Ajar

Product Introduction

1. Definition: Ajar is a macOS utility application (specifically, a menu bar utility) for Apple Silicon Macs that intelligently manages system behavior based on user activity and hardware state. It operates through two core modules: Lid Angle Sync and Awake.
2. Core Value Proposition: Ajar exists to make your Mac respond automatically to your physical actions and workflow context, eliminating manual toggles and preventing unnecessary sleep interruptions. Its primary value is context-aware automation for Mac power management and display settings, enhancing productivity and user experience.

Main Features

1. Lid Angle Sync: This feature maps the physical hinge angle of a MacBook's lid to three system outputs: display brightness, keyboard backlight intensity, and system volume. It uses a single, user-adjustable Bézier curve to define the relationship. The MacBook's built-in hinge sensor provides the angle data. Ajar reads manual adjustments to these outputs as user preference at that specific angle, anchoring the curve for future automatic adjustments.
2. Awake Rules Engine: Ajar's keep-awake functionality is driven by a signal-based rules engine, not a simple timer. It monitors system states and file activity to determine when to prevent idle sleep. Rules are built from six conditions (App, Process, Wi-Fi, Disk, Power, Lid Angle) that can be combined logically. For example, it can keep the Mac awake only while a specific app is in the foreground and the machine is plugged into power.
3. AI Agent Session Detection: A built-in rule specifically targets AI coding agents like Claude Code, Codex, and Gemini CLI. It works by monitoring the session files these agents write to disk, watching for changes in the file's modification timestamp. As long as the file is being updated (indicating the agent is "thinking" or running tools), Ajar holds the system awake, bypassing the standard keyboard/mouse idle timer.

Problems Solved

1. Pain Point: Manual, repetitive adjustment of display brightness and volume when moving between environments (e.g., from a dark room to a bright office). Context-aware automation solves this.
2. Pain Point: Macs entering sleep mode during long-running automated tasks (rendering, encoding, sync jobs, AI agent sessions) because the system detects no direct user input. Intelligent sleep prevention solves this.
3. Target Audience: Power users and professionals including software developers (especially those using AI coding assistants), video editors, audio engineers, data scientists, and anyone who runs long-duration background processes on their Mac.
4. Use Cases: Keeping a Mac awake during a Final Cut Pro render; preventing sleep during an ffmpeg encode or rsync transfer; ensuring an AI coding session isn't interrupted by sleep; automatically dimming screens and lowering volume when closing a MacBook lid in a meeting.

Unique Advantages

1. Differentiation: Unlike other keep-awake apps that function as simple toggle switches or countdown timers, Ajar is signal-driven. It activates only when a predefined condition is met and deactivates immediately when the condition ends, preventing battery drain from forgotten "always on" states.
2. Key Innovation: The Lid Angle Sync feature is a novel integration of hardware sensor data (the hinge) with multiple software output controls. The use of a single draggable control point to shape the response curve for brightness, backlight, and volume simultaneously is a unique and intuitive user interface approach for system automation.

Frequently Asked Questions (FAQ)

1. Does Ajar work with external monitors on a MacBook? Yes, for Apple Studio Displays, which follow the same lid-angle curve as the built-in display. Support for other external display brands is on the development roadmap. The Awake features work universally.
2. Will Ajar drain my MacBook's battery life? No, Ajar is designed to be efficient. It only blocks the system's idle sleep timer; the display will still dim and sleep on its normal schedule. The Mac will enter full sleep immediately once all active Awake rules (like a running process or mounted disk) are no longer active. It does not run resource-intensive polling loops.
3. What happens if I manually change my brightness or volume while using Lid Angle Sync? Ajar intelligently interprets a manual adjustment as your preferred setting for the current lid angle. It uses this new value to anchor and recalibrate its entire response curve, then continues to scale the outputs relative to the lid angle from that new anchor point. It learns from your override.
4. Which Mac models and macOS versions are compatible with Ajar? Ajar requires an Apple Silicon Mac (M-series chip) running macOS 14 Sonoma or later. The Awake rules engine works on all compatible models, including desktops like Mac Studio. The Lid Angle Sync feature requires a MacBook with a built-in hinge sensor.