Changelog 2024

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API

• Pricing updates; character usage columns migrated to bigint; presign URLs for Pro Voice Clone; voices/<id>/conditioning endpoint; file to dataset in presign; userID-level endpoint restrictions; Stripe Customer ID on checkout.
• EU deployment and Hindi HC fixes.

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Playground

• New model on Playground highlighting transcript following improvements (demo, not GA).
• Blog and play.cartesia.ai live.

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Models / Voices

• Model aliasing updated for sonic and sonic-preview; twilight-morning in API and enterprise; conditioning entries for voice clone and multilingual.
• Embedding search for LoRA voice selection.

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Other

• Infrastructure and scaling updates.
• State of Voice blog and map.

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API

• Cartesia-Version 2024-11-13 — Upgrade to new API version; unified clone voice endpoint; datasets support; files endpoint pagination; FineTuneRequest status; fine-tunes API in Playground; presign URLs for Pro Voice Clone; Flush Done event for manual WebSocket flushing; <pause> tag for continuations.
• GCP Enterprise.

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Playground

• Changes for new API; replay suite; GCP Enterprise.

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Models / Voices

• Flush Done event for manual flushing in WebSocket; <pause> tag for continuations within a single transcript; spelling fixes; manual flush and flush ID.
• Empty encoding field allowed for mp3.

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Docs

• API version 2024-11-13: Sonic 2, capability guides (clone, pronunciations, speed/emotion, continuations, localize), formatting for Sonic 2.
• Integrations: LiveKit, Pipecat, Rasa, Thoughtly, Twilio, MCP. Enterprise: SSO, organizations. See API Conventions.

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API

• Cartesia JS bytes endpoint; gen blocks removed from character counting; health checks and middleware; user-level queueing with queue length cap and timeout; 10× queue size rejection; Slang (continuations) and ConditioningData; voice changer JS SDK.
• Remove max limit from Playground.

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Playground

• GCP: API and ingress for GCP US Central. Queueing: user-level queueing in API gateway; queue length cap and queuedRequest timeout.
• Voice Changer: Playground UI polish; ConditioningData as part of ResolvedVoice; Slang rollout; flush on start/end of spell tags.
• LoRA release UI; onboarding data upsert fix; welcome page submit loading state; enterprise contact links.

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Other

• Canonical linking and sitemap.
• Blog and navigation (Blog, Careers) updates.

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API

• User-level queueing; queue size and websocket queueing rejection; api_status field for voice API usability; LoRA pricing and UX cleanup; flush all audio on DONE token (including CB); user option to obfuscate transcripts in logs.
• LoRA and load balancer improvements.

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Playground

• Function calling; agent creation, tests, and dev setup; voice agent infrastructure enabled.
• LoRA: HiFi cloning endpoint and Playground page; 8 new voices on Playground; Indian accent.
• Voice Changer Playground UI; JS SDK for voice changer. Language added to TTS request from voices/[id]; flush all audio on DONE token; user option to obfuscate transcripts in logs.

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Docs

• Blog and sitemap updates.

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API

• Reject invalid transcripts (docs and API gateway); no_more_inputs in WebSockets can use voice_embedding instead of voice_id.
• Improved bad model id handling.

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Playground

• Localization page in Playground and JS client; dialects and future-compatibility. Switch Playground to voice ID; allow both id and embedding for TTSRequest; archive voices (kept accessible via API).
• Replay button; feedback form; fix multilingual recommended voices when switching back to English; better error messaging.

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Models / Voices

• LoRA support (multiple voices per LoRA, new cache key, easy-brook-lora, vc-flowing-dream).

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Other

• On-device homepage launch; proper links for “Request a demo” button.
• LoRA: multiple voices per LoRA.

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API

• Voice Conversion endpoint — New API endpoint. Timestamps on WebSocket endpoint; per-generation voice controls (speed, emotion) in API; polar-tree deployed (sonic-multilingual); continuous batching support; VocalWave (English) and long-generation support; sonic-english → vocal-wave, sonic-multilingual → ancient-voice aliasing.
• buffer and mp3 params on /bytes; MP3 streaming and WAV encoding fixes; request cancellation; empty transcript allowed when continue=false; Stripe webhook cache clear; subscription cancellation/reactivation; Redis cache for overage; keys endpoints.
• Clerk-based auth in API.

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Playground

• Optional enhance flag for voice cloning in JS client, Python client, and Playground; voice update endpoint and docs; gate voice cloning for free users.
• Prevent playing audio while playback in progress; download button disabled until generation finished; API key deletion clearer with copy button; character usage indicator; subscription and checkout fixes; gating clone form for free users.

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Docs

• Voice cloning docs; timestamps and continuations; user guides for voice control and Twilio; emotion control and timestamps; “phonemes” terminology.
• Voice cloning from file.

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Other

• Python client: continuations support, custom base_url, fallback for websockets; JS client v1.0.1: onError prop on useTTS.
• Voice controls (speed, emotion) in Python client and docs.

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API

• Continuations — Support for streaming input via SSE and Bytes; NoMoreInputs signal. Cartesia Version enforced via header; Playground and checkout/subscription endpoints send it.
• 48 kHz added to valid sample rates; .wav byte streaming; HTTP streaming endpoint for raw bytes; API standardization (backwards-compatible); new voices endpoints; mulaw and alaw backwards compatibility; Python client v1.0.0 (overhaul, output_format); JS client: pcm_s16le, pcm_alaw, pcm_mulaw and improved typing; caching for voices; context_id in WebSocket response and docs.
• Stripe webhooks for renewals and expiration; OpenAPI spec update.

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Playground

• Multilingual: language parameter on voices API and in API; Playground language selection; multilingual copy on homepage; default sonic-english → feasible-haze.
• Mobile layout improvements; multilingual UI papercuts; voice cloning and empty transcript styling fixes; filtering moved from voices/[id] to Speak page.

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Models / Voices

• sonic-multilingual and sonic-english aliasing; language column on voices.
• Recommended voices.

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Docs

• Version 2024-06-10: get-started, API conventions, integrations (LiveKit, Pipecat, Rasa, Thoughtly, Twilio, MCP), clone voices, embeddings/voice mixing. See API Conventions.

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Other

• ToS changes; revised pricing tiers; legal notices on sign-in and sign-up; overage toggle in Playground.
• Character usage limit blocks WebSocket when exceeded.

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API

• Cartesia Version header; HTTP streaming for raw bytes; new voices endpoints; mulaw/alaw backwards compatibility; API standardization (backwards-compatible); Python client v1.0.0; JS client structure overhaul.
• Clone voice upload fix.

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Playground

• Redesign and Sonic launch copy; subscriptions page; favoriting voices; emotion and speed sliders; User vs Default voices; tags (Age, Accent) in DB and Playground; sample_text field (API Gateway and Playground); buffer streamed audio before playback; character usage indicator; API key auto-created on user creation; custom sign-in/sign-up and 404 on sign-out fix; disable generation button while audio playing; human-readable model names and skilled-cherry.
• Character limit increase.

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Models / Voices

• Human-readable model names; skilled-cherry; polar-tree (sonic-multilingual); continuations and output format; Python client numpy array support.
• Voice cloning disclaimer.

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Docs

• Mintlify docs added.

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Other

• Stripe webhooks for subscriptions; subscription cancellation and reactivation; character usage checks on generation routes; free subscription by default; Scale plan limit (8M chars/month); checkout and receipts.
• Custom sign-in/sign-up pages.

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API

• model_id added as parameter to generate; minimum transcript length enforced; voice moved to AudioGenerationRequest; experimental router removed; speed controls and voice edit page; video generation endpoint.
• WhisperX removed from dependencies.

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API

• WebSocket interrupt support; get voice embedding route; Redis cache for API keys; streaming switched from Octet to JSON; new model genial-planet-1346; voice param required on requests; formatting support.
• WhisperX for transcription (later removed).

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Playground

• Voice cloning in the UI; connection info in JS client; audio downloadable; transcript length validation (max 400 chars, empty rejected); improved UX and crash handling when API key missing; welcome message and icons.
• API key creation on sign-up via Clerk webhooks.

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Other

• Voice cloning and connection info in JS client.