Skyrim AI NPC Mods: Mantella, CHIM, SkyrimNet

AI NPC mods let you talk to Skyrim's characters out loud and hear them answer in voice, with memories of what you did together. The three big ones in 2026 are Mantella, CHIM and SkyrimNet. Be clear about what they are: mods for players on PC, not tools for making games, and not something we sell or earn from. They connect Skyrim to a language model you choose and a voice engine. This guide compares them using each project's own pages and docs, checked on October 18, 2026.

Side by side

Mantella

What it does

Mantella lets you have real-time voice conversations with NPCs by chaining speech-to-text, a language model and text-to-speech. Its docs say over 3,000 NPCs have their own background descriptions, NPCs remember past conversations (a summary is saved per NPC), and they can perform 20+ actions. With a vision-capable model, a screenshot of your game is passed to the model each time you reply. Idle NPCs can start "radiant" conversations with each other, and you can talk to up to 5 nearby NPCs in a group conversation. It supports 20+ languages.

Requirements

Mantella requires Windows 10 or 11, the Skyrim Script Extender (SKSE) and a list of support mods on its install page. It's fully playable on Skyrim SE, AE (up to version 1.6.1170) and VR, and has a separate Fallout 4 install guide. Required mods include Address Library, FonixData (for lip sync), SkyUI, UIExtensions and the Microsoft Visual C++ Redistributable. The docs also say Skyrim shouldn't be installed under Program Files, Mantella must load after the Unofficial Skyrim Special Edition Patch if you use it, and "No NPC Greetings" is recommended so vanilla lines don't interrupt.

Costs you can verify

The mod is free and open source. The quick start has you create a free OpenRouter account and paste an API key. The v0.14 release (April 21, 2026) switched the default model to a free Gemma 4 model, and the docs list "Gemma 4 26B A4B (free)". You can pick other free or paid models on OpenRouter, use OpenAI, or run a local model with koboldcpp. Voices: Piper is bundled and local (English only). xVASynth and XTTS are optional, and the docs list external XTTS on RunPod "from $0.14/hr" with a $10 minimum credit purchase.

Limits

The docs warn that smaller models may struggle with long conversations and memory summaries. They also note a reported crash when used with Fuz Ro D'oh, and that the bundled local XTTS exe doesn't work with NVIDIA 5000-series GPUs (there's a separate workaround).

CHIM (formerly Herika)

What it does

CHIM, by Dwemer Dynamics, describes itself as "a large AI framework for Skyrim built around meaningful gameplay with NPCs". NPCs around you can be added to the AI system automatically, including vanilla NPCs, modded NPCs, followers and even horses. You can talk by microphone or type in an in-game chat box. CHIM uses biographies and profile data to keep each NPC's roleplay grounded, and you can customize personalities, voices and behavior per NPC or per profile. Through actions and Director Mode, NPCs can carry out requests, and you can start and advance supported vanilla quests through dialogue. The CHIM Interact power lets you describe what you do to a person or object. Modders can plug their own mods in with custom biographies and roleplay rules.

Herika is retired

The Herika Nexus page says "THIS MOD IS NO LONGER SUPPORTED" and points to CHIM. CHIM is maintained by the same team, Dwemer Dynamics.

Requirements

CHIM has two parts. The first is the DwemerDistro server, a WSL2 Linux environment you install once; you need virtualization enabled in your BIOS and the Windows features Virtual Machine Platform, Windows Hypervisor Platform and Windows Subsystem for Linux turned on. The second is the AIAgent SKSE plugin, installed with your mod manager, which needs Address Library, ConsoleUtilSSE NG, PapyrusUtil, powerofthree's Papyrus Extender, SSE Display Tweaks, SkyUI, UIExtensions, Prisma UI and Media Keys Fix SKSE. Skyrim VR has its own requirement list. The install guide offers GPU components (CUDA, Chatterbox, Pocket-TTS) depending on how powerful your NVIDIA GPU is.

Costs you can verify

The mod is free. CHIM's install guide assumes you use OpenRouter for the language model, lists "($5)" next to it, and calls OpenRouter "by far the easiest way" to set up the first time. You can switch to other AI services later. Setup also offers a local Player2 connector instead of an OpenRouter key.

Limits

It's the heaviest setup of the three. Nexus's virus-scan field for CHIM shows "Some suspicious files", and CHIM's install guide says antivirus programs often false-flag less popular .exe files like its launcher, and that the launcher's source code is on GitHub. Download only from the official Nexus page or the developers' site.

SkyrimNet

What it does

SkyrimNet gives NPCs natural voice or text conversations, memories recalled by meaning (a local vector memory), awareness of their surroundings through game data and on-screen vision ("OmniSight"), and an extensible action system: follow, fight, trade, sing and more. Its site says over 3,000 characters come with hand-written personalities, and everyone else gets one generated automatically. For modders, it can be extended in Papyrus or C++, driven from an MCP server with 50+ tools, and extended with community plugins.

Requirements

SkyrimNet is a native Windows DLL that loads inside Skyrim as a single SKSE plugin, with "No WSL. No Python launcher." It needs Skyrim SE/AE/VR with SKSE, Address Library, Papyrus Extender, PapyrusUtil, Prisma UI and a few more mods listed on GitHub. A local dashboard at localhost:8080 handles characters, memories, events and voices.

Costs you can verify

The site lists it as free for Windows. You bring an OpenRouter key, any OpenAI-compatible endpoint or a local model. SkyrimNet lets you assign different models to different jobs, such as a fast, cheap model for picking actions and a smarter one for dialogue. Piper is the default voice and runs on the CPU with no GPU needed. Optional engines include PocketTTS, XTTS, Chatterbox and Zonos (on your PC or a rented cloud GPU), Kokoro (narrator only), and the ElevenLabs and Inworld cloud APIs. An optional VastAI page can rent a cloud GPU for heavier voice models.

Limits

Its GitHub page says vanilla quest dialogue trees still run through Skyrim's normal system, and integrating the two is on the roadmap.

Step-by-step: getting started

1. Use the PC version of Skyrim SE, AE or VR, and install SKSE plus a mod manager such as Mod Organizer 2 or Vortex.
2. Pick one AI NPC mod. Don't stack Mantella, CHIM and SkyrimNet in the same load order.
3. Install the requirements listed on that mod's own install page, in the order it gives.
4. Set up the language model. Create an OpenRouter account and API key (or set up a local model), and start with a free model to see how it feels.
5. Choose a voice engine. Start with the default local option (Piper) before you pay for cloud voices.
6. Test in a new save, then tune response speed and memory settings.
7. Watch your spending. If you switch to paid models, set a limit with your AI provider.

Example things to say in game

These are examples of the kind of conversation the mods are built for, not lines from their docs.

• "Lydia, wait here. I'm going in alone." (SkyrimNet's homepage shows a similar exchange.)
• "What do you think of the war between the Stormcloaks and the Empire?"
• "Follow me to Riverwood, and tell me if you see anything strange."
• "Do you remember what happened at Bleak Falls Barrow?"

The rules: Nexus, voices and consent

On Nexus, AI dialogue and voices fall under the AI-Generated Content tag, and CHIM's Nexus page carries it. Nexus says AI content isn't against its rules, but it may be removed after a credible complaint from the affected voice actor or rights holder, and it asks modders to avoid AI voice acting unless they have explicit permission. That matters most if you share voice packs or recordings. Some voice engines these mods support can clone voices from samples, which is exactly the kind of use voice actors objected to in 2023. If you use a cloud voice service, its rules apply too: ElevenLabs, for example, bans cloning a living person's voice without consent. For the full set of platform rules, see AI tools for game modding and the rules.

Common mistakes

• Looking for these on Xbox or PS5. They're built on SKSE for PC.
• Installing the retired Herika instead of CHIM.
• Running two AI NPC frameworks at once.
• Picking a large paid model on day one, before checking what a free or cheap model gives you.
• Skipping a mod's listed requirements, such as Prisma UI, PapyrusUtil or Address Library.
• Sharing clips or voice packs that imitate real actors without permission.

Which should you pick?

• First time, want it free: Mantella, with its default free model and Piper voice.
• Want the most gameplay systems: CHIM, if you're comfortable setting up a WSL2 server.
• Want the lightest install and fine control over models: SkyrimNet.
• Making your own voiced characters to share instead: use original voices from ElevenLabs or a live NPC platform like Inworld. Compare them in the best AI tools for game audio.

Modding Minecraft instead? See the best AI Minecraft mod makers. Building your own game with talking NPCs? Browse AI voices and NPC dialogue tools or Convai.