Bootstrap a modular AI agent with OpenRouter SDK, extensible hooks, and optional Ink TUI

Build a Modular AI Agent with OpenRouter This skill helps you create a modular AI agent with: Standalone Agent Core Runs independently, extensible via hooks OpenRouter SDK Unified access to 300+ language models Optional Ink TUI Beautiful terminal UI (separate from agent logic) Architecture Prerequisites Get an OpenRouter API key at: https://openrouter.ai/settings/keys ⚠️ Security: Never commit API keys. Use environment variables. Project Setup Step 1: Initialize Project Step 2: Install Dependencies Step 3: Create tsconfig.json Step 4: Add Scripts to package.json File Structure Step 1: Agent Core with Hooks Create src/agent.ts the standalone agent that can run anywhere: Step 2: Define Tools Create src/tools.ts : Step 3: Headless Usage (No UI) Create src/headless.ts use the agent programmatically: Run headless: OPENROUTER API KEY=sk or ... npm run start:headless Step 4: Ink TUI (Optional Interface) Create src/cli.tsx a beautiful terminal UI that uses the agent with items based streaming: Run TUI: OPENROUTER API KEY=sk or ... npm start Understanding Items Based Streaming The OpenRouter SDK uses an items based streaming model a key paradigm where items are emitted multiple times with the same ID but progressively updated content. Instead of accumulating chunks, you replace items by their ID . How It Works Each iteration of getItemsStream() yields a complete item with updated content: For function calls, arguments stream progressively: Why Items Are Better Traditional (accumulation required): Items (complete replacement): Benefits: No manual chunk management each item is complete Handles concurrent outputs function calls and messages can stream in parallel Full TypeScript inference for all item types Natural Map based state works perfectly with React/UI frameworks Extending the Agent Add Custom Hooks Use with HTTP Server Use with Discord Agent API Reference Constructor Options Option Type Default Description apiKey string required OpenRouter API key model string 'openrouter/auto' Model to use instructions string 'You are a helpful assistant.' System prompt tools Tool[] [] Available tools maxSteps number 5 Max agentic loop iterations Methods Method Returns Description send(content) Promise<string Send message with streaming sendSync(content) Promise<string Send message without streaming getMessages() Message[] Get conversation history clearHistory() void Clear conversation setInstructions(text) void Update system prompt addTool(tool) void Add tool at runtime Events Event Payload Description message:user Message User message added message:assistant Message Assistant response complete item:update StreamableOutputItem Item emitted (replace by ID, don't accumulate) stream:start Streaming started stream:delta (delta, accumulated) New text chunk stream:end fullText Streaming complete tool:call (name, args) Tool being called tool:result (name, result) Tool returned result reasoning:update text Extended thinking content thinking:start Agent processing thinking:end Agent done processing error Error Error occurred Item Types (from getItemsStream) The SDK uses an items based streaming model where items are emitted multiple times with the same ID but progressively updated content. Replace items by their ID rather than accumulating chunks. Type Purpose message Assistant text responses function call Tool invocations with streaming arguments function call output Results from executed tools reasoning Extended thinking content web search call Web search operations file search call File search operations image generation call Image generation operations Discovering Models Do not hardcode model IDs they change frequently. Use the models API: Fetch Available Models Dynamic Model Selection in Agent Using openrouter/auto For simplicity, use openrouter/auto which automatically selects the best available model for your request: Models API Reference Endpoint : GET https://openrouter.ai/api/v1/models Response : { data: OpenRouterModel[] } Browse models : https://openrouter.ai/models Resources OpenRouter Docs: https://openrouter.ai/docs Models API: https://openrouter.ai/api/v1/models Ink Docs: https://github.com/vadimdemedes/ink Get API Key: https://openrouter.ai/settings/keys

create-agent