Async uses a prepaid wallet billing model. Top up your balance and pay only for what you use — no subscriptions or commitments required.How It Works#
1.
Create a wallet — automatically created when you sign up (includes $0.10 free credit)
2.
Top up — add funds anytime via credit card
3.
Use the API — balance is deducted per usage (audio duration)
4.
Auto top-up (optional) — automatically refill when balance drops below a threshold
Pricing#
| Feature | Model | Price | Unit |
|---|
| Text-to-Speech (Standard) | async_flash_v1.5, async_flash_v1.0 | $0.50 | per hour of generated audio |
| Text-to-Speech (Pro) | async_pro_v1.0 | $1.00 | per hour of generated audio |
| Speech-to-Text | async_asr_v1.0 | $0.50 | per hour of processed audio |
| Voice Cloning | — | Included | no additional charge |
Free Tier#
Every account includes 10 minutes of free audio generation — no credit card required.API Key Permissions#
Each API key can be scoped to specific features:| Permission | Access |
|---|
tts_standard | Flash series TTS models |
tts_pro | Pro series TTS models |
asr | Speech-to-Text |
voices_read | List and retrieve voices |
voices_write | Create, update, delete voices (includes read) |
If no permissions are selected when creating a key, it has access to all features.Quotas#
| Quota | Default | Description |
|---|
| Rate limit | 20/min | Maximum API requests per minute |
| Concurrency | 1 | Maximum parallel requests |
| Voice clones | 3 | Maximum custom voices |
Need higher limits? Request a quota increase from the Wallet page in the developer console.Managing Your Wallet#
Auto top-up: Configure automatic refills (e.g. add $10 when balance drops below $2)
Payment history: View all transactions and invoices
Usage analytics: Monitor consumption in the Usage page Modified at 2026-07-06 11:31:45
