Channels

A channel connects the agent to a place where people write: it receives a message, hands it to the core, and delivers the answer back, in whatever form that place understands (a card in Google Chat, a stream of events over HTTP). The core sees only the message and who sent it, never the channel, so the same agent answers the same way everywhere.

Mercury has two channels today:

• Google Chat: the agent is a Chat app people message directly or add to a space.
• HTTP: an interface for a chat you build yourself, a web page or another program, which receives the answer as it’s written.

Like plugins, a channel is active when the configuration declares it:

mercury.config.ts

channels: [googleChatChannel, httpChannel],

A declared channel with no settings stays silent and says so in the log, so you can declare one before you’ve set it up.

The terminal

mfw repl opens a terminal on the agent. It isn’t a channel: it’s a console for whoever runs the agent, there’s no login (whoever can type in it already holds the container), and it sees every tool. Use it to try things while you build, never as the way people reach the agent.

Conversations, sessions and turns

A turn is one exchange: a message comes in, the model works on it (calling tools when it needs them), and one answer goes out. A conversation is the sequence of turns the model remembers as one thread. What counts as one depends on the channel: on Google Chat, a direct message or a space is one stream, and a long silence starts a new conversation; over HTTP, the person opens as many conversations as they want and comes back to any of them, as in any chat app. Memory explains what the agent keeps of each.

Inside Mercury a conversation is a session: the history the model gets at every turn, kept under a key made of who is writing and which conversation it is, so the same conversation id sent by someone else is a session of their own. Two messages in the same session are answered one after the other, never at once; different people, and different conversations of the same person, run in parallel.

Who is writing

Every channel says who sent a message: Google Chat knows the account, the HTTP channel asks an auth provider to check the token the caller sends. People and roles explains how that becomes a person, with their own memory and permissions.