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Guided prefetch with manifest heartbeating - AWS Elemental MediaTailor

Guided prefetch with manifest heartbeating

For live SGAI streams, you can enable manifest-based ad prefetching by adding aws.guidedPrefetchMode=MANIFEST to your session initialization request:

https://777788889999.mediatailor.us-east-1.amazonaws.com/v1/master/777788889999/myOrigin/index.m3u8?aws.insertionMode=GUIDED&aws.guidedPrefetchMode=MANIFEST

When enabled, MediaTailor appends a session identifier (?aws.sessionId=<id>) as a query parameter to each interstitial media manifest (/v1/i-media) URL in the multivariant playlist. Each time the player refreshes an i-media manifest, the request reaches MediaTailor with the session ID, which MediaTailor uses to enqueue prefetch requests for upcoming ad breaks.

  • The aws.guidedPrefetchMode parameter accepts two values: MANIFEST (enabled) and OFF (disabled, default).

  • Guided prefetch mode is only valid for SGAI sessions. Using it with stitched sessions returns an error.

  • DASH does not yet support guided prefetch mode.

  • Guided prefetch is independent of reporting mode — beacons fire at playback time, not at prefetch time.

  • Do not cache i-media manifests in your CDN when using guided prefetch. The prefetch mechanism depends on the player's manifest refresh requests reaching MediaTailor directly. If your CDN caches /v1/i-media responses, MediaTailor does not receive the heartbeat requests and cannot trigger prefetching.