What’s new in 0.6

Engine 0.6.0 lets a process work with sound, images and stored recordings, share a limited number of slots across deployments, and loop back to a wait as many times as it needs. Every feature below has a walkthrough you can run on your own machine with the bundled stub model server, so no provider key is needed.

Feature	What it gives you	Try it
Audio in model calls	`audio` parts on a user turn, formats written as media types, `audioOutput` for a spoken answer, and `audio` / `transcript` / `audioPreserved` on the reply. `require:` gains `audio-input`, `audio-output`, `audio-understanding` and `video-understanding`.	Audio, images and video
`voice: pipeline`	Speech-to-text, then a text model, then text-to-speech, through an `llm.speech` provider, for models that take no audio.	The voice pipeline
Video and image understanding (preview)	Video clips, sampled frames and a one-frame `image` part.	Try it
Native `gemini` provider	Gemini’s own API, which carries audio, images and video.	Providers
Structured answers	A call with `json: true` gets the parsed answer under `json`, so a flow reads its fields directly.	The reply
Media references and object stores	Named object stores in the engine configuration. A media part gives `{ref, sha256}` instead of inline data, and the channel reads it from `llm.media-store`.	Recordings and media references
`q:audit capture="media"`	Audit events carry media references, never the media.	Recordings: the audit trail
Erasure and retention delete recordings	Subject erasure and terminal retention delete the referenced objects and amend the audit events.	Recordings: erasure and retention
Capacity pools and `session-end:`	Named, cluster-wide slot counts drawn from by inbound and outbound channels. A full pool answers 503 inbound and holds outbound requests in the outbox. A session can end before its instance does.	Capacity pools and sessions
Re-enterable waits	A loop back to a message catch, user task, timer or channel call parks a new wait each time round.	Waiting at the same node again
Live audio sessions (preview)	`AudioSession` and `require: [realtime]`, opened through an `llm` channel by a media transport, not by a process.	Live audio sessions

Telephony, IVRs, meetings and WebRTC are not part of this engine. They live in the separate open-source repository sutra-voice, which builds on the pieces above.

Before you try a walkthrough

Every walkthrough runs from the root of a checkout of this repository. It needs:

Docker with Compose v2, plus curl, python3, sha256sum and GNU base64 (on macOS, use base64 -i <file> wherever a walkthrough says base64 -w0 <file>);
an engine image and the sutra CLI, both 0.6.0 or later.

The compose files default to the published ghcr.io/startr-trade/sutra:0.6.0 image, and Installation installs the CLI. To run a walkthrough against your own checkout instead, build both from it:

make image                                        # builds sutra-rust-engine:dev
(cd rust && cargo build --profile release-it -p sutra-cli)
export PATH="$PWD/rust/target/release-it:$PATH"   # the sutra CLI you just built
export SUTRA_ENGINE_IMAGE=sutra-rust-engine:dev   # every example's compose file reads this

Each example’s compose file names its own Compose project (sutra-ai-advanced, sutra-media-recordings, sutra-capacity-pools, sutra-review-loop) and publishes the engine on a dynamic loopback port, so the stacks never collide with each other or with anything you already run. Each walkthrough ends by removing its own stack with docker compose -p <project> down -v.

The output shown in each walkthrough was copied from a real run against the stub. Instance ids, timestamps and audio bytes differ on every run.

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Sutra

What’s new in 0.6

Before you try a walkthrough