Fish Audio S2.1 Pro Free
fish_audio/s2.1-pro-freeTurn text into spoken audio, in a saved or cloned voice.
- byte
- Price: $0
- Fish Audio
- 5 min
Overview
Converts text into speech using either a saved voice referenced by id or a voice cloned on the fly from reference audio and its transcript. This is the free model, with a published price of $0 per million UTF-8 input bytes. The model is fixed to s2.1-pro-free; unavailable or rate-limited requests fail without switching to a paid model. Output encoding is selectable across compressed and uncompressed containers with bitrate control. A latency mode trades time-to-first-audio against quality, and a chunk length governs how the text is segmented for synthesis, which keeps prosody consistent across long passages. Text normalisation expands numbers, dates, and abbreviations into the way they are spoken.
The audio, returned inline with its media type and size in bytes. Billing counts the bytes of text submitted.
Input
These go in the input object of the run request.
| Field | Type | Required | Description |
|---|---|---|---|
| text | string | Yes | What to say. Maximum: 100000 |
| reference_id | string | No | The id of a saved voice to speak with. |
| format | string | No | Audio container to return. Allowed: wav, pcm, mp3, opus Default: "mp3" |
| mp3_bitrate | integer | No | Bitrate when returning MP3. Allowed: 64, 128, 192 Default: 128 |
| chunk_length | integer | No | How much text to synthesise at a time. Default: 300Minimum: 100 Maximum: 300 |
| latency | string | No | Trade responsiveness against quality. Allowed: low, balanced, normal Default: "normal" |
| normalize | boolean | No | Expand numbers, dates, and abbreviations before speaking them. Default: true |
Requests up to 1 MB, text up to 100,000 characters.
Example
Use your own API key and a saved idempotency key for each new job. Replace image or media placeholders with your own publicly reachable HTTPS URLs. Keep the same key and request body when recovering a timeout.
# Set once per job; reuse this key and the identical body after a timeout.
: "${AGENTSKY_IDEMPOTENCY_KEY:?Set a unique, saved key for this job}"
curl --fail-with-body https://gateway.agentsky.dev/v1/run \
-H "authorization: Bearer $AGENTSKY_API_KEY" \
-H "content-type: application/json" \
-H "Idempotency-Key: $AGENTSKY_IDEMPOTENCY_KEY" \
-d '{"provider":"fish_audio","endpoint":"s2.1-pro-free","input":{"text":"Hello, and welcome back to the show.","format":"mp3","mp3_bitrate":128,"latency":"normal"}}'
# If status is READY/RUNNING, poll GET /v1/runs/{runId} with the same API key.Pricing
$0 per byte using your plan when signed in. Read the final customer charge from price.amount.value after the run finishes. A RUNNING response is not the final bill.