agentgateway

The developer interface for agentgateway
Chat with any LLM. Test MCP tools. Browse resources. Run A2A agents.
All from your editor sidebar.

Why?

agentgateway is an open-source AI agent communication proxy — routing to any LLM provider, orchestrating MCP tools, and enabling agent-to-agent collaboration.

This extension brings all of that into your editor. Instead of switching between terminals, curl commands, and web UIs to test your gateway setup, you get a native VS Code experience with streaming chat, interactive tool testing, and live resource browsing.

One extension. Every provider. Every tool. Every agent.

Highlights

Talk to any LLM — OpenAI, Anthropic, Google, Mistral, local models — whatever your gateway routes to. Stream responses in real time with full markdown rendering and syntax highlighting.

Test MCP tools without writing code — The playground auto-generates forms from tool schemas. Fill in parameters, hit execute, see results. No curl, no scripts.

Switch gateways instantly — Dev, staging, production — configure multiple agentgateway instances and switch between them from the chat toolbar. No restart needed.

Track what you spend — Per-message and per-conversation token counts, right in the chat. Know exactly how many tokens each interaction costs.

Send code to chat — Select code in your editor, hit Cmd+L, and it appears as a dismissible context chip in the chat. Ask the LLM about it, get explanations, request changes.

Agentic tool loops — The LLM doesn't just respond — it can invoke MCP tools, get results, and continue reasoning. Full agentic loop, visible in the chat with collapsible tool call cards.

Features at a Glance

Chat

Tools & Resources

Configuration

Quick Start

1. Start agentgateway

# Local
agentgateway -f agw-config.yaml

# Or via Kubernetes
kubectl port-forward svc/agentgateway 8080:8080 -n <namespace>

2. Install the Extension

git clone https://github.com/sebastianmaniak/agw-vscode-extension.git
cd agw-vscode-extension
npm install && npm run compile
npx @vscode/vsce package --no-dependencies --allow-missing-repository
code --install-extension agw-vscode-0.2.0.vsix

3. Configure

Open Settings (Cmd+,) and search for agw:

{
  "agw.llmEndpoint": "http://localhost:8080/openai",
  "agw.mcpEndpoint": "http://localhost:8080/mcp",
  "agw.apiKey": "your-api-key",       // optional
  "agw.defaultModel": "gpt-4o"        // optional
}

4. Go

Click the agentgateway icon in the Activity Bar. Start chatting.

Multi-Gateway Profiles

Running multiple gateways? Configure them all and switch instantly:

{
  // Default gateway (always available)
  "agw.llmEndpoint": "http://localhost:8080/openai",
  "agw.mcpEndpoint": "http://localhost:8080/mcp",

  // Additional gateways
  "agw.gateways": [
    {
      "name": "Production",
      "llmEndpoint": "https://prod-gw.example.com/openai",
      "mcpEndpoint": "https://prod-gw.example.com/mcp",
      "apiKey": "prod-key"
    },
    {
      "name": "Anthropic",
      "llmEndpoint": "http://localhost:8080/anthropic",
      "mcpEndpoint": "http://localhost:8080/mcp"
    }
  ]
}

A gateway dropdown appears in the input toolbar. Switching reconnects automatically — new models, new tools, zero friction.

Keyboard Shortcuts

Development

npm run watch        # Auto-rebuild on changes
npm run check-types  # Type checking
npm test             # Run tests
npm run test:watch   # Watch mode

Press F5 to launch an Extension Development Host with the extension loaded.

src/
├── extension.ts                # Entry point, activation, handler wiring
├── types.ts                    # Shared types (config, API, messages)
├── gateway/
│   ├── client.ts               # HTTP client with health check fallback
│   ├── chat.ts                 # SSE streaming + token usage capture
│   ├── models.ts               # Model listing with graceful fallback
│   ├── mcp.ts                  # MCP JSON-RPC over Streamable HTTP
│   └── a2a.ts                  # A2A protocol (agent cards + tasks)
├── state/
│   └── conversation.ts         # Chat history + globalState persistence
├── providers/
│   ├── chatViewProvider.ts     # Webview provider + agentic completion loop
│   └── toolTreeProvider.ts     # Sidebar tree view for MCP tools
└── webview/
    ├── index.ts                # Preact app (4 tabs + overlay system)
    ├── styles.css              # VS Code theme-aware styles
    └── components/
        ├── ChatPanel.ts        # Cursor-style input bar + action menu
        ├── MessageBubble.ts    # Markdown rendering + Copy/Insert actions
        ├── McpPlayground.ts    # Tool testing with dynamic forms
        ├── ResourceBrowser.ts  # MCP resource viewer
        ├── A2aPlayground.ts    # A2A agent card + task sender
        ├── ConversationList.ts # History browser
        ├── SystemPromptEditor.ts
        ├── PromptTemplates.ts
        └── ToolCallCard.ts     # Collapsible tool call/result cards

Compatibility

Install via .vsix in any VS Code-compatible editor.

Built by SebbyCorp · agentgateway.dev · Apache-2.0