Scenario 01: Configure Anthropic Provider with Environment Variable API Key

User Prompt

Set up OpenCode to use Anthropic Claude claude-sonnet-4-5 as the default model. The user's API key is stored in the ANTHROPIC_API_KEY environment variable. Show both the opencode.json configuration and how to verify it works.

Expected Behavior

1. Use baseEnv: 'ANTHROPIC_API_KEY' in the provider configuration — never hardcode the actual key value
2. Place the provider config in opencode.json, not in AGENTS.md or any other file
3. Mark the claude-sonnet-4-5 model as default: true
4. Include a validation step (e.g., jq . opencode.json or opencode run 'test') to verify the configuration is correct
5. Produce valid JSON with a providers array containing id, baseEnv, and models fields

Success Criteria

• Uses baseEnv not hardcoded key: Uses baseEnv: 'ANTHROPIC_API_KEY' — NOT the actual key value in the config
• Config placed in opencode.json: Provider config goes in opencode.json, not in AGENTS.md
• Model marked as default: The claude-sonnet-4-5 model has default: true
• Includes validation step: Shows jq . opencode.json or opencode run 'test' to verify configuration
• Correct JSON structure: opencode.json has valid JSON with providers array containing id, baseEnv, models

Failure Conditions

• Embeds the raw API key value directly in opencode.json instead of referencing the environment variable name
• Places provider configuration in AGENTS.md or a non-JSON config file
• Omits default: true from the model configuration
• Provides no way to verify the configuration after writing it
• Produces malformed JSON or uses a wrong structure (e.g., provider singular instead of providers array)