OpenCode

Use XiaoYuan AI with OpenCode, the open source AI coding assistant.

Prerequisites

• OpenCode installed
• API key from https://ai.xiaoyuan.co.uk

Configuration

OpenCode provides flexible configuration options for custom API endpoints.

Step 1: Access Settings

Open OpenCode settings:

• Command: Ctrl/Cmd + ,
• Menu: File → Preferences → Settings
• Or search: "OpenCode Settings"

Step 2: Configure API

Navigate to API Configuration and set:

Setting	Value
Provider	Custom / OpenAI Compatible
Base URL	https://ai.xiaoyuan.co.uk/v1
API Key	Your XiaoYuan API key
Model	claude-opus-4-8

Configuration File Method

Edit OpenCode's configuration file:

~/.config/opencode/settings.json

{
  "opencode.api.provider": "custom",
  "opencode.api.baseUrl": "https://ai.xiaoyuan.co.uk/v1",
  "opencode.api.key": "your-api-key-here",
  "opencode.api.model": "claude-opus-4-8",
  "opencode.api.timeout": 60000
}

~/.config/opencode/config.yaml

api:
  provider: custom
  baseUrl: https://ai.xiaoyuan.co.uk/v1
  key: your-api-key-here
  model: claude-opus-4-8
  timeout: 60000

Environment Variables

Use environment variables for security:

# Add to ~/.bashrc or ~/.zshrc
export OPENCODE_API_KEY="your-xiaoyuan-api-key"
export OPENCODE_BASE_URL="https://ai.xiaoyuan.co.uk/v1"
export OPENCODE_MODEL="claude-opus-4-8"

Then in OpenCode settings:

{
  "opencode.api.baseUrl": "${OPENCODE_BASE_URL}",
  "opencode.api.key": "${OPENCODE_API_KEY}",
  "opencode.api.model": "${OPENCODE_MODEL}"
}

Usage

Chat Interface

Access OpenCode's chat interface:

• Keyboard: Ctrl/Cmd + Shift + L
• Sidebar: Click AI icon
• Command: "OpenCode: Open Chat"

Example conversation:

You: Explain this function
Claude: This function implements...

Inline Code Completion

OpenCode provides inline suggestions as you type:

1. Start typing code
2. Wait for suggestions (or press Ctrl + Space)
3. Accept with Tab or Enter
4. Navigate with arrow keys

Code Actions

Right-click on code to access AI actions:

• Explain Code - Get detailed explanation
• Refactor - Improve code structure
• Add Documentation - Generate comments
• Fix Issues - Suggest bug fixes
• Optimize - Improve performance

Command Palette

Press Ctrl/Cmd + Shift + P and search for:

• OpenCode: Ask AI
• OpenCode: Generate Code
• OpenCode: Review Code
• OpenCode: Write Tests

Features

Multi-File Context

OpenCode can analyze multiple files:

1. Select files in explorer
2. Right-click → Include in AI Context
3. Ask questions about the selected files

Git Integration

OpenCode integrates with Git:

• Review Changes - Analyze git diff
• Generate Commit Messages - AI-powered commits
• Explain History - Understand code evolution

Configuration:

{
  "opencode.git.enabled": true,
  "opencode.git.autoGenerateCommits": true,
  "opencode.git.includeContext": true
}

Terminal Integration

Use AI in the integrated terminal:

# Ask Claude about shell commands
$ opencode ask "How do I find large files?"

# Generate shell scripts
$ opencode generate "script to backup database"

# Explain errors
$ opencode explain "$(npm run build 2>&1)"

Advanced Configuration

Custom Model Parameters

Fine-tune Claude's behavior:

{
  "opencode.api.model": "claude-opus-4-8",
  "opencode.api.parameters": {
    "temperature": 0.7,
    "max_tokens": 8192,
    "top_p": 0.9,
    "top_k": 40,
    "stream": true
  }
}

Context Windows

Configure how much context to send:

{
  "opencode.context.maxTokens": 150000,
  "opencode.context.includeImports": true,
  "opencode.context.includeDocstrings": true,
  "opencode.context.scanDepth": 3
}

Custom Prompts

Create reusable prompts:

{
  "opencode.customPrompts": [
    {
      "name": "Code Review",
      "prompt": "Review this code for:\n1. Bugs and edge cases\n2. Performance issues\n3. Security vulnerabilities\n4. Code style and best practices",
      "shortcut": "Ctrl+Shift+R"
    },
    {
      "name": "Add Tests",
      "prompt": "Generate comprehensive unit tests for this code, including edge cases and error scenarios.",
      "shortcut": "Ctrl+Shift+T"
    }
  ]
}

Workspace Settings

Create project-specific settings in .vscode/settings.json:

{
  "opencode.api.baseUrl": "https://ai.xiaoyuan.co.uk/v1",
  "opencode.api.key": "${XIAOYUAN_API_KEY}",
  "opencode.api.model": "claude-opus-4-8",
  "opencode.project.context": {
    "framework": "React",
    "language": "TypeScript",
    "style": "functional"
  }
}

Extensions

Language-Specific Extensions

OpenCode supports language-specific AI features:

Python:

{
  "opencode.python.analyzeTypes": true,
  "opencode.python.suggestTypeHints": true,
  "opencode.python.lintIntegration": "ruff"
}

JavaScript/TypeScript:

{
  "opencode.typescript.suggestTypes": true,
  "opencode.typescript.refactorToHooks": true,
  "opencode.typescript.modernSyntax": true
}

AI-Powered Debugging

Enable AI debugging assistance:

{
  "opencode.debug.enabled": true,
  "opencode.debug.explainErrors": true,
  "opencode.debug.suggestFixes": true
}

Verification

Test your setup:

1. Open OpenCode
2. Press Ctrl/Cmd + Shift + L to open chat
3. Type: "Hello! What model are you?"
4. Verify Claude responds as Opus 4.8

Or test code generation:

Generate a function to calculate fibonacci numbers

Troubleshooting

Connection Issues

Error: Failed to connect to API

Solutions:

1. Verify base URL: https://ai.xiaoyuan.co.uk/v1
2. Check API key is valid
3. Test connection:

curl https://ai.xiaoyuan.co.uk/v1/models \
  -H "Authorization: Bearer your-api-key-here"

4. Check proxy settings if behind corporate firewall

Authentication Failed

Error: 401 Unauthorized

Solutions:

• Confirm API key is correct
• Check for extra spaces or newlines
• Regenerate API key at https://ai.xiaoyuan.co.uk
• Verify environment variable is set correctly:

  echo $OPENCODE_API_KEY

Model Not Found

Error: Model 'claude-opus-4-8' not found

Solutions:

• Use exact model name: claude-opus-4-8
• Alternative formats: claude-opus-4.8 or claude-opus-4-latest
• Check API service status

Slow Performance

If responses are slow:

1. Reduce context size:

   {
     "opencode.context.maxTokens": 50000
   }

2. Disable unnecessary features:

   {
     "opencode.inlineCompletion.enabled": false,
     "opencode.autoExplain.enabled": false
   }

3. Enable streaming:

   {
     "opencode.api.parameters.stream": true
   }

Rate Limit Errors

Error: 429 Too Many Requests

Solutions:

• Reduce request frequency
• Increase debounce delay:

  {
    "opencode.debounce.delay": 1000
  }

• Check your API tier and limits
• Upgrade account if needed

Tips & Best Practices

1. Use Keyboard Shortcuts

Learn key shortcuts for faster workflow:

• Ctrl/Cmd + L - Quick chat
• Ctrl/Cmd + K - Generate code
• Ctrl/Cmd + . - Quick actions
• Ctrl/Cmd + / - Toggle AI suggestions

2. Provide Project Context

Help Claude understand your project:

Create .opencode/context.md:

# Project Context

- Framework: Next.js 14
- Database: PostgreSQL with Prisma
- Auth: NextAuth.js
- Styling: Tailwind CSS
- Testing: Vitest + Testing Library

3. Iterative Development

Work in iterations:

1. Generate initial implementation
2. Test and review
3. Ask for specific improvements
4. Refine until complete

4. Use Comments for Guidance

Guide AI with comments:

// Generate a function that:
// 1. Fetches user data from API
// 2. Validates the response
// 3. Caches result for 5 minutes
// 4. Handles errors gracefully

5. Leverage Chat History

Build on previous context:

You: Create a user service
Claude: [generates code]
You: Now add authentication
Claude: [adds auth to existing code]
You: Add rate limiting
Claude: [enhances with rate limiting]

Integration Examples

GitHub Copilot Migration

Switching from GitHub Copilot? OpenCode with XiaoYuan AI provides similar features:

Copilot Feature	OpenCode Equivalent
Inline completions	opencode.inlineCompletion
Chat	Ctrl/Cmd + Shift + L
Fix issues	Code actions menu
Explain code	Right-click → Explain

CI/CD Integration

Use OpenCode in CI pipelines:

# .github/workflows/code-review.yml
name: AI Code Review
on: [pull_request]

jobs:
  review:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Install OpenCode CLI
        run: npm install -g opencode-cli
      - name: Review Changes
        env:
          OPENCODE_API_KEY: ${{ secrets.XIAOYUAN_API_KEY }}
          OPENCODE_BASE_URL: https://ai.xiaoyuan.co.uk/v1
        run: opencode review --diff

VS Code Devcontainer

Use in development containers:

// .devcontainer/devcontainer.json
{
  "extensions": ["opencode.vscode-opencode"],
  "settings": {
    "opencode.api.baseUrl": "https://ai.xiaoyuan.co.uk/v1",
    "opencode.api.key": "${localEnv:XIAOYUAN_API_KEY}"
  }
}

Support

Need help?

1. Check Getting Started
2. Review API Key guide
3. Visit OpenCode documentation
4. Contact XiaoYuan AI support at https://ai.xiaoyuan.co.uk