How to Automate Text to Speech with the Fish Audio API

The Fish Audio API lets you generate speech from code, so you can batch a folder of scripts into audio files or wire voice into an app. It uses a simple REST call with an API key, and there is an official Python SDK that wraps the same endpoint.

Do this after you already have a cloned or selected voice in the web app. The API needs a voice reference ID, which the dashboard shows for every voice you own or bookmark.

How do you get a Fish Audio API key?

Sign in, open your account settings, and look for the API keys section. Generate a key and copy it once — treat it like a password. Store it in an environment variable rather than pasting it into scripts you might share.

How do you generate speech with Python?

Install the SDK, then make a call with three inputs: text, a voice reference ID, and an output format.

1. pip install fish-audio-sdk (or use plain requests against the REST endpoint).
2. Set FISH_API_KEY in your environment.
3. Load your text, pass the voice ID, and request mp3.
4. Write the returned bytes to a file per script.

A batch loop over 50 short scripts typically finishes in a couple of minutes on the hosted API.

What are the rate limits and costs?

The API meters usage by characters, same as the web app. A request can hold long text, but splitting into paragraph-sized chunks improves stability and lets you retry only the failed piece. Costs scale with characters generated; heavy volumes justify a paid plan over the free cap.

How do you handle long scripts and errors?

Chunk by paragraph, keep a list of finished files, and skip any chunk already on disk. Retry a failed chunk two or three times with a short delay before moving on. Log the voice ID and text length per file so you can trace a bad render later.

When should you use the API over the web app?

Use the API when the work is repetitive and volume is high — podcast pipelines, e-learning narration, localization. Stay in the web app for one-off clips, since tweaking a line there is faster than re-running a script. The API has no live preview, so expect to listen to output files during setup.

Key Takeaways

• The Fish Audio API generates speech from code using an API key and a voice reference ID.
• Install the Python SDK or call the REST endpoint directly.
• Meter usage is by characters, matching the web app.
• Chunk long text and retry only failed pieces.
• Best for batch narration and localization, not one-off tweaks.

Last updated October 2026. Tool details at Fish Audio.