clack

name: clack description: Comprehensive guidance for building and debugging JavaScript and TypeScript CLIs with @clack/core and @clack/prompts, backed by bundled upstream source and examples. Use when implementing clack prompt flows, deciding between core primitives and styled prompts, adapting clack examples, or validating clack API usage.

Clack CLI Skill

Use this skill to implement reliable interactive CLIs with @clack/core and @clack/prompts.

Workflow

1. Decide whether to use @clack/prompts or @clack/core.
2. Read only the minimum reference files needed for the task.
3. Start from the closest example in references/examples/.
4. Implement cancellation handling after every prompt.
5. Add UX polish (intro, outro, spinner, progress, tasks, log, taskLog, stream) when useful.
6. Verify imports against export maps in references/docs/prompts-exports.ts and references/docs/core-exports.ts.

Pick the Right Layer

Use @clack/prompts by default.

• Choose it for production-ready styling and quick delivery.
• Use it when the request maps to standard prompt types: text, confirm, select, multiselect, grouped prompts, logs, spinners, progress, tasks, or streaming logs.

Use @clack/core when lower-level control is required.

• Choose it for custom rendering, custom prompt behavior, or unstyled primitives.
• Use it when the request needs direct prompt classes (TextPrompt, SelectPrompt, ConfirmPrompt, Prompt) or deep customization.

Mandatory Safety Patterns

Handle cancellation on every prompt result.

import * as p from '@clack/prompts';

const value = await p.text({ message: 'Your name?' });
if (p.isCancel(value)) {
  p.cancel('Operation cancelled.');
  process.exit(0);
}

Start and close sessions cleanly for user-facing CLIs.

p.intro('create-app');
// prompts
p.outro('Done');

Prompt Design Guidance

Use these defaults unless the user asks otherwise.

• text: provide validate for required or constrained input.
• confirm: use for binary decisions; avoid coercing free-form text.
• select: use for mutually exclusive choices.
• multiselect or groupMultiselect: use for multi-choice and hierarchical multi-choice flows.
• group: gather structured answers while preserving dependencies between steps.
• spinner and progress: wrap long-running tasks and update status clearly.
• tasks: execute sequential task blocks with spinner status.
• taskLog: stream subprocess output and finish with success/failure.
• stream: render async or tokenized output (for LLM-style streaming).

Implementation Sequence

1. Inspect user requirements and identify required prompt primitives.
2. Read the nearest example under references/examples/.
3. Confirm function/class availability from:
   • references/docs/prompts-exports.ts
   • references/docs/core-exports.ts
4. If behavior is unclear, inspect source under:
   • references/source/prompts/
   • references/source/core/
5. Implement with cancellation guards and clear terminal messaging.
6. Keep fallback behavior for non-interactive contexts when requested (see spinner and CI-oriented examples).

Reference Loading Strategy

Start with these files.

• references/docs/prompts-readme.md
• references/docs/core-readme.md
• references/INDEX.md

Load specific source files only as needed.

• Prompts wrapper internals: references/source/prompts/*.ts
• Core prompt primitives: references/source/core/prompts/*.ts
• Core utility behavior: references/source/core/utils/*.ts

Example-First Mapping

Use this quick mapping to avoid re-inventing flows.

• General prompt suite: references/examples/basic/index.ts
• Validation: references/examples/basic/text-validation.ts
• Autocomplete: references/examples/basic/autocomplete.ts
• Autocomplete multi-select: references/examples/basic/autocomplete-multiselect.ts
• Defaults: references/examples/basic/default-value.ts
• Filesystem path prompt: references/examples/basic/path.ts
• Spinner basics: references/examples/basic/spinner.ts
• Spinner cancellation: references/examples/basic/spinner-cancel.ts
• Advanced spinner cancellation: references/examples/basic/spinner-cancel-advanced.ts
• CI-oriented spinner behavior: references/examples/basic/spinner-ci.ts
• Timer-style spinner updates: references/examples/basic/spinner-timer.ts
• Progress bar: references/examples/basic/progress.ts
• Task log streaming: references/examples/basic/task-log.ts
• Stream utility: references/examples/basic/stream.ts
• Changesets integration flow: references/examples/changesets/index.ts

Quality Bar

Before finalizing any clack implementation:

• Confirm every import exists in the current exports file.
• Ensure cancellation flow always exits safely.
• Ensure prompt wording is short and unambiguous.
• Ensure long-running operations provide visible status.
• Ensure selected layer (core vs prompts) matches customization needs.