Configuration

Tandem Engine uses a layered configuration system that prioritizes settings from different sources. This allows for global defaults, per-project overrides, and environment-based secrets.

Configuration Layers

Settings are resolved in the following order (highest priority first):

1. Environment Variables: Secrets and explicit overrides.
2. Managed Config: managed_config.json (for automated/managed environments).
3. Project Config: .tandem/config.json in your workspace.
4. Global Config: ~/.config/tandem/config.json (Linux/Mac) or %APPDATA%\tandem\config.json (Windows).

Environment Variables

Provider Keys

Tandem automatically maps standard API key variables to their respective providers:

• OPENAI_API_KEY → openai
• ANTHROPIC_API_KEY → anthropic
• OPENROUTER_API_KEY → openrouter
• GROQ_API_KEY → groq
• MISTRAL_API_KEY → mistral
• TOGETHER_API_KEY → together
• COHERE_API_KEY → cohere
• GITHUB_TOKEN → copilot
• AZURE_OPENAI_API_KEY → azure
• VERTEX_API_KEY → vertex
• BEDROCK_API_KEY → bedrock

Ollama

• OLLAMA_URL: Overrides the default Ollama URL (default: http://127.0.0.1:11434/v1).

System paths

• TANDEM_GLOBAL_CONFIG: Override the path to the global configuration file.
• TANDEM_STATE_DIR: Override the directory where the engine stores its state (logs, database, etc.).

Config File Format

The configuration file is a simple JSON object.

{
  "default_provider": "anthropic",
  "providers": {
    "anthropic": {
      "default_model": "claude-3-5-sonnet-latest"
    },
    "openai": {
      "default_model": "gpt-4o"
    },
    "ollama": {
      "url": "http://localhost:11434/v1",
      "default_model": "llama3"
    }
  }
}

Setup Wizard

When you first run the Tandem TUI, if no providers are configured, it will launch a Setup Wizard to help you configure your default_provider and model. This configuration is saved to your global config file.