Go CLI / TUI

Build around see → select → act → see the result. Keep context visible, common actions discoverable, and navigation responsive while work runs. These are opinionated defaults for new tools and features; respect existing contracts.

Boundaries and defaults

• Use for Go commands, dashboards, pickers, wizards, and interaction fixes. A one-shot picker need not become a full-screen dashboard.
• Prefer Cobra for a command tree; Bubble Tea, Bubbles, and Lip Gloss for TUI; Huh when a form earns its complexity. A tiny CLI can use flag. Retain a working framework in an existing project.
• Read go.mod before examples. For greenfield work, choose compatible stable Charm versions, verify Go requirements, and pin go.mod/go.sum.
• Lazygit's implementation is an in-tree gocui fork, not Bubble Tea. Borrow interaction principles without copying its Git actions, layout, or every key.
• This is a development skill, not a Lazygit usage guide or general Go tutorial. Release-channel work can use the optional cli-release-distribution guide. No other skill is required to use this package.

Workflow

• 1. Ground the task. Read the command tree, services, config, terminal setup, and tests. Identify the repeated task, necessary state, target OSes, and whether it needs a command, picker, wizard, or dashboard. For a distributed CLI, include its installation and upgrade paths in the interaction scope. Infer from the repo; ask only about consequential product choices that remain unknown.
• 2. Define the interaction. Sketch the primary screen and one complete action path using the compact contract below. Record focus, keyboard behavior, entry conditions, and failure/cancel behavior before wiring widgets.
• 3. Build a vertical slice. Connect a real operation from CLI and UI to the same domain service, validation, and result. Keep handlers and views thin; add packages as responsibilities grow, rather than generating empty layers.
• 4. Complete the states. Handle loading, successful empty results, errors, refresh, cancellation, resize, and return from overlays or external programs. Add configuration for actual recurring preferences.
• 5. Verify and finish. Run relevant checks, fix failures, and exercise the interaction in a PTY. Report changes, evidence, and untested paths. For a published CLI, verify how an existing installation reaches the next version; a successful fresh install alone does not cover that journey. Complete an authorized build request; do not stop after producing a design.

Compact interaction contract

Use in working notes or the implementation explanation. Do not require a new specification file for a small change; omit inapplicable rows.

Task:           repeated action and state needed to decide
Surface:        command / inline picker / wizard / dashboard
Layout:         list, detail/preview, status; narrow-screen behavior
Navigation:     focus, arrows + Vim aliases, search, Back, help
Entry:          bare command, flags, --interactive, non-TTY/JSON
Operation:      shared service, validation, target, result, cancellation
State:          selection identity, async ownership, freshness, failure
Configuration:  preferences, paths, precedence, effective-config view
Acceptance:     input sequence and observable expected result

Interaction invariants

1. Stable context. Keep pane roles, per-view selection, scroll, and filter. Refresh follows identity, not an old row number. Show focus separately from selection and status colors.
2. Two navigation vocabularies. Support arrows and j/k, Tab/Shift+Tab for focus, and context-appropriate h/l. Add gg/G for long lists. No required normal/insert mode. Advertise only applicable actions.
3. Typing owns printable keys. Route events through the modal and focused widget before navigation shortcuts. Typing j, q, /, or an action's mnemonic in a field must not invoke that action.
4. Discoverable speed. Provide a short contextual footer, ? help, and an action menu when needed. Derive hints and dispatch from the same effective bindings and availability definitions.
5. Immediate feedback. Render available state before slow discovery; allow navigation during I/O. Show pending, success, and failure while retaining useful rows. Avoid decorative motion that competes with the task.
6. Proportional confirmation. Destructive actions name the exact target and consequence. Reversible navigation stays immediate. A mutating wizard ends with one meaningful review/submit step.

Read interaction-design.md when laying out screens or implementing navigation, filtering, help, mouse behavior, or resize.

CLI and wizard entry policy

Parse flags and validate syntax before deciding whether to prompt. Interactive behavior follows intent, not merely the existence of a terminal.

Global options such as --config and --color do not alone signal business command intent. An explicit UI request without a usable TTY or combined with JSON output is an error. Make equivalent operations scriptable; keep stdout clean and diagnostics separate.

Read cli-wizards-config.md for commands, guided setup, validation, configuration, or shell integration.

Implementation and verification references

• Read charm-stack.md when selecting dependencies, finding an existing component, or adapting version-sensitive examples. It maps needs to official libraries/tools; it is not a bulk-install instruction.
• Read async-terminal.md for background work, startup performance, or terminal handoffs. It includes dev-cli lessons with sources and performance evidence guidance.
• Read agent-facing-cli.md when a tool needs an embedded operational skill or a dependable automation interface. Keep agent and human entry points on the same services; a bundled skill is optional.
• Read go-distribution.md when preparing a Go CLI for other users: start with the actual main-package install path, version reporting, published tags, and separate source/module packaging boundaries; add package managers when the release needs them.
• Read shell-completion.md for native generators, user install/status, fpath activation, offline candidates and real shell tests.
• Read shell-context.md when exporting a parent-shell environment, owning persistent connections, or generating consumer configuration.
• Read self-update.md when making a CLI installable, preparing its first release, or adding an upgrade command. Choose source, release assets, or the owning package manager from evidence; verify the effective installed copy while preserving local builds by default.
• Read verification.md before declaring an interaction implemented. Select applicable cases, use deterministic state tests, and exercise a real PTY; screenshots cannot prove input behavior.

Installed-tool lifecycle

For a CLI with supported, versioned user installations, provide a discoverable upgrade entry point and a read-only upgrade --check by default. Follow an established equivalent command name when the project already has one. If the product deliberately omits this entry point, record the reason and its supported external upgrade path; do not leave it out simply because the task focused on the dashboard. Experimental one-off programs need no release machinery.

An explicit upgrade should execute the supported owning package manager under the CLI's normal confirmation policy. A recognized, supported Homebrew install should not stop at printing brew upgrade. Keep manual guidance for unsupported or ambiguous ownership. A small manager adapter is enough; this default does not require adding a standalone downloader or compiler. When a manager requires the running program to exit, expose an observable handoff and a final-result query; accepted work is not completed work. Updating the CLI must remain separate from updating its managed service, data, or configuration.

Gotchas

• Charm v1/v2 examples are not interchangeable. Bubble Tea v2 uses charm.land/bubbletea/v2, tea.KeyPressMsg, and View() tea.View; v1 uses the older module, tea.KeyMsg, and View() string. Huh/Bubbles must match the model generation. A UX fix is not permission to migrate the app.
• Async wrappers can still freeze startup. Blocking constructors, config probes, first-frame work, or synchronous Update/View work block input. Move the actual slow work into effects.
• Late results remain late after cancellation. Correlate results with the current request before changing state. Cancelled waiting also does not prove a remote write was rolled back.
• Bytes/runes are not terminal widths. Use ANSI-aware cell measurement and grapheme-safe truncation; test Chinese, combining marks, and emoji. Clamp sizes after subtracting actual borders/padding, including tiny resizes.
• A character device is not necessarily a TTY. Detect the actual input and output terminals. Machine-output intent suppresses UI even with a TTY.
• A flag default is not an explicit override. Preserve changed-flag information for explicit false, 0, and empty values. Cobra validation hooks can run before RunE; check ordering before expecting a wizard to fill a required flag.
• os.UserConfigDir() does not enforce XDG everywhere. macOS uses Application Support. Implement the chosen XDG policy explicitly; persistent state belongs outside both disposable cache and the preferences file.
• Nested terminal readers compete. Integrate a form into the current model or release/suspend the outer program before running another reader. Restore terminal modes before children/editors and on handled exit paths.

This package contains instructions and references, not a generator or starter. Preferences are original synthesis; project observations and official contracts are identified in the references.