Replays capture browser sessions as video recordings that you can view or download later. You have full control over when replays start and stop, allowing you to capture specific interactions or workflows.

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Starting and stopping recordings

To start recording a browser session, use the replays API on an active browser: 
import { Kernel } from '@onkernel/sdk';

const kernel = new Kernel();
const kernelBrowser = await kernel.browsers.create();

// Start recording
const replay = await kernel.browsers.replays.start(kernelBrowser.session_id);
console.log(`Recording started with ID: ${replay.replay_id}`);

// ... perform some automation ...

// Stop the recording
await kernel.browsers.replays.stop(replay.replay_id, { id: kernelBrowser.session_id });
console.log("Recording stopped and processing...");

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Multiple recordings per session

You can create multiple replay recordings for a single browser session. Each recording gets a unique replay_id and can be started and stopped independently: 
// First recording
const replay1 = await kernel.browsers.replays.start(kernelBrowser.session_id);
// ... perform some automation ...
await kernel.browsers.replays.stop(replay1.replay_id, { id: kernelBrowser.session_id });

// Second recording
const replay2 = await kernel.browsers.replays.start(kernelBrowser.session_id);
// ... perform different automation ...
await kernel.browsers.replays.stop(replay2.replay_id, { id: kernelBrowser.session_id });

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Downloading all replays

To access all replays for a browser session, list and access them via url or as downloads: 
import fs from 'fs';
import { Buffer } from 'buffer';
// List all replays for the session
const replays = await kernel.browsers.replays.list(kernelBrowser.session_id);

for (const replay of replays) {
    console.log(`Replay ID: ${replay.replay_id}`);
    console.log(`View URL: ${replay.replay_view_url}`);
    
    // Download the mp4 file
    const videoData = await kernel.browsers.replays.download(
        replay.replay_id,
        { id: kernelBrowser.session_id }
    );

    const content = await videoData.blob();
    const buffer = Buffer.from(await content.arrayBuffer());

    // Save to file
    const filename = `replay-${replay.replay_id}-${kernelBrowser.session_id}.mp4`;
    fs.writeFileSync(filename, buffer);
}