build— agent skill

name: build description: Feature development pipeline - research, plan, track, and implement major features. argument-hint: [subcommand] [name] metadata: author: Shpigford version: "1.0"

Feature development pipeline - research, plan, track, and implement major features.

When to Use

• You need a structured workflow for building a major feature across research, planning, implementation, and tracking.
• The task involves moving a feature through named phases such as research, implementation, progress, or phase.
• You want one command to coordinate status, next steps, and phased delivery for a feature effort.

Instructions

This command manages a 4-phase feature development workflow for building major features. Parse $ARGUMENTS to determine which subcommand to run.

Arguments provided: $ARGUMENTS

Argument Parsing

Parse the first word of $ARGUMENTS to determine the subcommand:

• research [name] → Run the Research phase
• implementation [name] → Run the Implementation phase
• progress [name] → Run the Progress phase
• phase [n] [name] → Run Phase n of the implementation
• status [name] → Show current status and suggest next step
• (empty or unrecognized) → Show usage help

If the feature name is not provided in arguments, you MUST use AskUserQuestion to prompt for it.

Subcommand: Help (empty args)

If no arguments provided, display this help:

/build - Feature Development Pipeline

Subcommands:
  /build research [name]        Deep research on a feature idea
  /build implementation [name]  Create phased implementation plan
  /build progress [name]        Set up progress tracking
  /build phase [n] [name]       Execute implementation phase n
  /build status [name]          Show status and next steps

Example workflow:
  /build research chat-interface
  /build implementation chat-interface
  /build progress chat-interface
  /build phase 1 chat-interface

Then use AskUserQuestion to ask what they'd like to do:

• question: "What would you like to do?"
• header: "Action"
• multiSelect: false
• options:
• label: "Start new feature research"

description: "Begin deep research on a new feature idea"

• label: "Continue existing feature"

description: "Work on a feature already in progress"

• label: "Check status"

description: "See what step to do next for a feature"

Subcommand: research

Step 1: Get Feature Name

If feature name not in arguments, use AskUserQuestion:

• question: "What's a short identifier for this feature? (lowercase, hyphens ok - e.g., 'chat-interface', 'user-auth', 'data-export'). Use 'Other' to type it."
• header: "Feature name"
• multiSelect: false
• options:
• label: "I'll type the name"

description: "Enter a short, kebab-case identifier for the feature"

Step 2: Check for Existing Research

Check if docs/{name}/RESEARCH.md already exists.

If it exists, use AskUserQuestion:

• question: "A RESEARCH.md already exists for this feature. What would you like to do?"
• header: "Existing doc"
• multiSelect: false
• options:
• label: "Overwrite"

description: "Replace existing research with fresh exploration"

• label: "Append"

description: "Add new research below existing content"

• label: "Skip"

description: "Keep existing research, suggest next step"

If "Skip" selected, suggest running /build implementation {name} and exit.

Step 3: Gather Feature Context

Use AskUserQuestion to understand the feature:

• question: "Describe the feature you want to build. What problem does it solve? What should it do? (Use 'Other' to describe)"
• header: "Description"
• multiSelect: false
• options:
• label: "I'll describe it"

description: "Provide a detailed description of the feature"

Step 4: Research Scope

Use AskUserQuestion:

• question: "What aspects should the research focus on?"
• header: "Focus areas"
• multiSelect: true
• options:
• label: "Technical implementation"

description: "APIs, libraries, architecture patterns"

• label: "UI/UX design"

description: "Interface design, user flows, interactions"

• label: "Data requirements"

description: "What data to store, schemas, privacy"

• label: "Platform capabilities"

description: "OS APIs, system integrations, permissions"

Step 5: Conduct Deep Research

Now conduct DEEP research on the feature:

1. Codebase exploration: Understand existing patterns, similar features, relevant code
2. Web search: Research best practices, similar implementations, relevant APIs
3. Technical deep-dive: Explore specific technologies, libraries, frameworks
4. Use AskUserQuestion FREQUENTLY: Validate assumptions, clarify requirements, get input on decisions

Research should cover:

• Problem definition and user needs
• Technical approaches and trade-offs
• Required data models and storage
• UI/UX considerations
• Integration points with existing code
• Potential challenges and risks
• Recommended approach with rationale

Step 6: Write Research Document

Create the directory if needed: docs/{name}/

Write findings to docs/{name}/RESEARCH.md with this structure:

# {Feature Name} Research

## Overview
[Brief description of the feature and its purpose]

## Problem Statement
[What problem this solves, why it matters]

## User Stories / Use Cases
[Concrete examples of how users will use this]

## Technical Research

### Approach Options
[Different ways to implement this, with pros/cons]

### Recommended Approach
[The approach you recommend and why]

### Required Technologies
[APIs, libraries, frameworks needed]

### Data Requirements
[What data needs to be stored/tracked]

## UI/UX Considerations
[Interface design thoughts, user flows]

## Integration Points
[How this connects to existing code/features]

## Risks and Challenges
[Potential issues and mitigation strategies]

## Open Questions
[Things that still need to be decided]

## References
[Links to relevant documentation, examples, articles]

Step 7: Next Step

After writing the research doc, inform the user:

"Research complete! Document saved to docs/{name}/RESEARCH.md

Next step: Run /build implementation {name} to create a phased implementation plan."

Subcommand: implementation

Step 1: Get Feature Name

If feature name not in arguments, use AskUserQuestion to prompt for it (same as research phase).

Step 2: Verify Research Exists

Check if docs/{name}/RESEARCH.md exists.

If it does NOT exist:

• Inform user: "No research document found at docs/{name}/RESEARCH.md"
• Suggest: "Run /build research {name} first to create the research document."
• Exit

Step 3: Check for Existing Implementation Doc

Check if docs/{name}/IMPLEMENTATION.md already exists.

If it exists, use AskUserQuestion:

• question: "An IMPLEMENTATION.md already exists. What would you like to do?"
• header: "Existing doc"
• multiSelect: false
• options:
• label: "Overwrite"

description: "Create a fresh implementation plan"

• label: "Append"

description: "Add new phases below existing content"

• label: "Skip"

description: "Keep existing plan, suggest next step"

If "Skip" selected, suggest running /build progress {name} and exit.

Step 4: Read Research Document

Read docs/{name}/RESEARCH.md to understand:

• The recommended approach
• Technical requirements
• Data models needed
• UI/UX design
• Integration points

Step 5: Design Implementation Phases

Break the research into practical implementation phases. Each phase should:

• Be independently valuable (deliver something usable)
• Be small enough to complete in a focused session
• Build on previous phases
• Have clear success criteria

Use AskUserQuestion to validate phase breakdown:

• question: "How granular should the implementation phases be?"
• header: "Phase size"
• multiSelect: false
• options:
• label: "Small phases (1-2 hours)"

description: "Many focused phases, easier to track progress"

• label: "Medium phases (half day)"

description: "Balanced approach, moderate number of phases"

• label: "Large phases (full day)"

description: "Fewer phases, each delivering significant functionality"

Step 6: Conduct Phase Research

For each phase you're planning, do targeted research:

• Web search for implementation specifics
• Review relevant code in the codebase
• Identify dependencies between phases

Use AskUserQuestion for any uncertainties about phase ordering or scope.

Step 7: Write Implementation Document

Write to docs/{name}/IMPLEMENTATION.md with this structure:

# {Feature Name} Implementation Plan

## Overview
[Brief recap of what we're building and the approach from research]

## Prerequisites
[What needs to be in place before starting]

## Phase Summary
[Quick overview of all phases]

---

## Phase 1: [Phase Title]

### Objective
[What this phase accomplishes]

### Rationale
[Why this phase comes first, what it enables]

### Tasks
- [ ] Task 1
- [ ] Task 2
- [ ] Task 3

### Success Criteria
[How to verify this phase is complete]

### Files Likely Affected
[List of files that will probably need changes]

---

## Phase 2: [Phase Title]

[Same structure as Phase 1]

---

[Continue for all phases]

---

## Post-Implementation
- [ ] Documentation updates
- [ ] Testing strategy
- [ ] Performance validation

## Notes
[Any additional context or decisions made during planning]

Step 8: Next Step

After writing the implementation doc, inform the user:

"Implementation plan complete! Document saved to docs/{name}/IMPLEMENTATION.md

Next step: Run /build progress {name} to set up progress tracking."

Subcommand: progress

Step 1: Get Feature Name

If feature name not in arguments, use AskUserQuestion to prompt for it.

Step 2: Verify Implementation Doc Exists

Check if docs/{name}/IMPLEMENTATION.md exists.

If it does NOT exist:

• Inform user: "No implementation document found at docs/{name}/IMPLEMENTATION.md"
• Suggest: "Run /build implementation {name} first."
• Exit

Step 3: Check for Existing Progress Doc

Check if docs/{name}/PROGRESS.md already exists.

If it exists, use AskUserQuestion:

• question: "A PROGRESS.md already exists. What would you like to do?"
• header: "Existing doc"
• multiSelect: false
• options:
• label: "Overwrite"

description: "Start fresh progress tracking"

• label: "Keep existing"

description: "Keep current progress, suggest next step"

If "Keep existing" selected, read the progress doc and suggest the next incomplete phase.

Step 4: Read Implementation Document

Read docs/{name}/IMPLEMENTATION.md to extract:

• All phase titles
• Tasks within each phase
• Success criteria

Step 5: Create Progress Document

Write to docs/{name}/PROGRESS.md with this structure:

# {Feature Name} Progress

## Status: Phase 1 - Not Started

## Quick Reference
- Research: `docs/{name}/RESEARCH.md`
- Implementation: `docs/{name}/IMPLEMENTATION.md`

---

## Phase Progress

### Phase 1: [Title from Implementation]
**Status:** Not Started

#### Tasks Completed
- (none yet)

#### Decisions Made
- (none yet)

#### Blockers
- (none)

---

### Phase 2: [Title]
**Status:** Not Started

[Same structure]

---

[Continue for all phases]

---

## Session Log

### [Date will be added as work happens]
- Work completed
- Decisions made
- Notes for next session

---

## Files Changed
(Will be updated as implementation progresses)

## Architectural Decisions
(Major technical decisions and rationale)

## Lessons Learned
(What worked, what didn't, what to do differently)

Step 6: Next Step

After creating progress doc:

"Progress tracking set up! Document saved to docs/{name}/PROGRESS.md

Next step: Run /build phase 1 {name} to begin implementation."

Subcommand: phase

Step 1: Parse Arguments

Parse arguments to extract:

• Phase number (if provided)
• Feature name (if provided)

If neither provided, prompt for both using AskUserQuestion.

Step 2: Get Feature Name

If feature name not determined, use AskUserQuestion to prompt for it.

Step 3: Verify All Docs Exist

Check that all three docs exist:

• docs/{name}/RESEARCH.md
• docs/{name}/IMPLEMENTATION.md
• docs/{name}/PROGRESS.md

If any missing, inform user which doc is missing and suggest the appropriate /build command to create it.

Step 4: Get Phase Number

If phase number not in arguments:

Read docs/{name}/IMPLEMENTATION.md to extract available phases.

Use AskUserQuestion to let user select:

• question: "Which phase would you like to work on?"
• header: "Phase"
• multiSelect: false
• options: [dynamically generated from phases found in IMPLEMENTATION.md, marking completed ones]

Step 5: Read All Context

Read all three documents to fully understand:

• The research and rationale (RESEARCH.md)
• The specific phase tasks and success criteria (IMPLEMENTATION.md)
• Current progress and decisions made (PROGRESS.md)

Step 6: Deep Research on Phase

Before starting implementation:

1. Web search for specific implementation details relevant to this phase
2. Codebase exploration for relevant existing code
3. Use AskUserQuestion to clarify any ambiguities about the phase requirements

Step 7: Execute Phase Work

Begin implementing the phase:

1. Work through each task in the phase
2. Use AskUserQuestion frequently for implementation decisions
3. Follow the "Always Works" philosophy - test as you go
4. Document decisions in PROGRESS.md as you make them

Step 8: Update Progress Document

As you work, update docs/{name}/PROGRESS.md:

• Mark tasks as completed
• Record decisions made and why
• Note any blockers encountered
• List files changed
• Add architectural decisions
• Update the session log with today's work

Update the phase status:

• "In Progress" when starting
• "Completed" when all tasks done and success criteria met

Step 9: Next Step

After completing the phase:

1. Read PROGRESS.md to determine next incomplete phase
2. Inform user of completion and suggest next action:

"Phase {n} complete! Progress updated in docs/{name}/PROGRESS.md

Next step: Run /build phase {n+1} {name} to continue with [next phase title]."

Or if all phases complete:

"All phases complete! The {feature name} feature implementation is done.

Consider:

• Running tests to verify everything works
• Updating documentation
• Creating a PR for review"

Subcommand: status

Step 1: Get Feature Name

If feature name not in arguments, use AskUserQuestion to prompt for it.

Step 2: Check Which Docs Exist

Check for existence of:

• docs/{name}/RESEARCH.md
• docs/{name}/IMPLEMENTATION.md
• docs/{name}/PROGRESS.md

Step 3: Determine Status and Next Step

Based on which docs exist:

No docs exist: "No documents found for feature '{name}'. Next step: Run /build research {name} to start."

Only RESEARCH.md exists: "Research complete for '{name}'. Next step: Run /build implementation {name} to create implementation plan."

RESEARCH.md and IMPLEMENTATION.md exist: "Research and implementation plan complete for '{name}'. Next step: Run /build progress {name} to set up progress tracking."

All three exist: Read PROGRESS.md to find current phase status. "Feature '{name}' is in progress. Current status: [Phase X - status] Next step: Run /build phase {next incomplete phase} {name} to continue."

If all phases complete: "Feature '{name}' implementation is complete!"

Important Guidelines

Use AskUserQuestion Liberally

Throughout all phases, use AskUserQuestion whenever:

• There's ambiguity in requirements
• Multiple approaches are possible
• You need to validate an assumption
• A decision will significantly impact the implementation
• You're unsure about scope or priority

Deep Research Expectations

"Deep research" means:

• Multiple web searches on different aspects
• Thorough codebase exploration
• Reading relevant documentation
• Considering multiple approaches
• Understanding trade-offs

Don't rush through research - it's the foundation for good implementation.

Progress Tracking

Keep PROGRESS.md updated in real-time during phase work:

• Don't wait until the end to update
• Record decisions as they're made
• Note blockers immediately
• This creates valuable context for future sessions

Scope Management

A key purpose of this workflow is preventing scope creep:

• Each phase should have clear boundaries
• If new requirements emerge, note them for future phases
• Don't expand the current phase's scope mid-implementation
• Use AskUserQuestion to validate if something is in/out of scope

Always Works Philosophy

When implementing phases:

• Test changes as you make them
• Don't assume code works - verify it
• If something doesn't work, fix it before moving on
• The goal is working software, not just written code

Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.