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🚀 OpenCode for GitHub Copilot Chat

Use 30+ frontier AI models (DeepSeek V4, Kimi K2.6, GLM-5.1, GPT-5.5, Claude Opus 4.7, Gemini 3.5, Grok…) in GitHub Copilot Chat — BYOK

Bring Your Own Key (BYOK) · OpenCode Zen (free + paid models) or Go ($10/mo subscription) · Works with native Copilot Agent Mode

CI VS Code Marketplace Version License: MIT VS Code PRs Welcome Stars

✨ Why you'll love it · ⚡ Quick Start (60 sec) · 🧠 Models · 📊 Compare · 🔧 Settings · ❓ FAQ · 💬 Community

💡 The elevator pitch

Copilot Chat is great — but its premium models cost $39/mo (Pro+), and the free tier is rate-limited. This extension plugs OpenCode's model gateway into Copilot Chat's model picker. OpenCode Zen gives you 2-5 rotating free models (Big Pickle is always free; DeepSeek V4 Flash, MiMo-V2.5, and others rotate) plus paid models like Claude Opus, GPT-5.5, and Gemini at pay-as-you-go rates. OpenCode Go ($10/mo, $5 first month promo) gives you a curated set of open models (DeepSeek V4 Pro, Kimi K2.6, GLM-5.1, Qwen3.7 Max, MiMo V2.5 Pro) with generous usage limits. You keep the native Copilot UI, tool-calling, and Agent Mode — you just get way more models, often cheaper than Copilot Pro+.

🔥 Why you'll love it

What you get
💸 Cheaper than Copilot Pro+ Copilot Free + OpenCode Zen free models = $0 for 2-5 rotating models (Big Pickle always free; DeepSeek V4 Flash, MiMo-V2.5, and others rotate). Paid Zen models (Claude Opus, GPT-5.5) available at pay-as-you-go rates. Go subscription $10/mo ($5 first month)
🌍 30+ frontier models DeepSeek V4, Kimi K2.6, GLM-5.1, Qwen3.7 Max, MiMo V2.5, MiniMax M2.7, Big Pickle, Nemotron — all in one picker
🤖 Full Agent Mode Tool-calling (read files, edit, run terminal) works natively — not just chat. Models also appear in the Agents window (Copilot CLI session)
🧠 Thinking controls Per-model reasoning effort (DeepSeek max, Qwen thinking_budget, MiniMax on/off, Mimo low/med/high)
📊 Live usage tracking Status bar shows Go subscription burn-rate across 5h / weekly / monthly tiers
🔌 Dual providers OpenCode Go ($10/mo subscription) + OpenCode Zen (free + paid models) — run both at once, switch instantly
🎯 Smart routing Each model family auto-routes to its native transport (/responses, /messages, streamGenerateContent, /chat/completions)
🖼️ Vision + PDF + Audio Multimodal models pass through image, PDF, audio, and video inputs
🔒 Your key, your control API key stored in VS Code SecretStorage — never leaves your machine

⚡ Quick Start (60 sec)

1.  Install GitHub Copilot Chat (free) ──────────────────────────── ✓
2.  Install this extension ──────────────────────────────────────── ✓
3.  Get an OpenCode Zen API key → opencode.ai/auth ─────────────── ✓
4.  Open Copilot Chat → click model → "Add Models" → OpenCode Zen ── ✓
5.  Paste API key → pick a free model → CHAT 🎉
📖 Detailed step-by-step with screenshots
  1. Install GitHub Copilot Chat — free, requires only a GitHub account.
  2. Install this extension from the VS Code Marketplace (or press F5 in this repo for dev mode).
  3. Get an API key:
    • Free models: Sign up at opencode.ai → grab an OpenCode Zen key. 2-5 models are truly free (Big Pickle is always free; DeepSeek V4 Flash Free, MiMo-V2.5 Free, and others rotate).
    • Paid Zen models (optional): Add a payment method to your Zen account to unlock Claude Opus, GPT-5.5, Gemini, and other paid models at pay-as-you-go rates. Adding $20+ balance also improves rate limits on free models.
    • OpenCode Go (optional): Subscribe to OpenCode Go ($10/mo, $5 first month promo) for curated open models like DeepSeek V4 Pro, Kimi K2.6, GLM-5.1, Qwen3.7 Max, MiMo V2.5 Pro.
  4. Open Copilot Chat (Cmd/Ctrl+Shift+I, or click the Copilot icon).
  5. Click the model picker (current model name) → Add Models…
  6. Select OpenCode Go or OpenCode Zen.
  7. Press Enter to accept the default group name.
  8. Paste your API key when prompted (stored securely in VS Code SecretStorage).
  9. Pick the models you want enabled.
  10. Select any OpenCode model from the picker and start chatting. 🚀

💡 Tips:

  • Go and Zen are separate provider groups — both can be active simultaneously. Switch anytime from the picker.
  • If a model shows in Language Models view but not the chat picker, hover its row and click the eye icon (👁) to enable it.
  • Set opencodego.freeOnly: false to reveal paid Zen models in the picker.

🎬 Demo

Copilot Chat model picker showing OpenCode models

Selecting an OpenCode model from the Copilot Chat model picker.

🧠 Models

The extension fetches live model lists on every startup from:

Provider Endpoint Cost
OpenCode Go https://opencode.ai/zen/go/v1/models $10/mo ($5 first month promo) — usage limits: 5h/$12, weekly/$30, monthly/$60
OpenCode Zen https://opencode.ai/zen/v1/models 2-5 rotating free models + pay-as-you-go for premium models

⭐ OpenCode Go (subscription — $10/mo, $5 first month promo)

Model Context Max Output Highlights
deepseek-v4-pro / deepseek-v4-flash 1,000,000 384,000 🧠 Reasoning off→max
qwen3.7-max 1,000,000 65,536 🧠 thinking_budget 4K–82K
mimo-v2.5-pro / mimo-v2-pro 1,048,576 128,000 🧠 Effort low→high
mimo-v2.5 1,000,000 128,000 Fast & cheap
kimi-k2.6 / kimi-k2.5 262,144 65,536 🧠 on/off
minimax-m3 512,000 131,072 🧠 on/off
minimax-m2.7 / minimax-m2.5 204,800 131,072 🧠 on/off
minimax-m2.1 / minimax-m2 204,800 131,072 🧠 on/off
glm-5.1 / glm-5 202,752 32,768 🧠 on/off
hy3-preview 256,000 64,000 Preview
ring-2.6-1t 262,000 66,000 Large context

🆓 OpenCode Zen — Free models (no payment needed)

OpenCode Zen offers 2-5 rotating free models — no balance required. Big Pickle is always free; other models rotate (DeepSeek V4 Flash Free, MiMo-V2.5 Free, Nemotron, etc.). Without a balance, rate limits are low. Adding $20+ to your Zen balance significantly improves rate limits on free models.

Note: Free models rotate periodically. The table below shows current offerings, but availability may change. Big Pickle is the only model guaranteed to always be free.

Model Context Max Output Vendor
big-pickle 200,000 128,000 🥒 Mystery box (always free)
deepseek-v4-flash-free 200,000 128,000 DeepSeek
mimo-v2.5-free 200,000 128,000 Xiaomi
nemotron-3-super-free 204,800 128,000 NVIDIA
north-mini-code-free 131,072 131,072 Cohere

💰 OpenCode Zen — Paid models (requires balance)

Add a payment method to your Zen account to unlock these models at pay-as-you-go rates.

Model Context Max Output Input / Output per 1M tokens
claude-opus-4-7 / claude-opus-4-6 1,000,000 128,000 $5 / $25
claude-sonnet-4-6 / claude-sonnet-4-5 1,000,000 64,000 $3 / $15
claude-haiku-4-5 200,000 64,000 $1 / $5
gpt-5.5 / gpt-5.5-pro 1,050,000 128,000 $5 / $30
gpt-5.4 / gpt-5.4-pro / gpt-5.4-mini 400,000–1,050,000 128,000 $0.75–$30 / $4.50–$180
gpt-5.3-codex / gpt-5.2 400,000 128,000 $1.75 / $14
gpt-5.1 / gpt-5 / gpt-5-nano 400,000 128,000 $0.05–$1.07 / $0.40–$8.50
gemini-3.5-flash / gemini-3.1-pro / gemini-3-flash 1,048,576 65,536 $0.50–$4 / $3–$18
grok-build-0.1 256,000 256,000 $1 / $2
qwen3.7-max / qwen3.6-plus / qwen3.5-plus 262,144–1,000,000 65,536 $0.20–$7.50
deepseek-v4-pro / deepseek-v4-flash 1,000,000 384,000 $0.14–$3.48
kimi-k2.6 / kimi-k2.5 262,144 65,536 $0.60–$4.00
glm-5.1 / glm-5 202,752 32,768 $1.00–$4.40
minimax-m2.7 / minimax-m2.5 204,800 131,072 $0.30 / $1.20

Set opencodego.freeOnly: false to show paid Zen models in the picker (default shows only free models).

🔬 How model metadata is resolved (3-tier fallback)

Limits and capabilities resolve in this priority order:

  1. Live metadata from OpenCode /models endpoint
  2. 6-hour models.dev snapshot cached in VS Code globalState
  3. Bundled fallback catalog shipped with the extension (works offline)

Deprecated/unavailable models are filtered before registration. Per-provider limits tracked separately (Go vs Zen) so shared models (e.g. glm-5.1, qwen3.6-plus) use correct values for each.

🛣️ Endpoint routing per model family
Family Endpoint Why
Zen GPT (gpt-*) /responses OpenAI native
Zen Gemini (gemini-*) :streamGenerateContent?alt=sse Google native
Zen Claude (claude-*) + Go MiniMax (minimax-m2.*) /messages Anthropic-compatible
Everything else (Qwen, DeepSeek, GLM, Kimi, MiMo…) /chat/completions OpenAI-compatible

All Qwen models use /chat/completions because they use OpenAI-native tool-calling format. Routing to Anthropic /messages broke tool calls.

📊 GitHub Copilot vs This Extension

GitHub Copilot has four tiers now — Free, Pro ($10/mo), Pro+ ($39/mo), and Max ($100/mo). Here's how BYOK via OpenCode compares:

Copilot Free Copilot Pro $10/mo Copilot Pro+ $39/mo OpenCode for Copilot Chat
💰 Cost $0 $10/mo $39/mo $0 with free Zen models · Go is $10/mo subscription
🤖 Models GPT-5 mini, Haiku 4.5 (2,000 completions) Pro catalog + Claude Code/Codex agents Premium (Opus) 30+ models: DeepSeek V4, Kimi K2.6, GLM-5.1, Qwen3.7, MiMo V2.5, MiniMax M2.7, + 2-5 rotating free models
🧠 Reasoning controls — Per-model (GitHub decides) Per-model (GitHub decides) Per-family thinking effort you control (DeepSeek max, Qwen thinking_budget, etc.)
🖼️ Multimodal Limited Yes (limited) Yes (limited) Vision + PDF + Audio + Video (per-model)
🔧 Agent Mode / tool-calling — ✅ ✅ ✅ Full (read, edit, terminal)
📊 Usage transparency Opaque Opaque Audit logs Status bar burn-rate + diagnostics report
🔌 Provider GitHub only GitHub only GitHub only Bring any OpenCode key — Go ($10/mo subscription) or Zen (free + paid), run both at once
🎁 Free frontier models? ❌ ❌ ❌ (paid tier only) ✅ 2-5 rotating free models via Zen (Big Pickle always free)
🚫 Rate limit 2,000 completions/mo Unlimited (rate-limited) 4× Pro credits Per OpenCode tier (Zen free has low limits without balance; Go has generous limits)

Not a replacement — this extension extends Copilot Chat. You still need the (free) Copilot Chat extension + a GitHub account. BYOK models bypass the Copilot subscription billing entirely — you pay OpenCode directly (or nothing, on Zen free).

💡 When to use which?

  • Copilot Free + OpenCode Zen → $0 total. Best for students, hobbyists, and trying frontier models.
  • Copilot Pro + OpenCode Go → $10/mo for Copilot's polish + $10/mo for DeepSeek Pro, Kimi K2.6, Qwen3.7 Max.
  • This extension alone → Already works with just Copilot Free. Keep Copilot for autocomplete, use OpenCode models for chat/agent when you need variety or free tier.

✨ Features Deep Dive

🧠 Thinking & Reasoning Controls

Per-model reasoning configuration, dynamically enhanced with reasoning_options from models.dev:

Family Options Setting
DeepSeek off / low / medium / high / max opencodego.thinking.deepseek
GLM on / off opencodego.thinking.glm
Kimi on / off opencodego.thinking.kimi
MiniMax off / on opencodego.thinking.minimax
Mimo (Xiaomi) off / low / medium / high opencodego.thinking.mimo
Qwen auto / on / off + thinking_budget (4096–81920) opencodego.thinking.qwen + .qwenBudget
Any future reasoning model off / on (auto-detected from models.dev) —

opencodego.debugReasoning — writes provider reasoning_content to Output → OpenCode for debugging.

📊 Usage Tracking

  • Go Usage Tracker — real-time burn-rate of OpenCode Go subscription:
    • Tracks 5-hour rolling ($12), weekly ($30), monthly ($60) tiers.
    • Client-side cost calc: token usage × per-model pricing (input/output/cache_read).
    • Status bar: Go: 27%·62%·75% — ⚠ warning when any tier exceeds 80%.
    • Persisted in VS Code globalState — survives restarts.
  • Response usage bar — latest prompt/output/total/cache summary after each response.
  • Normalized usage DataPart — emits usage MIME so Copilot Chat's context widget shows accurate token counts.

🪟 Agents Window (Copilot CLI) Support

OpenCode models appear in the VS Code Agents window model picker when starting a Copilot CLI / Background agent session — not just the regular Chat view. Two sets of models are available:

Provider Appears under Notes
opencodego / opencodezen Local Normal models, no targetChatSessionType. From VS Code ≥1.126 they appear naturally in the Local section (once the extension loads in the sessions window).
opencodego-agent / opencodezen-agent Copilot Agent variants with targetChatSessionType: "copilotcli". Picked up by CopilotChatSessionsProvider for agent sessions.

How it works:

Setting Default What it controls
opencodego.agentsWindow true Registers agent-host providers at runtime
opencodego.showAgentModelsInManagePanel false Shows agent vendors in the Manage Language Models panel

Setup:

  1. Agent models are enabled by default (agentsWindow: true). No changes needed for basic usage.
  2. Add this to your VS Code settings.json to enable the extension in the Agents window process: 
    "extensions.supportAgentsWindow": {
  "ltmoerdani.opencode-copilot-chat": true
}
  3. Reload the window (Developer: Reload Window).
  4. Open the Agents window → start a new session → select Copilot CLI as the agent type.
  5. Open the model picker — OpenCode models appear under Local (normal models) and Copilot (agent-host variants).

Normal OpenCode models (opencodego, opencodezen) appear in the Local section of the Agents window picker from VS Code ≥1.126 onwards. On ≤1.125 they may require the supportAgentsWindow setting. Agent-host variants (opencodego-agent, opencodezen-agent) appear under Copilot because they carry targetChatSessionType: "copilotcli" and are matched by CopilotChatSessionsProvider.

To manage agent API keys separately or see agent vendors in the Manage panel, enable:

"opencodego.showAgentModelsInManagePanel": true

🛠️ Smart Routing & Reliability

  • Native endpoint routing per family (see Models table)
  • Tool-calling forwarded in correct format per endpoint (OpenAI tool_calls vs Anthropic tool_use)
  • Sticky gateway headers (x-opencode-session, x-opencode-request, x-opencode-client) for affinity
  • Request & stream timeouts — defaults 600s total / 120s idle; configurable
  • ground tag filtering — opencodego.stripThinkTags (auto strips MiniMax only, always, never)

🔍 Diagnostics

Command What it does
OpenCode Go: Diagnostics Markdown report of all Go models + recent request summaries
OpenCode Zen: Diagnostics Same for Zen
OpenCode: Model Picker Diagnostics All registered models (Go + Zen + Copilot) side-by-side

🔧 Settings

Setting Default Description
opencodego.temperature 0.2 Sampling temperature (0–2)
opencodego.maxTokens 0 Max output token override (0 = per-model max)
opencodego.maxInputTokens 0 Context window override (0 = per-model default)
opencodego.debugReasoning false Log reasoning_content to Output panel
opencodego.requestTimeoutSeconds 600 Total request timeout
opencodego.streamIdleTimeoutSeconds 120 Cancel if stream goes idle
opencodego.showUsageStatusBar true Show usage summary in status bar
opencodego.freeOnly true Zen: free models only. false = include paid
opencodego.agentsWindow true Expose agent-host model variants (targetChatSessionType) for the Agents window
opencodego.showAgentModelsInManagePanel false Show agent vendors in Manage Language Models panel
opencodego.stripThinkTags "auto" Strip <think> tags (never/auto/always)
opencodego.thinking.deepseek "off" off/low/medium/high/max
opencodego.thinking.glm "off" on/off
opencodego.thinking.kimi "off" on/off
opencodego.thinking.minimax "off" off/on
opencodego.thinking.mimo "off" off/low/medium/high
opencodego.thinking.qwen "off" auto/on/off
opencodego.thinking.qwenBudget "auto" auto/4096/16384/32768/81920
📜 Full settings reference with descriptions

All settings live under the OpenCode namespace in VS Code Settings. Run Preferences: Open Settings (UI) and search opencode.

🎛️ Commands

The easiest way to manage your key is Settings → Language Models (gear ⚙). For advanced use, open the Command Palette (Cmd/Ctrl+Shift+P):

Command Description
OpenCode Go: Manage Provider Manage legacy API key, refresh models, test connection
OpenCode Go: Set API Key Store/update legacy OpenCode Go API key
OpenCode Go: Diagnostics Report of Go models + request history
OpenCode Zen: Diagnostics Report of Zen models + request history
OpenCode: Model Picker Diagnostics All registered models (Go + Zen + Copilot) side-by-side
OpenCode: Set Thinking Effort… Per-family thinking mode picker
OpenCode Go: Show Usage Details Detailed Go subscription usage breakdown

❓ FAQ

Do I need Copilot Pro, Pro+, or Max?

No. You only need the free GitHub Copilot Chat extension and any GitHub account — even the Copilot Free tier works. BYOK models bypass Copilot's subscription billing entirely.

If you already pay for Copilot Pro ($10), Pro+ ($39), or Max ($100), you can still use this extension alongside it — keep Copilot for autocomplete, switch to OpenCode models in chat when you want variety, free tier, or specific models GitHub doesn't offer.

Is it really free? What's the catch?

OpenCode Zen offers 2-5 rotating free models — no balance required. Big Pickle is always free; other models rotate (DeepSeek V4 Flash Free, MiMo-V2.5 Free, Nemotron, etc.). Without a balance, rate limits are low. Adding $20+ to your Zen balance significantly improves rate limits on free models. Paid Zen models (Claude Opus, GPT-5.5, Gemini, etc.) require adding a payment method — they're pay-as-you-go.

OpenCode Go is a subscription — $10/mo ($5 first month promo) — with generous usage limits (5h/$12, weekly/$30, monthly/$60). It unlocks curated open models like DeepSeek V4 Pro, Kimi K2.6, GLM-5.1, Qwen3.7 Max, MiMo V2.5 Pro. When you hit the limit, you can continue using the free Zen models.

This extension is free and open source — you never pay us. You pay OpenCode directly (or nothing, on Zen free).

Does Agent Mode / tool-calling work?

Yes — fully. The extension forwards VS Code tool schemas in the correct format for each endpoint (OpenAI tool_calls or Anthropic tool_use). Copilot Agent can read files, search, edit, and run terminal commands through any OpenCode model.

Where is my API key stored?

In VS Code's SecretStorage — the same encrypted store used by GitHub auth. It never leaves your machine and is never sent anywhere except directly to opencode.ai.

Can I use Go and Zen at the same time?

Yes. They're separate provider groups. Add both via Language Models → Add Models…, enter each key separately, and switch between them from the chat model picker anytime.

A model shows in Language Models but not the chat picker — why?

Hover its row in the Language Models view and click the eye icon (👁) to toggle visibility.

Tool calls loop forever on Qwen — help?

Known issue with qwen3.6-plus-free on broad agent tasks (see issue #1). Workaround: set opencodego.thinking.qwen: "off" and use a narrower task scope, or switch to a paid Qwen model.

How do I use OpenCode models in the Agents window (Copilot CLI)?

Agent models are enabled by default (opencodego.agentsWindow: true). Just add this to your VS Code settings.json:

"extensions.supportAgentsWindow": {
  "ltmoerdani.opencode-copilot-chat": true
}

Then reload the window, open the Agents window, start a Copilot CLI session, and pick any OpenCode model from the picker. See the Agents Window section above for details.

How do I report a bug or request a model?

Open an issue — pick the Bug Report or Feature Request template. Include the diagnostics report (OpenCode Go: Diagnostics or OpenCode Zen: Diagnostics).

🏗️ Architecture

flowchart LR
    A[VS Code Copilot Chat] -->|model picker| B{Which vendor?}
    B -->|Copilot| C[GitHub models]
    B -->|OpenCode Go| D[Go API Key]
    B -->|OpenCode Zen| E[Zen API Key]

    D --> F[Smart Router]
    E --> F

    F -->|GPT| G[" /responses "]
    F -->|Gemini| H[" :streamGenerateContent "]
    F -->|Claude + MiniMax| I[" /messages "]
    F -->|Qwen/DeepSeek/GLM/Kimi/MiMo| J[" /chat/completions "]

    G & H & I & J --> K[opencode.ai gateway]
    K --> L[SSE Stream]
    L -->|tool_calls / tool_use| A
    L -->|usage DataPart| M[Status Bar]
    L -->|context hook| N[Context Widget]
Loading

See docs/architecture/ for the full provider architecture, routing, and metadata resolution docs.

🤝 Contributing

Contributions welcome! Whether it's a typo fix, new model support, or a screenshot — every PR counts.

📋 See CONTRIBUTING.md for guidelines. 💬 Discussions: GitHub Discussions 🐞 Bugs: Issue Tracker

Development

npm install      # install deps
npm run compile  # build TypeScript
npm run watch    # watch mode
npm run package  # build .vsix

Press F5 in VS Code to launch an Extension Development Host.

📈 Roadmap

  • 🎥 Demo GIF + screenshots
  • 🌐 GitHub Pages landing page
  • 📦 Publish to VS Code Marketplace
  • 🏷️ Verified publisher badge
  • 🔔 Webhook for new OpenCode models
  • 🎨 Custom model aliases / favorites
  • 📊 Usage charts webview panel
  • 🌍 i18n (id, zh, ja)

Have an idea? Start a discussion or open a feature request.

⭐ Star History

GitHub stars  👆 Star this repo if it saved you money or unlocked a model you needed!

Star History Chart

💬 Community

GitHub Discussions Issues X / Twitter Reddit

If this saves you money or unlocks a model you needed — ⭐ star the repo and share it!

📄 License

MIT © 2026 ltmoerdani

OpenCode is a trademark of opencode.ai. This project is independent and not affiliated with GitHub, Microsoft, Anthropic, OpenAI, Google, or any model provider.

About

Use 30+ AI models (DeepSeek, Kimi, GLM, Claude, GPT-5.5, Gemini, Grok) in GitHub Copilot Chat — free via BYOK. No Copilot Pro needed.

opencode.ai

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chat ai opencode vscode gemini openai vscode-extension glm copilot language-model grok claude kimi llm byok anthropic qwen deepseek agent-mode free-models

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