Hazel
Watch selected folders and apply transparent file rules with previews and logs
The core loop is small enough for a capable coding agent to produce a useful local version in one sitting. For Hazel, watch selected folders and apply transparent file rules with previews and logs. The hard boundary is mature filesystem automation, rule depth, apple integrations, and reliability, plus os integration polish and maintenance.
Build verification: not recorded. How we judge buildability
What you give up
- mature filesystem automation, rule depth, Apple integrations, and reliability
- years of OS-version edge cases
- large extension ecosystem
- cross-device sync
- commercial support and rapid compatibility fixes
Why people still pay
People still pay for Hazel because small utilities are technically reproducible, but customers pay for polish and immediate fixes when an OS update breaks a daily habit. The recurring cost buys permissions, accessibility APIs, sandboxing, signing, notarization, OS regressions, updates, backups, and support, not just the visible interface.
Your build guide
The stack, security requirements, and agent rules for a focused replacement.
Before you start
- Runtime and tools: Swift, SwiftUI/AppKit and SQLite on macOS, with secrets in Keychain where needed.
- Before starting: A Mac, the current Xcode toolchain and a documented permission checklist; distribution signing is a separate delivery task.
Use these project rules and optional skill references alongside the prompt. Review each skill before adding it to your agent; the AGENTS.md export includes the same guidance.
Project rule — domain: Store WatchedFolder, RuleVersion, FileFingerprint, PlannedAction and Receipt; exclude destination folders from reprocessing and detect name collisions before touching the source.
Project rule — scope and recovery: Default to dry-run and keep an undo map. Rules cannot execute arbitrary shell scripts initially; disappearing volumes and revoked folder permissions pause processing rather than deleting records.
Project rule — acceptance: Drop a partially downloaded file, then finish it and create a same-name destination; wait for stability, preview the collision and never overwrite either file silently.
Project rule — delivery: document real setup commands and permissions; do not claim a build, accuracy level, performance result or security certification that has not been demonstrated.
Recommended skill: swiftui-expert-skill — design native SwiftUI state, accessible controls and permission/error views for the proposed Apple-platform interface. Follow the maintainer's installation instructions and match its requirements to the chosen runtime.
Recommended skill: swift-concurrency — isolate capture, background work and UI updates, and make cancellation invalidate late callbacks. Follow the maintainer's installation instructions and match its requirements to the chosen runtime.
Implementation plan
Phase 1
Pin the working slice and create its example input: Watch a user-selected download folder, preview file-matching rules, and move or rename approved files with a reversible operation log. Confirm setup: A Mac, the current Xcode toolchain and a documented permission checklist; distribution signing is a separate delivery task.
Phase 2
Implement persistence and write-time invariants before decorating the UI: Store WatchedFolder, RuleVersion, FileFingerprint, PlannedAction and Receipt; exclude destination folders from reprocessing and detect name collisions before touching the source.
Phase 3
Connect the working view to real saved state. Ask for each operating-system permission when its feature is used. Handle denial and revocation without a loop; show permission status and keep local history deletable.
Phase 4
Expose the app-specific limits and recovery path in context: Default to dry-run and keep an undo map. Rules cannot execute arbitrary shell scripts initially; disappearing volumes and revoked folder permissions pause processing rather than deleting records.
Phase 5
Walk through this concrete acceptance case and preserve its exported evidence: Drop a partially downloaded file, then finish it and create a same-name destination; wait for stability, preview the collision and never overwrite either file silently. Finish the README and backup/restore instructions; report unfinished capabilities explicitly.
Build the following focused alternative to Hazel. Implement the focused workflow below first; the verdict is not evidence of a completed or production-certified build. WORKING SLICE Watch a user-selected download folder, preview file-matching rules, and move or rename approved files with a reversible operation log. SETUP AND ARCHITECTURE Use Swift, SwiftUI/AppKit and SQLite on macOS, with secrets in Keychain where needed. Prerequisites: A Mac, the current Xcode toolchain and a documented permission checklist; distribution signing is a separate delivery task. Before integrating anything, record actual versions and permissions, plus model files or provider limits only where used, in the README; make unavailable dependencies visible rather than simulating success. DOMAIN MODEL AND INVARIANTS Store WatchedFolder, RuleVersion, FileFingerprint, PlannedAction and Receipt; exclude destination folders from reprocessing and detect name collisions before touching the source. IMPLEMENTATION CONTRACT Ask for each operating-system permission when its feature is used. Handle denial and revocation without a loop; show permission status and keep local history deletable. Provide an input/setup view, the main work view, and a review/export view appropriate to this workflow. Preserve the last saved state if a job or save fails. Include empty, loading, permission-denied, partial and retryable-error states. Log identifiers and error categories without secret values or unnecessary private content. APP-SPECIFIC BOUNDARY AND RECOVERY Default to dry-run and keep an undo map. Rules cannot execute arbitrary shell scripts initially; disappearing volumes and revoked folder permissions pause processing rather than deleting records. ACCEPTANCE SCENARIO Drop a partially downloaded file, then finish it and create a same-name destination; wait for stability, preview the collision and never overwrite either file silently. Also reopen the app after an interrupted operation, confirm the saved record/export remains inspectable, and document the recovery action. These are implementation acceptance requirements, not a claim that this guide has been tested. DELIVERY Deliver a runnable repository with migrations or project-format versioning, a non-sensitive example, environment/permission setup, the exact manual acceptance steps, and a backup/export-and-restore walkthrough. Implement the working slice before optional integrations; list any deferred paid-product capabilities honestly. Do not add capabilities outside the working slice just to resemble the original product. PROJECT RULES FOR AGENTS.md Keep the domain invariants above executable at the write boundary. Propose scope changes before adding providers or permissions. Never fabricate source evidence, publish results, identity matches or successful delivery. Preserve user originals and require an explicit confirmation for destructive changes or external publication.
$ open in your agent (prompt prefilled, you press enter), copy the prompt or copy or download AGENTS.md
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Alternatives to building your own
FForelHazel's folder rules, previews, history, and Finder tags, fresh enough that the paint is still wet.open source↗no votes, no pay-to-list · just what's real
Hazel pricing
| plan | monthly | annual (per mo) | what you get |
|---|---|---|---|
| hazel 6 | — | — | Single-user perpetual licence for Hazel 6 and all Hazel 6 updates.One-time $42. |
| hazel 6 family pack | — | — | Up to 5 members of one private household; perpetual Hazel 6 licence.One-time $65. |
| upgrade to hazel 6 | — | — | Upgrade from any previous Hazel version while retaining the existing single/family licence type.One-time $20. |
free tierno free tier
billingone-time purchase; no monthly or annual plan; trial available
hidden costsFuture major versions can require a paid upgrade, although the purchased Hazel 6 version keeps working. Volume licensing is quoted separately.
pricing sources checked 2026-08-14 · pricing source ↗
Questions about Hazel
Can you build your own Hazel with AI?
The verdict is yes for the scoped workflow. The core loop is small enough for a capable coding agent to produce a useful local version in one sitting. For Hazel, watch selected folders and apply transparent file rules with previews and logs. The hard boundary is mature filesystem automation, rule depth, apple integrations, and reliability, plus os integration polish and maintenance.
What does the Hazel build prompt cover?
The prompt starts with this scope: Watch a user-selected download folder, preview file-matching rules, and move or rename approved files with a reversible operation log. Full-product capabilities excluded from the comparison include: mature filesystem automation, rule depth, Apple integrations, and reliability; years of OS-version edge cases; large extension ecosystem. Follow the implementation plan and its prerequisites before expanding the build.
How do I use the prompt, AGENTS.md and agent skills?
Start with the Hazel prerequisites and stack, then copy the prompt into your coding agent. Save the project rules as AGENTS.md in the project root. Linked skills are optional packages or source instructions for specific tasks; review their current contents and install only those matching the chosen stack. A skill does not supply API credentials or verify the finished app.
How long will this Hazel project take?
The catalogue estimate is one sitting for the limited scope. Setup, integration approvals, debugging, deployment and ongoing maintenance can add time. This is an estimate, not a delivery guarantee.
What would I give up by replacing Hazel?
mature filesystem automation, rule depth, Apple integrations, and reliability; years of OS-version edge cases; large extension ecosystem; cross-device sync; commercial support and rapid compatibility fixes. People still pay for Hazel because small utilities are technically reproducible, but customers pay for polish and immediate fixes when an OS update breaks a daily habit. The recurring cost buys permissions, accessibility APIs, sandboxing, signing, notarization, OS regressions, updates, backups, and support, not just the visible interface.
What can I use instead of building Hazel?
Forel: Hazel's folder rules, previews, history, and Finder tags, fresh enough that the paint is still wet. Check each option's license, hosting needs and feature limits.