Skills System

How Scaffold OS Knows
What It's Building

36 curated skills. 1,300+ indexed. Auto-activated by project type.
Quality gates that block release on FAIL — not on opinion.

Architecture

From project type to domain expertise — in one step

The skills system activates automatically. You declare what you're building — the engine matches a profile and loads the right domain expertise before the first line of architecture is written.

Step 1
Project type detected

Build target is identified from your architecture — SaaS, mobile, data pipeline, enterprise, etc.

Step 2
Profile matched

One of 11 project profiles is selected. Each profile maps to a curated set of domain skills.

Step 3
Skills loaded into session

Selected skills are injected into the agent's context at session start — domain expertise ready before any build decisions are made.

Step 4
Lazy invocation during build

Each skill is invoked at the right moment — not all at once. Zero token bloat. Maximum domain precision.

Skill Tiers

Two tiers, one clear boundary

The curated tier is what activates automatically. The extended catalog is what you reach for when you need something specialized.

Tier 1 — Curated
36
Scaffold-native domain skills

Auto-loaded into your agent session based on project type. Structured with explicit role, what to look for, output format, and escalation rules.

  • ✓ Auto-activated per profile — zero manual setup
  • ✓ Planning, Specialist, Quality Gate, and Domain categories
  • ✓ Invoked at precisely the right build phase
  • ✓ Advisory reviews + blocking quality gates
Tier 2 — Extended Catalog
1,300+
Indexed skills, available on demand

Not loaded by default — they'd bloat context. Accessible on demand when you need a specific domain covered that's outside the curated set.

  • → On-demand skill search via the build-time catalog
  • → Covers every domain from Solidity to iOS forensics
  • → Browse all at skills-catalog.html
  • → Superpowers = HOW to execute. Skills = WHAT expertise.
Curated Skills

36 curated skills across 4 categories

These are Scaffold-native. Written with explicit role definition, domain scope, output format, and escalation rules. Each is invoked at the right moment — never loaded all at once.

Invoked during the planning and architecture phase — before any implementation begins. Advisory output: CLEAR / CONCERNS / FLAG.

Engineering Review

Technical feasibility review — architecture assumptions, scalability concerns, implementation risks.

Invoke: Before architecture is locked
Design Review

UX and product design review — user journey, interface assumptions, clarity of value delivery.

Invoke: Alongside engineering review for user-facing products
Business Review

Business viability review — market fit, competitive positioning, revenue model, go-to-market.

Invoke: During planning, after demand validation
Investigate

Deep research into a technical approach, library, or architectural pattern before committing.

Invoke: When unfamiliar technology is the primary architectural choice
Office Hours

Open-ended exploration to surface unconsidered directions before scope or architecture is defined.

Invoke: Early-stage exploration, pre-scope

Domain expert reviews during implementation and architecture phases. Advisory output: CLEAR / CONCERNS / FLAG. FLAG surfaces issues to the developer — it does not block.

Frontend Engineer

Component architecture, rendering performance, accessibility, Core Web Vitals.

Invoke: All frontend feature work
Backend Engineer

API design, data modeling, service boundaries, error handling patterns.

Invoke: API design, data model reviews
Mobile Engineer

Offline-first patterns, push notifications, app store requirements, native UX conventions.

Invoke: All mobile feature work
ML Engineer

ML pipeline design, model evaluation strategy, data validation, training infrastructure.

Invoke: Any ML component design
DevOps Engineer

Infrastructure, CI/CD, containerization, cloud deployment, monitoring setup.

Invoke: Infrastructure design, deployment pipeline
Database Architect

Schema design, query optimization, indexing strategy, migration planning, N+1 prevention.

Invoke: Schema design, complex query optimization
API Designer

REST/GraphQL design, versioning strategy, contract design, backward compatibility.

Invoke: API endpoint design, breaking change assessment
Technical Architect

System design, service topology, cross-cutting concerns, architectural trade-off analysis.

Invoke: Multi-service architecture, major tech choices
QA Engineer

Testing strategy, coverage targets, E2E planning, regression risk assessment.

Invoke: Test plan design, coverage gap review
Security Engineer

Threat modeling, secure code patterns, auth architecture, secrets management, vulnerability triage.

Invoke: Auth design, user data, payment features
Data Engineer

Data pipeline design, schema evolution, transformation testing, data contract governance.

Invoke: Data pipeline architecture, ETL/ELT design
SRE

Reliability engineering, SLO definition, incident response, observability, runbook design.

Invoke: Infrastructure reliability, SLO/SLA definition
Technical Writer

API documentation, developer guides, changelog quality, README clarity, onboarding effectiveness.

Invoke: Before any public API release
UX Architect

User flows, information architecture, interaction design patterns, usability heuristics.

Invoke: User-facing product design, navigation architecture

Mandatory checks before feature completion or phase transition. Output: PASS / ADVISORY / FAIL. Only FAIL blocks release — and a human must explicitly acknowledge it.

Security Audit

OWASP top 10, auth vulnerabilities, secrets management, injection risks, secure defaults.

Invoke: Before any auth, payment, or user-data feature completes
Dependency Scan

Package vulnerabilities, license compliance, outdated dependencies, supply chain risk.

Invoke: Before every major phase completion
Performance Review

Load time, query efficiency, caching strategy, bundle size, bottleneck identification.

Invoke: Before release prep, after data-heavy features
Accessibility Audit

WCAG 2.1 AA compliance, screen reader compatibility, keyboard navigation, color contrast.

Invoke: Before any public-facing UI goes to release
API Contract Review

Breaking change detection, versioning compliance, backward compatibility assessment.

Invoke: Before any external API version bump
Data Privacy Review

GDPR compliance, PII handling, data retention policies, consent flows, data minimization.

Invoke: Any feature that collects or processes personal data
Infrastructure Security

IAM roles, network exposure, secrets rotation, container security, cloud misconfiguration.

Invoke: Infrastructure provisioning, before deployment
Mobile Security

Certificate pinning, secure local storage, biometric auth, runtime protection, deep link safety.

Invoke: Mobile auth features, before app store submission
Visual QA

Live-site visual regression, layout fidelity, cross-browser rendering, responsive breakpoints.

Invoke: Before any public-facing UI release; conditional for visual-heavy products

Specialized knowledge for specific project domains. Auto-activated when the matching domain is detected in your architecture. Advisory output.

E-Commerce

Cart flow design, inventory sync patterns, pricing matrix logic, checkout conversion.

Invoke: All commerce features — cart, checkout, inventory, orders
SaaS Billing

Subscription lifecycle, usage metering, upgrade/downgrade flows, dunning, proration.

Invoke: Any billing or subscription feature
ML Evaluation

Model metrics, A/B evaluation, rollout strategy, drift detection, evaluation harness design.

Invoke: Model selection, evaluation pipeline design
Enterprise Integration

Enterprise system integration patterns, data sync strategy, API governance, enterprise auth.

Invoke: Any enterprise system integration
Data Pipeline

ETL patterns, transformation testing, schema evolution, data contract design.

Invoke: Data pipeline architecture, transformation logic
CMS Architecture

Content modeling, editorial workflows, multi-tenancy patterns, headless API design.

Invoke: CMS content model design, editorial workflow architecture
Realtime Systems

WebSocket patterns, event ordering guarantees, consistency models, presence systems.

Invoke: Any real-time feature — live updates, collaborative editing
Marketing Launch

Landing page conversion optimization, analytics instrumentation, SEO fundamentals.

Invoke: Marketing site build, launch page design
Enforcement Model

Advisory vs. Blocker — a precise distinction

Not every issue should stop the build. Scaffold OS makes a formal distinction between advisory signals (for human judgment) and blocking gates (where failure requires human acknowledgment before proceeding).

Planning & Specialist Skills — Advisory only

These reviews surface information. The developer decides what to act on. No build is blocked by advisory output.

CLEAR No concerns identified — proceed confidently
CONCERNS Issues found worth addressing — developer decides
FLAG Significant issue surfaced to the developer — advisory, not blocking

Quality Gates — Enforcement

These are structural checks. FAIL does not just flag — it prevents release. A human must explicitly acknowledge the FAIL to proceed.

PASS Gate cleared — proceed to release
ADVISORY Non-critical findings — documented, not blocking
FAIL Release blocked — human acknowledgment required to proceed
Project Profiles

11 profiles. One match per project.

When your project type is detected, one of these profiles is selected. Each profile determines which domain skills activate for your session. Click to expand patterns.

Greenfield Web

SaaS product, web application, or REST/GraphQL API service.

20 skills active
saasweb-appnextjsreactspanodefastapidjangovue
Greenfield Mobile

iOS, Android, or cross-platform mobile application.

16 skills active
mobilereact-nativeflutteriosandroidexpo
Enterprise SaaS

Enterprise platform built on or integrated with Salesforce, SAP, or ServiceNow.

18 skills active
salesforcesapservicenowenterprisecrmerp
AI / ML System

LLM application, multi-agent architecture, or ML model pipeline.

15 skills active
llmragmlembeddingsagent-systemfine-tuning
Cloud Infrastructure

DevOps platform, infrastructure-as-code, or cloud infrastructure project.

14 skills active
awsgcpazurekubernetesterraformpulumi
Data Pipeline

Analytics engineering, data warehouse, or ETL/ELT pipeline project.

13 skills active
snowflakedbtdatabricksairflowbigqueryspark
Commerce

Ecommerce store, marketplace, or commerce platform.

15 skills active
shopifywoocommerceecommercemarketplacestore
CMS

Content management system, headless CMS, or content-driven platform.

12 skills active
wordpressstrapighostcontentfulsanitypayload
Marketing Site

Marketing website, product landing page, or launch site.

8 skills active
marketinglanding-pagelaunchcontent-site
Workflow Automation

Workflow automation platform or multi-system integration project.

10 skills active
automationworkflowintegration-platformiPaaS
Existing Codebase

Existing codebase being reverse-engineered, retrofitted, or migrated.

9 skills active
existinglegacyarchaeologyretrofitmigration

Go deeper into the full catalog

Browse all 1,300+ indexed skills organized by domain, filtered by tier — or see how skills integrate into the build protocol.