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Using the API Key

To authenticate your API calls, you must include an x-api-key header with your secret API key.

Example using cURL:

curl -X POST \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_SUPER_SECRET_API_KEY" \
  -d '{ "userId": "user-test-123" }' \
  https://your-agenttest-backend.example.com/experiment/my-prompt-test/assign

Replace YOUR_SUPER_SECRET_API_KEY with the actual API key you’ve configured for your backend instance, and https://your-agenttest-backend.example.com with the URL of your deployed AgentTest backend.

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Setting up the API Key

The API key is defined in the .env file in the root of your AgentTest backend project. You need to set the API_KEY variable:

# .env file
DATABASE_URL="your_supabase_connection_string"
API_KEY="your_super_secret_api_key_here"
# Other variables like PORT can also be here
# PORT=3001
  • Choose a strong, unique string for your API key.
  • This API_KEY value is what the backend server will expect in the x-api-key header.

Keep your API key secure! Your API key grants access to your AgentTest backend, including assigning variants and logging results. Do not expose it in client-side browser code or commit it to your version control system if the .env file is not gitignored (by default, .env files should be in .gitignore). Treat it like a password.

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Unauthenticated Requests

If an API request is made without an x-api-key header, or if the provided key is invalid, the server will respond with a 401 Unauthorized HTTP status code.

{
  "error": "Unauthorized"
}