Configure DeepSeek V3 in Windsurf IDE (Cascade)

Windsurf is the next-gen AI editor by Codeium, powered by Cascade, an agent engine that deeply understands your codebase. While Windsurf has official DeepSeek integration, you can also Bring Your Own Key (BYOK) to significantly cut costs.

Why DeepSeek + Windsurf?

• Cascade Flow: Windsurf's agent moves beyond simple autocomplete to executing multi-step tasks.
• DeepSeek V3: Performance rivals Claude 3.5 Sonnet but at 1/50th the API cost.
• BYOK: Use your own DeepSeek API Key to access powerful models without a Windsurf Pro subscription.

Configuration Steps

Windsurf supports adding custom "OpenAI Compatible" models.

1. Open Settings: Click the gear icon in the bottom right, or press Cmd + ,.
2. Find "Provider": Search for model provider or look for Cascade settings.
3. Add Custom Model:
   • Provider: Select OpenAI Compatible.
   • Base URL: https://api.deepseek.com
   • API Key: sk-your-deepseek-key
   • Model Name: deepseek-chat (for V3)

Note: If you don't see a "Add Custom Model" button in the UI, try editing ~/.codeium/windsurf/config.json.

Tips

• Flow Mode: Switch to "Flow" mode in the chat sidebar. Cascade will read/write files automatically. DeepSeek V3 excels here at understanding complex refactoring instructions.
• Context Management: DeepSeek V3 supports 64k/128k context, so you can safely @ mention multiple files.

FAQ

Q: Why don't I see my model? A: Ensure you've selected deepseek-chat from the model dropdown menu in the Cascade chat interface.

Q: It's slow? A: Official API can be slow during peak hours. Try switching Base URL to SiliconFlow: https://api.siliconflow.cn/v1 with model deepseek-ai/DeepSeek-V3.