Toast when action complete with actual files modified. Windows only and requires toast.exe on path. https://github.com/shanselman/toasty

opencode-toast.ts

import type { Plugin } from "@opencode-ai/plugin";

// Plays a small toast when OpenCode goes idle.
// Customize the command, title, and messages with OPENCODE_BELL_* env vars.

declare const process: {
    env: Record<string, string | undefined>;
};

type OpenCodeEvent = {
    type?: string;
    properties?: {
        filesModified?: number | readonly unknown[];
        files?: number | readonly unknown[];
    };
};

type NotificationConfig = {
    command: string;
    title: string;
    taskCompleteMessage: string;
    idleMessage: string;
};

const DEFAULT_CONFIG: NotificationConfig = {
    command: "toasty.exe",
    title: "OpenCode",
    taskCompleteMessage: "Task complete",
    idleMessage: "Idle prompt",
};

function readNotificationConfig(): NotificationConfig {
    const env = process.env;

    return {
        command: env.OPENCODE_BELL_COMMAND?.trim() || DEFAULT_CONFIG.command,
        title: env.OPENCODE_BELL_TITLE?.trim() || DEFAULT_CONFIG.title,
        taskCompleteMessage:
            env.OPENCODE_BELL_TASK_COMPLETE_MESSAGE?.trim() || DEFAULT_CONFIG.taskCompleteMessage,
        idleMessage: env.OPENCODE_BELL_IDLE_MESSAGE?.trim() || DEFAULT_CONFIG.idleMessage,
    };
}

function hasChanges(value: number | readonly unknown[] | undefined): boolean {
    if (typeof value === "number") {
        return value > 0;
    }

    return Array.isArray(value) && value.length > 0;
}

function selectNotificationMessage(
    files: number | readonly unknown[] | undefined,
    config: NotificationConfig,
): string {
    return hasChanges(files) ? config.taskCompleteMessage : config.idleMessage;
}

export const OpenCodeToast: Plugin = async ({ $ }) => {
    const config = readNotificationConfig();

    return {
        event: async ({ event }) => {
            const e = event as OpenCodeEvent;

            if (e.type !== "session.idle") {
                return;
            }

            const props = e.properties ?? {};
            const files = props.filesModified ?? props.files;
            const message = selectNotificationMessage(files, config);

            await $`${config.command} ${message} -t ${config.title}`.quiet().nothrow();
        },
    };
};