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Delivery networks and capabilities
Video has to travel from the venue's encoder to every viewer's phone over a delivery network. Vabu Streams sits in front of the network so that you write your code once. This page explains how to keep that code independent of the network.
The provider field
Every live stream and asset has a read-only provider field. It names the network that carries that video. In test mode it is simulated.
json
{ "id": "ls_01J9ZQ4M8T3K6Y2E5W7N0B1C9D", "object": "live_stream", "provider": "simulated" }Show it in a log or a support screen if you like. Do not branch on it. When Vabu adds networks or moves an account, a check on the name would break and a check on a capability would not.
Today each account runs on one network that Vabu chooses for it. A second network can carry a live stream as a standby: see Staying on air. Choosing a network by audience region, with Nairobi first, is on What's coming.
Capabilities
A capability is something a network can do. Networks differ, so a few capabilities are not on every stream. Check the thing itself.
| You want to | How to know | If it is not there |
|---|---|---|
| Send video over SRT | ingest.srt_url is set | Use rtmp_url |
| Send video over WHIP from a browser | ingest.whip_url is set | Use RTMP or SRT from an encoder |
| Use a backup address | ingest.rtmp_backup_url is set | Rely on the reconnect window |
| Run an audio-only stream | Create the stream with audio_only: true. The response confirms it. | A 422 provider_rejected error says why |
| Keep latency low | Create the stream with latency_mode: "low". The response shows what you got. | Use standard |
| Forward to other platforms | POST a simulcast target. status on the target says if it was accepted. | Targets with status: "errored" were refused |
| Cut clips from an asset | POST /v1/streams/assets/{id}/clips | A 409 asset_not_ready error means wait for ready |
| Sign playback tokens yourself | POST /v1/streams/signing_keys | 409 dedicated_environment_required |
Two rules keep your code safe:
- Read the response, not the plan. Look at the fields you got back and branch on them.
- Treat a refusal as information.
422 provider_rejectedand409errors tell you what the network cannot do, in words you can show your team.
Ordered sources
A playback grant returns sources, an ordered list of links, with a failover rule. Play the first, and switch after failover.max_errors fatal errors in failover.window_seconds. Today the list has one item. Write the switch now, and a second source will work the day it appears. See playback and sessions.
Vabu events, not network events
Networks send their own signals when an encoder connects or a file is ready. You never see them. Vabu turns them into its own events, such as streams.live_stream.active and streams.asset.ready, with the same shape whatever the network. See stream events.