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. You can stop at a vendor's stall, but you cannot ask them anything. A Cyberpunk 2077 AI NPC mod built on Neocortex fixes that: street vendors and fixers answer the player in their own words, your car and holo-calls respond to voice commands, and a netrunner runs a quiz in a back room. This guide walks through one complete gig first, then the rest.

Screenshot: Cyberpunk 2077 © CD PROJEKT RED

Who this Cyberpunk 2077 AI NPC mod guide is for

PC modders who want NPCs that talk, and who are comfortable writing Lua or a compiled scripting language. If you have installed Cyber Engine Tweaks mods before, you have already met most of the stack below. If you have not, the Cyberpunk 2077 modding wiki documents all of it.

The Cyberpunk 2077 modding stack

Cyberpunk 2077 has a mature set of community frameworks:

• 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.
• RedHttpClient is a RED4ext plugin that sends HTTPS requests from Redscript and CET. RedData adds JSON support. Together they are the web-request layer a talking NPC needs.

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. Community mods have already wired chat AI into Night City through CET, which shows the stack can carry it.

A gig with Rook Varga, start to finish

Rook Varga is an original fixer who works out of a Kabuki back room and sizes the player up before offering work. In the Neocortex node editor, Rook gets a Personality, an Emotion profile, Knowledge, a Voice and the Actions your mod handles. You can test the whole conversation in the browser for free before writing a line of Redscript.

A Conversation Flow keeps Rook on script for the side gig: the pitch, the haggling, the deal and the payout. The player can talk freely, and each beat returns a checkpoint keyword (flowState) your Redscript code reacts to.

Your mod sends each line to /v3/chat 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. A Redscript call 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
  }
}

Replies come back with lines your mod shows as subtitles and plays as voice from /v3/audio/generate or /v3/audio/stream. 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.

Screenshot: Cyberpunk 2077 © CD PROJEKT RED

Vendors, voice and a netrunner quiz

The Kabuki noodle vendor

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. The same chat call that drives Rook drives the vendor.

Car and holo-call commands

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, with no cloud round trip. 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.

Sable's quiz at the Afterlife

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 through /v3/quiz. Your mod pays out eddies for a clean run.

Patches, CDPR's rules and fair play

Every major game patch can break the core frameworks, so check their pages after an update and retest on a separate save.

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.

Next steps

1. Install the frameworks: RED4ext, Cyber Engine Tweaks and Redscript, plus RedHttpClient and RedData for networking and JSON.
2. Design Rook in the Neocortex node editor and test the gig in the browser for free.
3. Add the extras you want: the gig's Conversation Flow, a quiz question set for Sable, 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.

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. Then open the Neocortex editor and give Rook a voice.

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

Frequently Asked Questions