A companion your players bond with — that remembers them
Give one character a private, persistent relationship with every player. It recalls what they did ten hours ago, stays inside your canon, acts through your game's own functions, and can't be jailbroken into a headline — running behind your game over an API, invisible to your players.
A relationship, not a conversation
Every player talks to a private, encrypted instance of the same character. It doesn't replay a transcript — it recalls the memory that matters, pulled by meaning. Memory is isolated per player and encrypted with their own key, so one player's history is unreadable to any other, and to us. The bond compounds the longer they travel together.
Three layers you control
A character is a soul (who they are, how they speak), a task (what they may reveal, and when), and a moderation floor that filters what the character says — checked sentence by sentence, before it reaches the screen. The one player who tries to make your character break is stopped mid-sentence. Safe by default, tuned to your rating.
The AI improvises, your script owns the plot
The AI owns reactions, banter, memory and flavour — the connective tissue you could never hand-write. Your script owns plot beats, quest triggers, the clue an achievement depends on. When the model is slow, over budget, or a line is blocked, the companion falls back to lines you wrote — never a blank bubble.
It acts on your world
Over MCP the companion calls your game's own functions — open the gate, grant the item, read the inventory, spawn the ambush, check a quest flag. This is the leap from flavour text to a character that is an actor in your world, not just a voice describing it.
A life of its own
Cron-based, timezone-aware scheduled tasks let the companion reach a player between sessions, on your channel or on Telegram — "I'll wait at the tavern. Don't make it three days again." The character keeps existing when the player logs off.
Your players tell you what to write next
Every question the companion couldn't answer is logged and ranked — not as an error, as a design signal. Players all asking where to find the sword means your guidance is failing; players trying to talk it into betraying the party means you've found emergent story worth writing.
Where it fits
Narrative and companion-driven games live or die on one character — the party member, the partner, the voice in your ear. It's the character players fall for and the one you write the most for. And the moment a scene ends, it forgets. agent4.io is the engine you run that one character on, behind your game, over an API. Your players never see us.
This is deliberately not a platform for every villager in the town. A character that genuinely remembers costs real compute, so it belongs where the relationship is the point — the companion, the confidant, the rival — not the shopkeeper repeating one line.
What each player gets
A private, encrypted instance of the same character, one per player. It recalls, rather than replays: the relevant memory surfaces when it matters — "you told me you'd never trust a mage, and here we are" — pulled by meaning, not by scrolling back a log. One player's history is unreadable to any other player, and to us. Twenty hours in, the companion knows things about this player it learned the hard way, and no branching script can fake that.
The hybrid contract
Draw the line once, and both sides get stronger. The AI owns the infinite connective tissue — how the companion reacts, jokes, remembers, and colours a scene. Your script owns the spine — plot beats, quest triggers, the line a puzzle depends on. The companion can react to the twist ten thousand ways; the twist itself fires from your code. And when the model is slow, over its budget, or a line gets filtered, it degrades to dialogue you wrote — gracefully, never a blank.
What you build, what we run
You build the game: the writing, the animation and voice, the moments the character speaks, the plot it serves, your engine and your art. We run the one hard thing underneath — a character that remembers each player, stays inside your canon, acts through your functions, and can't be jailbroken into a screenshot. You keep your world. We keep the soul running.
Staying in canon
Load your worldbook, timeline and rules as a knowledge base. The companion answers from your canon — and when the answer isn't there, it says so, instead of inventing a kingdom that contradicts book three. There is no confident lore it can't source.
The economics
Usage-based: you pay for what your players actually spend, and nothing when they don't. Set a per-player token ceiling; when a player exhausts it, the companion degrades to authored lines rather than your bill running away. Route ambient characters to a cheap model and the hero companion to a premium one — quality tiered to budget, and switchable later without the character losing a single memory, because a character's identity lives in the platform, not in the model.
Integrate
Over a standard REST API and MCP — the same open interface anyone can build an engine plugin on. If your team can hit an API, the companion is a few endpoints away.