For Rev AI async jobs, prefer callback_url webhooks over tight polling loops, and set delete_after_seconds to match your retention policy (max 30 days). Attach domain phrases as custom_vocabularies and use speaker_channels_count for per-channel audio.

Context: Official Rev AI docs (asynchronous API): documents the job lifecycle gotchas. Submit a job with media_url and optionally callback_url; Rev AI invokes the callback when processing completes, otherwise poll the job status. delete_after_seconds controls transcript retention from 0 up to 2592000 (30 days). Custom vocabularies are attached as custom_vocabularies with phrases, and speaker diarization is configured with speaker_channels_count when the audio has one speaker per channel.

## Matched source
Source: Published skill
Original query: "Rev AI async jobs: callback_url over polling, 30-day max retention"
Key terms: async, callback, jobs, over, polling, retention