Cyberpunk 2077 AI NPC Mod: Talking Fixers and Voice Commands

Night City is packed with people, and almost none of them will hold a conversation. A Cyberpunk 2077 AI NPC mod built on Neocortex lets street vendors and fixers answer the player in their own words, adds voice commands for your car and holo-calls, and runs a netrunner quiz in a back room. Here is what you could build and how it fits on top of Cyber Engine Tweaks, RED4ext and Redscript.

Screenshot: Cyberpunk 2077 © CD PROJEKT RED

What you could build with Neocortex in Cyberpunk 2077

Street vendors and fixers you can talk to

Start with a noodle vendor in Kabuki who knows every rumor on the block. Give them a Personality type, an Emotion profile and a Knowledge base from a TXT file of local gangs, prices and gossip. Then add an original fixer, say Rook Varga, who works out of a Kabuki back room and sizes the player up before offering work. Your mod sends each line with recent events ("the player just fought off Tyger Claws", "street cred went up") and nearby objects such as a vending machine or a parked car. Replies come back in voice, every line carries an emotion tag like ANGRY or CURIOUS, and actions like { "name": "OPEN_DOOR", "targetId": "door_02" } or SHOW_SHOP tell your mod what to run.

A Conversation Flow keeps Rook on script for a side gig: the pitch, the haggling, the deal and the payout, each returning a checkpoint keyword your Redscript code reacts to.

Voice commands for the car and holo-calls

Design a command set with actors ("car", "phone", "radio"), actions ("bring", "call", "open", "play") and objects ("my car", "my fixer", "the trunk", "the next station"). Players say "bring my car" or "open the trunk and call my fixer", and your mod receives clean commands, including several actions in one sentence. It works push-to-talk or always-listening, offline, in multiple languages, using the Neocortex Voice Commands library on the player's machine. Our post on on-device voice commands for game mods explains the approach. Voice Commands is a licensed SDK: contact us for a Voice Commands license.

A netrunner quiz

At a table in the Afterlife, an original netrunner called Sable runs a quiz on quickhacks, cyberware and Night City's corps. The question set lives in the Neocortex dashboard and the quiz engine (Team plan) handles questions, scoring and the leaderboard. Your mod pays out eddies for a clean run.

How Cyberpunk 2077 modding works

Cyberpunk 2077 has a mature set of community frameworks, documented on the Cyberpunk 2077 modding wiki.

• Cyber Engine Tweaks (CET) lets you script mods in Lua, with access to game types and functions, a console and a Dear ImGui overlay that is handy for prototype UI. It requires RED4ext.
• RED4ext is the script extender that loads native C++ plugins and provides the SDK for extending the engine.
• Redscript is a compiled scripting language that works with the game's own scripting runtime, so you can hook game classes directly.
• ArchiveXL loads custom resources, such as new appearances or UI assets for your characters, without replacing existing files.

For web requests, scripts use a helper plugin: RedHttpClient is a RED4ext plugin that sends HTTPS requests from Redscript and CET, and RedData adds JSON support. Subtitles can start in a CET overlay and move to native-looking widgets with Redscript. Generated voice needs native audio playback, which belongs in a RED4ext plugin next to the network code. Every major game patch can break the core frameworks, so check their pages after an update. Community mods have already wired chat AI into Night City through CET, which shows the stack can carry it.

Screenshot: Cyberpunk 2077 © CD PROJEKT RED

How Neocortex fits in

• Dialogue. The mod reads game state and sends it to a Neocortex character through /v3/chat, shows the reply as subtitles, plays the voice from /v3/audio/generate or /v3/audio/stream, and runs the actions the character returns.
• Story beats. Conversation Flows steer gigs and scenes, returning checkpoint keywords (flowState) the mod reacts to.
• Quizzes. The quiz engine runs question-and-answer games through /v3/quiz.
• Voice commands. On-device voice commands turn spoken phrases into game actions without a cloud round trip.

A Redscript call to /v3/chat with RedHttpClient and RedData could look like this:

import RedHttpClient.*
import RedData.Json.*

public class FixerChat {
  let apiKey: String; // read from the player's config file
  let sessionId: String;
  public func Say(characterId: String, line: String) {
    let ids = new JsonArray();
    ids.AddItemString(characterId);
    let body = new JsonObject();
    body.SetKey("characterIds", ids);
    body.SetKeyString("message", line);
    body.SetKeyString("playerId", "player-1");
    body.SetKeyString("sessionId", this.sessionId);
    let headers: array<HttpHeader> = [HttpHeader.Create("x-api-key", this.apiKey)];
    AsyncHttpClient.PostJson(HttpCallback.Create(this, n"OnReply"), "https://api.neocortex.link/v3/chat", body, headers);
  }
  private cb func OnReply(response: ref<HttpResponse>, data: array<Variant>) {
    let reply = response.GetJson() as JsonObject;
    this.sessionId = reply.GetKeyString("sessionId"); // then read "messages" for lines and actions
  }
}

Getting started with your Cyberpunk 2077 AI NPC mod

1. Install the frameworks. RED4ext, Cyber Engine Tweaks and Redscript, plus RedHttpClient and RedData for networking and JSON.
2. Design the character in the Neocortex node editor: Personality, Emotion, Knowledge, Voice and the Actions your mod handles. Test it in the browser for free.
3. Add the extras: a Conversation Flow for a gig, a quiz question set for the netrunner, or a car and phone command set.
4. Connect from Redscript or CET, prototype subtitles in a CET window, then polish the UI.
5. Keep the API key in a config file each player fills in. Never put your key in a mod you share.
6. Test on a separate save and retest after each game patch.

Mod policy and fair play

CD Projekt Red's Fan Content Guidelines allow mods that respect the game's EULA, and they rule out selling mods or putting them behind a paywall. Cyberpunk 2077 is single-player, so keep your mod free, non-commercial and out of anyone else's game. Use a designed voice or one you own the rights to, and have each player use their own Neocortex API key.

Start with our foundation post on on-device voice commands for game mods, see how the same ideas work in the Fallout 4 AI NPC mod guide, or browse every game in our AI NPC and voice command mods index.

Tool versions and links checked October 2026. Modding tools change often; check each project's page for the latest release.

Frequently Asked Questions