Your first API keys: Deepgram + Gemini
No programming is needed: create a key for each service, then paste it into KeroTranslate's settings. The maintainer has tested this combination using Deepgram's free credits and Gemini's free tier.
What is an API? Why do I need a key?
An API lets an app ask an external service to do work. KeroTranslate uses external services to turn stream audio into text and translate it. An API key is a private access key that lets the extension use a service through your account. It is issued separately from your login password.
| Service | Its job in KeroTranslate | What you need |
|---|---|---|
| Deepgram | Turns stream audio into text. STT means speech recognition. | A Deepgram account and API key |
| Gemini | Translates captions and comments, then translates back for re-MTL. | A Google account and Gemini API key |
For comment translation alone, start with the Gemini key. Add Deepgram for audio captions. With this combination, tab audio goes to Deepgram; recognized text, comments and translations go to Gemini.
1. Create a Deepgram key
- Open the Deepgram Console and register or sign in.
- Select your project at the top-left, then Settings → API Keys → Create a New API Key. A project groups keys and usage; one is created when you register.
- Name the key
KeroTranslate. If asked for a permissions role, choose Member; choose an expiry appropriate for your use, then Create Key. Official role reference - Copy and securely keep the key. Its full secret cannot be displayed again.
Use the key itself, not its name or project ID. If labels have changed, follow Deepgram's key creation guide.
2. Create a Gemini key
- Open Google AI Studio's API keys page, sign in with Google, and review the initial terms if prompted.
- Use the automatically created key, or select Create API key and select/create your own project as needed.
- Copy the key. If an existing project is missing, use Projects → Import projects.
- To try the free tier, check that the project's billing tier is Free Tier. You do not need to proceed through Set up billing to upgrade it.
Google's key creation guide · Free tier and billing
3. Add the keys to KeroTranslate
Open Settings & API keys from the Chrome toolbar icon, or use the main panel's gear button.
| Setting | Select or paste |
|---|---|
| Speech to text | Deepgram |
| Deepgram API key | Your key from step 1 |
| Translation + re-MTL | Gemini |
| Gemini API key | Your key from step 2 |
| Gemini model ID | Try the default first. If unavailable, check which model IDs your API project supports. |
In the store build, read the audio/text processing disclosure at the top of Settings, check the consent box, then click Save settings. Older GitHub Beta builds may not show this consent box. Keys survive Chrome restarts in the same profile and extension installation. Saving settings stops active caption capture; restart it if needed.
First, type a short comment into Original and check that MTL and re-MTL appear. For captions, play a YouTube Live stream with audio and use Start captions in the main panel (open the toolbar icon once on that tab first if Chrome asks you to) on that tab. You do not need to post a chat message to test it.
Free usage and common problems
| Item | What to know |
|---|---|
| Deepgram free usage | Uses a credit balance. Check the console for eligibility, balance and expiry. Credits are not unlimited usage or a guaranteed monthly refill. Current pricing and conditions |
| Gemini free usage | Free Tier covers eligible models within usage limits. Availability and limits depend on the model and project. Pricing · Checking active limits |
| Invalid key / authentication error | Check the correct service's field, complete key text and expiry. |
| Rate-limit / quota error | Check remaining credits and limits. Wait as instructed; for request-rate limits, try adjusting Request gap. Spacing cannot replenish an exhausted allowance. |
| Lost or exposed key | Revoke/delete it in the service's console, create a replacement and save that in the extension. |
Treat keys like passwords: never post them in chat, GitHub or public screenshots. Gemini's free tier may use inputs and outputs for service improvement; review Google's pricing and data-use information and avoid confidential content.
Official instructions and pricing checked October 17, 2026. Screens and free allowances can change. The tested combination refers to the maintainer's environment, not every account or model.
Start with these timing settings
Request gap defaults to 1 second; Caption hold defaults to 5 seconds. The gap is the minimum spacing between requests, not a promise that translation finishes in one second. Increase it to 2–6 seconds if you hit request-rate limits and check your provider limits. Back-translation also consumes API usage.
Other providers
You only need Deepgram and Gemini to follow this walkthrough; you do not need accounts with every provider. Put other keys in their matching settings fields. See the DeepL API quickstart and DeepSeek API documentation. An API plan may be separate from a consumer chat or translation subscription.
Saving and deleting keys
Paste keys into the extension settings, never this guide. The store build saves credentials and the automatic-unlock key in the same Chrome profile. Delete all API keys removes saved credentials; revoke the key in the provider console to disable it at the provider. Read the privacy policy.