Bring Your Own Translation API Key

By default, the machine translate command uses a free, third-party translation service that is not owned, operated, or maintained by inlang. For higher reliability and control, you can bring your own Google Cloud Translation or DeepL API key. Choose a provider with INLANG_MACHINE_TRANSLATE_PROVIDER and set the matching API key environment variable before running the command.

For many projects, coding agents can produce better translation drafts than generic machine translation because they can use surrounding product and code context. Consider using an agent-driven workflow when translation quality matters more than fully automated CI output.

Provider selection

Set INLANG_MACHINE_TRANSLATE_PROVIDER to choose the translation service:

Provider	Env var	API key env var
Community-operated translation service at translate.demosjarco.dev (default)	demosjarco or unset (when no API key is set)	none
Google Translate	google	INLANG_GOOGLE_TRANSLATE_API_KEY
DeepL	deepl	INLANG_DEEPL_API_KEY

When INLANG_MACHINE_TRANSLATE_PROVIDER is unset, the CLI uses Google or DeepL if the matching API key is set, and otherwise falls back to the community-operated translation service at translate.demosjarco.dev.

Community-operated translation service

The free service at translate.demosjarco.dev is used by default when no API key is configured. It is a community-run, third-party service — it is not owned, operated, or maintained by inlang. It requires no setup and no API key:

npx @inlang/cli machine translate --project ./project.inlang

Stability is not guaranteed and the service may be unavailable at any time. Provide your own API key for higher reliability and control. If the service is unreachable, throttling requests, or returns a response the CLI can't parse, the command fails with a non-zero exit code and tells you how to switch to your own provider.

You can optionally pin a specific model with DEMOSJARCO_TRANSLATE_MODEL. When unset, the service picks its default model.

export DEMOSJARCO_TRANSLATE_MODEL="@cf/google/gemma-4-26b-a4b-it"

You can also opt in to Zero Data Retention (ZDR) with DEMOSJARCO_TRANSLATE_ZDR. When set to true, the CLI asks the service to process your request without retaining any data. This applies only to the community-operated service and has no effect on the Google or DeepL providers.

export DEMOSJARCO_TRANSLATE_ZDR="true"

Google Translate setup

1. Create a Google Cloud project

Go to the Google Cloud Console and create a new project, or select an existing one.

2. Enable the Cloud Translation API

Enable the Cloud Translation API (Basic) for your project. The CLI uses the v2 REST API.

Follow the Cloud Translation setup guide for detailed instructions.

3. Generate an API key

1. In the Google Cloud Console, go to APIs & Services > Credentials
2. Click Create Credentials and select API key
3. Copy the generated key

4. Set the environment variables

export INLANG_MACHINE_TRANSLATE_PROVIDER="google"
export INLANG_GOOGLE_TRANSLATE_API_KEY="your-google-api-key"

To make this permanent, add it to your shell profile (~/.bashrc, ~/.zshrc, etc.):

echo 'export INLANG_MACHINE_TRANSLATE_PROVIDER="google"' >> ~/.bashrc
echo 'export INLANG_GOOGLE_TRANSLATE_API_KEY="your-google-api-key"' >> ~/.bashrc
source ~/.bashrc

For CI/CD pipelines, add the key as a secret environment variable in your CI provider's settings.

DeepL setup

1. Create a DeepL API account

Sign up for a DeepL API plan (Free or Pro).

2. Generate an API key

Copy your API key from the DeepL account dashboard. Free API keys end with :fx and use the api-free.deepl.com endpoint automatically.

3. Set the environment variables

export INLANG_MACHINE_TRANSLATE_PROVIDER="deepl"
export INLANG_DEEPL_API_KEY="your-deepl-api-key"

To make this permanent, add it to your shell profile (~/.bashrc, ~/.zshrc, etc.):

echo 'export INLANG_MACHINE_TRANSLATE_PROVIDER="deepl"' >> ~/.bashrc
echo 'export INLANG_DEEPL_API_KEY="your-deepl-api-key"' >> ~/.bashrc
source ~/.bashrc

For CI/CD pipelines, add both variables as secrets in your CI provider's settings.

See the DeepL API quickstart for more details.

Usage

Once the environment variables are set, run machine translate:

npx @inlang/cli machine translate --project ./project.inlang