Environment Variables

Reviewed by Proof · Updated

Definition

An environment variable is a named value set outside your code, such as an API key, that your program reads when it runs.

Key takeaways

  • Keep secrets like your luv13 key in an environment variable, not in source code.
  • These docs use LUV13_API_KEY as the name for your luv13 key.
  • Set it in your shell, a .env file that git ignores, or your host's secret settings.
  • Read it in code with os.environ (Python) or process.env (Node.js).
  • Many OpenAI-compatible tools also read OPENAI_API_KEY and a base URL variable. Check each tool's docs for the exact names.

Setting one

In a macOS or Linux shell, for the current session:

export LUV13_API_KEY="paste-your-key-here"

To keep it across sessions, add that line to your shell profile, such as ~/.zshrc or ~/.bashrc.

On Windows PowerShell, for the current session:

$env:LUV13_API_KEY = "paste-your-key-here"

Using a .env file

Many projects keep local settings in a .env file and load it with a library such as python-dotenv or Node's --env-file flag. If you do:

  • Add .env to .gitignore before you create it.
  • Commit a .env.example with the variable names and no real values.

Reading it in code

import os
key = os.environ["LUV13_API_KEY"]   # fails loudly if it's missing
const key = process.env.LUV13_API_KEY;
if (!key) throw new Error("LUV13_API_KEY is not set");

Example

Once the variable is set, the shell fills it in for you:

curl https://api.luv13.ai/v1/chat/completions \
  -H "Authorization: Bearer $LUV13_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "luv13/glm-5.3-flash", "messages": [{"role": "user", "content": "Hi"}]}'

For more on keeping keys safe, see API Key Best Practices.