| name | react-router-prisma-app-architecture |
| description | Own React Router + Prisma app-code architecture, route boundaries, UI structure, and verification for Vite-based web apps. Use when the request mentions React Router routes, loaders or actions, component boundaries, use cases, domain models, Prisma-backed server code, Fluent UI, responsive UI, charts, Playwright UI verification, or app-structure refactoring. Do not use this skill for `/docs/spec` planning, Azure platform setup, app registration, end-user auth contract design, or release delivery. |
React Router Prisma App Architecture
Overview
Use this skill as the default architecture workflow for a React Router SPA that uses Vite and Prisma v7. Use it from initial bootstrap through ongoing implementation. Keep FlatRoute modules declarative, view files thin, data access server-only, and dependency direction explicit before writing code.
This skill owns code structure, dependency direction, UI guardrails, and verification for the app codebase. Do not use it to define cloud provider choice, identity provisioning, secret-store topology, IaC layout, or deployment infrastructure; let a companion hosting skill add those concerns while preserving these rules.
This skill also does not own /docs/spec, /docs/plans/plan.md, commit-log workflow, branch naming workflow, or PR management; use a repository workflow skill for those concerns and keep this skill focused on app code.
For new or unstandardized UI work, prefer Fluent UI React v9 and a quiet, simple visual presentation. Keep primary labels and layouts concise, and move only supplemental, non-essential detail into Tooltip or InfoLabel patterns.
When data visualization is required, prefer the simplest accessible chart that matches the analytical task and keep chart interaction lightweight.
For responsive behavior, prefer guidance that keeps the same feature usable on both desktop and mobile rather than treating mobile-first as a universal process requirement.
If a companion hosting skill explicitly overrides runtime mode or config bootstrap, keep these architecture and boundary rules and let the companion override only the hosting-specific pieces.
Quick Start
- Always read
references/layout-and-module-placement.md before deciding where code should live.
- Run a placement preflight before implementing:
- list every new file, moved file, and extracted file
- assign the exact canonical target path for each file before writing code
- if a file does not fit the canonical layout, stop and revise the placement plan before creating a new directory
- Classify the requested change:
- route composition
- presentational UI
- client interaction flow
- server use case
- persistence or external integration
- domain rule
- cross-boundary contract or utility
- Place code in the canonical layout:
app/routes/app/components/<feature>/app/components/shared/app/lib/client/usecase/app/lib/client/usecase/<feature>/use-<feature>.tsapp/lib/client/usecase/<feature>/state.tsapp/lib/client/usecase/<feature>/reducer.tsapp/lib/client/usecase/<feature>/selectors.tsapp/lib/client/usecase/<feature>/handlers.tsapp/lib/client/infrastructure/app/lib/client/infrastructure/api/app/lib/client/infrastructure/browser/app/lib/server/usecase/app/lib/server/infrastructure/app/lib/server/infrastructure/config/app/lib/server/infrastructure/repositories/app/lib/server/infrastructure/gateways/app/lib/domain/entities/app/lib/domain/value-objects/app/lib/domain/policies/app/lib/domain/services/app/lib/domain/repositories/
- Read the narrowest additional reference file after the layout reference:
Non-Negotiable Rules
- Keep dependency direction inward:
app/routes and app/components depend on client-facing orchestration, never on Prismaapp/lib/client/usecase depends on domain and client adaptersapp/lib/server/usecase depends on domain and repository portsapp/lib/server/infrastructure implements repository ports and external integrationsapp/lib/domain/* depends only on other domain modules
- Lock file placement before coding. Name the exact target file paths first, then implement.
- Keep feature-local presentational components in
app/components/<feature>/. Use app/components/shared/ only for feature-agnostic UI that is already reused or clearly about to be reused across features.
- Keep Prisma imports inside
app/lib/server/infrastructure/.
- Keep
app/components/ presentational. Allow only ephemeral UI state there, such as local input focus or disclosure toggles.
- Prefer Fluent UI React v9 (
@fluentui/react-components) for new UI work unless the repository already has a clear design-system standard or an approved migration plan says otherwise.
- Keep UI visually simple: concise labels, low-noise layouts, restrained text density, and deliberate spacing over decorative complexity.
- Use Tooltip or InfoLabel for supplemental, non-essential detail. Do not hide required labels, key instructions, validation messages, or critical status only inside a Tooltip.
- When rendering charts, choose the simplest chart that matches the task: line charts for continuous trends over time, and bar or column charts for comparing discrete categories or ranked values.
- Keep charts low-noise and accessible: avoid 3D or decorative chart junk, avoid color-only encoding, and keep critical values or explanations discoverable without hover.
- For important charts, provide a nearby text summary and, when exact inspection matters, an accessible table or equivalent non-hover path to the underlying values.
- Build responsive UI so the same feature stays capable on both desktop and mobile, using fluid layout primitives and content-driven breakpoints rather than device-name-specific forks or fixed desktop widths.
- Support narrow-screen reflow and avoid ordinary horizontal scrolling for app UI. Do not lock orientation unless a single orientation is genuinely essential.
- Do not rely on hover-only or fine-pointer-only interaction for primary actions, labels, or critical explanation. Keep a touch and keyboard path for the same task.
- Keep touch targets and spacing mobile-usable. Meet at least WCAG 2.2 minimum target size expectations or provide equivalent spacing, and use larger targets when practical.
- For UI-affecting changes, verify the actual rendered result with Playwright before pushing instead of relying only on code inspection.
- Prefer accessible locators and web-first assertions in Playwright, and check the touched flow at the relevant route and viewport sizes.
- Keep async state, mutation handlers, and derived view models in
app/lib/client/usecase/.
- Co-locate
state, reducer, selector, and handler modules inside the owning feature directory under app/lib/client/usecase/<feature>/.
- Do not create horizontal buckets such as
app/state/, app/reducers/, app/stores/, app/handlers/, or app/lib/client/usecase/state/.
- Keep route modules responsible for HTTP, loader/action wiring, and top-level composition only.
- Validate at the correct layer: transport shape in routes or API adapters, application rules in use cases, business invariants in domain.
- Default client-side data access to
api adapters plus DTO mapping inside the owning use case. Introduce a client-side repository abstraction only for clear multi-source or local-first requirements.
- Instantiate repositories and gateways in a composition root or dependency factory, not inside domain models or use cases.
- Prefer React Router's official Vite-powered bootstrap for new projects. Use plain
create-vite only when you intentionally choose a lower-level React Router mode or must retrofit an existing starter.
- Fix Prisma usage to Prisma ORM v7.x. Treat non-v7 setup as migration work, not as an equal baseline.
- Do not put cloud-provider provisioning, app registration, secret-store policy, IaC topology, or release-infrastructure rules in this skill. Keep those in a companion hosting skill while preserving these code-level boundaries.
- Keep authorization, serialization, migration steps, background side effects, and barrel exports intentional rather than ad hoc.
- Treat thread safety mainly as async safety and request safety: avoid module-level mutable state, keep request context out of singletons, and rebuild transaction-scoped dependencies per request.
- Keep feature internals private by default and avoid circular dependencies across extracted modules.
- Use
class only when identity, invariants, or lifecycle matter. Prefer composition over inheritance, and keep DTO or transport shapes as type plus function-based modules.
- Use
interface for stable object-shaped ports or contracts with multiple implementations. Use type for DTOs, unions, mapped shapes, and local view-model shapes.
- Use
unknown at trust boundaries when a value exists but its shape is not yet proven. Narrow or parse it immediately; do not let raw unknown drift into use cases, components, or domain models.
- Keep one concept under one owner. Consolidate duplicate same-role modules only when they represent the same concept in the same boundary.
- Build business behavior around domain models and domain language, but do not force UI state, DTOs, or infrastructure concerns into
domain.
- Keep constants in the narrowest owning module or feature. Extract repeated stable literals into
constants.ts only when they have one clear owner; do not build a global constants dump.
- Do not create a generic common bucket. Keep code in the narrowest owning layer, and duplicate small utilities until a stable abstraction is obvious.
- Do not create alternate top-level buckets such as
app/features/, app/modules/, app/hooks/, app/services/, app/utils/, app/types/, or app/store/ unless an explicit migration plan or companion skill requires them.
- If a file does not fit the canonical layout, revise the plan before implementation instead of inventing a convenience directory.
- Prefer direct replacement over compatibility aliases when renaming architecture terms.
Implementation Workflow
Placement Preflight For Every Change
- Read
references/layout-and-module-placement.md first.
- Write the exact target paths for every created or moved file before touching code.
- Confirm that each target path matches one canonical owner:
- route HTTP composition:
app/routes/
- feature-local presentational UI:
app/components/<feature>/
- shared presentational UI:
app/components/shared/
- client orchestration and state:
app/lib/client/usecase/<feature>/
- client adapters:
app/lib/client/infrastructure/
- server orchestration:
app/lib/server/usecase/
- server integrations and Prisma:
app/lib/server/infrastructure/
- domain concepts and ports:
app/lib/domain/
- If any planned file lacks a clear owner, fix the placement plan before implementing.
0. Bootstrap new projects correctly
- When starting from scratch, follow
references/project-bootstrap.md before writing features.
- Prefer
create-react-router for this skill's architecture because it already aligns with Vite, route modules, and SPA mode.
- Add Prisma v7, the correct driver adapter,
@react-router/fs-routes, and SPA configuration before layering domain or use-case code.
- Add Fluent UI React v9 early for new UI work so components, theming, and accessibility patterns stay consistent from the first screen.
- Before substantial feature work begins, prefer installing the baseline dependencies the project already knows it will need so architecture work does not drift around missing packages mid-implementation.
- When hosting, identity, or deployment requirements appear, keep this skill on code-level architecture and hand the platform-specific decisions to the companion hosting skill.
1. Model the change around a use case
- Name the user intent first.
- Put invariants in
domain/entities or domain/value-objects, and put cross-entity rules in domain/policies or domain/services when they do not naturally belong to one model.
- Put behavior where the state lives: entity behavior on entities, value normalization on value objects, cross-entity rules on policies, and orchestration on services or use cases.
- Keep literals local until they become stable, named concepts. Extract only when the name improves readability or the value is reused inside one clear boundary.
- Treat untrusted data as
unknown first, then narrow it at the boundary with a parser, schema, or type guard before promoting it to a DTO or domain shape.
- When two modules appear to serve the same role, first ask whether they are actually the same concept in the same layer. Merge duplicates inside one boundary, but keep separate shapes when one is a DTO, one is a view model, or one is a domain model.
- Put repository interfaces in
domain/repositories.
- Keep request or response shapes next to the route, API client, or use case that owns them. Promote them only after the boundary is stable and truly reused.
- Do not move transport
Request or Response types into domain just because several modules share them.
2. Keep view logic out of components
- Build a custom Hook, controller, or view-model module in
app/lib/client/usecase/ for each non-trivial screen or interaction flow.
- When the interaction has enough complexity to need submodules, create a feature directory and keep the use case internals there.
- Keep feature-specific presentational components in
app/components/<feature>/ by default. Promote a component to app/components/shared/ only after it proves to be truly feature-agnostic.
- Prefer composing views from Fluent UI primitives before introducing custom low-level controls.
- Keep on-screen copy terse. Put optional elaboration behind Tooltip, InfoLabel, Popover, or a similar secondary affordance only when the extra detail is not required for task completion.
- Keep purely presentational responsive adaptation in CSS, layout primitives, and presentational components. Move breakpoint-aware state into
usecase only when it changes interaction flow or data loading behavior.
- For chart-heavy views, keep series transformation, grouping, filtering, and drill state in
app/lib/client/usecase/, and keep chart components focused on rendering, theming, and accessibility wiring.
- Let that module own:
- async calls
- reducer logic
- derived screen state
- event handlers
- error and pending mapping
- Pass view-ready props into
app/components/<feature>/ or app/components/shared/ when the component is genuinely cross-feature.
3. Use React Router primitives before inventing new state containers
- Use loader data for route reads.
- Use action or fetcher state for mutations.
- Use navigation or fetcher pending state instead of duplicating network flags in component state.
- Add client state only for interaction state that is not already owned by the router.
4. Move DTOs through the client boundary explicitly
- Return JSON DTOs from route loaders, actions, or API endpoints.
- Let
client/infrastructure/api fetch those DTOs.
- Rebuild client-facing objects or value objects inside the owning use case only when that adds real value.
- Do not expect server-side
Entity instance identity to cross the network boundary.
5. Assemble dependencies at the edge
- Keep
usecase and domain code constructor-injected.
- Build repository, gateway, and service instances in route loaders, actions, server entry points, or dedicated dependency factories.
- Prefer manual DI with explicit factory functions before introducing a DI container.
- Recreate request-scoped dependencies such as transaction-bound repositories from the current request or transaction context.
6. Validate and map errors by layer
- Keep request parsing and input shape validation at the HTTP or client transport boundary.
- Keep use-case rule validation in
server/usecase or client/usecase.
- Keep invariant enforcement in
domain.
- Map domain, application, and infrastructure errors to transport responses at the edge.
7. Keep authorization and serialization explicit
- Resolve authentication at the edge, but keep authorization decisions in use cases or domain policies.
- Convert
Date, ids, money-like values, and value objects at boundaries rather than leaking transport or ORM shapes inward.
8. Keep mutable state scoped
- Do not store request-specific state in module globals or singleton services.
- Pass auth context, user context, tenant context, and correlation metadata explicitly.
- Keep transaction handles scoped to the current transaction only.
- Treat client-side async race conditions as correctness issues and guard against stale responses.
9. Use explicit compromises for stateful flows
- For chat, streaming, session, playback, or wizard-style flows, allow a feature-local controller or store when lifecycle and identity genuinely matter.
- Keep that compromise inside
app/lib/client/usecase/<feature>/ rather than spreading mutable state across routes or components.
- Split durable state, ephemeral runtime state, and infrastructure handles explicitly.
10. Push side effects and migrations into explicit workflows
- Keep schema changes, background jobs, external notifications, and indexing side effects visible and testable.
- Do not hide them inside random route handlers or repositories.
- Use barrel exports sparingly and only when they do not obscure ownership or create cycles.
11. Verify before push
- Run targeted tests for the touched area.
- Run typecheck and lint or the project quality gate.
- Audit for boundary drift and forbidden imports.
- For UI-affecting changes, run the touched route in Playwright and confirm the rendered result, interaction states, and responsive layout.
- Fix architecture violations before pushing even if tests pass.
12. Refactor overloaded files in phases
- When a
ts or tsx file has too many responsibilities, do not rewrite it in one jump.
- Follow the hotspot workflow in
references/hotspot-refactor-workflow.md.
- When several hotspots exist, start with the one that combines correctness risk, change frequency, and boundary damage rather than the one that is merely largest.
- Separate analysis, planning, extraction sequencing, execution, and verification.
- Move one stable seam at a time and keep the file working after each batch.
Placement Guide
- Need feature-local pure rendering and markup:
app/components/<feature>/
- Need reusable pure UI primitives or shared Fluent UI composition wrappers:
app/components/shared/
- Need route composition or loader/action bridging:
app/routes/
- Need client-side state, handlers, reducers, selectors, or orchestration:
app/lib/client/usecase/<feature>/
- Need browser APIs, API clients, or router adapters:
app/lib/client/infrastructure/
- Need endpoint-specific API clients:
app/lib/client/infrastructure/api/
- Need browser-only adapters such as storage, clipboard, media queries, or channel APIs:
app/lib/client/infrastructure/browser/
- Need a business invariant or behavior-rich model:
app/lib/domain/entities/
- Need a small immutable business concept with validation:
app/lib/domain/value-objects/
- Need cross-entity business rules: prefer
app/lib/domain/policies/
- Need domain-level orchestration that is still infrastructure-free:
app/lib/domain/services/
- Need a repository port or domain-facing persistence contract:
app/lib/domain/repositories/
- Need server orchestration:
app/lib/server/usecase/
- Need Prisma, file system, or external service code:
app/lib/server/infrastructure/
- Need platform-specific server config bootstrap or config readers:
app/lib/server/infrastructure/config/
- Need persistence implementations:
app/lib/server/infrastructure/repositories/
- Need external SDK or HTTP adapters:
app/lib/server/infrastructure/gateways/
- Need a reusable type or utility: place it with the owning route, use case, or domain module first; extract only after repeated reuse proves the boundary
References
