Talk to an NPC that thinks up its lines on the spot. AI NPC Kit puts an NPC you can actually converse with into your VRChat world. Both the NPC's lines and the reply choices you pick from are generated by an AI every time, so no two conversations are the same. A receptionist for your lobby, a quest giver for your adventure map, a bartender with a personality. HOW IT WORKS - VRChat world (Udon) -> your own Cloudflare Worker -> the LLM (Claude by default, or any OpenAI-compatible API) - No client mods, no OSC, no bot accounts: it runs entirely as world content - Conversation memory, the NPC's persona and cost protection live in the Worker - The player interacts and picks one of up to 4 generated replies (2 to 4, configurable); only the speaker talks to the server and the result is synced to everyone, late joiners included FEATURES - Persona in one line of config ("shy librarian", "gruff gatekeeper", "cheerful merchant" ...) - Daily request cap, per-conversation turn limit and per-IP rate limit protect your API bill - Two adapters: Anthropic (default: claude-haiku-4-5, structured output for reliable JSON) and OpenAI-compatible (OpenAI, Groq, local llama.cpp ...) - Setup window in Unity (NipaShop > AI NPC Setup, English / Japanese): "Generate Sample NPC In Scene", then "Generate And Bake URL Pool" - Replace the sample capsule with any model you like REQUIREMENTS - Unity 2022.3.22f1 / VRChat SDK3 Worlds / UdonSharp (bundled with the SDK) - A Cloudflare account (free plan is enough) - An Anthropic API key (recommended) or an OpenAI-compatible API key. API usage is paid by you; with the default claude-haiku-4-5 a conversation costs well under one cent - Visitors need "Allow Untrusted URLs" enabled in VRChat settings (the NPC tells them if it is off) INSTALL (about 10 minutes) 1. npm i -g wrangler, then wrangler login 2. In the server folder: wrangler deploy, then wrangler secret put API_KEY 3. Import the unitypackage, open NipaShop > AI NPC Setup, paste your Worker URL 4. Generate the sample NPC, bake the URLs, swap in your model 5. Build & Test, enable Allow Untrusted URLs, and talk to the NPC NOTES - Udon cannot create URLs at runtime, so free text input is not possible; the kit uses AI-generated reply choices instead. The dialogue itself is fully generated. - String Loading is limited to 1 request per 5 seconds per client; the kit has a built-in cooldown. - Your API key never leaves the Worker (stored as a secret). The world contains no secrets. - Tested on PC. Quest (Android) is supported by design but not verified on device. - AI output cannot be guaranteed. Use within your persona settings and the moderation rules of your LLM provider. - Future changes to VRChat or the LLM providers may affect operation. CONTENTS - AiNpcKit.unitypackage (Udon scripts + setup window) - server/ (Cloudflare Worker: wrangler.toml, src/index.js) - README_EN.txt (setup, persona editing, troubleshooting) - LICENSE_EN.txt LICENSE - See the included license. Modifying it and embedding it in your own worlds (public included) is fine. Copying, transferring, uploading or reselling the kit itself is prohibited. - The author is not liable for API charges or any damage arising from use.