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Environment Variables

Reference environment variables in BAML using the env. prefix.

Syntax​

env.YOUR_VARIABLE_NAME
warning

Environment variables with spaces in their names are not supported.

Example​

client<llm> MyCustomClient {
    provider "openai"
    options {
        model "gpt-4o"
        // Set the API key using an environment variable
        api_key env.MY_SUPER_SECRET_API_KEY
    }
}

Error Handling​

Errors for unset environment variables are only thrown when the variable is accessed. If your BAML project has 15 environment variables and only 1 is used for the function you're calling, only that one will be checked.

Setting Environment Variables​

Shell​

export MY_SUPER_SECRET_API_KEY="sk-..."

.env File​

MY_SUPER_SECRET_API_KEY=sk-...

Programmatically​

You can also pass environment variables via with_options:

from baml_client import b

my_b = b.with_options(env={"MY_SUPER_SECRET_API_KEY": "sk-..."})
result = my_b.MyFunction("input")

See Also​