Channel Types

Type definitions for channels, external channels, and channel handles in Noetic.

Channel

A typed communication channel for inter-step message passing.

interface Channel<T> {
  readonly name: string;
  readonly schema: ZodType<T>;
  readonly mode: 'value' | 'queue' | 'topic';
  readonly capacity?: number;
}

Field	Type	Required	Description
`name`	`string`	yes	Unique channel name
`schema`	`ZodType<T>`	yes	Zod schema for message validation
`mode`	`'value' \| 'queue' \| 'topic'`	yes	Channel semantics
`capacity`	`number`	no	Maximum buffered messages (for queue/topic modes)

Channel Modes

Mode	Behavior
`'value'`	Holds a single value. New sends overwrite the previous value.
`'queue'`	FIFO buffer. Sends enqueue, receives dequeue.
`'topic'`	Pub/sub broadcast. All receivers get every message.

ExternalChannel

An external channel extends Channel with an external flag, enabling cross-process communication.

interface ExternalChannel<T> extends Channel<T> {
  readonly external: true;
}

Field	Type	Required	Description
`name`	`string`	yes	Unique channel name
`schema`	`ZodType<T>`	yes	Zod schema for message validation
`mode`	`'value' \| 'queue' \| 'topic'`	yes	Channel semantics
`capacity`	`number`	no	Maximum buffered messages
`external`	`true`	yes	Marks channel as externally accessible

ChannelHandle

A handle for sending messages into a channel from outside the agent execution context.

interface ChannelHandle<T> {
  send(value: T): void;
  readonly closed: boolean;
  readonly channel: Channel<T>;
}

Field	Type	Description
`send`	`(value: T) => void`	Send a value into the channel
`closed`	`boolean`	Whether the handle is closed (execution completed)
`channel`	`Channel<T>`	Reference to the underlying channel

Context Channel Methods

The Context object provides three methods for channel interaction:

interface Context {
  send<T>(channel: Channel<T>, value: T): void;
  recv<T>(channel: Channel<T>, opts?: { timeout?: number }): Promise<T>;
  tryRecv<T>(channel: Channel<T>): T | null;
}

Method	Description
`send(channel, value)`	Send a value to the channel. Non-blocking.
`recv(channel, opts?)`	Receive a value. Blocks until available or timeout.
`tryRecv(channel)`	Non-blocking receive. Returns `null` if no value available.