Herald: designable notifications for macOS

Herald: designable notifications for macOS

What it is

A Growl-style notification service for the Mac. Apps, scripts and AI agents send notifications; Herald draws persistent, interactive banners that you design.

What it does

An app declares the data it can send, and you lay out on a grid exactly how its banners look: text, images, badges, progress, Rive animation and buttons. Banners stay until you deal with them, sit above everything and never steal focus. Every banner, spoken message and action goes into a searchable per-app history, and replies (typed or recorded, with a transcript) go back to the sender.

Features

• Grid-based banner designer with nine alignment points; stacks and per-app grouping
• Actions: URLs, callbacks, commands, scripts and Apple Shortcuts; commands confirm inside the banner
• Snooze, history search, quiet hours, local voice (Kokoro text-to-speech)
• Local HTTP API and an MCP layer; optional Cloudflare relay and MCP events so remote agents can send and get replies
• Templates exportable as bundles; Rive banners

Capabilities

Agent and script notifications that need an answer ("approve this?"), build and job alerts, and notifications that look the way you want.

Compatibility

• macOS 13.1 Ventura or later, Apple Silicon
• Any app that can make an HTTP request or speak MCP

Availability

Free, open source (MIT), v1.9.2 (2026-10-05); DMG on GitHub Releases and Forge, signed and notarized.

Under the hood

Native Swift menu bar app with a local HTTP API, an MCP server, and an optional Cloudflare relay.