AI Sports and Race Commentators: A Two-Voice Booth

Game commentary usually means a few hundred recorded lines on shuffle, and by the third season players can finish every sentence. Neocortex lets you put two AI commentators in a booth, a play-by-play voice and a colour voice, who react to what actually happened in this race, recap the big moments and fill quiet laps with their own banter.

What it looks like

Thunderbowl Karts is an original kart racer with a season of cups on circuits built from cliffs, carnivals and canyon roads. Up in the booth sit Rory Blaze, a fast, loud play-by-play caller who loves an overtake, and Dottie Mercer, a three-time champion turned colour commentator who has seen every mistake in the book and isn't shy about naming them.

Final lap at Sugarcliff. The player has been stuck in third behind Nitro Nan for two laps. Then, at the hairpin, they dive inside her. The game sends a summarised event and forces Rory to speak first:

Rory: And there it is! The move at the hairpin, the player is up to second! Dottie: Nan left that door open twice last lap. In this sport you don't get a third invitation.

Through the long back straight nothing much happens, so the game requests an ambient turn and the booth fills it: Dottie wonders whether the leader's tyres will last, Rory recalls the crash on this same straight two races ago. After the flag, the game sends the race in four lines of summary and asks for a recap. Dottie gives her verdict on the player's driving, mostly kind, slightly smug.

One thing to plan for: commentary arrives a beat after the event. A reply has to be generated and voiced, so the booth is great at reacting, explaining and recapping, and the wrong tool for calling a photo finish on the exact frame. Keep a short recorded call or sound cue for those instants, and let the AI booth come in right after with the reaction.

How Neocortex makes it work

• Group chat. Both commentators share one conversation, so they hand off, agree and argue like a real booth (Pro and Team plans, up to six characters per chat).
• Events. Your race logic sends summarised moments as events: "the player overtook Nitro Nan for second at the hairpin", "the leader spun out at turn four".
• Ambient turns. A group chat request with no message lets the booth talk on its own during quiet laps, half-time or the walk to the starting grid.
• Forced speaker. The AI director normally picks who talks. For a big moment, set speakerCharacterId so the play-by-play voice takes the call.
• Short turns. Use maxTurns to cap how many turns the booth takes per request, so a reaction stays punchy and doesn't spill over the next overtake.
• Voices. Each commentator streams in their own voice. Custom voices, cloned from a short sample or designed from a text description like "an excitable race announcer", are on Pro (5) and Team (20).
• Emotions. Every line carries an emotion tag, so your booth animations or on-screen graphics can match Rory's excitement.
• Languages. Characters speak more than 20 languages, so the same booth can commentate in each player's language.
• Session memory. Keep one session per cup or season and the booth can call back to earlier races in it.

Ideas to build

Match day in a football manager. Your match engine simulates the game and sends key events: goals, cards, substitutions, a shot off the post. The booth reacts to each, then at half-time the pundit questions the player's tactics. Nobody needs a frame-perfect call when the match is a simulation.

Esports-style replays. After a round in a tactical shooter, the player watches a replay with commentary built from the round's event log. Latency stops mattering in a replay, so you can feed events a few seconds ahead of the playback and the commentary lands with the action.

A fighting game announcer. One big voice between rounds. The announcer introduces the fighters, reacts to how the last round went ("she hasn't blocked a low kick all night") and hypes the deciding round. The knockout call itself stays a recorded line.

The pit wall on team radio. A single race engineer, not a booth, talks to the player over the radio. The game sends lap times, tyre wear and gaps as events, and the player can ask questions back. A single character works on every plan.

Building it

The booth runs through the Unity SDK, the Unreal Engine plugin, the Godot addon (beta), or the Web API from any engine. Your race or match logic stays the source of truth; the booth only describes it.

1. Design two commentators with contrasting personalities, a voice each and a shared knowledge of your league: drivers, circuits, rivalries.
2. Decide what is worth a call. Pick a handful of event types, like overtakes, crashes, final laps and records, and summarise each in one sentence.
3. Send events and request turns, forcing the play-by-play voice for big moments and letting the director pick otherwise.
4. Fill the gaps with ambient turns on a timer when nothing has happened for a while.
5. Keep instant calls recorded, like the finish-line shout, and let the booth react right after.
6. Test a race in the dashboard's group preview, feeding events by hand to tune timing and tone.

A big-moment call:

const res = await fetch("https://api.neocortex.link/v3/chat", {
  method: "POST",
  headers: {
    "x-api-key": apiKey, // load from your own config, never hard-code it
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    characterIds: [rory, dottie],
    sessionId,               // one session per cup
    speakerCharacterId: rory, // the play-by-play voice takes this one
    events: [{ priority: 1, content: "Final lap: the player passed Nitro Nan at the hairpin for second" }],
    // no "message": the booth reacts on its own
  }),
});
const { sessionId: next, messages } = await res.json();

Drop stale events. If an overtake happened ten seconds ago and another just happened, send only the newest, so the booth always talks about the present.

Commentators are one of our AI NPC, ambient AI and voice command use cases. For crowds and towns that react to the same events, read NPCs that react to world events, and for background talk between characters, see ambient NPC conversations. The dynamic characters page and the group chat docs cover the rest. Start with one booth, one race and three kinds of event.

Checked October 2026.

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