diff --git a/apps/frontend/src/main/pr-review-state-manager.ts b/apps/frontend/src/main/pr-review-state-manager.ts
new file mode 100644
index 00000000..01ba68fb
--- /dev/null
+++ b/apps/frontend/src/main/pr-review-state-manager.ts
@@ -0,0 +1,162 @@
+import { createActor } from 'xstate';
+import type { ActorRefFrom } from 'xstate';
+import type { BrowserWindow } from 'electron';
+import { prReviewMachine, type PRReviewEvent, type PRReviewContext } from '../shared/state-machines';
+import type { PRReviewProgress, PRReviewResult } from '../preload/api/modules/github-api';
+import { IPC_CHANNELS } from '../shared/constants';
+import { safeSendToRenderer } from './ipc-handlers/utils';
+
+type PRReviewActor = ActorRefFrom<typeof prReviewMachine>;
+
+/**
+ * Build a deduplication key from snapshot state + relevant context fields.
+ * PR reviews need to emit even when state stays the same but context changes
+ * (e.g., progress updates within 'reviewing' state).
+ */
+function buildContextKey(snapshot: { context: PRReviewContext }): string {
+  const ctx = snapshot.context;
+  const progressKey = ctx.progress
+    ? `${ctx.progress.phase}:${ctx.progress.progress}:${ctx.progress.message}`
+    : 'none';
+  const resultKey = ctx.result ? ctx.result.overallStatus : 'none';
+  const errorKey = ctx.error ?? 'none';
+  return `${progressKey}|${resultKey}|${errorKey}`;
+}
+
+export class PRReviewStateManager {
+  private actors = new Map<string, PRReviewActor>();
+  private lastStateByPR = new Map<string, string>();
+  private getMainWindow: () => BrowserWindow | null;
+
+  constructor(getMainWindow: () => BrowserWindow | null) {
+    this.getMainWindow = getMainWindow;
+  }
+
+  handleStartReview(projectId: string, prNumber: number): void {
+    const actor = this.getOrCreateActor(projectId, prNumber);
+    actor.send({ type: 'START_REVIEW', prNumber, projectId } satisfies PRReviewEvent);
+  }
+
+  handleStartFollowupReview(projectId: string, prNumber: number, previousResult?: PRReviewResult): void {
+    const actor = this.getOrCreateActor(projectId, prNumber);
+    if (previousResult) {
+      actor.send({ type: 'START_FOLLOWUP_REVIEW', prNumber, projectId, previousResult } satisfies PRReviewEvent);
+    } else {
+      actor.send({ type: 'START_REVIEW', prNumber, projectId } satisfies PRReviewEvent);
+    }
+  }
+
+  handleProgress(projectId: string, prNumber: number, progress: PRReviewProgress): void {
+    const actor = this.getActor(projectId, prNumber);
+    if (!actor) return;
+    actor.send({ type: 'SET_PROGRESS', progress } satisfies PRReviewEvent);
+  }
+
+  handleComplete(projectId: string, prNumber: number, result: PRReviewResult): void {
+    const actor = this.getActor(projectId, prNumber);
+    if (!actor) return;
+
+    // Detect external review (result arrives with 'in_progress' status from outside)
+    if (result.overallStatus === 'in_progress') {
+      actor.send({ type: 'DETECT_EXTERNAL_REVIEW' } satisfies PRReviewEvent);
+    } else {
+      actor.send({ type: 'REVIEW_COMPLETE', result } satisfies PRReviewEvent);
+    }
+  }
+
+  handleError(projectId: string, prNumber: number, error: string): void {
+    const actor = this.getActor(projectId, prNumber);
+    if (!actor) return;
+    actor.send({ type: 'REVIEW_ERROR', error } satisfies PRReviewEvent);
+  }
+
+  handleCancel(projectId: string, prNumber: number): void {
+    const actor = this.getActor(projectId, prNumber);
+    if (!actor) return;
+    actor.send({ type: 'CANCEL_REVIEW' } satisfies PRReviewEvent);
+  }
+
+  handleClearReview(projectId: string, prNumber: number): void {
+    const key = this.getKey(projectId, prNumber);
+    const actor = this.actors.get(key);
+    if (actor) {
+      actor.send({ type: 'CLEAR_REVIEW' } satisfies PRReviewEvent);
+      actor.stop();
+      this.actors.delete(key);
+    }
+    this.lastStateByPR.delete(key);
+  }
+
+  handleAuthChange(): void {
+    for (const [key, actor] of this.actors) {
+      actor.stop();
+      // Emit cleared (idle) state to renderer for each PR
+      this.emitStateToRenderer(key, null);
+    }
+    this.actors.clear();
+    this.lastStateByPR.clear();
+  }
+
+  getState(projectId: string, prNumber: number): ReturnType<PRReviewActor['getSnapshot']> | null {
+    const actor = this.getActor(projectId, prNumber);
+    if (!actor) return null;
+    return actor.getSnapshot();
+  }
+
+  clearAll(): void {
+    for (const [, actor] of this.actors) {
+      actor.stop();
+    }
+    this.actors.clear();
+    this.lastStateByPR.clear();
+  }
+
+  // ---------------------------------------------------------------------------
+  // Private
+  // ---------------------------------------------------------------------------
+
+  private getOrCreateActor(projectId: string, prNumber: number): PRReviewActor {
+    const key = this.getKey(projectId, prNumber);
+    const existing = this.actors.get(key);
+    if (existing) return existing;
+
+    const actor = createActor(prReviewMachine);
+
+    actor.subscribe((snapshot) => {
+      const stateValue = String(snapshot.value);
+      const contextKey = buildContextKey(snapshot);
+      const currentKey = `${stateValue}:${contextKey}`;
+      if (this.lastStateByPR.get(key) === currentKey) return;
+      this.lastStateByPR.set(key, currentKey);
+      this.emitStateToRenderer(key, snapshot);
+    });
+
+    actor.start();
+    this.actors.set(key, actor);
+    return actor;
+  }
+
+  private getActor(projectId: string, prNumber: number): PRReviewActor | null {
+    return this.actors.get(this.getKey(projectId, prNumber)) ?? null;
+  }
+
+  private getKey(projectId: string, prNumber: number): string {
+    return `${projectId}:${prNumber}`;
+  }
+
+  private emitStateToRenderer(
+    key: string,
+    snapshot: ReturnType<PRReviewActor['getSnapshot']> | null
+  ): void {
+    const stateValue = snapshot ? String(snapshot.value) : 'idle';
+    const context = snapshot ? snapshot.context : null;
+
+    safeSendToRenderer(
+      this.getMainWindow,
+      IPC_CHANNELS.GITHUB_PR_REVIEW_STATE_CHANGE,
+      key,
+      stateValue,
+      context
+    );
+  }
+}