Skip to main content
Change your AI provider, viewport, or other settings after initial setup.
Both npm create libretto@latest and npx libretto setup handle initial configuration for you. The commands on this page are for changing settings after the fact.

​
Changing your AI provider

1

Run the configure command

Pick the provider you want to switch to:
npx libretto ai configure <openai|anthropic|gemini|vertex>
You can also pin a specific model version:
npx libretto ai configure openai/gpt-4o
2

Set your environment variable

Add the environment variable for your provider (see table below) to your shell or a .env file at the project root.
3

Install the provider's AI SDK

Install the matching SDK package for your provider (see table below):
npm install @ai-sdk/openai

​
AI Provider Reference

ProviderDefault modelEnvironment variableSDK package
openaiopenai/gpt-5.4OPENAI_API_KEY@ai-sdk/openai
anthropicanthropic/claude-sonnet-4-6ANTHROPIC_API_KEY@ai-sdk/anthropic
geminigoogle/gemini-3-flash-previewGEMINI_API_KEY@ai-sdk/google
vertexvertex/gemini-2.5-flashGOOGLE_CLOUD_PROJECT@ai-sdk/google-vertex
To view the current configuration, run npx libretto ai configure with no arguments. To clear it, pass --clear.

​
Config file reference

The config file is at .libretto/config.json. You can edit it directly or use the CLI commands above. 
{
  "version": 1,
  "snapshotModel": "openai/gpt-5.4",
  "provider": "local",
  "viewport": { "width": 1280, "height": 800 },
  "sessionMode": "write-access"
}
​
version
number
required
Config schema version.
​
snapshotModel
string
Optional. A provider/model-id string (e.g. openai/gpt-5.4). The AI model used by npx libretto snapshot to analyze page state. Set via npx libretto ai configure.
​
provider
string
Optional. The browser provider to use. Must be "local", "kernel", or "browserbase". Defaults to "local". Can be overridden per-command with --provider or the LIBRETTO_PROVIDER environment variable. Resolution order: --provider flag → LIBRETTO_PROVIDER env var → this config field → "local".
​
viewport
object
Optional, manually set. Default browser window size (width and height in pixels) used by open and run when you don’t pass --viewport. Defaults to 1366x768 if not set.
​
sessionMode
string
Optional, manually set. Default access mode for new sessions created by open, connect, and run. Must be "read-only" or "write-access". Defaults to "write-access" when omitted. Pass --read-only or --write-access to open, connect, or run to override when creating a session.
​
windowPosition
object
Optional, manually set. Sets the initial position of the headed browser window on screen. Has no effect in headless mode.