name: ring:writing-trds description: "Writing a Technical Requirements Document that designs the technical architecture of the system or feature: components and boundaries, data flow, integration points, and failure modes — in technology-agnostic patterns, plus auth/pagination and BFF contracts for fullstack. Gate 3 of ring:planning-large-features (after ring:mapping-feature-relationships, before ring:designing-api-contracts) and Gate 2 of ring:planning-small-features (after ring:writing-prds, before ring:writing-plans). Use when the PRD passed validation. Skip when the PRD is unvalidated or the architecture is already documented."
TRD Creation — Architecture Before Implementation
When to use
- PRD passed Gate 1
- Feature Map passed Gate 2 (Large Track only)
- About to design technical architecture
Skip when
- PRD not validated → complete Gate 1 first
- Architecture already documented → proceed to API Design (Large) or plan (Small)
- Pure business requirement change → update PRD
Sequence
Runs before: ring:designing-api-contracts (Large Track) / ring:writing-plans (Small Track) Runs after: ring:mapping-feature-relationships (Large Track) / ring:writing-prds (Small Track)
The TRD designs the technical architecture of the system or feature: components and their boundaries, data flow between them, integration points, and failure modes — using technology-agnostic patterns before concrete technology choices.
Handling Missing Information
When specific details are not provided (tech stack, architecture, team size, deployment model, etc.):
- Infer from project name, context, existing codebase patterns, and git history
- Document assumptions explicitly in a
## Assumptionssection at the top of the TRD - NEVER block execution to ask clarifying questions — assume and proceed
- Flag assumptions that carry high risk for the reader to validate (mark as
⚠️ Assumption:) - The only valid exception: tech stack ambiguity in Step 0 when auto-detection fails and no codebase files exist to infer from
Step -1: Design Validation Check (UI Features Only, Conditional)
Read PRD and detect UI indicators (user stories with "see", "view", "click", "page", "screen", "button", "form"; features involving login, dashboard, settings, reports, notifications).
If feature has UI:
- Check
docs/pre-dev/{feature}/design-validation.md(produced by a standalone ring:validating-ux-completeness run, if one happened) - If present → honor its verdict: "DESIGN VALIDATED" proceeds; any other verdict means fix the listed design gaps before (or alongside) the TRD
- If absent → proceed and add to
## Assumptions:⚠️ UX risk: no design validation ran for this UI feature — consider a standalone ring:validating-ux-completeness pass
If backend-only: Skip to Step 0.
Step 0: Tech Stack Definition (HARD GATE)
Step 0.1: Auto-Detect or Ask
go.modexists → Gopackage.jsonwith react/next → Frontend TSpackage.jsonwith express/fastify/nestjs → Backend TS- Ambiguous → AskUserQuestion: "What is the primary technology stack?"
Step 0.2: Load Ring Standards via WebFetch
| Tech Stack | Standards to Load |
|---|---|
| Go Backend | golang/index.md + devops.md + sre.md |
| TypeScript Backend | typescript.md + devops.md + sre.md |
| TypeScript Frontend | frontend.md + devops.md |
| Full-Stack TypeScript | typescript.md + frontend.md + devops.md + sre.md |
WebFetch base URL: https://raw.githubusercontent.com/LerianStudio/ring/main/dev-team/docs/standards/
Step 0.3: Read PROJECT_RULES.md
Check: docs/PROJECT_RULES.md → docs/STANDARDS.md (legacy) → if neither exists, note the absence and proceed with Ring standards.
Step 0.4: Analyze PRD and Suggest Technologies
Read PRD, extract requirements, suggest technologies per category, confirm with user.
AskUserQuestion: "What deployment model?" Options: Cloud, On-Premise, Hybrid
Step 0.5: Document in TRD Metadata
TRD header must include: feature, gate: 3 (Large) / gate: 2 (Small), deployment.model, tech_stack.primary, tech_stack.standards_loaded[], project_technologies[] (category, prd_requirement, choice, rationale per decision). On Large Track this flows to Gates 4–6.
Mandatory Workflow
| Phase | Activities |
|---|---|
| 1. Analysis | PRD (required); Feature Map (Large Track); identify NFRs (performance, security, scalability); map domains to components |
| 2. Architecture Definition | Choose style (Microservices, Modular Monolith, Serverless); design components with explicit boundaries; define interfaces; model data flow end-to-end; plan integration points and patterns; design security |
| 3. Failure Modes | For each component and integration point: what fails, how it is detected, how the system degrades or recovers (timeout/retry/circuit-break/fallback); consistency under partial failure |
| 4. Gate Validation | All domains mapped; component boundaries clear; interfaces technology-agnostic; data ownership explicit; failure modes covered; quality attributes achievable; no specific products named |
Technology Abstraction Rules
| Element | Say This (✅) | Not This (❌) |
|---|---|---|
| Database | "Relational Database" | "PostgreSQL 16" |
| Cache | "In-Memory Cache" | "Redis" or "Valkey" |
| Message Queue | "Message Broker" | "RabbitMQ" |
| Object Storage | "Blob Storage" | "MinIO" or "S3" |
| Web Framework | "HTTP Router" | "Fiber" or "Express" |
| Auth | "JWT-based Authentication" | "specific library" |
TRD never includes: product names with versions, package manager commands, cloud service names (RDS, Lambda), framework-specific terms, container/orchestration specifics, CI/CD tool names.
Authentication/Authorization Architecture (If Required)
| Auth Type | TRD Description |
|---|---|
| User only | "Token-based authentication with stateless validation" |
| User + permissions | "Token-based authentication with role-based access control (RBAC)" |
| Service-to-service | "Machine-to-machine authentication with client credentials" |
| Full | "Dual-layer authentication: user tokens + client credentials for services" |
For Go services: reference golang/security.md → Access Manager Integration in TRD so engineers know implementation patterns.
License Manager Architecture (If Required)
| License Type | TRD Description |
|---|---|
| Single-org | "Global license validation at service startup with fail-fast behavior" |
| Multi-org | "Per-request license validation with organization context" |
For Go services: reference golang/security.md → License Manager Integration.
Frontend-Backend Integration (If Fullstack)
Read api_pattern from research.md frontmatter (bff or none).
If api_pattern: none: Document "Static Frontend — no API layer needed."
If api_pattern: bff: TRD MUST include ## Integration Patterns section:
- Pattern: BFF (Backend-for-Frontend)
- Frontend calls BFF API routes (Next.js API Routes recommended)
- BFF aggregates data from multiple backend services
- Sensitive API keys stored server-side
- Data Flow: Frontend → BFF API Route → Backend Service(s) → Database(s)
BFF Contracts section (MANDATORY when api_pattern: bff):
- BFF Route + Frontend Consumer + Request/Response contracts (flat, no
dataenvelope) - Error contracts per BFF route
- Backend API mapping (BFF route → backend APIs called → aggregation logic)
- Task ownership: Frontend Engineer owns BFF (consumer proximity, type safety chain)
HARD RULE: Client-side code MUST NEVER call backend APIs directly. api_pattern: direct does not exist for dynamic data.
Design System Configuration (UI Features)
Auto-detect from package.json: @lerianstudio/sindarian-ui, @radix-ui/*, @shadcn/ui, @chakra-ui/*, @mui/material, etc.
TRD must include ## Design System Configuration section:
- UI library + version
- CSS framework + config file
- Theme variables (color scale, spacing, component-specific)
- Component availability matrix (table: Component Needed / Available / Notes)
- Variant mapping (Design Intent → Correct Variant → Wrong variant)
- Required CSS imports in globals.css
Pagination Strategy (Required for List Endpoints)
| Strategy | Best For | Performance |
|---|---|---|
| Cursor-Based | >10k records, infinite scroll | O(1) |
| Page-Based (Offset) | <10k records, admin interfaces | O(n) |
| Page-Based + Total Count | "Page X of Y" UI | 2 queries |
| No Pagination | Very small bounded sets (<100) | — |
Document in TRD: API Patterns → Pagination → Strategy + Rationale
ADR Template
**ADR-00X: [Pattern Name]**
- **Context**: [Problem needing solution]
- **Options**: [List with trade-offs - no products]
- **Decision**: [Selected pattern]
- **Rationale**: [Why this pattern]
- **Consequences**: [Impact of decision]
Gate Validation Checklist (Gate 3 Large / Gate 2 Small)
| Category | Requirements |
|---|---|
| Architecture Completeness | All PRD features mapped; DDD boundaries; clear responsibilities; stable interfaces |
| Data Design | Ownership explicit; models support PRD; consistency strategy; flows documented end-to-end |
| Failure Modes | Each component and integration point has failure behavior defined: detection, degradation, recovery |
| Quality Attributes | Performance targets set; security addressed; scalability path clear |
| Integration Readiness | External deps identified (by capability); patterns selected; errors considered |
| Technology Agnostic | Zero product names; capabilities abstract; can swap tech without redesign |
| Design System (UI) | Library specified; CSS framework; theme variables; component matrix; variant mapping |
Gate Result: ✅ PASS → API Design / Gate 4 (Large) or plan / Gate 3 (Small) | ⚠️ CONDITIONAL (remove product names) | ❌ FAIL (too coupled or failure modes missing)
Document Placement
| Structure | trd.md Location |
|---|---|
| single-repo | docs/pre-dev/{feature}/trd.md |
| monorepo | docs/pre-dev/{feature}/trd.md (root) |
| multi-repo | Both repos: {backend.path}/docs/pre-dev/{feature}/trd.md AND {frontend.path}/... |