What is cast0?
A text-to-podcast API for developers and AI agents. Send any text via a single HTTP call, get a published podcast episode with an RSS feed - ready to play in Apple Podcasts, Overcast, Pocket Casts, or any podcast app.
Who is it for?
Developers and AI enthusiasts running agents that produce more content than they have time to read - morning briefings, research summaries, weekly digests. If your AI writes it, cast0 can voice it.
How do I add podcast output to my AI agent?
The cleanest way is the cast0 MCP server. Connect it once in Claude Desktop, Claude.ai, Claude Code, Cursor, ChatGPT, Codex, or VS Code, and your agent gets three tools: create, get, and list episodes. See cast0.ai/mcp for per-client setup. Or call the API directly with one POST request.
Which podcast apps does it work with?
Any app that supports RSS feeds - Apple Podcasts, Overcast, Pocket Casts, Castro, and more. If it accepts an RSS URL, it works with cast0.
Can it handle long text?
Yes - no length limit. cast0 chunks and stitches the audio transparently. Hour-long episodes are fine.
Which AI tools work with cast0?
Anything that can make an HTTP request - Claude, Claude Code, ChatGPT, OpenClaw, Cursor, OpenAI Agents, custom scripts. No SDK required.
How is it different from NotebookLM?
NotebookLM gives you a fixed two-host conversation as an audio file. cast0 gives you a published episode in your real podcast feed, in your chosen voice, callable from any AI via API. No clicking, no uploading - your agent does it automatically.
How long does it take to generate an episode?
Episodes generate asynchronously - typically under a minute for short pieces, a few minutes for longer ones. The API returns a job ID immediately and the episode appears in your feed once it is ready.
Can I choose the voice?
Yes. Each podcast has its own voice setting - pick from 30 Gemini voices (the default, best quality model) or 9 OpenAI TTS voices, and adjust the speed. You can change it any time from the podcast settings.
Can episodes have intro music?
Yes. Pick a track from the built-in music library and a style (intro, intro and outro, or outro only) in the podcast settings - every episode is mixed automatically, the API call stays the same. Episodes can also open with a teaser that plays as a cold open, mixed with the intro music.
What languages are supported?
cast0 supports 70+ languages including English, Spanish, French, German, Japanese, Portuguese, Chinese, and more. Send text in any supported language and it will be voiced correctly.
Do I need to know how to code?
Not necessarily. If you use Claude.ai, you can upload our skill file and ask it to create episodes for you - no code needed. The API is there if you want to integrate it into your own agents or scripts.
Is there a free tier?
Yes - free to start, no credit card required. The free tier includes about 20,000 characters per month (roughly 25 minutes of audio on the best quality model), with a 15,000 character cap per episode. Pro is $5/month for more monthly minutes and unlimited episode length. See cast0.ai/pricing for details, or bring your own OpenAI TTS key for unlimited episodes on OpenAI models.
Can I keep my podcast private?
Yes. Each podcast has its own unique, unguessable feed URL. Share it with whoever you want, or keep it entirely private.