Vistralo writes the narration with OpenAI and speaks it with HeyGen. Your plan decides whose accounts with those two companies a job runs on.
On Pro and Studio
Your plan includes AI narration. Vistralo runs it on its own OpenAI and HeyGen accounts. You need no keys, and neither company bills you for it. Each AI walkthrough counts towards your plan's monthly number, as it always has.
The "AI narration" tab in Settings says: "Your plan includes AI narration. Vistralo writes it with OpenAI and speaks it with HeyGen on its own accounts, so you need no keys. To run narration on your own accounts instead, add your keys below."
You can still add keys of your own. Each provider shows "Included" until you save your own key, and "Your key" after that. Each provider is handled on its own: a saved OpenAI key is used for writing the script even if HeyGen stays included, and the other way round. Whichever provider runs on your key bills you for what it uses.
On Free
On the Free plan you add API keys from your own OpenAI and HeyGen accounts, and each company bills you for what you use. The "AI narration" tab says: "On the Free plan, Vistralo writes the narration with OpenAI and speaks it with HeyGen using keys from your own accounts, and each provider bills you for what you use. Pro and Studio include AI narration with no keys needed."
Before you add keys
Create an API key in your OpenAI account and one in your HeyGen account. Both companies explain how in their own documentation.
Adding them
- Open Settings from the foot of the sidebar and go to "AI narration".
- Under "Provider keys", paste the keys. On Free the fields are "OpenAI API key" and "HeyGen API key". On Pro and Studio they are "Your own OpenAI key (optional)" and "Your own HeyGen key (optional)".
- Under "Voice and spending", set "Most a job may cost (US dollars)". See Cost caps.
- Press "Save AI settings".
On Free, each provider shows "Saved" once its key is on file, and "Not added" until then. The key itself is never shown again.
How the keys are kept
The Settings page says: "Keys are encrypted in this browser for the worker alone. Nobody can read them back, including you, so a saved key is shown only as “Saved”." On Pro and Studio the last words read "“Your key”" instead.
In practice: your browser encrypts each key before it is sent. Only the worker that runs your jobs can open it. Nobody using the app, you included, can read a saved key back.
Replacing or withdrawing a key
On Free, once a key is saved its field becomes "Replace the OpenAI key" or "Replace the HeyGen key". On Pro and Studio the field keeps its name. Paste a new key there and save. The hint reads "Leave empty to keep the saved key." To be certain a key can no longer be used, revoke it in the provider's own dashboard.
If saving is refused
"The worker that makes walkthroughs has not published its encryption key yet, so keys cannot be saved." means the service that would receive the keys is not ready. Try again later, and write to us if it persists.
If a job says a key is missing
Keys are checked when a job runs. On Free, a job with no keys fails with: "On the Free plan, AI narration needs your own OpenAI and HeyGen keys. Add them in Settings, under AI narration, or choose Pro or Studio, which include it." Add the keys, then use "Retry AI voice-over" on the project.