v0.21 — terminal intelligence, native viewing and core workflow polish

Planning umbrella, not a claim of implementation. Baseline is the current verified dev after v0.20.0 release/maintenance; recheck exact SHA before implementation. One substantial v0.21 delivery with independently reviewable slices and honest release gates. Do not auto-create a v0.22 milestone or expand scope without maintainer review.

Product goal

Make the existing real-shell/PTY frontend more useful and reliable for viewing files/output, editing small text files, tracking finite commands, understanding output, managing context, and personalizing appearance. Keep the composer, shell input ownership, raw transcript and terminal-host interoperability authoritative.

Do not build a Bash/zsh education platform. #398 is a separately deferred, optional future contextual NMSh guided tour and is not a v0.21 dependency or public website feature.

Priority / linked scope

Required reliability/integration gates

• Flaky: Fish adapter lifecycle test teardown races fish_update_completions #403 — reproduce/fix Fish test teardown race without hiding a product leak; keep Flaky: Fish can lose keys typed right after a handed-over read returns #356 separate.
• Flaky: queuedHighlight composer/queue classification is not settled after one event-loop turn #408 — distinguish queued-highlight async test flake from a real user-visible classification race; deterministic synchronization, no arbitrary sleeps.
• Inline multi-line ANSI progress redraws can accumulate duplicate transcript lines #388 — reproduce/fix multiline ANSI progress redraw duplication, preserving raw authoritative output and normal PTY behavior.
• Protect foreground input, compositor cursor, queue and active reads/passthrough against regression in every feature slice.

Core v0.21 feature slices

• Native read-only /view: files, logs, output and document previews #397 / Native Markdown/text experience: reader, lightweight editor and optional providers #402 — read-only native /view for bounded files, logs, Markdown, diff and completed output, reusing existing Markdown renderer; then a bounded opt-in native plain-text editor with explicit safe open/save/cancel/undo and atomic, symlink-safe save rules. Full IDE, LSP and arbitrary external-editor registry are not required.
• Semantic Output: adaptive overview and detail, raw-preserving folding, providers and copy modes #386 — adaptive deterministic semantic output: overview/detail or enhanced primary view only when useful, source-backed and reversible; retain pristine raw bytes and copy/search modes; security and narrow-render tests. No universal parser or AI-grading layer.
• /track: periodically refresh a command's output in one live block #393 — complete /track on the already-shipped background-task/supervisor foundation, preserving /watch semantics. PR Track live commands with /track (initial slice of #393) #394 is a draft implementation source, not merge-ready. Enforce finite repeatable commands, bounds, cancellation, no overlapping runs, lifecycle, proper in-place state and truthful output/copy/search.
• Native module catalog: Starship / Oh My Posh coverage audit and prioritized ports #364 / Module observability: explain visibility, provenance, collection timings and cache state #365 — prioritize a small audited set of missing native context modules, plus visibility/provenance/cache/collection-time diagnostics. No untrusted workspace code execution, unsafe environment reads or arbitrary external dependency downloads.
• Expand bundled theme catalog: Ayu, Kanagawa, Everforest, Flexoki, Material & more #401 — additional bundled, offline theme families/variants with provenance and contrast/accessibility checks; no host-terminal config writes.
• Terminal-native action controls: reusable styles, semantic states and safe fallbacks #336 — reusable native action controls and safe interaction states only to the extent they simplify the above surfaces without adding a parallel UI framework.

Explicitly outside v0.21

• Future: contextual NMSh Learn — interactive guide to using notMyShell #398 Learn Mode / courses, certificates, course grader or sandbox.
• Managed Targets future: Codex/OpenCode adapters, capability evidence and named provider profiles #339/Future research: Claude Remote Control compatibility and per-profile launch policy #340 managed Codex/OpenCode or remote control; /worktrees: terminal-first Git worktree discovery, navigation and safe management #337/GitHub terminal workspace: PR and issue search, review and supported remote actions #338 expanded GitHub/worktree writes; Terminal-first workspace: sidebars, external workspace navigation and developer control surfaces #330–Contextual right panel: keyboard-first diff, detail and review presentation #332 experimental workspace program expansion. Preserve shipped first slices and keep experimental UI Off by default.
• /tmux Studio: status, appearance, Context modules and workspace integration #333 tmux Studio, Setup Cat integration profiles: progressive onboarding for tmux, editors and provider agents #334 onboarding profiles, Configurable semantic keymap and terminal-host conflict guidance #335 keymap remapping, Terminal Settings: safe Ghostty + kitty config editor in /appearance #399 host Ghostty/kitty settings writes, Theme Bridge and semantic terminal integration #304 expansive Theme Bridge, Future security/runtime: enforced isolation for executable NMSh Portable Mods #341 executable-mod runtime, Future: hosted SSH demo for NMSh #296 hosted SSH demo.
• Composer history: advance past multiline recalls consistently and show position on a free edge #389 composer history change until reproduced. Flaky: Fish can lose keys typed right after a handed-over read returns #356 Fish immediate-key loss remains open, separate and deferred unless hard release evidence escalates it.
• Heavy IDE, universal plugin/provider systems, unnecessary agent platforms, automatic release/deploy authorization.

Engineering plan

1. Baseline audit: exact released/working branch SHA, AGENTS.md, CONTRIBUTING.md, PR/issue reconciliation, maintained T7 workspace, existing frontend/service architecture and tests. Do not recreate shipped Background tasks: supervised long-running commands, task bar above the composer, and conservative suggestions #382 supervisor, present markdown system or theme catalog.
2. Specifications and tests first, small dependency ordered PR slices. Audit PTY escape/raw handling, renderer ownership, keyboard focus, persistence, security and resource limits.
3. One primary Opus Extra High agent for coherent architecture and lower repeated context. No subagents by default; allow bounded Sonnet delegation only by later explicit cost/ownership justification.
4. External T7 fail-closed for disposable worktrees, build/test outputs and caches; leave source worktrees and OS-managed locations intact. Don't run redundant full suites on each slice; focused tests until integration gate.
5. Release gates: named regression tests, macOS/Linux/Node 22/26 CI, security/performance smoke, 8 GB Mac budget and human physical Ghostty/Terminal.app QA; explicitly list unsupported hosts. Exact tag/release only after authorization and acceptance. No claim that green CI equals physical validation.
6. Docs/site: current versioned docs and release notes, no Learn promotion. The NMSh site is live at https://nmsh.raisecaterror.com/; keep Cloudflare production deployment manual-only with required protected-environment approval.

Definition of done: every accepted feature is integrated, user-reachable, documented and verified at the exact commit; remaining partial features have accurate issues and disclosure. After the first substantial slice, present an evidence-based option to expand v0.21 rather than manufacturing an automatic v0.22.