Say Hello to the Player2 NPC API

Conversation History Simplified 🚀

We just shipped a brand-new set of NPC endpoints for the Player2 developer platform. If you’ve ever wrestled with rolling your own conversation buffer, counting tokens, or retrying requests when your in-game AI buddy got too chatty, you can breathe easy: we’ll do it all for you now.

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What’s in the box?

Endpoints:

• Spawn an NPC
  POST /npc/games/{game_id}/npcs/spawn
  Spin up an LLM-powered NPC on the client.

• Chat with an NPC
  POST /npc/games/{game_id}/npcs/{npc_id}/chat
  Send a single chat line to that NPC.

• Stream NPC replies
  GET /npc/games/{game_id}/npcs/responses
  Receive the model’s replies as an SSE stream.

• Despawn an NPC
  POST /npc/games/{game_id}/npcs/{npc_id}/kill
  Cleanly remove the NPC when you’re done.

No more manually assembling chat histories or juggling token counts—just hit chat and keep playing.
(Full schema in the bundled OpenAPI spec under the NPC tag.)

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Real-world cleanup: AI Gods before & after

Old flow
Our sample mod used to maintain a ConversationHistory object, merge prompts, and orchestrate a multi-step CompletableFuture dance on every player message:

updateNewCharacter(mod)
    .thenComposeAsync(newChar -> {
        String processed = mod.addPlayerStatusToUsrMessage(rawMsg);
        mod.addProcessedUserMessage(processed);
        return CompletableFuture.supplyAsync(() -> {
            return Player2APIService.completeConversation(mod.getConversationHistory());
        }, IO_POOL);
    })
    .thenAcceptAsync(resp -> {
        // 30+ lines of post-processing…
    });

New flow
With the NPC API, the entire history-management layer is gone—just two lines:

String playerName = mod.player.getName().getString();
Player2APIService.completeConversation(rawMsg, playerName);

That’s ~40 lines → 2, and a whole category of bugs wiped out.

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We foot the cloud bill, you ship gameplay

• Usage credits, not API keys
  Players top-up inside the Player2 desktop app—no proxying or rate-limiting on your end.

• Predictable costs
  We meter tokens, voices, and STT per end-user, so you won’t get surprise invoices.

• Zero-config scaling
  Whether you spawn one villager or one hundred, we handle concurrency for you.

Focus on epic boss prompts, emergent quests, or NPC gossip—we’ll handle the boring stuff.

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Try it today

1. Download the Player2 Client and explore the Swagger UI at http://127.0.0.1:4315/docs.

2. Check out the AI Gods PR #6 for a concrete migration path.

3. Ship something cool and share it on our Discord.

Happy hacking—and we can’t wait to see the NPC antics you build!