Assistant UI Svelte Project 2025

Project Overview

What I Built

I built a Svelte 5 + SvelteKit 2 scaffold for a ChatGPT-style chat interface: sticky, pill-shaped composer; a scrollable message thread with clear user/assistant alignment; smooth auto-scroll to the latest message; and accessible, keyboard-friendly interaction. The experience mirrors ChatGPT’s proven UX so it feels familiar and intuitive.

Beyond the surface UI, it is intentionally designed as a standalone, reusable foundation that can plug into any conversational AI or agent backend. The layout and component architecture are structured for streaming APIs, richer message rendering, and multi-turn state. It draws heavy inspiration from assistant-ui and is tailored for reuse in my other work, notably DOC_Project_2025.

Why I Built It

• Skill goal: Learn Svelte while creating a production-ready chat UI scaffold.
• Practical goal: Build a reusable, well-structured component library for future LLM-powered tools.

Current Status

The ChatGPT-style framework is complete and running locally, with:

• Scrollable message list and sticky-bottom composer
• Auto-scroll on new messages
• Accessible, keyboard-friendly input
• Visual consistency between empty and active states

Responses are currently mocked—the architecture is ready for a streaming LLM backend.

Challenges and How I Solved Them

• Keeping the composer fixed while allowing scrollable content: Solved with a two-row CSS Grid and position: sticky shell.
• Reliable auto-scroll to latest message: Used Svelte runes ($effect) to update scrollTop on messages change.
• Preventing empty sends & ensuring keyboard focus: Added a conditional disabled state and explicit focus handling.
• Maintaining visual consistency between empty and chat views: Reused composer styles across both UI states.
• ARM64 Windows dependency warnings: Implemented a clean reinstall flow (clear cache, remove lockfile and node_modules, reinstall).

Future Possibilities

• Real LLM/agent backend with streaming
• Theme system (dark mode, high-contrast mode)
• Persistent conversations (LocalStorage, IndexedDB, or server DB)
• Rich message rendering (Markdown, syntax highlighting, file attachments)
• Advanced keyboard UX (shortcuts, multi-line editing, resend)
• Testing suite (Vitest, Playwright) + CI/CD pipeline

TL;DR

A reusable Svelte 5 + SvelteKit 2 ChatGPT-style chat UI (sticky composer, scrollable aligned thread, auto-scroll, a11y) designed to plug into real LLM/agent backends; currently mocked but architected for streaming, richer messages, and multi-turn state—ready to reuse across projects like DOC_Project_2025.

Project Duration: August 2025
Technologies: Svelte 5, SvelteKit 2, Vite 7, TypeScript, Less, Node.js, npm, Git