DeepSeek V4 for Copilot Chat

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Pick DeepSeek V4 from the Copilot Chat model picker — and keep everything else Copilot already gives you.

Love DeepSeek's price-performance but don't want to give up GitHub Copilot's agent mode, tool calling, and polished UI? This extension adds DeepSeek V4.1 Flash and other DeepSeek models to the Copilot Chat model selector — with native vision or Vision Proxy, thinking mode, and your own API key.

Why this extension?

• Don't replace Copilot — power it up. No new sidebar, no new chat UI to learn. Just a new model in the picker you already use.
• Agent mode, tool calling, instructions, MCP, skills — all of it still works. Copilot's entire stack, now running on DeepSeek.
• Two ways to work with images. V4.1 Flash and Flash Vision Exp receive image attachments natively. V4 Flash and Pro keep their existing text context while a configurable Vision Proxy turns images into descriptions.
• BYOK, pay DeepSeek directly. Your API key, your bill, your rate limits. Stored in the OS keychain, never on disk.

Features

DeepSeek models in the model picker

The picker includes V4.1 Flash and three legacy V4 entries, with long context, tool calling, and configurable thinking effort.

Native Vision and Vision Proxy

Choose the image path that fits the conversation:

• DeepSeek V4.1 Flash and Flash Vision Exp handle image attachments natively, without Vision Proxy.
• The DeepSeek V4 Flash and Pro entries use Vision Proxy: an image-capable model first describes each attachment, then the main DeepSeek model receives the description with the conversation. Auto mode selects Flash Vision Exp when available, while an explicitly configured VS Code model or API endpoint remains supported.

Context caching requires a full match with a cached prefix. Choose V4.1 Flash for new conversations and plan when to migrate existing ones.

Thinking Mode and Effort Control

Supports DeepSeek's thinking mode and reasoning_content. none disables thinking mode; low, high (default), and max set the thinking effort.

Inherits Every Copilot Capability

Because this plugs into Copilot's native provider API, you get the full stack for free:

• Agent mode — autonomous multi-step tasks
• Tool calling — file edits, terminal, workspace search, Git, tests
• Instructions & skills — all your .instructions.md, AGENTS.md, and skills just work
• Prompt caching stats — DeepSeek's cache hit rate logged in the output channel so you can see the savings

Secure by Default

API key lives in VS Code's SecretStorage (OS keychain on macOS / Windows / Linux). Never in settings.json, never in your Git history.

Zero Runtime Dependencies

Pure VS Code API + Node.js built-ins. No Python, no Docker, no local proxy server to babysit.

Getting Started

Prerequisites

• VS Code 1.116 or later. This extension relies on non-public Copilot Chat APIs that may break on newer VS Code versions — report an issue if you hit one.
• GitHub Copilot subscription (Free / Pro / Enterprise — the free tier works)
• DeepSeek API key from platform.deepseek.com, or a compatible provider token when using a custom deepseek-copilot.baseUrl

Installation

Install from the registry used by your editor:

1. Microsoft VS Code — install from VS Code Marketplace.
2. Editors that use Open VSX — install from Open VSX.

Usage

1. Run DeepSeek: Set API Key from the Command Palette (Cmd+Shift+P)
2. Paste your key or compatible provider token (official DeepSeek keys usually start with sk-)
3. Open Copilot Chat, click the model picker, and choose DeepSeek V4.1 Flash
4. That's it — chat away

Models

Model Entry	Image Handling	Thinking Effort	Official API Status
DeepSeek V4.1 Flash	Native image input	none / low / high / max	Recommended for new conversations
DeepSeek V4 Flash	Vision Proxy	none / low / high / max	Model retired; legacy name still accepted
DeepSeek V4 Pro	Vision Proxy	none / low / high / max	Retires on September 14, 2026 at 12:00 Beijing time
DeepSeek V4 Flash Vision Exp	Native image input	none / low / high / max	Model retired; legacy name still accepted

All four entries support thinking mode, tool calling, and 1M token context. See the official Models & Pricing documentation for retirement, routing, and billing details.

Settings

Setting	Default	Description
deepseek-copilot.baseUrl	https://api.deepseek.com	API endpoint — change for self-hosted / proxied deployments
deepseek-copilot.requestHeaders	{}	Custom headers for chat completions. Configuration guide
deepseek-copilot.maxTokens	0	Max output tokens (0 = API default). Useful for cost control
deepseek-copilot.modelIdOverrides	prefilled official ID map	API model IDs to send for V4.1 Flash and the three legacy V4 entries. Change only for compatible third-party APIs with different model names
deepseek-copilot.debugMode	minimal	Diagnostic mode: minimal for token usage only, metadata for privacy-preserving logs, or verbose for full request dumps and pipeline snapshots under extension global storage. Full dumps may include sensitive prompt text, tool schemas, file snippets, and image descriptions. Use DeepSeek: Open Request Dumps Folder to open the dump location
deepseek-copilot.visionModel	(auto)	Vision Proxy used by V4 Flash and Pro. Auto mode selects Flash Vision Exp when available; configure another VS Code model or API endpoint with DeepSeek: Configure Vision Proxy
deepseek-copilot.visionPrompt	(built-in)	Prompt used by V4 Flash/Pro's Vision Proxy to describe image attachments. It does not affect native V4.1 Flash or Flash Vision Exp requests
deepseek-copilot.experimental.stabilizeToolList	false	Experimental. Tries to pre-activate VS Code/Copilot virtual tools so the DeepSeek API tools parameter is more complete and stable across turns. May improve context-cache hit rate when enabled tools change between turns. Can increase input tokens because more function definitions may be included; cache-hit input tokens are cheaper but still count toward usage. Usually leave it off with 64 or fewer enabled tools unless the tool list still changes across turns; do not enable it with more than 128 enabled tools

Thinking Effort is configured from Copilot Chat's model picker for each DeepSeek model.

Example settings.json override for compatible API proxies:

{
  "deepseek-copilot.modelIdOverrides": {
    "deepseek-flash": "your-v4.1-flash-model-id",
    "deepseek-v4-flash": "your-flash-model-id",
    "deepseek-v4-pro": "your-pro-model-id",
    "deepseek-v4-flash-vision-exp": "your-vision-model-id"
  }
}

Compared to alternatives

	This extension	Local proxy (e.g. LiteLLM)	Standalone DeepSeek extensions
Works inside Copilot Chat	✅	✅	❌ separate UI
Agent mode, tools, skills	✅	✅	⚠️ reimplemented
Vision support	✅ native + proxied	❌	❌
No extra process to run	✅	❌	✅
One-click install	✅	❌	✅
API key in OS keychain	✅	❌	⚠️ varies

License

MIT