Open Dungeon Master
Multiplayer D&D 5e campaigns with an AI Dungeon Master that can narrate on the Claude Code or Codex subscription you already pay for.
About Open Dungeon Master
Open Dungeon Master runs multiplayer and solo Dungeons & Dragons 5e campaigns with an AI Dungeon Master, on your own machine. The AI drives the session, requests rolls, starts encounters and plays NPCs, while server-side engines enforce the 5e rules, dice and hit points. The narrator is whichever AI you already have: a local model, an API key, or the Claude Code or Codex subscription you already pay for, signed in on the computer that runs the server.
Can you use your ChatGPT plan in Open Dungeon Master?
Yes. Your ChatGPT subscription, through Codex signed in on the server's computer. Open Dungeon Master's own page says: "Bring a local model, an API key, or the Claude Code or Codex subscription you already pay for."
How to connect your plan
Claude Pro or Max
- On the computer that runs the Open Dungeon Master server, install Claude Code and sign in.
- Start the server with npm or systemd (the Docker image needs an agent program built in).
- Pick Claude Code in Admin > Agent program; it narrates on your own subscription.
ChatGPT Plus or Pro
- On the computer that runs the Open Dungeon Master server, install Codex and sign in.
- Start the server with npm or systemd, or build the Docker image with
AGENT_PROGRAMS=@openai/codexand sign in once inside it. - Pick Codex in Admin > Agent program; it narrates on your own subscription.
