AI NPC tools and SDKs
| Tool | Best for | Pricing | Free plan |
|---|---|---|---|
| Convai | Developers who want ready-made voice NPCs with memory, actions and lip sync in Unity or Unreal | Free plan (100 interactions a month); Indie Dev $29/month ($22/month billed yearly); higher tiers up to $1,199/month (as of October 2026) | Yes |
| Inworld AI | Teams building cloud-powered talking characters who want text-to-speech, speech recognition and LLMs from one provider | Pay as you go (On-Demand, $0/month) with TTS-2 at $25 per 1M characters and speech recognition at $0.15/hour; monthly plans from $25 lower the rates (as of October 2026) | Yes |
| LLM for Unity | Unity developers who want AI characters that run offline on the player's device at no per-use cost | Open source (Apache-2.0) | Yes |
| NobodyWho | Godot developers who want offline AI characters with tool calling and speech, at no per-use cost | Open source (EUPL-1.2) | Yes |
| NVIDIA ACE | Studios building voice-driven characters that run locally on players' GPUs, in Unreal or a custom engine | Open source (MIT (Unreal plugins, Audio2Face-3D SDK); Apache-2.0 (Game Agent SDK); models under NVIDIA Open Model License or custom licenses) | – |
| Player2 | Indie developers and modders who want AI NPCs without paying for model APIs | Free for developers and players; Player2 says it pays the API costs, with free models plus daily credits for frontier models | Yes |
ConvaiTalking AI characters for Unity, Unreal and the web
Inworld AIVoice, speech and LLM APIs for AI characters
LLM for UnityRun local LLM characters inside Unity
NobodyWhoLocal LLMs for Godot NPCs and other platforms
NVIDIA ACENVIDIA models and SDKs for on-device game characters
Player2Free AI NPC APIs served through a player app
Compiled by AIGamer from each tool's own pages; we haven't tested every tool hands-on. Prices change, so check the tool's site before you buy.