Integration boundary
What connects to what
Cartesia streaming speech chunks are sent while they are generated so Motion Server can stay ahead of playback and AvatarKit can render the matching motion locally.
Prerequisites
- Current Cartesia TTS credentials and access
- Spatius App ID, Avatar ID, and an approved session-token flow
- A defined audio source, format, sample rate, and interruption policy
- A test environment that matches the target browser, device, or server runtime
Implementation path
Build a testable baseline
- 1
Confirm the current Cartesia TTS version and read both linked first-party sources.
- 2
Run the smallest official Spatius sample without the partner dependency to establish an avatar baseline.
- 3
Connect Cartesia TTS at the audio or session boundary described in the architecture section.
- 4
Verify audio format, pacing, interruption, reconnect, cleanup, and credential isolation.
- 5
Record versions, target devices, network conditions, failures, and rollback behavior before production.
Decision guidance
Best for and not best for
Best for
- Teams already committed to Cartesia TTS
- Developers who want to keep the avatar layer separable from the conversation stack
Not best for
- Teams requiring an unverified integration to be treated as production-ready
- Buyers looking for a fully managed end-to-end avatar-video service
Evidence-aware assessment
Advantages and limitations
Advantages
- Adds a Cartesia TTS-specific implementation decision instead of a generic provider list
- Keeps the Spatius rendering boundary explicit
- Provides a concrete validation and failure checklist
Limitations
- Do not feed an already playback-paced stream back into Spatius. Convert unsupported encodings and guarantee mono PCM s16le plus an explicit matching sample rate.
- Current package and API versions still require release-time verification
- No first-party benchmark for this exact combined stack is included in the supplied evidence
Do not feed an already playback-paced stream back into Spatius. Convert unsupported encodings and guarantee mono PCM s16le plus an explicit matching sample rate. Indexing this guide does not convert an architecture blueprint into a claimed native connector; run and document the validation checklist before production use.
Page-specific FAQ
Implementation questions
Is Cartesia TTS a native Spatius connector?
The supplied evidence classifies this as a documented path. Recheck the linked first-party sources for the current support boundary.
What must be tested before production?
Credentials, audio access and format, sample rate, interruption, reconnect, backpressure, cleanup, privacy, versions, and target-device behavior.
Does this page include performance results?
No. It does not publish latency, FPS, bandwidth, or reliability numbers for this exact combined stack without a reproducible first-party test.
Primary evidence
Sources and verification
Reviewed 2026-08-10. Recheck versions and implementation details before publication.
Continue exploring