Environment Variables¶

This page documents all environment variables used by the application and how to manage them securely across environments.

Variables Reference¶

Variable	Required	Default	Description
`OPENAI_API_KEY`	✅ Yes	—	Your OpenAI API key. Application will raise a `ValueError` on startup if missing.
`DATABASE_URL`	❌ No	`dbn-poc-database.db`	Path to the SQLite database file. Relative or absolute.
`VANNA_MODEL`	❌ No	`gpt-4o`	The OpenAI model passed to Vanna. Use `gpt-4o-mini` for a cost-optimised option.
`APP_NAME`	❌ No	`DBN Analytics POC API`	API title displayed in the Swagger UI header.

Create a .env file in the project root:

.env

OPENAI_API_KEY="sk-proj-..."
DATABASE_URL="dbn-poc-database.db"
VANNA_MODEL="gpt-4o"

Never commit .env

The .gitignore and .dockerignore files both exclude .env. Verify this before pushing to a public repository.

On Fly.io, secrets are injected into the container at runtime. They are encrypted at rest and never exposed in image layers.

Set a secret:

fly secrets set OPENAI_API_KEY="sk-proj-..."

View all set secrets (names only, not values):

fly secrets list

Remove a secret:

fly secrets unset OPENAI_API_KEY

When running the Docker image locally:

docker run -p 8080:8080 \
  -e OPENAI_API_KEY="sk-proj-..." \
  -e VANNA_MODEL="gpt-4o-mini" \
  dbn-analytics-poc

Or use a --env-file:

docker run -p 8080:8080 --env-file .env dbn-analytics-poc