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Agent Team

Cornerstone is built by a team of 10 specialized Claude Code agents. Each agent has its own system prompt, persistent memory, and clearly defined responsibilities.

The Agents​

Product Owner​

Role: Defines epics, user stories, and acceptance criteria. Manages the product backlog.

  • Breaks requirements into actionable user stories with clear acceptance criteria
  • Maintains the GitHub Projects board
  • Validates that completed work meets requirements
  • Gates PR approval -- only approves after verifying all agent responsibilities are fulfilled

Product Architect​

Role: System design, database schema, API contract, and architectural decisions.

  • Designs schema additions and API endpoints for each epic
  • Writes Architectural Decision Records (ADRs) on the GitHub Wiki
  • Maintains the API Contract and Schema wiki pages
  • Reviews PRs for architecture compliance

UX Designer​

Role: Visual design, design tokens, brand identity, and component styling specifications.

  • Defines the CSS custom property token system
  • Creates visual specs for UI stories (which tokens, states, responsive behavior)
  • Maintains the Style Guide wiki page
  • Reviews frontend PRs for token adherence and accessibility

Backend Developer​

Role: Server-side implementation.

  • Implements Fastify API endpoints and business logic
  • Writes database queries using Drizzle ORM
  • Handles authentication, authorization, and session management
  • Does not write tests (owned by QA)

Frontend Developer​

Role: Client-side implementation.

  • Builds React components, pages, and interactions
  • Implements the typed API client layer
  • References the UX Designer's visual specs for styling
  • Does not write tests (owned by QA)

QA Integration Tester​

Role: Unit tests and integration tests.

  • Writes Jest unit tests targeting 95%+ coverage on all new code
  • Writes integration tests using Fastify's app.inject() method
  • Validates performance budgets and audits accessibility
  • Reports bugs with structured reproduction steps

E2E Test Engineer​

Role: End-to-end browser tests.

  • Writes Playwright E2E tests covering UAT scenarios
  • Manages the testcontainer infrastructure (app, OIDC provider, proxy)
  • Tests across desktop, tablet, and mobile viewports
  • Must confirm all E2E tests pass before manual UAT proceeds

Security Engineer​

Role: Security audits and vulnerability reviews.

  • Reviews every PR for OWASP Top 10 vulnerabilities
  • Audits authentication/authorization implementations
  • Scans dependencies for CVEs
  • Maintains the Security Audit wiki page

UAT Validator​

Role: User acceptance testing.

  • Translates acceptance criteria into concrete UAT scenarios (Given/When/Then)
  • Coordinates with QA and E2E agents for test feasibility
  • Produces step-by-step manual validation instructions for the user
  • Manages the validation loop until the user approves

Docs Writer​

Role: User-facing documentation.

  • Maintains this documentation site (docs/ workspace)
  • Updates the README.md as a lean project overview
  • Documents new features after each epic ships

Communication Patterns​

Agents communicate through:

  • GitHub Issues -- user stories, acceptance criteria, UAT scenarios
  • GitHub PRs -- code review comments and approvals
  • GitHub Wiki -- architecture, API contract, schema, security audit
  • Agent memory -- persistent notes shared across sessions
  • CLAUDE.md -- shared conventions and workflow rules

Attribution​

All agents identify themselves in their work:

  • Commits include a Co-Authored-By trailer with the agent name and model
  • GitHub comments are prefixed with the agent name in bold brackets (e.g., **[backend-developer]**)