GitHub Copilot Integration

Quick Start

# 1. Start BitRouter
bitrouter serve

# 2. Add to VS Code settings.json
# "github.copilot.advanced": {
#   "debug.overrideProxyUrl": "http://localhost:8787"
# }

# 3. Reload VS Code — Copilot now routes through BitRouter

What You Get

✅ 25+ LLM providers - Route Copilot requests through any BitRouter provider
✅ VS Code + CLI - Both the extension and gh copilot CLI are supported
✅ Cost tracking - Monitor spending across all Copilot sessions
✅ BYOK support - Bring your own API keys for Business/Enterprise plans
✅ Fallback routing - Automatic failover when a provider is unavailable

Installation

Prerequisites

# VS Code extension — search "GitHub Copilot" in Extensions panel
# or install via CLI:
code --install-extension GitHub.copilot

# GitHub Copilot CLI (optional)
gh extension install github/gh-copilot

Connect to BitRouter

Choose your approach based on your VS Code version and Copilot plan:

Option 1: Debug Proxy Override (Stable VS Code, any plan)

// .vscode/settings.json or user settings
{
  "github.copilot.advanced": {
    "debug.overrideProxyUrl": "http://localhost:8787",
    "debug.testOverrideProxyUrl": "http://localhost:8787"
  }
}

Reload VS Code after saving. This routes all Copilot completions and chat through BitRouter.

Option 2: BYOK Custom Endpoint (VS Code Insiders, Business/Enterprise)

// chatLanguageModels.json (Command Palette: "Chat: Manage Language Models")
[
  {
    "name": "BitRouter",
    "vendor": "customendpoint",
    "apiKey": "your-bitrouter-key",
    "apiType": "chat-completions",
    "models": [
      {
        "id": "claude-3-5-sonnet-latest",
        "name": "BitRouter → Claude 3.5 Sonnet",
        "url": "http://localhost:8787/v1/chat/completions",
        "toolCalling": true,
        "vision": false,
        "maxInputTokens": 200000,
        "maxOutputTokens": 8192
      },
      {
        "id": "gpt-4o",
        "name": "BitRouter → GPT-4o",
        "url": "http://localhost:8787/v1/chat/completions",
        "toolCalling": true,
        "vision": true,
        "maxInputTokens": 128000,
        "maxOutputTokens": 4096
      }
    ]
  }
]

Option 3: Copilot CLI (gh copilot)

export COPILOT_PROVIDER_BASE_URL="http://localhost:8787/v1"
export COPILOT_MODEL="claude-3-5-sonnet-latest"
export COPILOT_PROVIDER_API_KEY="your-bitrouter-key"
export COPILOT_OFFLINE="true"   # prevent silent fallback to GitHub-hosted models

gh copilot suggest "create a docker-compose for a postgres + redis stack"
gh copilot explain "$(cat main.go)"

Essential Configuration

Multi-Provider Routing

# ~/.bitrouter/config.yaml
routes:
  # Copilot completions — fast, cheap model
  - match: "copilot/completions/*"
    provider: openai
    model: gpt-4o-mini

  # Copilot Chat — more capable model
  - match: "copilot/chat/*"
    provider: anthropic
    model: claude-3-5-sonnet-latest

  # Complex refactoring tasks
  - match: "copilot/chat/refactor/*"
    provider: openai
    model: o1-preview

  # Local models via Ollama
  - match: "copilot/local/*"
    provider: ollama
    model: codellama:34b
    endpoint: http://localhost:11434

HTTP Proxy (Network-Level)

For corporate environments that need all traffic routed through a proxy:

{
  "http.proxy": "http://localhost:8787",
  "http.proxySupport": "on",
  "http.proxyStrictSSL": false
}

# Or via environment variables
export HTTPS_PROXY=http://localhost:8787
export HTTP_PROXY=http://localhost:8787

Cost Budgets

budgets:
  copilot:
    daily: 10.00
    per_session: 2.00
    alert_threshold: 0.80   # alert at 80% of budget

Common Recipes

Recipe: Inline Completions vs Chat Routing

routes:
  # Fast, low-latency for inline completions
  - match: "copilot/completions/*"
    provider: openai
    model: gpt-4o-mini
    max_latency_ms: 800

  # Full-context chat with Claude
  - match: "copilot/chat/*"
    provider: anthropic
    model: claude-3-5-sonnet-latest

Recipe: Fallback Chain

routes:
  - match: "copilot/*"
    provider: anthropic
    model: claude-3-5-sonnet-latest
    fallback:
      - provider: openai
        model: gpt-4o
      - provider: deepseek
        model: deepseek-coder

Recipe: Cost-Optimized Setup

routes:
  - match: "copilot/*"
    rules:
      - if: context_tokens < 4000
        provider: openai
        model: gpt-4o-mini
      - if: context_tokens >= 4000
        provider: deepseek
        model: deepseek-coder

Monitoring

Usage Dashboard

# Copilot session summary
bitrouter sessions list --agent copilot

# Token usage by model
bitrouter usage breakdown --agent copilot --group-by model

# Daily spend
bitrouter costs breakdown --agent copilot --period day

Latency Tracking

# P95 latency per route
bitrouter stats latency --agent copilot

# Provider comparison
bitrouter providers benchmark --agent copilot

Troubleshooting

🔴 Copilot Not Using BitRouter

# Verify BitRouter is running
curl http://localhost:8787/health

# Check VS Code setting is saved
code --list-extensions | grep copilot
# Open settings.json, confirm debug.overrideProxyUrl is set

# Reload VS Code window
# Command Palette: "Developer: Reload Window"

🟡 BYOK Endpoint Not Appearing in Chat

# Confirm you're on VS Code Insiders with a Business/Enterprise plan
# Open Command Palette: "Chat: Manage Language Models"
# Re-enter the chatLanguageModels.json configuration

# Test the endpoint directly
curl http://localhost:8787/v1/models

🔵 Copilot CLI Falling Back to Cloud

# Ensure COPILOT_OFFLINE=true is set
echo $COPILOT_OFFLINE

# Verify base URL includes /v1
echo $COPILOT_PROVIDER_BASE_URL   # should end with /v1

# Test the endpoint
curl http://localhost:8787/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{"model":"gpt-4o","messages":[{"role":"user","content":"hello"}]}'

Advanced Features

Workspace-Scoped Routing

// .vscode/settings.json (project-level, overrides user settings)
{
  "github.copilot.advanced": {
    "debug.overrideProxyUrl": "http://localhost:8787"
  }
}

Commit this to your repo so every team member routes through the shared BitRouter instance.

Enterprise Proxy with Auth

# ~/.bitrouter/config.yaml
providers:
  copilot_enterprise:
    type: github_copilot
    enterprise_url: https://github.yourcompany.com
    auth: bearer
    route_prefix: "copilot/enterprise/*"

Model Overrides by File Type

routes:
  - match: "copilot/*"
    rules:
      - if: file_extension in [".py", ".ipynb"]
        model: deepseek-coder-v2
      - if: file_extension in [".rs", ".go"]
        model: claude-3-5-sonnet-latest
      - default:
        model: gpt-4o-mini

GitHub Copilot