Reference
Voices
Sulafat narrates by default. Pick any of the 30 narrators and it speaks every supported language in the same voice, with the emotion your script calls for.
Narrators
Every narrator speaks every narration language, so a course keeps one consistent voice from English to Hindi to
Japanese. They perform rather than read: each scene gets its own tone, and inline audio tags add a whisper, a laugh
or a pause exactly where the script asks for one. Ids look like chasca:sulafat, the default.
Warm and friendly
- Sulafat Warm Default
Warm and natural, like a favorite teacher. The all-purpose default.
chasca:sulafat - Achird Friendly
Friendly and approachable, like a helpful colleague.
chasca:achird - Callirrhoe Easy-going
Easy-going and relaxed. Makes hard ideas feel light.
chasca:callirrhoe - Umbriel Easy-going
Laid-back and conversational, never in a hurry.
chasca:umbriel - Zubenelgenubi Casual
Casual and down to earth, like a podcast host.
chasca:zubenelgenubi - Vindemiatrix Gentle
Gentle and patient. Good for sensitive or reflective topics.
chasca:vindemiatrix
Clear and informative
- Charon Informative
Informative and assured, like a documentary narrator.
chasca:charon - Rasalgethi Informative
Measured and informative, with quiet authority.
chasca:rasalgethi - Sadaltager Knowledgeable
Knowledgeable and curious, like a favorite professor.
chasca:sadaltager - Iapetus Clear
Clear and steady. Every word lands.
chasca:iapetus - Erinome Clear
Crisp and clear. Ideal for step-by-step walkthroughs.
chasca:erinome - Schedar Even
Even and balanced. Neutral narration for any topic.
chasca:schedar
Bright and upbeat
- Zephyr Bright
Bright and cheerful, with energy that keeps things moving.
chasca:zephyr - Autonoe Bright
Bright and articulate. Lively without being loud.
chasca:autonoe - Puck Upbeat
Upbeat and playful. Great for hooks and social clips.
chasca:puck - Laomedeia Upbeat
Upbeat and encouraging, with real momentum.
chasca:laomedeia - Sadachbia Lively
Lively and expressive. High energy for dynamic topics.
chasca:sadachbia - Fenrir Excitable
Excitable and animated. Made for surprising facts.
chasca:fenrir - Leda Youthful
Youthful and playful. A good fit for younger audiences.
chasca:leda
Smooth and polished
- Algieba Smooth
Smooth and polished. Premium brand narration.
chasca:algieba - Despina Smooth
Smooth and flowing narration that feels effortless.
chasca:despina - Aoede Breezy
Breezy and light, like an easy conversation.
chasca:aoede - Pulcherrima Forward
Forward and engaging. Holds attention from the first line.
chasca:pulcherrima
Firm and confident
- Kore Firm
Firm and confident. Clear guidance with conviction.
chasca:kore - Orus Firm
Firm and grounded. Steady, trustworthy narration.
chasca:orus - Alnilam Firm
Firm and direct. Straight to the point.
chasca:alnilam
Soft and textured
- Achernar Soft
Soft and calm. Soothing for reflective topics.
chasca:achernar - Enceladus Breathy
Breathy and intimate, like a late-night storyteller.
chasca:enceladus - Gacrux Mature
Mature and wise. Warm authority for serious subjects.
chasca:gacrux - Algenib Gravelly
Gravelly and characterful. Stands out in a feed.
chasca:algenib
For younger audiences, Leda sounds like an older kid explaining to younger ones, and pairs well with the Crayon drawing style.
Directing the narrator
Chasca writes the direction for you: a voice style for the whole video, a short delivery note per scene, and a few audio tags where the voice should change. When you send your own scene graph you can write them yourself.
- voiceStyle: who the narrator is for this video and how they feel about the topic.
- delivery (per scene): the emotional beat, like “hushed intrigue building to surprise”.
- Audio tags in the narration, in square brackets: emotions such as
[curious],[excited]or[warmly], delivery such as[whispers]or[slowly], reactions such as[laughs]or[sighs], and pauses ([short pause],[long pause]). Tags are performed, never spoken, drawn or captioned. Write them in English in any language.
{
"voiceStyle": "A delighted science teacher sharing a favorite everyday mystery.",
"scenes": [{
"delivery": "curious wonder building to a reveal",
"narration": "[curious] Sunlight looks white, but it carries every color… [amazed] so blue reaches your eye from every direction."
}]
} Discovering voices
The catalog can grow, so don’t hard-code lists: ask the API. GET /v1/voices needs no key, and every
entry includes its tone, its group and a preview_url you can play.
# every narrator, each with a preview you can play
curl "https://app.trychasca.com/api/v1/voices" Then pass the id as voice when you create a video:
curl -X POST https://app.trychasca.com/api/v1/explainer \
-H "Authorization: Bearer $CHASCA_API_KEY" \
-H "Content-Type: application/json" \
-d '{ "input": "Why the sky is blue", "language": "ja", "voice": "chasca:kore" }'
Previews are plain MP3s at GET /v1/voices/:id/preview.mp3. In the SDK, call
listVoices(). Voice ids from earlier versions (like chasca:nova) still work and map to the
closest narrator.
Your own voice
Every plan can narrate in your own voice. In the app, open My voices, pick a language and read a short story out loud for one minute. Chasca cleans up the recording, learns how you sound and plays you a one-minute sample. From then on your voice sits above the narrators in every video’s options, at no extra cost.
Free includes 1 custom voice, Solo 1, Plus 3, Pro 5, Max 10, Team 30 and Enterprise 30. A voice speaks the language it was recorded in, so a video it narrates is in that language. Only you can use your voices, and deleting one deletes its recording.
Through the API, your ready voices are listed under custom in GET /v1/voices, with ids like
clone:… that you pass as voice. The custom voices page
walks through recording one.
Already recorded the narration? In the app, attach the recording on the Create page and tick Use as the narration: the video keeps every word as you said it and draws in time with it, for up to 1 minute on Free and 30 minutes on paid plans. See your own voiceover.
Pronunciations
A narrator guesses how to say a name it has never heard. To set one, add it in Settings, under
Pronunciations: the word as it is written and how it sounds, such as Siobhan said “Shi-vawn” or SQL
said “sequel”. Every new video says it that way, with every narrator and custom voice, while the board and captions
keep your spelling. On a finished video, pick Pronunciation under Change one thing: only the scenes
that say the word are recorded again, free. Through the API, send pronunciations when you create a
video. See Pronunciations.
Pace
Every voice can be relaxed, balanced (default) or brisk. Narration is tuned to
land around 140–160 words per minute, a comfortable pace for following along.