Sonic 3.5 API
Run cartesia/sonic-3.5 through FastInfra's OpenAI-compatible API.
Pay per token, no subscription, routed to the cheapest available provider.
Sonic 3.5 pricing
Billed per token used. Prices sync automatically from wholesale providers.
| Direction | Price per 1M tokens |
|---|---|
| Input | — |
| Output | — |
Served by 1 provider
Requests route to Together AI by default (cheapest).
Pin a specific provider with the :provider suffix.
| Provider | Upstream model ID |
|---|---|
| together | cartesia/sonic-3.5 |
Call Sonic 3.5 in 30 seconds
Works with any OpenAI SDK — change the base URL and API key only.
Python
from openai import OpenAI
client = OpenAI(api_key="YOUR_API_KEY", base_url="https://api.fastinfra.ai/v1")
response = client.chat.completions.create(
model="cartesia/sonic-3.5",
messages=[{"role": "user", "content": "Hello!"}]
)
print(response.choices[0].message.content)curl
curl https://api.fastinfra.ai/v1/chat/completions \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "cartesia/sonic-3.5",
"messages": [{"role": "user", "content": "Hello!"}]
}'Sonic 3.5 — common questions
How much does the cartesia/sonic-3.5 API cost?
On FastInfra, cartesia/sonic-3.5 costs Pay-per-token pricing via provider routing. Billing is per token used, with no subscription.
Is cartesia/sonic-3.5 compatible with the OpenAI SDK?
Yes. FastInfra exposes cartesia/sonic-3.5 through an OpenAI-compatible endpoint at https://api.fastinfra.ai/v1 — point any OpenAI SDK at that base URL with a FastInfra API key and keep your existing code.
Which providers serve cartesia/sonic-3.5?
cartesia/sonic-3.5 is available from 1 provider(s): together. Requests route to Together AI by default (cheapest); append ":provider" to the model ID to pin one.
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