Define system architecture from approved PRD and research. Produces architecture doc, data model, API contracts, ADRs. Requires user approval. Must run after ship-spec.

Architecture — System design

Name: Ship Architect
Author: HarambeeAI

Pre-condition

.claude/state/PRD.md must exist and be approved (check progress.json).

Process

Read PRD.md + RESEARCH.md + PROJECT.md.
Produce ARCHITECTURE.md with:
- Tech stack with rationale for each choice
- System architecture (component-level: frontend, backend, database, external services)
- Data model (full schema definitions with types, relations, constraints)
- API endpoints (method, path, request/response shape, auth requirements)
- Infrastructure layout (hosting: Railway, Vercel, Supabase, etc.)
- Architecture Decision Records for non-obvious choices:
```
ADR-001: [Decision title]
  Context: [Why this decision was needed]
  Decision: [What was decided]
  Rationale: [Why this option over alternatives]
  Consequences: [What this means for implementation]
```
Save to .claude/state/ARCHITECTURE.md and .claude/state/decisions.md.
Create .claude/state/ROADMAP.md — phases ordered by dependency from the PRD.
Present architecture to the user for approval (approve / adjust).
After approval, present build mode selection:

"How do you want to proceed with implementation? A. Guided mode (default) — I plan each phase and wait for your go. B. Autonomous mode — I build everything without stopping. /bayes-ship:ship-auto C. Semi-autonomous — I pause between phases for a checkpoint. /bayes-ship:ship-auto --checkpoints"
Update progress.json: set phases.architecture.status to "approved".
Output next step based on user's build mode choice.

Gate

User MUST explicitly approve architecture before any implementation.