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This page lists what DeckTalk needs, what decktalk setup downloads, and which commands spend ElevenLabs credits. Read it before you set up a new machine or a CI runner, and before your first voiced build.

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Software

DeckTalk needs Python 3.12 or later. It runs on Linux, macOS, and Windows.
  • DeckTalk has two Python dependencies, Playwright and static-ffmpeg. Your installer adds both.
  • Playwright includes its own browser driver, so you do not need Node.
  • decktalk setup downloads Chromium, ffmpeg, and KaTeX. You install nothing else by hand.
The quickstart installs DeckTalk with uv, pipx, or pip.

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Accounts

A silent build needs no account and no API key. A voiced build needs two values from ElevenLabs. Put both values in .env in the project directory, or set them in the environment. A value that starts with <, such as <your-elevenlabs-key>, counts as unset. Part 3 of the quickstart shows where the values go.

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What spends credits

Only two parts of DeckTalk call ElevenLabs. The narrate stage calls the text-to-speech endpoint, and decktalk soundscape calls the sound effects and music endpoints. A voiced section costs the characters of its whole text. An edit therefore costs every changed section in full, not only the changed sentences. A ten-minute narration is about 9,000 characters. A silent build stops when the project has voiced takes. With --force, it empties the narration cache, so the next voiced build voices every section again. A silent build and a voiced build explains the cache. To see a run before it spends credits, use --dry-run or preflight. None of these commands calls the API:
  • decktalk narrate --dry-run prints the text of each section, and which sections a voiced run would voice, with their characters.
  • decktalk preflight prints the same plan, resolves every cue, and estimates each reveal from frozen frames.
  • decktalk soundscape --dry-run prints every request.
These commands never spend credits: a silent build, setup, init, doctor, preflight, beats, record, measure, check, assemble, verify, shots, status, and runtime.

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ElevenLabs plans

Every ElevenLabs plan can call the API, including the free plan. The free plan has three limits for a video you publish:
  • It has no commercial license.
  • The title of published content must include “elevenlabs.io” or “11.ai”.
  • It cannot use Voice Library voices through the API.
For a video you publish, start with the Starter plan.

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What setup downloads

decktalk setup makes three downloads, one time per machine. decktalk doctor then reports on each download. To move DeckTalk’s cache, set DECKTALK_CACHE_DIR.

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Linux system libraries

On Linux, setup passes --with-deps to Playwright, and Playwright installs Chromium’s system libraries with apt-get.
  1. Playwright runs apt-get through sudo.
  2. If sudo is missing, it uses su root -c.
  3. If setup runs as root, it uses neither.
If the distribution has no apt-get, this download fails. setup then stops before it downloads ffmpeg and KaTeX.

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If a download is missing

  • KaTeX download failed. setup warns and continues. decktalk init then warns that KaTeX is not cached, and the new project’s pages load KaTeX from a CDN.
  • KaTeX is not cached. doctor prints warning in the katex row and exits 0, because pages load KaTeX from a CDN. With --strict, it exits 1.
  • setup never ran. static-ffmpeg downloads ffmpeg the first time DeckTalk needs it.
  • static-ffmpeg cannot give ffmpeg. DeckTalk uses the ffmpeg on your PATH.
DECKTALK_FFMPEG and DECKTALK_FFPROBE override every ffmpeg source above.

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Time

Recording runs in real time, one section after another. A first silent build of the scaffold took about 276 seconds on a MacBook Pro with Apple M5 Pro and 64 GB memory. The video it made is 257.72 seconds long. A slower machine takes longer. Rebuild one section shows how to record only the sections that changed.

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The ffmpeg license

The ffmpeg builds that static-ffmpeg downloads are GPL builds. DeckTalk runs ffmpeg as a separate process and does not link against it. THIRD_PARTY_NOTICES.md lists the license of each build. To use an ffmpeg build of your own, set DECKTALK_FFMPEG and DECKTALK_FFPROBE to its two executables.

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