Agentmaster

Agentmaster is a fork of Microsoft Windows Terminal (MIT) that turns the terminal into a manager for multiple Claude Code sessions.

One Windows Terminal–based app that manages N Claude Code sessions across M working directories — letting you fully interact with each session and giving the app 100% programmatic control (inject prompts, read output, drive state).

Each session is a real claude.exe on a ConPTY connection: a full-fidelity terminal with a shared stdin (you and the orchestrator coexist), output tapped for the UI, and semantic state taken from Claude Code hooks — never screen-scraping.

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The Manager tab

Agentmaster adds a pinned, leftmost, non-closable Manager tab (tab 0, open by default) split into three selection-synced regions:

• Triage Board (top) — sessions as cards in state columns (Running · Waiting-for-you · Needs-approval · Error).
• Explorer Tree (bottom-left) — the working directories → their sessions, with LOCAL/GLOBAL/EXTERNAL scope, a sort toggle (newest / oldest / most-active / A–Z / by-PID), smart per-directory tab naming and per-directory tab color.
• Flight Plan (bottom-right) — a per-session prompt queue plus Autopilot; it records the full message history, tagging whether each prompt was queued by you or typed straight into the terminal.

Flight Plan / Autopilot — queue prompts; on turn-complete (the Claude Stop hook) the next queued prompt is auto-sent. Approvals and clarifying questions are handled separately.

Highlights

• Launch & manage — spawn a claude.exe in any working directory; full terminal fidelity with a shared stdin so you and the orchestrator both drive the same session.
• Adopt any claude — a claude you type yourself into an ordinary tab is managed too (a transparent PATH shim auto-wires it for hooks), not just Manager-launched ones.
• Fleet Observer — out-of-band detection that finds, correlates, and enriches every Claude session — even a hand-typed one that fires zero hooks — by reading each process's cwd / cmdline / env and its transcript. No hooks, no settings, fully read-only and invisible to the shell.
• External sessions — surfaces Claude running outside the manager (other Windows Terminals, cmd/console), enriched from its transcript (title, git branch, model · effort, timing); view its conversation read-only, or Adopt it to resume into a managed, controllable tab.
• Autopilot — turn-complete auto-advance with Full / Semi-auto / Manual modes and backstops (stop-on-error, max-auto-sends, pause-on-human-input, global pause).
• Per-tab badge — every terminal tab carries a top-right HUD: a linked Claude shows status + model · effort · kind + Autopilot mode + queued count, while any other tab shows a dim ○ kind · unlinked badge that flips live as the tab's activity changes.
• Persistence + archive/restore — sessions, plan templates, recent dirs, and per-directory tab colors persist under %USERPROFILE%\.agentmaster\. Sessions live as Open ⇄ Archived; restore resumes via claude --resume (transcript-gated) and reloads the Flight Plan. Archiving is non-destructive — your Claude transcripts on disk are never deleted.
• Multi-window workspace — one engine shared across all windows; each window persists its geometry, Manager lens, tab layout and focused tab, and reopens on the next launch, with a recover button for windows closed along the way.
• One value per concept — a session's title is one value shared by the Explorer row, the Windows Terminal tab title, and the persisted record; a tab's color is one value per working directory.
• Settings cog — global Claude-session config (skip-permissions, model, env vars) and Autopilot defaults, persisted to settings.json.
• Coexists with Windows Terminal — installs side-by-side under its own package identity, so your real Windows Terminal / Dev install is left untouched.

Status

All milestones M0–M8 + session restore are complete, built, deployed under the Agentmaster package identity, and verified end-to-end (Launch → real claude.exe on a ConPTY → --settings hooks → PowerShell forwarder → named pipe → registry → state machine → UI, plus claude --resume restore on reopen). The standalone engine harness passes its checks (src/cascadia/TerminalApp/AgentMaster/tests/).

The Fleet Observer (O1–O7) is complete — the out-of-band detection layer that manages every Claude session, including hand-typed ones that fire no hooks. Workspace persistence (M9–M14) is largely landed: M9 (one process-wide engine shared by all windows) and most of M10 (per-window UI-state records — geometry re-apply, Manager-lens restore, focused-tab restore, and multi-window reopen) are shipped and live-verified; routing a restored session back into its owning window is the main piece still in progress.

See doc/agentmaster/IMPLEMENTATION.md for the milestone tracker.

Download & install

One line, no download — paste into PowerShell. It fetches the installer in memory, downloads the bundle, trusts the signing certificate (one UAC prompt, for the cert only), and installs the version you pick (here 0.4.0 — every release page shows a one-liner pinned to that version):

& ([scriptblock]::Create((irm https://raw.githubusercontent.com/Nucs/Agentmaster/agentmaster/tools/Install-Agentmaster.ps1))) -Version 0.4.0

Add -Portable for a cert-free, no-admin install, and/or -Launch to start it right after:

& ([scriptblock]::Create((irm https://raw.githubusercontent.com/Nucs/Agentmaster/agentmaster/tools/Install-Agentmaster.ps1))) -Version 0.4.0 -Portable -Launch

Options: -Version X.Y.Z (omit for latest) · -Portable (no cert / no admin) · -Launch · -Prerelease · -Force · -Uninstall (see tools/Install-Agentmaster.ps1).

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Or grab the assets yourself from Releases:

• Portable — download Agentmaster_<version>_x64.zip (or _arm64), unzip anywhere, and run WindowsTerminal.exe in place. No install and no certificate required. The zip is fully self-contained: Terminal settings live in <unzip>\settings and all Agentmaster state in <unzip>\profile — nothing outside the folder is touched.
• MSIX bundle — the .msixbundle is self-signed, so trust Agentmaster.cer once (Import-Certificate -FilePath Agentmaster.cer -CertStoreLocation Cert:\LocalMachine\TrustedPeople), then double-click the bundle or Add-AppxPackage it. Installed, it runs as the agentmaster execution alias / the Agentmaster Start-menu entry.

On first launch the installed app asks which profile folder to use — Production (%USERPROFILE%\.agentmaster), Development (%USERPROFILE%\.agentmaster-dev), or Browse… for any folder. A profile holds everything the app persists (sessions, Flight Plans, window layouts, settings — including Terminal's own settings under <profile>\terminal\); each install remembers its own choice (change it later: Manager tab → ⚙ → Profile). See doc/agentmaster/PROFILES.md.

Requires Windows 10 2004 (19041) or later, on x64 or arm64, with the native Claude Code build (a real claude.exe) installed — via the native installer or npm i -g @anthropic-ai/claude-code (npm ships the same native binary) or claude install. Agentmaster auto-detects it on PATH, in %USERPROFILE%\.local\bin, or behind an npm claude.cmd; if none is found it gates Claude actions and points you to install or Browse to it (the Settings cog also takes an explicit claude.exe override). A pure-Node claude CLI is not supported. Agentmaster installs side-by-side under its own package identity, so any existing Windows Terminal install is left untouched — and the release identity (Agentmaster, alias agentmaster) is likewise distinct from a from-source dev build (AgentmasterDev, alias agentmasterdev), so the two coexist without sharing any state. (To build from source instead, see Building below.)

Architecture & docs

• doc/agentmaster/DESIGN.md — full design (the "Native Graft" + the three-region Manager tab).
• doc/agentmaster/IMPLEMENTATION.md — milestones & build.
• doc/agentmaster/HOOKS.md — the Claude Code hooks bridge.
• doc/agentmaster/OBSERVER.md — the Fleet Observer (out-of-band pull correlation + activity).
• doc/agentmaster/TAB_OVERLAY.md — the per-tab link badge.
• doc/agentmaster/PERSISTENCE.md — workspace persistence (M9–M14).
• doc/agentmaster/PROFILES.md — release/dev package identities + the per-install state profiles (first-launch picker, migration, coexistence).
• CLAUDE.md — the working notes: status by area, build/deploy details, gotchas, and the correctness rules.

Where the code lives

All additions are marked Agentmaster, kept additive where practical so rebasing onto upstream stays cheap:

• src/cascadia/TerminalApp/AgentManagerContent.{h,cpp} — the Manager tab content (the C1 UI).
• src/cascadia/TerminalApp/AgentMaster/ — the engine (plain C++, no WinRT): SessionRegistry, HooksBridge, ClaudeSpawn, Scheduler, Engine (the process-wide shared engine), Persistence, the Fleet Observer (ProcessInspect, ProcessObserver, Activity), and tests/ (a standalone harness).
• src/cascadia/TerminalApp/AgentTabOverlay.{h,cpp} — the per-tab link badge overlay.
• Small touches in TerminalPage.{h,cpp}, Tab.{h,cpp}, and TabManagement.cpp at the integration points, plus the registrations in TerminalAppLib.vcxproj.
• src/cascadia/CascadiaPackage/Package-Rel.appxmanifest + Package-Dev.appxmanifest — the two package identities: Agentmaster (what releases ship; alias agentmaster) and AgentmasterDev (the local dev loose layout; alias agentmasterdev) — distinct from each other and from real Windows Terminal, so all of them coexist.

Building

Requires the Windows Terminal toolchain: VS 2022 + the Desktop Development with C++ and Universal Windows Platform Development workloads + the Windows SDK (10.0.22621 / 26100). The build entry is OpenConsole.slnx (slnx format).

A convenience wrapper builds just the app target in parallel:

# first build (restores packages)
pwsh -ExecutionPolicy Bypass -File .\tools\Build-Agentmaster.ps1
# inner loop (packages already restored)
pwsh -ExecutionPolicy Bypass -File .\tools\Build-Agentmaster.ps1 -NoRestore

Raw equivalent:

msbuild OpenConsole.slnx /m /p:Configuration=Debug /p:Platform=x64 /t:Terminal\CascadiaPackage

See CLAUDE.md (Building FAST) for incremental-build tips, lib-only compile checks, and Defender exclusions.

Deploy & run

A packaged app can't be launched by running WindowsTerminal.exe directly — it must be deployed. Deploy the loose layout (what Visual Studio F5 does — no signing/cert/admin):

# one-time per machine (or after the manifest changes)
Add-AppxPackage -Register ".\src\cascadia\CascadiaPackage\bin\x64\Debug\AppxManifest.xml" -ForceUpdateFromAnyVersion

The loose layout registers the dev identity (AgentmasterDev — deliberately distinct from the released Agentmaster package, so both can be installed at once). Launch via the agentmasterdev execution alias, the Agentmaster Dev Start-menu entry, or:

Start-Process "shell:appsFolder\AgentmasterDev_56k4f06dsfp9r!App"

Runtime/session state lives in the install's profile folder (picked on first launch; the dev default is %USERPROFILE%\.agentmaster-dev\ — see doc/agentmaster/PROFILES.md); tail hooks.log there to confirm the engine is live and that spawned sessions' hooks arrive.

Relationship to Windows Terminal

Agentmaster is a fork of microsoft/terminal at tag v1.24.2372. The upstream Windows Terminal code, documentation, and third-party notices are retained — see NOTICE.md. For everything about Windows Terminal itself (the console host, shared components, general build/contribution guidance), refer to the upstream repository and aka.ms/terminal-docs. The pristine upstream tree is preserved on the main branch; Agentmaster's work lives on the agentmaster branch.

License

Agentmaster is licensed under the MIT License, the same license as upstream Windows Terminal. The original Copyright (c) Microsoft Corporation notice is retained alongside the fork author's copyright, per the terms of the MIT License.

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This feels like the entire codebase went into Form1.cs, but patience and careful designing made this little gem.