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Aizen

Aizen is a native macOS workspace for parallel development built with Swift and libghostty — per-branch environments with terminals, file browser, built-in browser, and agent sessions for Claude, Codex, Gemini, and other ACP agents. Now freemium: free core app plus Pro ($59/yr) and Lifetime ($179) tiers.

Key takeaways

  • Repositioned as an agentic-first 'workspace for parallel development' — per-branch environments with terminal, files, browser, and agent sessions, plus libgit2 Git, CI tracking, and an MCP marketplace
  • Now freemium: free core app, Pro at $5.99/mo or $59/yr, Lifetime at $179 — still GPL-3.0 open source
  • Actively shipping — 15 releases between mid-March and late May 2026 (v1.0.68 → v1.0.82), but Apple Silicon only after dropping Intel support at v1.0.71

FAQ

What is Aizen?

Aizen is a native macOS workspace for parallel development — each project or branch gets its own environment with terminal panes, file tabs, browser tabs, agent sessions, and Git context, built with Swift, libghostty, and libgit2.

How much does Aizen cost?

The core app is free and GPL-3.0 open source. Paid tiers add priority support: Pro at $5.99/month or $59/year, or a one-time $179 Lifetime purchase.

Who competes with Aizen?

cmux (native terminal with notifications), Arbor (Rust worktree manager), and Emdash (GUI with issue trackers). For full orchestration, Tembo.

What agents does Aizen support?

Claude, Codex, Gemini, and other ACP-compatible agents, with agent sessions scoped per environment and access to an MCP server marketplace.

Does Aizen run on Intel Macs?

No — Aizen dropped Intel support at v1.0.71 (March 2026) and is Apple Silicon only.

Executive Summary

Aizen has repositioned from a git worktree manager into "a macOS workspace for parallel development" — run agents, terminals, and browsers side by side across every branch.[1] Each project or branch gets its own environment with terminal panes, file tabs, browser tabs, agent sessions, and Git context.[2] Built with Swift, libghostty (GPU-accelerated terminals), and libgit2 (native Git), it's signed and notarized — and as of 2026 has moved to a freemium model with Pro and Lifetime tiers, while staying GPL-3.0 open source.

AttributeValue
CompanyVivy Company
Founded2025 (repo created October)
FundingNot publicly disclosed
HeadquartersUnknown
GitHub Stars~262 (as of June 2026)

Product Overview

Aizen's core concept is now workspaces and environments: "group active projects into workspaces, then create environments for the branches or tasks that are active right now."[1] Each environment keeps its own terminal, files, browser, agent sessions, Git context, and review state — worktree mechanics handled automatically rather than as the headline feature.

Key Capabilities

CapabilityDescription
Per-Environment SessionsTerminal panes, file tabs, browser tabs, and agent chat per branch/task
libghostty TerminalsGPU-accelerated rendering, split panes, themes, optional tmux persistence
Agent SessionsClaude, Codex, Gemini, and other ACP agents; MCP server marketplace
Native Git (libgit2)Stage, commit, push, pull, merge, branch; inline PR diffs
CI TrackingGitHub Actions and GitLab CI integration
ExtrasVoice input, attachments, Xcode integration, CLI companion tool

Product Surfaces

SurfaceDescriptionAvailability
macOS AppNative Swift/AppKit desktop appGA

Technical Architecture

Aizen is a native Swift application that embeds libghostty for terminal rendering[3] and libgit2 for direct Git operations.[1] It dropped Intel support at v1.0.71 (March 2026) and is Apple Silicon only.[4]

Key Technical Details

AspectDetail
DeploymentmacOS app (signed, Apple Silicon only) or build from source
RuntimeNative Swift, libghostty, libgit2
Model(s)None — delegates to agent CLIs / ACP agents
IntegrationsGit worktrees, ACP agents, MCP servers, GitHub Actions, GitLab CI, Xcode
Open SourceYes (GPL-3.0)

Strengths

  • Complete per-environment workspace — Terminal + files + browser + agent sessions + Git context per branch; most cohesive workspace model in the category[2]
  • Native Swift + libghostty + libgit2 — GPU-accelerated terminals with split panes and tmux persistence; instant native Git operations[1]
  • Rapid shipping cadence — 15 releases between mid-March and late May 2026 (v1.0.68 → v1.0.82)[5]
  • Broadened scope — ACP agent support, MCP marketplace, CI tracking, PR review with inline diffs, voice input, CLI companion[1]
  • GPL-3.0 open source with sustainable pricing — Free core app plus paid tiers funding ongoing development

Cautions

  • Apple Silicon only — Intel support was dropped at v1.0.71 in March 2026, a move one reviewer called "controversial"[4]
  • GPL-3.0 license — More restrictive than MIT; may deter commercial forks
  • Small community — ~262 stars and 18 forks as of June 2026; no Hacker News or Reddit discussion found, so adoption signal is thin[2]
  • Unknown company — Vivy Company has no visible funding or team information[6]
  • Fast-moving scope — Repositioned from worktree manager to full workspace within months; feature surface is growing faster than community validation

What Developers Say

Independent commentary on Aizen is scarce as of June 2026 — no Hacker News threads or notable Reddit discussions were found. The most substantive third-party coverage is a Bright Coding review (April 2026):[4]

"Aizen transforms your macOS into an agentic-first command center where every project branch gets its own isolated environment" — Bright Coding

"GPU acceleration eliminates the lag and input delay that plague traditional terminal emulators" — Bright Coding

On the critical side, the same review flagged the platform decision:

"Apple Silicon-only by design... made the controversial decision to drop Intel support" — Bright Coding


Pricing & Licensing

TierPriceIncludes
Free$0Full core app
Pro$5.99/mo or $59/yrPriority support, funds development
Lifetime$179 one-timePermanent access, priority support

Licensing model: GPL-3.0 open source — free to use, modifications must be shared under GPL. Paid tiers (introduced after the March 2026 profile) primarily fund development and add priority support.[1]


Competitive Positioning

Direct Competitors

CompetitorDifferentiation
cmuxTerminal with notifications — Aizen has file browser, built-in browser, Git UI, and chat per environment
ArborRust worktree manager with remote support — Aizen has richer per-environment workspace
EmdashGUI with 20+ agents and issue trackers — Aizen has more cohesive workspace model plus CI tracking
TemboFull orchestration platform — Aizen is individual developer tooling

When to Choose Aizen Over Alternatives

  • Choose Aizen when: You want the most complete per-worktree workspace (terminal + files + browser + chat)
  • Choose cmux when: You want notification management across many terminal sessions
  • Choose Arbor when: You need remote machine support

Ideal Customer Profile

Best fit:

  • Apple Silicon Mac developers wanting a cohesive workspace per branch or task
  • Developers who value native app performance and Ghostty compatibility
  • Solo developers managing 3-10 parallel agent tasks

Poor fit:

  • Cross-platform teams and Intel Mac users (support dropped at v1.0.71)
  • Enterprise users needing governance, SSO, or signed commits
  • Developers wanting cloud execution or team features

Viability Assessment

FactorAssessment
Financial HealthNot publicly disclosed — now has paid tiers (Pro/Lifetime) funding development
Market PositionEarly — ~262 stars as of June 2026 (up from ~158 in March), niche
Innovation PaceVery active — 15 releases March-May 2026, latest v1.0.82 on May 22[5]
Community/EcosystemLimited — small GitHub community, no visible HN/Reddit discussion
Long-term OutlookUncertain but improving — monetization path now exists, backing still unknown

Bottom Line

Aizen has the most cohesive per-environment workspace model in the category — terminal, files, browser, agent sessions, and Git context all scoped to each branch or task — and it's broadened well beyond worktree management with MCP marketplace, CI tracking, and PR review. The shipping cadence (15 releases in ~10 weeks) and the new freemium model are positive viability signals. But it remains from an unknown company with thin community validation (~262 stars, no visible HN/Reddit discussion), and the Apple Silicon-only and GPL-3.0 choices narrow its addressable audience.

Recommended for: Apple Silicon Mac developers wanting a complete, cohesive workspace per branch with native performance.

Not recommended for: Cross-platform teams, Intel Mac users, enterprise users, or anyone needing team/cloud features.

Outlook: Aizen is executing fast and now has a monetization path. If Vivy Company converts shipping velocity into community traction, it could become the strongest native Mac workspace in this segment — but as of June 2026 adoption evidence hasn't caught up to the product's ambition.


Research by Ry Walker Research • methodology