What Is SCTE-35 and Why It Matters for Live Streaming Ads

If you want to sell ads inside a live stream, the platforms on the other side need to know exactly when a break starts and ends. That is the job of SCTE-35.

What SCTE-35 is

SCTE-35 is the industry standard for signaling cue points in a video stream. A cue tells downstream systems "an ad break starts here" (often called CUE-OUT) and "the program returns here" (CUE-IN). The markers travel inside the stream itself, in the MPEG transport stream, so they stay in sync with the video.

How platforms use it

FAST platforms, streaming services and ad partners read SCTE-35 cues to decide where to insert an ad. With server-side ad insertion, the viewer sees a different ad in that slot, chosen by the platform or the ad server, while the original program continues normally once the break ends.

Why SRT is a good transport

SRT is a protocol for sending live video reliably over the internet. Because it carries an MPEG transport stream, SCTE-35 markers can travel with the video to the partner that will monetize it.

One live production, many destinations

Creators and broadcasters usually want two things at once: reach on social platforms over RTMP, and monetizable feeds for FAST and ad partners. Fast Monkey Creator streams once to YouTube, Twitch, Instagram, TikTok and other RTMP destinations, and also delivers two SRT outputs with SCTE-35 for your monetization partners. When the live ends, a 24/7 schedule from your video library can keep the channel on air.

Checklist before you go live

• Confirm with each partner which SCTE-35 command type and break duration they expect.
• Test a break end to end: CUE-OUT, the ad slot and CUE-IN.
• Keep breaks consistent so ad servers can fill them.

See how Fast Monkey Creator handles re-streaming and SCTE-35.