArchived();
+            return $this->success([
+                'plans' => $plans->map(fn ($plan) => [
+                    'slug' => $plan->slug,
+                    'title' => $plan->title,
+                    'status' => $plan->status,
+                    'progress' => $plan->getProgress(),
+                    'updated_at' => $plan->updated_at->toIso8601String(),
+                ])->all(),
+                'total' => $plans->count(),
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return $this->error($e->getMessage());
         }
-
-        if ($status !== null) {
-            $query->where('status', $status);
-        }
-
-        $plans = $query->get();
-
-        return $this->success([
-            'plans' => $plans->map(fn ($plan) => [
-                'slug' => $plan->slug,
-                'title' => $plan->title,
-                'status' => $plan->status,
-                'progress' => $plan->getProgress(),
-                'updated_at' => $plan->updated_at->toIso8601String(),
-            ])->all(),
-            'total' => $plans->count(),
-        ]);
     }
 }
diff --git a/Mcp/Tools/Agent/Plan/PlanUpdateStatus.php b/Mcp/Tools/Agent/Plan/PlanUpdateStatus.php
index 9581fe0..6a4c917 100644
--- a/Mcp/Tools/Agent/Plan/PlanUpdateStatus.php
+++ b/Mcp/Tools/Agent/Plan/PlanUpdateStatus.php
@@ -4,8 +4,8 @@ declare(strict_types=1);
 
 namespace Core\Mod\Agentic\Mcp\Tools\Agent\Plan;
 
+use Core\Mod\Agentic\Actions\Plan\UpdatePlanStatus;
 use Core\Mod\Agentic\Mcp\Tools\Agent\AgentTool;
-use Core\Mod\Agentic\Models\AgentPlan;
 
 /**
  * Update the status of a plan.
@@ -47,26 +47,26 @@ class PlanUpdateStatus extends AgentTool
 
     public function handle(array $args, array $context = []): array
     {
+        $workspaceId = $context['workspace_id'] ?? null;
+        if ($workspaceId === null) {
+            return $this->error('workspace_id is required');
+        }
+
         try {
-            $slug = $this->require($args, 'slug');
-            $status = $this->require($args, 'status');
+            $plan = UpdatePlanStatus::run(
+                $args['slug'] ?? '',
+                $args['status'] ?? '',
+                (int) $workspaceId,
+            );
+
+            return $this->success([
+                'plan' => [
+                    'slug' => $plan->slug,
+                    'status' => $plan->status,
+                ],
+            ]);
         } catch (\InvalidArgumentException $e) {
             return $this->error($e->getMessage());
         }
-
-        $plan = AgentPlan::where('slug', $slug)->first();
-
-        if (! $plan) {
-            return $this->error("Plan not found: {$slug}");
-        }
-
-        $plan->update(['status' => $status]);
-
-        return $this->success([
-            'plan' => [
-                'slug' => $plan->slug,
-                'status' => $plan->fresh()->status,
-            ],
-        ]);
     }
 }
diff --git a/Mcp/Tools/Agent/Session/SessionContinue.php b/Mcp/Tools/Agent/Session/SessionContinue.php
index 4faea62..712088d 100644
--- a/Mcp/Tools/Agent/Session/SessionContinue.php
+++ b/Mcp/Tools/Agent/Session/SessionContinue.php
@@ -4,8 +4,8 @@ declare(strict_types=1);
 
 namespace Core\Mod\Agentic\Mcp\Tools\Agent\Session;
 
+use Core\Mod\Agentic\Actions\Session\ContinueSession;
 use Core\Mod\Agentic\Mcp\Tools\Agent\AgentTool;
-use Core\Mod\Agentic\Services\AgentSessionService;
 
 /**
  * Continue from a previous session (multi-agent handoff).
@@ -47,32 +47,27 @@ class SessionContinue extends AgentTool
     public function handle(array $args, array $context = []): array
     {
         try {
-            $previousSessionId = $this->require($args, 'previous_session_id');
-            $agentType = $this->require($args, 'agent_type');
+            $session = ContinueSession::run(
+                $args['previous_session_id'] ?? '',
+                $args['agent_type'] ?? '',
+            );
+
+            $inheritedContext = $session->context_summary ?? [];
+
+            return $this->success([
+                'session' => [
+                    'session_id' => $session->session_id,
+                    'agent_type' => $session->agent_type,
+                    'status' => $session->status,
+                    'plan' => $session->plan?->slug,
+                ],
+                'continued_from' => $inheritedContext['continued_from'] ?? null,
+                'previous_agent' => $inheritedContext['previous_agent'] ?? null,
+                'handoff_notes' => $inheritedContext['handoff_notes'] ?? null,
+                'inherited_context' => $inheritedContext['inherited_context'] ?? null,
+            ]);
         } catch (\InvalidArgumentException $e) {
             return $this->error($e->getMessage());
         }
-
-        $sessionService = app(AgentSessionService::class);
-        $session = $sessionService->continueFrom($previousSessionId, $agentType);
-
-        if (! $session) {
-            return $this->error("Previous session not found: {$previousSessionId}");
-        }
-
-        $inheritedContext = $session->context_summary ?? [];
-
-        return $this->success([
-            'session' => [
-                'session_id' => $session->session_id,
-                'agent_type' => $session->agent_type,
-                'status' => $session->status,
-                'plan' => $session->plan?->slug,
-            ],
-            'continued_from' => $inheritedContext['continued_from'] ?? null,
-            'previous_agent' => $inheritedContext['previous_agent'] ?? null,
-            'handoff_notes' => $inheritedContext['handoff_notes'] ?? null,
-            'inherited_context' => $inheritedContext['inherited_context'] ?? null,
-        ]);
     }
 }
diff --git a/Mcp/Tools/Agent/Session/SessionEnd.php b/Mcp/Tools/Agent/Session/SessionEnd.php
index e1d407b..34f57e5 100644
--- a/Mcp/Tools/Agent/Session/SessionEnd.php
+++ b/Mcp/Tools/Agent/Session/SessionEnd.php
@@ -4,8 +4,8 @@ declare(strict_types=1);
 
 namespace Core\Mod\Agentic\Mcp\Tools\Agent\Session;
 
+use Core\Mod\Agentic\Actions\Session\EndSession;
 use Core\Mod\Agentic\Mcp\Tools\Agent\AgentTool;
-use Core\Mod\Agentic\Models\AgentSession;
 
 /**
  * End the current session.
@@ -47,32 +47,27 @@ class SessionEnd extends AgentTool
 
     public function handle(array $args, array $context = []): array
     {
-        try {
-            $status = $this->require($args, 'status');
-        } catch (\InvalidArgumentException $e) {
-            return $this->error($e->getMessage());
-        }
-
         $sessionId = $context['session_id'] ?? null;
-
         if (! $sessionId) {
             return $this->error('No active session');
         }
 
-        $session = AgentSession::where('session_id', $sessionId)->first();
+        try {
+            $session = EndSession::run(
+                $sessionId,
+                $args['status'] ?? '',
+                $args['summary'] ?? null,
+            );
 
-        if (! $session) {
-            return $this->error('Session not found');
+            return $this->success([
+                'session' => [
+                    'session_id' => $session->session_id,
+                    'status' => $session->status,
+                    'duration' => $session->getDurationFormatted(),
+                ],
+            ]);
+        } catch (\InvalidArgumentException $e) {
+            return $this->error($e->getMessage());
         }
-
-        $session->end($status, $this->optional($args, 'summary'));
-
-        return $this->success([
-            'session' => [
-                'session_id' => $session->session_id,
-                'status' => $session->status,
-                'duration' => $session->getDurationFormatted(),
-            ],
-        ]);
     }
 }
diff --git a/Mcp/Tools/Agent/Session/SessionList.php b/Mcp/Tools/Agent/Session/SessionList.php
index 7d0cf5a..551147c 100644
--- a/Mcp/Tools/Agent/Session/SessionList.php
+++ b/Mcp/Tools/Agent/Session/SessionList.php
@@ -4,8 +4,8 @@ declare(strict_types=1);
 
 namespace Core\Mod\Agentic\Mcp\Tools\Agent\Session;
 
+use Core\Mod\Agentic\Actions\Session\ListSessions;
 use Core\Mod\Agentic\Mcp\Tools\Agent\AgentTool;
-use Core\Mod\Agentic\Services\AgentSessionService;
 
 /**
  * List sessions, optionally filtered by status.
@@ -50,54 +50,34 @@ class SessionList extends AgentTool
 
     public function handle(array $args, array $context = []): array
     {
+        $workspaceId = $context['workspace_id'] ?? null;
+        if ($workspaceId === null) {
+            return $this->error('workspace_id is required');
+        }
+
         try {
-            $status = $this->optionalEnum($args, 'status', ['active', 'paused', 'completed', 'failed']);
-            $planSlug = $this->optionalString($args, 'plan_slug', null, 255);
-            $limit = $this->optionalInt($args, 'limit', null, min: 1, max: 1000);
+            $sessions = ListSessions::run(
+                (int) $workspaceId,
+                $args['status'] ?? null,
+                $args['plan_slug'] ?? null,
+                isset($args['limit']) ? (int) $args['limit'] : null,
+            );
+
+            return $this->success([
+                'sessions' => $sessions->map(fn ($session) => [
+                    'session_id' => $session->session_id,
+                    'agent_type' => $session->agent_type,
+                    'status' => $session->status,
+                    'plan' => $session->plan?->slug,
+                    'duration' => $session->getDurationFormatted(),
+                    'started_at' => $session->started_at->toIso8601String(),
+                    'last_active_at' => $session->last_active_at->toIso8601String(),
+                    'has_handoff' => ! empty($session->handoff_notes),
+                ])->all(),
+                'total' => $sessions->count(),
+            ]);
         } catch (\InvalidArgumentException $e) {
             return $this->error($e->getMessage());
         }
-
-        $sessionService = app(AgentSessionService::class);
-
-        // Get active sessions (default)
-        if ($status === 'active' || $status === null) {
-            $sessions = $sessionService->getActiveSessions($context['workspace_id'] ?? null);
-        } else {
-            // Query with filters
-            $query = \Core\Mod\Agentic\Models\AgentSession::query()
-                ->orderBy('last_active_at', 'desc');
-
-            // Apply workspace filter if provided
-            if (! empty($context['workspace_id'])) {
-                $query->where('workspace_id', $context['workspace_id']);
-            }
-
-            $query->where('status', $status);
-
-            if ($planSlug !== null) {
-                $query->whereHas('plan', fn ($q) => $q->where('slug', $planSlug));
-            }
-
-            if ($limit !== null) {
-                $query->limit($limit);
-            }
-
-            $sessions = $query->get();
-        }
-
-        return [
-            'sessions' => $sessions->map(fn ($session) => [
-                'session_id' => $session->session_id,
-                'agent_type' => $session->agent_type,
-                'status' => $session->status,
-                'plan' => $session->plan?->slug,
-                'duration' => $session->getDurationFormatted(),
-                'started_at' => $session->started_at->toIso8601String(),
-                'last_active_at' => $session->last_active_at->toIso8601String(),
-                'has_handoff' => ! empty($session->handoff_notes),
-            ])->all(),
-            'total' => $sessions->count(),
-        ];
     }
 }
diff --git a/Mcp/Tools/Agent/Session/SessionStart.php b/Mcp/Tools/Agent/Session/SessionStart.php
index 3e3458f..f2605c4 100644
--- a/Mcp/Tools/Agent/Session/SessionStart.php
+++ b/Mcp/Tools/Agent/Session/SessionStart.php
@@ -5,10 +5,8 @@ declare(strict_types=1);
 namespace Core\Mod\Agentic\Mcp\Tools\Agent\Session;
 
 use Core\Mcp\Dependencies\ToolDependency;
+use Core\Mod\Agentic\Actions\Session\StartSession;
 use Core\Mod\Agentic\Mcp\Tools\Agent\AgentTool;
-use Core\Mod\Agentic\Models\AgentPlan;
-use Core\Mod\Agentic\Models\AgentSession;
-use Illuminate\Support\Str;
 
 /**
  * Start a new agent session for a plan.
@@ -70,48 +68,29 @@ class SessionStart extends AgentTool
 
     public function handle(array $args, array $context = []): array
     {
-        try {
-            $agentType = $this->require($args, 'agent_type');
-        } catch (\InvalidArgumentException $e) {
-            return $this->error($e->getMessage());
+        $workspaceId = $context['workspace_id'] ?? null;
+        if ($workspaceId === null) {
+            return $this->error('workspace_id is required. Ensure you have authenticated with a valid API key and started a session, or provide a valid plan_slug to infer workspace context. See: https://host.uk.com/ai');
         }
 
-        // Use circuit breaker for Agentic module database calls
-        return $this->withCircuitBreaker('agentic', function () use ($args, $context, $agentType) {
-            $plan = null;
-            if (! empty($args['plan_slug'])) {
-                $plan = AgentPlan::where('slug', $args['plan_slug'])->first();
-            }
-
-            $sessionId = 'ses_'.Str::random(12);
-
-            // Determine workspace_id - never fall back to hardcoded value in multi-tenant environment
-            $workspaceId = $context['workspace_id'] ?? $plan?->workspace_id ?? null;
-            if ($workspaceId === null) {
-                return $this->error('workspace_id is required. Ensure you have authenticated with a valid API key and started a session, or provide a valid plan_slug to infer workspace context. See: https://host.uk.com/ai');
-            }
-
-            $session = AgentSession::create([
-                'session_id' => $sessionId,
-                'agent_plan_id' => $plan?->id,
-                'workspace_id' => $workspaceId,
-                'agent_type' => $agentType,
-                'status' => 'active',
-                'started_at' => now(),
-                'last_active_at' => now(),
-                'context_summary' => $args['context'] ?? [],
-                'work_log' => [],
-                'artifacts' => [],
-            ]);
+        try {
+            $session = StartSession::run(
+                $args['agent_type'] ?? '',
+                $args['plan_slug'] ?? null,
+                (int) $workspaceId,
+                $args['context'] ?? [],
+            );
 
             return $this->success([
                 'session' => [
                     'session_id' => $session->session_id,
                     'agent_type' => $session->agent_type,
-                    'plan' => $plan?->slug,
+                    'plan' => $session->plan?->slug,
                     'status' => $session->status,
                 ],
             ]);
-        }, fn () => $this->error('Agentic service temporarily unavailable. Session cannot be created.', 'service_unavailable'));
+        } catch (\InvalidArgumentException $e) {
+            return $this->error($e->getMessage());
+        }
     }
 }
diff --git a/Mcp/Tools/Agent/Task/TaskToggle.php b/Mcp/Tools/Agent/Task/TaskToggle.php
index eec0a77..266ec76 100644
--- a/Mcp/Tools/Agent/Task/TaskToggle.php
+++ b/Mcp/Tools/Agent/Task/TaskToggle.php
@@ -5,9 +5,8 @@ declare(strict_types=1);
 namespace Core\Mod\Agentic\Mcp\Tools\Agent\Task;
 
 use Core\Mcp\Dependencies\ToolDependency;
+use Core\Mod\Agentic\Actions\Task\ToggleTask;
 use Core\Mod\Agentic\Mcp\Tools\Agent\AgentTool;
-use Core\Mod\Agentic\Models\AgentPhase;
-use Core\Mod\Agentic\Models\AgentPlan;
 
 /**
  * Toggle a task completion status.
@@ -64,66 +63,22 @@ class TaskToggle extends AgentTool
 
     public function handle(array $args, array $context = []): array
     {
+        $workspaceId = $context['workspace_id'] ?? null;
+        if ($workspaceId === null) {
+            return $this->error('workspace_id is required');
+        }
+
         try {
-            $planSlug = $this->requireString($args, 'plan_slug', 255);
-            $phaseIdentifier = $this->requireString($args, 'phase', 255);
-            $taskIndex = $this->requireInt($args, 'task_index', min: 0, max: 1000);
+            $result = ToggleTask::run(
+                $args['plan_slug'] ?? '',
+                $args['phase'] ?? '',
+                (int) ($args['task_index'] ?? 0),
+                (int) $workspaceId,
+            );
+
+            return $this->success($result);
         } catch (\InvalidArgumentException $e) {
             return $this->error($e->getMessage());
         }
-
-        $plan = AgentPlan::where('slug', $planSlug)->first();
-
-        if (! $plan) {
-            return $this->error("Plan not found: {$planSlug}");
-        }
-
-        $phase = $this->findPhase($plan, $phaseIdentifier);
-
-        if (! $phase) {
-            return $this->error("Phase not found: {$phaseIdentifier}");
-        }
-
-        $tasks = $phase->tasks ?? [];
-
-        if (! isset($tasks[$taskIndex])) {
-            return $this->error("Task not found at index: {$taskIndex}");
-        }
-
-        $currentStatus = is_string($tasks[$taskIndex])
-            ? 'pending'
-            : ($tasks[$taskIndex]['status'] ?? 'pending');
-
-        $newStatus = $currentStatus === 'completed' ? 'pending' : 'completed';
-
-        if (is_string($tasks[$taskIndex])) {
-            $tasks[$taskIndex] = [
-                'name' => $tasks[$taskIndex],
-                'status' => $newStatus,
-            ];
-        } else {
-            $tasks[$taskIndex]['status'] = $newStatus;
-        }
-
-        $phase->update(['tasks' => $tasks]);
-
-        return $this->success([
-            'task' => $tasks[$taskIndex],
-            'plan_progress' => $plan->fresh()->getProgress(),
-        ]);
-    }
-
-    /**
-     * Find a phase by order number or name.
-     */
-    protected function findPhase(AgentPlan $plan, string|int $identifier): ?AgentPhase
-    {
-        if (is_numeric($identifier)) {
-            return $plan->agentPhases()->where('order', (int) $identifier)->first();
-        }
-
-        return $plan->agentPhases()
-            ->where('name', $identifier)
-            ->first();
     }
 }
diff --git a/Mcp/Tools/Agent/Task/TaskUpdate.php b/Mcp/Tools/Agent/Task/TaskUpdate.php
index 9f724b2..09d2c96 100644
--- a/Mcp/Tools/Agent/Task/TaskUpdate.php
+++ b/Mcp/Tools/Agent/Task/TaskUpdate.php
@@ -5,9 +5,8 @@ declare(strict_types=1);
 namespace Core\Mod\Agentic\Mcp\Tools\Agent\Task;
 
 use Core\Mcp\Dependencies\ToolDependency;
+use Core\Mod\Agentic\Actions\Task\UpdateTask;
 use Core\Mod\Agentic\Mcp\Tools\Agent\AgentTool;
-use Core\Mod\Agentic\Models\AgentPhase;
-use Core\Mod\Agentic\Models\AgentPlan;
 
 /**
  * Update task details (status, notes).
@@ -73,71 +72,24 @@ class TaskUpdate extends AgentTool
 
     public function handle(array $args, array $context = []): array
     {
-        try {
-            $planSlug = $this->requireString($args, 'plan_slug', 255);
-            $phaseIdentifier = $this->requireString($args, 'phase', 255);
-            $taskIndex = $this->requireInt($args, 'task_index', min: 0, max: 1000);
+        $workspaceId = $context['workspace_id'] ?? null;
+        if ($workspaceId === null) {
+            return $this->error('workspace_id is required');
+        }
 
-            // Validate optional status enum
-            $status = $this->optionalEnum($args, 'status', ['pending', 'in_progress', 'completed', 'blocked', 'skipped']);
-            $notes = $this->optionalString($args, 'notes', null, 5000);
+        try {
+            $result = UpdateTask::run(
+                $args['plan_slug'] ?? '',
+                $args['phase'] ?? '',
+                (int) ($args['task_index'] ?? 0),
+                (int) $workspaceId,
+                $args['status'] ?? null,
+                $args['notes'] ?? null,
+            );
+
+            return $this->success($result);
         } catch (\InvalidArgumentException $e) {
             return $this->error($e->getMessage());
         }
-
-        $plan = AgentPlan::where('slug', $planSlug)->first();
-
-        if (! $plan) {
-            return $this->error("Plan not found: {$planSlug}");
-        }
-
-        $phase = $this->findPhase($plan, $phaseIdentifier);
-
-        if (! $phase) {
-            return $this->error("Phase not found: {$phaseIdentifier}");
-        }
-
-        $tasks = $phase->tasks ?? [];
-
-        if (! isset($tasks[$taskIndex])) {
-            return $this->error("Task not found at index: {$taskIndex}");
-        }
-
-        // Normalise task to array format
-        if (is_string($tasks[$taskIndex])) {
-            $tasks[$taskIndex] = ['name' => $tasks[$taskIndex], 'status' => 'pending'];
-        }
-
-        // Update fields using pre-validated values
-        if ($status !== null) {
-            $tasks[$taskIndex]['status'] = $status;
-        }
-
-        if ($notes !== null) {
-            $tasks[$taskIndex]['notes'] = $notes;
-        }
-
-        $phase->update(['tasks' => $tasks]);
-
-        return $this->success([
-            'task' => $tasks[$taskIndex],
-        ]);
-    }
-
-    /**
-     * Find a phase by order number or name.
-     */
-    protected function findPhase(AgentPlan $plan, string|int $identifier): ?AgentPhase
-    {
-        if (is_numeric($identifier)) {
-            return $plan->agentPhases()->where('order', (int) $identifier)->first();
-        }
-
-        return $plan->agentPhases()
-            ->where(function ($query) use ($identifier) {
-                $query->where('name', $identifier)
-                    ->orWhere('order', $identifier);
-            })
-            ->first();
     }
 }
diff --git a/Routes/api.php b/Routes/api.php
index 2aff966..1cd2ab0 100644
--- a/Routes/api.php
+++ b/Routes/api.php
@@ -3,6 +3,10 @@
 declare(strict_types=1);
 
 use Core\Mod\Agentic\Controllers\Api\BrainController;
+use Core\Mod\Agentic\Controllers\Api\PhaseController;
+use Core\Mod\Agentic\Controllers\Api\PlanController;
+use Core\Mod\Agentic\Controllers\Api\SessionController;
+use Core\Mod\Agentic\Controllers\Api\TaskController;
 use Illuminate\Support\Facades\Route;
 
 /*
@@ -10,18 +14,56 @@ use Illuminate\Support\Facades\Route;
 | Agentic API Routes
 |--------------------------------------------------------------------------
 |
-| Brain (OpenBrain knowledge store) endpoints.
+| Brain, Plans, Sessions, Phases, and Tasks endpoints.
 | Auto-wrapped with 'api' middleware and /api prefix by ApiRoutesRegistering.
 |
 */
 
-Route::middleware(['api.auth', 'api.scope.enforce'])
-    ->prefix('brain')
-    ->name('brain.')
-    ->group(function () {
+// Health check (no auth required)
+Route::get('health', fn () => response()->json(['status' => 'ok', 'timestamp' => now()->toIso8601String()]));
+
+// Authenticated endpoints
+Route::middleware(['api.auth', 'api.scope.enforce'])->group(function () {
+
+    // Brain (OpenBrain knowledge store)
+    Route::prefix('brain')->name('brain.')->group(function () {
         Route::post('remember', [BrainController::class, 'remember'])->name('remember');
         Route::post('recall', [BrainController::class, 'recall'])->name('recall');
         Route::delete('forget/{id}', [BrainController::class, 'forget'])->name('forget')
             ->where('id', '[0-9a-f-]+');
         Route::get('list', [BrainController::class, 'list'])->name('list');
     });
+
+    // Plans
+    Route::prefix('plans')->name('plans.')->group(function () {
+        Route::get('/', [PlanController::class, 'index'])->name('index');
+        Route::get('{slug}', [PlanController::class, 'show'])->name('show');
+        Route::post('/', [PlanController::class, 'store'])->name('store');
+        Route::patch('{slug}', [PlanController::class, 'update'])->name('update');
+        Route::delete('{slug}', [PlanController::class, 'destroy'])->name('destroy');
+
+        // Phases (nested under plans)
+        Route::prefix('{slug}/phases')->name('phases.')->group(function () {
+            Route::get('{phase}', [PhaseController::class, 'show'])->name('show');
+            Route::patch('{phase}', [PhaseController::class, 'update'])->name('update');
+            Route::post('{phase}/checkpoint', [PhaseController::class, 'checkpoint'])->name('checkpoint');
+
+            // Tasks (nested under phases)
+            Route::prefix('{phase}/tasks')->name('tasks.')->group(function () {
+                Route::patch('{index}', [TaskController::class, 'update'])->name('update')
+                    ->where('index', '[0-9]+');
+                Route::post('{index}/toggle', [TaskController::class, 'toggle'])->name('toggle')
+                    ->where('index', '[0-9]+');
+            });
+        });
+    });
+
+    // Sessions
+    Route::prefix('sessions')->name('sessions.')->group(function () {
+        Route::get('/', [SessionController::class, 'index'])->name('index');
+        Route::get('{id}', [SessionController::class, 'show'])->name('show');
+        Route::post('/', [SessionController::class, 'store'])->name('store');
+        Route::post('{id}/end', [SessionController::class, 'end'])->name('end');
+        Route::post('{id}/continue', [SessionController::class, 'continue'])->name('continue');
+    });
+});