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Build an App
Walk a user through building a digital health app from start to finish. This skill orchestrates the other skills in this repository — it asks a few questions, decides which planning skills are needed, runs them in order, and hands off to implementation.
When to Use
Use this skill when a user wants to:
- build a new digital health app from scratch
- figure out where to start on a health app idea
- go from idea to running code with guidance at each step
Do not use this skill if the user wants to run a specific skill directly (e.g., they ask for FHIR data model design). Let them use that skill on its own.
Working Style
You are a conversational guide. Explain what each step does and why before running it. Ask focused questions. Let the user review and adjust after each step. Move at their pace — do not rush through planning.
Step 1: Understand the Idea
Ask these questions to understand what the user wants to build:
- "What health problem are you trying to solve, and for whom?"
- "Is this tied to a research study, or is it a standalone product?"
- "Does the app need to work on both iOS and Android, or is Apple-only fine?"
- "Will it collect health data from the phone (like HealthKit, step counts, heart rate)?"
- "How far along are you — just an idea, have detailed requirements, or ready to start coding?"
If the user already has a clear problem statement, skip question 1 and use what they gave you.
Step 2: Decide What's Needed
Based on the answers, select which skills to run. Not every project needs every skill.
Always include:
- — define the problem clearly before building
- — choose the right template and clone it
digital-health-ux-planning
- — turn plans into a milestone-based build sequence
Include when relevant:
| Condition | Skill | Why |
|---|
| App stores health data (vitals, assessments, patient records) | health-data-model-planning
| Defines entities, relationships, and FHIR mappings |
| App needs FHIR interoperability or connects to EHRs | | Maps clinical concepts to concrete FHIR resources |
| App handles PHI, needs HIPAA review, or has regulatory concerns | digital-health-compliance-planning
| Identifies privacy, regulatory, and governance requirements |
| App is part of a research study with enrollment and assessments | digital-health-study-planning
| Plans the study protocol, consent, and data collection |
Present the selected skills to the user with a brief explanation of each. Let them add or remove any before proceeding.
If the user says they already have requirements or just want to code:
Check if planning documents already exist in
in their project. If some are there, skip those skills and pick up where they left off. If they have an
, skip straight to building.
Step 3: Run Each Skill
Work through the selected skills in this order. For each one:
- Tell the user what the skill does and what it will produce (one sentence)
- Read the skill's SKILL.md and follow its instructions
- After completion, verify the output was saved to the correct path
- Briefly summarize what was produced before moving to the next skill
Order and output paths
| # | Skill | Output Path | What it Produces |
|---|
| 1 | | docs/planning/need-statement.md
| Need statement: problem, population, outcome |
| 2 | | Cloned template repository | Working project directory with template code |
| 3 | digital-health-ux-planning
| docs/planning/ux-brief.md
| User journeys, onboarding, workflows |
| 4 | digital-health-study-planning
| docs/planning/study-brief.md
| Study protocol, enrollment, assessments |
| 5 | health-data-model-planning
| docs/planning/data-model-brief.md
| Entities, relationships, FHIR recommendations |
| 6 | | docs/planning/fhir-data-model.md
| FHIR resources, terminology, relationships |
| 7 | digital-health-compliance-planning
| docs/planning/compliance-brief.md
| Privacy domains, controls, required decisions |
| 8 | | docs/implementation-plan.md
| Milestone-based build sequence |
Skills marked as not needed in Step 2 are skipped.
After running
(skill 2), all subsequent outputs are saved inside the cloned template repository.
Between each skill, ask: "Ready to move on to the next step, or do you want to adjust anything?"
Step 4: Start Building
After
saves
docs/implementation-plan.md
, summarize everything that was produced:
Here's what we built:
Project: [cloned template path]
Planning documents:
docs/planning/need-statement.md
docs/planning/ux-brief.md
docs/planning/data-model-brief.md (if created)
docs/planning/fhir-data-model.md (if created)
docs/planning/compliance-brief.md (if created)
docs/planning/study-brief.md (if created)
Implementation plan:
docs/implementation-plan.md
[N] milestones, starting with [Milestone 1 name]
Ready to start building Milestone 1?
If the user says yes, read
docs/implementation-plan.md
, find Milestone 1, and begin implementing it.
Guardrails
- Do not skip needs-finding unless the user explicitly has a well-defined need statement already.
- Do not skip platform selection unless the user has already cloned a template repository.
- Respect the user's pace. Let them review and adjust after each skill completes. Do not auto-advance without checking.
- Do not force unnecessary planning. If a simple app does not handle PHI, do not run compliance planning. If it does not use FHIR, do not run FHIR data model design.
- Handle the "skip to coding" case. If the user already has planning docs in , acknowledge them and pick up from wherever they left off. If they have an implementation plan, skip straight to building.
- Each skill is interactive. When you read a skill's SKILL.md and follow its instructions, the user should participate — answer questions, review outputs, provide input. Do not simulate their answers.