# sif8d/mern-todo-app architecture

> Architecture diagram of the GitHub repository sif8d/mern-todo-app, generated by GitDiagram from its file tree, README and a sample of source files (last updated 2026-09-29). It is an AI-made overview: check details against the source.

- Interactive diagram: https://gitdiagram.com/sif8d/mern-todo-app
- Repository: https://github.com/sif8d/mern-todo-app

## Overview

This is a full-stack todo manager: users browse all, completed, or pending tasks, create and edit entries, change completion, and delete them. The React interface dispatches Redux async actions that call the Express API; the API validates relevant title and YouTube-link constraints, operates on MongoDB records, and returns refreshed lists. The client also provides task details, empty/loading states, and theme switching. The README is empty, so capability and wiring evidence comes from the supplied source excerpts; some component and store internals were not sampled.

Main entry points: [`client/src/components/Todos.tsx`](https://github.com/sif8d/mern-todo-app/blob/main/client/src/components/Todos.tsx) (Todo views), [`client/src/features/TodoSlice.ts`](https://github.com/sif8d/mern-todo-app/blob/main/client/src/features/TodoSlice.ts) (Todo state and API), [`client/src/app/store.ts`](https://github.com/sif8d/mern-todo-app/blob/main/client/src/app/store.ts) (Redux store), [`server/routes/todoRouter.js`](https://github.com/sif8d/mern-todo-app/blob/main/server/routes/todoRouter.js) (Todo routes)

## Diagram (Mermaid)

```mermaid
flowchart TD

subgraph group_client["React client"]
  node_entry["Client entry<br/>[main.tsx]"]
  node_app["App shell<br/>[App.tsx]"]
  node_todos["Todo views<br/>[Todos.tsx]"]
  node_todoitem["Todo item<br/>[Todo.tsx]"]
  node_dialogs["Task dialogs<br/>[Dialogs.tsx]"]
  node_empty["Empty states<br/>[Empty.tsx]"]
  node_store["Redux store<br/>[store.ts]"]
  node_slice["Todo state and API<br/>[TodoSlice.ts]"]
  node_toast["Toast UI<br/>[toast.tsx]"]
end

subgraph group_api["Todo API"]
  node_router["Todo routes<br/>[todoRouter.js]"]
  node_server["HTTP server<br/>[app.js]"]
end

subgraph group_persistence["MongoDB persistence"]
  node_dbconnect["DB connection<br/>[db.js]"]
  node_model["Todo model<br/>[Todo.js]"]
end

node_user(("User"))
node_mongo[("MongoDB")]

node_user -->|"uses"| node_todos
node_entry -->|"renders"| node_app
node_app -->|"shows"| node_todos
node_todos -->|"renders tasks"| node_todoitem
node_todos -->|"shows states"| node_empty
node_todos -->|"opens dialogs"| node_dialogs
node_todos -->|"selects and dispatches"| node_store
node_dialogs -->|"dispatches actions"| node_store
node_store -->|"holds state"| node_slice
node_slice -->|"sends HTTP requests"| node_router
node_slice -->|"queues notifications"| node_toast
node_server -->|"mounts routes"| node_router
node_server -->|"connects"| node_dbconnect
node_router -->|"queries and mutates"| node_model
node_model -->|"persists records"| node_mongo
node_dbconnect -->|"opens connection"| node_mongo

click node_entry "https://github.com/sif8d/mern-todo-app/blob/main/client/src/main.tsx"
click node_app "https://github.com/sif8d/mern-todo-app/blob/main/client/src/App.tsx"
click node_todos "https://github.com/sif8d/mern-todo-app/blob/main/client/src/components/Todos.tsx"
click node_todoitem "https://github.com/sif8d/mern-todo-app/blob/main/client/src/components/Todo.tsx"
click node_dialogs "https://github.com/sif8d/mern-todo-app/blob/main/client/src/components/Dialogs.tsx"
click node_empty "https://github.com/sif8d/mern-todo-app/blob/main/client/src/components/Empty.tsx"
click node_store "https://github.com/sif8d/mern-todo-app/blob/main/client/src/app/store.ts"
click node_slice "https://github.com/sif8d/mern-todo-app/blob/main/client/src/features/TodoSlice.ts"
click node_toast "https://github.com/sif8d/mern-todo-app/blob/main/client/%40/components/ui/toast.tsx"
click node_router "https://github.com/sif8d/mern-todo-app/blob/main/server/routes/todoRouter.js"
click node_server "https://github.com/sif8d/mern-todo-app/blob/main/server/app.js"
click node_dbconnect "https://github.com/sif8d/mern-todo-app/blob/main/server/config/db.js"
click node_model "https://github.com/sif8d/mern-todo-app/blob/main/server/models/Todo.js"

classDef toneNeutral fill:#f8fafc,stroke:#334155,stroke-width:1.5px,color:#0f172a
classDef toneBlue fill:#dbeafe,stroke:#2563eb,stroke-width:1.5px,color:#172554
classDef toneAmber fill:#fef3c7,stroke:#d97706,stroke-width:1.5px,color:#78350f
classDef toneMint fill:#dcfce7,stroke:#16a34a,stroke-width:1.5px,color:#14532d
classDef toneRose fill:#ffe4e6,stroke:#e11d48,stroke-width:1.5px,color:#881337
classDef toneIndigo fill:#e0e7ff,stroke:#4f46e5,stroke-width:1.5px,color:#312e81
classDef toneTeal fill:#ccfbf1,stroke:#0f766e,stroke-width:1.5px,color:#134e4a
class node_entry,node_app,node_todos,node_todoitem,node_dialogs,node_empty,node_store,node_slice,node_toast,node_user toneBlue
class node_router,node_server,node_mongo toneAmber
class node_dbconnect,node_model toneMint
```

## Components

### React client

- [Client entry](https://github.com/sif8d/mern-todo-app/blob/main/client/src/main.tsx): `client/src/main.tsx`
- [App shell](https://github.com/sif8d/mern-todo-app/blob/main/client/src/App.tsx): `client/src/App.tsx`
- [Todo views](https://github.com/sif8d/mern-todo-app/blob/main/client/src/components/Todos.tsx): `client/src/components/Todos.tsx`
- [Todo item](https://github.com/sif8d/mern-todo-app/blob/main/client/src/components/Todo.tsx): `client/src/components/Todo.tsx`
- [Task dialogs](https://github.com/sif8d/mern-todo-app/blob/main/client/src/components/Dialogs.tsx): `client/src/components/Dialogs.tsx`
- [Empty states](https://github.com/sif8d/mern-todo-app/blob/main/client/src/components/Empty.tsx): `client/src/components/Empty.tsx`
- [Redux store](https://github.com/sif8d/mern-todo-app/blob/main/client/src/app/store.ts): `client/src/app/store.ts`
- [Todo state and API](https://github.com/sif8d/mern-todo-app/blob/main/client/src/features/TodoSlice.ts): `client/src/features/TodoSlice.ts`
- [Toast UI](https://github.com/sif8d/mern-todo-app/blob/main/client/%40/components/ui/toast.tsx): `client/@/components/ui/toast.tsx`

### Todo API

- [Todo routes](https://github.com/sif8d/mern-todo-app/blob/main/server/routes/todoRouter.js): `server/routes/todoRouter.js`
- [HTTP server](https://github.com/sif8d/mern-todo-app/blob/main/server/app.js): `server/app.js`

### MongoDB persistence

- [DB connection](https://github.com/sif8d/mern-todo-app/blob/main/server/config/db.js): `server/config/db.js`
- [Todo model](https://github.com/sif8d/mern-todo-app/blob/main/server/models/Todo.js): `server/models/Todo.js`

### Other components

- **User**
- **MongoDB**

## Connections

- User → Todo views: uses
- Client entry → App shell: renders
- App shell → Todo views: shows
- Todo views → Todo item: renders tasks
- Todo views → Empty states: shows states
- Todo views → Task dialogs: opens dialogs
- Todo views → Redux store: selects and dispatches
- Task dialogs → Redux store: dispatches actions
- Redux store → Todo state and API: holds state
- Todo state and API → Todo routes: sends HTTP requests
- Todo state and API → Toast UI: queues notifications
- HTTP server → Todo routes: mounts routes
- HTTP server → DB connection: connects
- Todo routes → Todo model: queries and mutates
- Todo model → MongoDB: persists records
- DB connection → MongoDB: opens connection