Generates one to four short voice candidates from a descriptive prompt. Preview audio is returned directly without creating a persistent voice profile.
Thresholds measure total prepaid funds, not spend. All keys and ASR share the pool; 429 responses have no Retry-After header. Free-tier fair-use conditions also apply.
Prices retain their published currencies and billing units below.
Published billing units · original currency · observed 13 Oct 2026
Category
Usage
Rate
Unit
Speech synthesis
Voice design1
$0.01
successful request
Rate conditions
One charge per successful API request, even when n returns multiple candidates. Authentication, validation, balance, concurrency and service errors are not billed.
Fish Audio terms permit Usage Data and Content to improve its models, including third-party components. Public terms do not establish universal zero retention. Free S2.1 has no DPA or TTFA guarantees; confirm production contractual terms separately. Voice inputs require appropriate rights.
Caching can reuse earlier input processing. Availability, lifetime and billing depend on the endpoint. A cache hit still generates a new response.
01 / INITIAL INPUTProcess & retain
The system processes eligible input and retains reusable state.
02 / LATER REQUESTCheck available state
Reuse depends on matching input, session state and the cache policy.
03 / CACHE HITReuse & generate
Reusing state can reduce repeated work. Any charges follow the billing rules below.
Fish Audio API
voice-design-1
Not verified
No model-specific prompt-cache contract or discount established. Voice references and previous-chunk conditioning are not billed prompt caching.
How it works
Not collected
No model-specific prompt-cache contract or discount established. Voice references and previous-chunk conditioning are not billed prompt caching.
Minimum reusable input
Not collected
No model-specific prompt-cache contract or discount established. Voice references and previous-chunk conditioning are not billed prompt caching.
Lifetime & refresh
Not collected
No model-specific prompt-cache contract or discount established. Voice references and previous-chunk conditioning are not billed prompt caching.
How to enable it
Not collected
No model-specific prompt-cache contract or discount established. Voice references and previous-chunk conditioning are not billed prompt caching.
Usage fields
Not collected
No model-specific prompt-cache contract or discount established. Voice references and previous-chunk conditioning are not billed prompt caching.
Billing rules
Not collected
No model-specific prompt-cache contract or discount established. Voice references and previous-chunk conditioning are not billed prompt caching.
Limits & data boundaries
Not collected
No model-specific prompt-cache contract or discount established. Voice references and previous-chunk conditioning are not billed prompt caching.
No verified cache rate for this endpoint. An empty rate is not a zero charge.
What the measurements say
No benchmark observations have been added for this model. We do not turn a vendor description into a performance score.
Latency and throughput depend on the host, request size, reasoning settings and load. There is no measured speed or global usage figure in this record.
The record behind the model
Why it is included
The official API documents this named managed model under Fish Audio service terms that reserve service IP and restrict reverse engineering. The reviewed official weight inventory does not publish this release; the separately downloadable S2 Pro and S1-mini are excluded. Exact internal checkpoint lineage remains unverified.
