OpenAI Assistants Template

Implements real-time streaming of OpenAI Assistant responses through Next.js API routes using Server-Sent Events (SSE), with frontend React components that progressively render text, code blocks, and images as tokens arrive. The Chat component manages streaming state and processes function call interruptions mid-stream, enabling responsive UX without waiting for complete assistant responses.

Manages OpenAI Assistant conversation threads through dedicated API endpoints (/api/assistants/threads) that create persistent thread objects, append messages, and retrieve full conversation history. The architecture maintains thread state server-side while the frontend Chat component manages local UI state, enabling multi-turn conversations with full context preservation across page reloads and sessions.

Provides TypeScript type definitions for OpenAI Assistants API responses and request payloads, enabling compile-time type checking across frontend and API route layers. The template uses OpenAI SDK's built-in types and defines custom types for application-specific data structures (thread IDs, message objects, function call results).

Implements a function calling loop where the Assistant API returns structured function call requests (tool_calls), the frontend Chat component intercepts these calls, executes them client-side using JavaScript, and submits results back via /api/assistants/threads/[threadId]/actions endpoint. The pattern uses OpenAI's tool_calls schema to define callable functions and maintains execution state until the assistant completes its response.

Provides file management capabilities through /api/assistants/files endpoint (GET/POST/DELETE) and File Viewer component that handles uploading files to OpenAI's file storage, listing uploaded files, and enabling file search tool for the assistant. Files are indexed by OpenAI's retrieval system, allowing the assistant to search and cite content from uploaded documents during conversations.

Enables the assistant to execute Python code through OpenAI's code interpreter tool by configuring the assistant with the code_interpreter tool. The template handles code execution requests from the assistant, displays code blocks and execution results in the Chat component using React Markdown, and supports rendering generated images or data visualizations from code execution.

Provides /api/assistants POST endpoint that creates or retrieves an OpenAI Assistant with predefined tools (file_search, code_interpreter, function calling), system instructions, and model configuration. The endpoint abstracts assistant setup, allowing the template to reuse the same assistant across all example pages and conversation threads without requiring manual API calls.

Implements a Message Rendering system in the Chat component that detects and formats different content types from assistant responses: plain text, code blocks (with syntax highlighting via React Markdown), images, and function call requests. The renderer uses markdown parsing to identify code blocks and applies appropriate styling and formatting for each content type.

Provides four example pages (/examples/basic-chat, /examples/function-calling, /examples/file-search, /examples/all) that demonstrate individual assistant capabilities in isolation and combined. Each example page is a standalone Next.js page component that imports the Chat component and configures it for specific use cases, serving as both documentation and copy-paste templates for developers.

Implements a complete middleware layer using Next.js API routes (app/api/assistants/*) that abstracts OpenAI SDK calls from the frontend, handling authentication, request validation, error handling, and response formatting. The middleware pattern isolates API key management server-side and provides a consistent interface for frontend components to interact with the Assistants API.

Implements conversation state management in the Chat component using React hooks (useState, useCallback) to track messages, streaming status, function call state, and file uploads. The component manages local UI state while delegating persistence to the server-side thread API, enabling responsive UI updates without blocking on API responses.