feat: session replay

* wip

* wip

* wip

* wip

* final fixes

* comments

* fix

packages/sdks/web/src/index.ts

@@ -7,11 +7,43 @@ import { OpenPanel as OpenPanelBase } from '@openpanel/sdk';
 export type * from '@openpanel/sdk';
 export { OpenPanel as OpenPanelBase } from '@openpanel/sdk';
 
+export type SessionReplayOptions = {
+  enabled: boolean;
+  sampleRate?: number;
+  maskAllInputs?: boolean;
+  maskTextSelector?: string;
+  blockSelector?: string;
+  blockClass?: string;
+  ignoreSelector?: string;
+  flushIntervalMs?: number;
+  maxEventsPerChunk?: number;
+  maxPayloadBytes?: number;
+  /**
+   * URL to the replay recorder script.
+   * Only used when loading the SDK via a script tag (IIFE / op1.js).
+   * When using the npm package with a bundler this option is ignored
+   * because the bundler resolves the replay module from the package.
+   */
+  scriptUrl?: string;
+};
+
+// Injected at build time only in the IIFE (tracker) build.
+// In the library build this is `undefined`.
+declare const __OPENPANEL_REPLAY_URL__: string | undefined;
+
+// Capture script element synchronously; currentScript is only set during sync execution.
+// Used by loadReplayModule() to derive the replay script URL in the IIFE build.
+const _replayScriptRef: HTMLScriptElement | null =
+  typeof document !== 'undefined'
+    ? (document.currentScript as HTMLScriptElement | null)
+    : null;
+
 export type OpenPanelOptions = OpenPanelBaseOptions & {
   trackOutgoingLinks?: boolean;
   trackScreenViews?: boolean;
   trackAttributes?: boolean;
   trackHashChanges?: boolean;
+  sessionReplay?: SessionReplayOptions;
 };
 
 function toCamelCase(str: string) {
@@ -66,6 +98,75 @@ export class OpenPanel extends OpenPanelBase {
       if (this.options.trackAttributes) {
         this.trackAttributes();
       }
+
+      if (this.options.sessionReplay?.enabled) {
+        const sampleRate = this.options.sessionReplay.sampleRate ?? 1;
+        const sampled = Math.random() < sampleRate;
+        if (sampled) {
+          this.loadReplayModule().then((mod) => {
+            if (!mod) return;
+            mod.startReplayRecorder(this.options.sessionReplay!, (chunk) => {
+              this.send({
+                type: 'replay',
+                payload: {
+                  ...chunk,
+                },
+              });
+            });
+          });
+        }
+      }
+    }
+  }
+
+  /**
+   * Load the replay recorder module.
+   *
+   * - **IIFE build (op1.js)**: `__OPENPANEL_REPLAY_URL__` is replaced at
+   *   build time with a CDN URL (e.g. `https://openpanel.dev/op1-replay.js`).
+   *   The user can also override it via `sessionReplay.scriptUrl`.
+   *   We load the IIFE replay script via a classic `<script>` tag which
+   *   avoids CORS issues (dynamic `import(url)` uses `cors` mode).
+   *   The IIFE exposes its exports on `window.__openpanel_replay`.
+   *
+   * - **Library build (npm)**: `__OPENPANEL_REPLAY_URL__` is `undefined`
+   *   (never replaced). We use `import('./replay')` which the host app's
+   *   bundler resolves and code-splits from the package source.
+   */
+  private async loadReplayModule(): Promise<typeof import('./replay') | null> {
+    try {
+      // typeof check avoids a ReferenceError when the constant is not
+      // defined (library build). tsup replaces the constant with a
+      // string literal only in the IIFE build, so this branch is
+      // dead-code-eliminated in the library build.
+      if (typeof __OPENPANEL_REPLAY_URL__ !== 'undefined') {
+        const scriptEl = _replayScriptRef;
+        const url = this.options.sessionReplay?.scriptUrl || scriptEl?.src?.replace('.js', '-replay.js') || 'https://openpanel.dev/op1-replay.js';
+
+        // Already loaded (e.g. user included the script manually)
+        if ((window as any).__openpanel_replay) {
+          return (window as any).__openpanel_replay;
+        }
+
+        // Load via classic <script> tag — no CORS restrictions
+        return new Promise((resolve) => {
+          const script = document.createElement('script');
+          script.src = url;
+          script.onload = () => {
+            resolve((window as any).__openpanel_replay ?? null);
+          };
+          script.onerror = () => {
+            console.warn('[OpenPanel] Failed to load replay script from', url);
+            resolve(null);
+          };
+          document.head.appendChild(script);
+        });
+      }
+      // Library / bundler context — resolved by the bundler
+      return await import('./replay');
+    } catch (e) {
+      console.warn('[OpenPanel] Failed to load replay module', e);
+      return null;
     }
   }
 

packages/sdks/web/src/replay/index.ts

@@ -0,0 +1,2 @@
+export { startReplayRecorder, stopReplayRecorder } from './recorder';
+export type { ReplayChunkPayload, ReplayRecorderConfig } from './recorder';

packages/sdks/web/src/replay/recorder.ts

@@ -0,0 +1,160 @@
+import type { eventWithTime } from 'rrweb';
+import { record } from 'rrweb';
+
+export type ReplayRecorderConfig = {
+  maskAllInputs?: boolean;
+  maskTextSelector?: string;
+  blockSelector?: string;
+  blockClass?: string;
+  ignoreSelector?: string;
+  flushIntervalMs?: number;
+  maxEventsPerChunk?: number;
+  maxPayloadBytes?: number;
+};
+
+export type ReplayChunkPayload = {
+  chunk_index: number;
+  events_count: number;
+  is_full_snapshot: boolean;
+  started_at: string;
+  ended_at: string;
+  payload: string;
+};
+
+let stopRecording: (() => void) | null = null;
+
+export function startReplayRecorder(
+  config: ReplayRecorderConfig,
+  sendChunk: (payload: ReplayChunkPayload) => void,
+): void {
+  if (typeof document === 'undefined' || typeof window === 'undefined') {
+    return;
+  }
+
+  // Stop any existing recorder before starting a new one to avoid leaks
+  if (stopRecording) {
+    stopRecording();
+  }
+
+  const maxEventsPerChunk = config.maxEventsPerChunk ?? 200;
+  const flushIntervalMs = config.flushIntervalMs ?? 10_000;
+  const maxPayloadBytes = config.maxPayloadBytes ?? 1_048_576; // 1MB
+
+  let buffer: eventWithTime[] = [];
+  let chunkIndex = 0;
+  let flushTimer: ReturnType<typeof setInterval> | null = null;
+
+  function flush(isFullSnapshot: boolean): void {
+    if (buffer.length === 0) return;
+
+    const payloadJson = JSON.stringify(buffer);
+    const payloadBytes = new TextEncoder().encode(payloadJson).length;
+
+    if (payloadBytes > maxPayloadBytes) {
+      if (buffer.length > 1) {
+        const mid = Math.floor(buffer.length / 2);
+        const firstHalf = buffer.slice(0, mid);
+        const secondHalf = buffer.slice(mid);
+        const firstHasFullSnapshot =
+          isFullSnapshot && firstHalf.some((e) => e.type === 2);
+        buffer = firstHalf;
+        flush(firstHasFullSnapshot);
+        buffer = secondHalf;
+        flush(false);
+        return;
+      }
+      // Single event exceeds limit — drop it to avoid server rejection
+      buffer = [];
+      return;
+    }
+
+    const startedAt = buffer[0]!.timestamp;
+    const endedAt = buffer[buffer.length - 1]!.timestamp;
+
+    try {
+      sendChunk({
+        chunk_index: chunkIndex,
+        events_count: buffer.length,
+        is_full_snapshot: isFullSnapshot,
+        started_at: new Date(startedAt).toISOString(),
+        ended_at: new Date(endedAt).toISOString(),
+        payload: payloadJson,
+      });
+      chunkIndex += 1;
+      buffer = [];
+    } catch (err) {
+      console.error('[ReplayRecorder] sendChunk failed', err);
+      throw err;
+    }
+  }
+
+  function flushIfNeeded(isCheckout: boolean): void {
+    const isFullSnapshot =
+      isCheckout ||
+      buffer.some((e) => e.type === 2); /* EventType.FullSnapshot */
+    if (buffer.length >= maxEventsPerChunk) {
+      flush(isFullSnapshot);
+    } else if (isCheckout && buffer.length > 0) {
+      flush(true);
+    }
+  }
+
+  const stopFn = record({
+    emit(event: eventWithTime, isCheckout?: boolean) {
+      buffer.push(event);
+      flushIfNeeded(!!isCheckout);
+    },
+    checkoutEveryNms: flushIntervalMs,
+    maskAllInputs: config.maskAllInputs ?? true,
+    maskTextSelector: config.maskTextSelector ?? '[data-openpanel-replay-mask]',
+    blockSelector: config.blockSelector ?? '[data-openpanel-replay-block]',
+    blockClass: config.blockClass,
+    ignoreSelector: config.ignoreSelector,
+  });
+
+  flushTimer = setInterval(() => {
+    if (buffer.length > 0) {
+      const hasFullSnapshot = buffer.some((e) => e.type === 2);
+      flush(hasFullSnapshot);
+    }
+  }, flushIntervalMs);
+
+  function onVisibilityChange(): void {
+    if (document.visibilityState === 'hidden' && buffer.length > 0) {
+      const hasFullSnapshot = buffer.some((e) => e.type === 2);
+      flush(hasFullSnapshot);
+    }
+  }
+
+  function onPageHide(): void {
+    if (buffer.length > 0) {
+      const hasFullSnapshot = buffer.some((e) => e.type === 2);
+      flush(hasFullSnapshot);
+    }
+  }
+
+  document.addEventListener('visibilitychange', onVisibilityChange);
+  window.addEventListener('pagehide', onPageHide);
+
+  stopRecording = () => {
+    // Flush any buffered events before tearing down (same logic as flushTimer)
+    if (buffer.length > 0) {
+      const hasFullSnapshot = buffer.some((e) => e.type === 2);
+      flush(hasFullSnapshot);
+    }
+    if (flushTimer) {
+      clearInterval(flushTimer);
+      flushTimer = null;
+    }
+    document.removeEventListener('visibilitychange', onVisibilityChange);
+    window.removeEventListener('pagehide', onPageHide);
+    stopFn?.();
+    stopRecording = null;
+  };
+}
+
+export function stopReplayRecorder(): void {
+  if (stopRecording) {
+    stopRecording();
+  }
+}

packages/sdks/web/src/types.d.ts

@@ -14,7 +14,9 @@ type ExposedMethodsNames =
   | 'clearRevenue'
   | 'pendingRevenue'
   | 'screenView'
-  | 'fetchDeviceId';
+  | 'fetchDeviceId'
+  | 'getDeviceId'
+  | 'getSessionId';
 
 export type ExposedMethods = {
   [K in ExposedMethodsNames]: OpenPanel[K] extends (...args: any[]) => any
@@ -38,7 +40,7 @@ type OpenPanelMethodSignatures = {
 } & {
   screenView(
     pathOrProperties?: string | TrackProperties,
-    properties?: TrackProperties,
+    properties?: TrackProperties
   ): void;
 };
 

packages/sdks/web/src/types.debug.ts

@@ -1,4 +1,5 @@
 // Test callable function API
+/** biome-ignore-all lint/correctness/noUnusedVariables: test */
 function testCallableAPI() {
   // ✅ Should work - correct callable syntax
   window.op('track', 'button_clicked', { location: 'header' });
@@ -29,6 +30,7 @@ function testDirectMethodAPI() {
   window.op.flushRevenue();
   window.op.clearRevenue();
   window.op.fetchDeviceId();
+  window.op.getDeviceId();
 
   // ❌ Should error - wrong arguments for track
   // @ts-expect-error - track expects (name: string, properties?: TrackProperties)