silk mulberry 1.5

silk mulberry 1.5 is our faster voice. you describe how it should sound in one natural sentence, then give it your text. it streams, so it’s a good fit for low-latency voice agents.

at a glance

field	value
model id	`mulberry`
language	hindi in devanagari, english in latin (code-mixed)
best for	low-latency narration, voice agents, and creative voices
steering	a natural-language `description`, optionally pinned to a named `speaker`
length	up to 2000 characters per request

quickstart

one call, one .wav file:

curl -X POST https://silk-api.rumik.ai/v1/tts \
  -H "Authorization: Bearer rk_live_•••••••••" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "mulberry",
    "text": "आज का episode थोड़ा अलग है।",
    "description": "a female 30s hindi voice, smooth timbre, conversational pacing, casual register, like a podcast host"
  }' \
  --output mulberry.wav

put the voice in description and your spoken text in text. the full request schema is in the API reference.

preset voices

description is what builds the voice, and it’s always required. leave speaker out and mulberry generates a voice to match the description you wrote. add speaker to pin one of twelve named voices instead:

voice	gender
`emma` `mia` `sophia` `ava` `ira` `siya` `aisha` `zoya`	female
`lucas` `noah` `theo` `adam`	male

send description alongside it, exactly as you would without a speaker:

curl -X POST https://silk-api.rumik.ai/v1/tts \
  -H "Authorization: Bearer rk_live_•••••••••" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "mulberry",
    "text": "आज का episode थोड़ा अलग है।",
    "description": "a female 30s hindi voice, smooth timbre, conversational pacing, casual register, like a podcast host",
    "speaker": "siya"
  }' \
  --output siya.wav

names are case-insensitive. send a name we don’t know and you get a voice built from your description, not an error, so a typo sounds like the wrong voice rather than failing loudly.

deprecating soon. the old numbered preset values still work for now and map to ira, siya, aisha and zoya, in that order. they’re going away, so move to the names above.

parameters

field	default	notes
`text`	n/a	required. up to 2000 characters.
`description`	n/a	required. natural-language voice description.
`speaker`	n/a	optional. a named voice, e.g. `siya`. still send `description`.
`temperature`	`0.6`	sampling temperature.
`top_p`	`0.95`	nucleus sampling.
`top_k`	`50`	top-k sampling.
`repetition_penalty`	`1.2`	penalise repeated tokens.
`max_new_tokens`	`2048`	output length cap. if a long line comes back cut off, raise it (up to `8192`).

getting truncated audio? if the returned speech stops before the end of your text, the generation hit the token cap. raise max_new_tokens above the default 2048, up to a maximum of 8192.

→ to write good descriptions, read the prompting guide.

documentation

SDK

integrations

cookbook

API reference

at a glance

quickstart

preset voices

parameters

​at a glance

​quickstart

​preset voices

​parameters

at a glance

quickstart

preset voices

parameters