Meet your Castmates.
Chat and roleplay with a cast of AI characters — right on your iPhone. Private by design, running entirely on-device. No accounts, no servers, no one watching.
Free during early access · iPhone · No sign-up
Detective Cross
Noir investigator · online
The lights were off when I got here. You expecting someone?
Cross leans against the doorframe, rain dripping from his coat. "Depends. You always answer questions with questions?"
Only the dangerous ones.
Why Castmates
Your imagination, in good company
A roleplay app that respects your privacy and never breaks character.
Private by design
Every conversation runs on-device. Nothing is sent to a server, there are no accounts, and your stories never leave your phone.
A cast of characters
Start with 32+ hand-crafted characters across genres — detectives, dragons, companions, villains — each with their own voice and backstory.
Create your own
Design custom characters with their own persona, tone, and world. Bring anyone you can imagine into the conversation.
They remember you
Persistent memory means your Castmates recall what happened across sessions, so the story keeps building every time you return.
Works offline
Because the model lives on your device, Castmates keeps going on a plane, on the subway, or anywhere with no signal.
Built for roleplay
Immersive, in-character responses with actions and scene-setting — not a chatbot pretending. The cast stays in role.
The cast
32 characters at launch — and counting
Every one hand-written with a distinct voice. Meet a few of them.
Detective Cross
Noir investigator
Kael
Ancient dragon
Countess Elise
Scheming aristocrat
Captain Morgan
Pirate legend
Dr. Voss
Rogue scientist
Yumi
Cheerful artist
Seraphina
Fallen knight
Zix
Curious android
Jack Sterling
Faded rockstar
Lyra
Wandering oracle
…plus companions, villains, historical figures, and anyone you create yourself.
Be first to meet the cast
Join the waitlist for early access to Castmates on iOS. We'll email you the moment it's ready — nothing else.
No spam. Unsubscribe anytime.