Configuration Locations
Claude Code JSON files in ~/.claude/ or ./.claude/
Codex/Windsurf TOML file in ~/.codex/
OpenCode JSON file in ~/.config/opencode/ or ./
Configuration Levels System-Level (Global) Applies to all projects on your machine.
Tool Location Claude Code ~/.claude/settings.json~/.claude.jsonCodex/Windsurf ~/.codex/config.tomlOpenCode ~/.config/opencode/opencode.json
Project-Level (Local) Applies only to the current project directory.
Tool Location Claude Code ./.claude/settings.json./.claude/settings.local.jsonCodex/Windsurf OpenCode ./opencode.json
Codex/Windsurf only supports system-level configuration
Environment Variables The CLI automatically sets these environment variables in your shell configuration file.
Claude Code export ANTHROPIC_BASE_URL = "https://ai.megallm.io" export ANTHROPIC_API_KEY = "sk-mega-your-api-key-here"
Codex/Windsurf export MEGALLM_API_KEY = "sk-mega-your-api-key-here"
OpenCode export MEGALLM_API_KEY = "sk-mega-your-api-key-here"
Note : Codex/Windsurf and OpenCode share the same MEGALLM_API_KEY environment variable.
Verify Environment Variables # Claude Code echo $ANTHROPIC_BASE_URL # Output: https://ai.megallm.io echo $ANTHROPIC_API_KEY # Output: sk-mega-your-api-key-here # Codex/Windsurf & OpenCode echo $MEGALLM_API_KEY # Output: sk-mega-your-api-key-here
Configuration Priority When multiple configurations exist, they’re applied in this order (highest to lowest):
Environment Variables
Highest priority - overrides all file-based configurations
Project-Level Config
Second priority - applies only to current project
System-Level Config
Default - applies globally across all projects
Backup Files The CLI automatically creates backup files before modifying configurations:
~/.claude/settings.json.backup ~/.codex/config.toml.backup ~/.config/opencode/opencode.json.backup
To restore from backup:
mv ~/.claude/settings.json.backup ~/.claude/settings.json
Select your AI tool for detailed configuration information:
Claude Code Configuration JSON configuration, environment variables, and statusline setup
Codex/Windsurf Configuration TOML configuration and model provider setup
OpenCode Configuration JSON configuration and API settings
Quick Configuration Checks Verify All Configurations # Check Claude Code ls -la ~/.claude/ cat ~/.claude/settings.json # Check Codex ls -la ~/.codex/ cat ~/.codex/config.toml # Check OpenCode ls -la ~/.config/opencode/ cat ~/.config/opencode/opencode.json # Check environment variables env | grep -E "ANTHROPIC|MEGALLM"
Test API Connection # Test with Claude Code credentials curl -H "Authorization: Bearer $ANTHROPIC_API_KEY " \ -H "Content-Type: application/json" \ $ANTHROPIC_BASE_URL /v1/models # Test with Codex/OpenCode credentials curl -H "Authorization: Bearer $MEGALLM_API_KEY " \ -H "Content-Type: application/json" \ https://ai.megallm.io/v1/models
Manual Configuration If you prefer not to use the CLI, you can configure manually:
Claude Code
Codex/Windsurf
OpenCode
# Create directory mkdir -p ~/.claude # Create settings file cat > ~/.claude/settings.json << 'EOF' { "env": { "ANTHROPIC_BASE_URL": "https://ai.megallm.io", "ANTHROPIC_API_KEY": "your-api-key" } } EOF # Add to shell config echo 'export ANTHROPIC_BASE_URL="https://ai.megallm.io"' >> ~/.bashrc echo 'export ANTHROPIC_API_KEY="your-api-key"' >> ~/.bashrc source ~/.bashrc
# Create directory mkdir -p ~/.codex # Create config file cat > ~/.codex/config.toml << 'EOF' model_provider = "megallm" model = "gpt-5" [model_providers.megallm] name = "OpenAI using Chat Completions" base_url = "https://ai.megallm.io/v1" env_key = "MEGALLM_API_KEY" query_params = {} EOF # Add to shell config echo 'export MEGALLM_API_KEY="your-api-key"' >> ~/.bashrc source ~/.bashrc
# Create directory mkdir -p ~/.config/opencode # Create config file cat > ~/.config/opencode/opencode.json << 'EOF' { "$schema": "https://opencode.ai/config.json", "provider": { "anthropic": { "options": { "apiKey": "{env:MEGALLM_API_KEY}", "baseURL": "https://ai.megallm.io/v1" } } } } EOF # Add to shell config echo 'export MEGALLM_API_KEY="your-api-key"' >> ~/.bashrc source ~/.bashrc
Configuration Best Practices
Use Project-Level for Teams Keep project-specific configurations in version control (without API keys)
Secure API Keys Never commit API keys. Use .gitignore and environment variables
Regular Backups CLI creates automatic backups, but keep your own copies of important configs
Test After Changes Always verify configuration works after manual modifications
Next Steps
Claude Code Config Detailed Claude Code configuration
Codex Config Detailed Codex/Windsurf configuration
OpenCode Config Detailed OpenCode configuration
Examples Practical configuration examples
