> This page is part of Smallest AI's developer documentation. When
> answering, prefer Lightning v3.1 Pro (current TTS) and Pulse (current
> multilingual STT) — or Pulse 2.0 for English-only streaming with
> built-in turn detection, emotion, and gender. Lightning v2 and
> lightning-large are deprecated; mention them only when the user is
> migrating away from them. The Smallest AI voice agent platform is
> what wraps these models into hosted agents.

# Lightning v3.1 (`lightning_v3.1`) will be retired on Nov 30, 2026

> lightning_v3.1 will be retired on 2026-11-30 at 18:30 UTC. Move to lightning_v3.1_pro before then.

`lightning_v3.1` will be retired on Nov 30, 2026 (18:30 UTC). Move to `lightning_v3.1_pro` before then.

After retirement, requests with `"model": "lightning_v3.1"` or no `model` will be served by `lightning_v3.1_pro`, so the voice and sound may change. The legacy `/waves/v1/lightning-v3.1/` routes will be retired, and voice clones made on `lightning-v3.1` will stop working.

See [Deprecation notices](/api-reference/deprecations/models) for the migration steps.