Project Types Reference

Quick lookup for type-specific questions, patterns, and recommended stacks.

Type Index

Type	Complexity	Default PRD	Recommended Stack
CLI Tool	Low	Minimal	Rust (clap)
REST API	Low-Medium	Minimal/Standard	Rust (axum)
Web App	Medium	Standard	Rust + HTMX
Telegram Bot	Medium	Standard	Rust (teloxide)
Discord Bot	Medium	Standard	Rust (serenity)
GraphQL API	Medium	Standard	Rust (async-graphql)
Mobile App	High	Full	Flutter/React Native
Data Pipeline	High	Full	Python/Rust
Browser Extension	Medium	Standard	TypeScript

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CLI Tool

Discovery Questions

1. Execution model: One-shot or interactive?
2. Arguments: Positional args, flags, or subcommands?
3. Output: Text, JSON, or files?
4. Config: Config file needed?

Patterns

• Use clap for argument parsing
• Support --json for machine output
• Use anyhow for error handling
• Exit codes: 0 success, 1 error

Stack

[dependencies]
clap = { version = "4", features = ["derive"] }
anyhow = "1"
serde_json = "1"  # if JSON output

Example Structure

src/
  main.rs      # Entry point, arg parsing
  lib.rs       # Core logic
  commands/    # Subcommand handlers (if needed)

---

REST API

Discovery Questions

1. Audience: Internal, public, or partner?
2. Auth: None, API Key, JWT, OAuth2?
3. Rate limiting: Needed?
4. Versioning: /v1/, header, or none?

Patterns

• OpenAPI spec first (consider)
• JSON responses with consistent error format
• Health endpoint required: GET /health
• Structured logging (tracing)

Stack

[dependencies]
axum = "0.8"
tokio = { version = "1", features = ["full"] }
serde = { version = "1", features = ["derive"] }
serde_json = "1"
tracing = "0.1"
tracing-subscriber = "0.3"

Example Structure

src/
  main.rs          # Server setup
  lib.rs           # Router, handlers
  routes/          # Route modules
  models/          # Data structures
  middleware/      # Auth, logging

---

Web App (SaaS)

Discovery Questions

1. Auth: Email/password, OAuth, magic link, or none?
2. Realtime: WebSocket, SSE, or none?
3. Multi-tenant: Yes/no?
4. Admin panel: Needed?

Patterns

• HTMX for interactivity (minimal JS)
• Server-rendered templates (Askama)
• Progressive enhancement
• CSRF protection on forms

Stack

[dependencies]
axum = "0.8"
tokio = { version = "1", features = ["full"] }
askama = "0.12"
askama_axum = "0.4"
tower-http = { version = "0.6", features = ["fs"] }

Example Structure

src/
  main.rs
  lib.rs
  routes/
  templates/
    base.html
    pages/
    components/
static/
  css/
  js/ (minimal)

---

Telegram Bot

Discovery Questions

1. Interaction: Commands, dialog, inline, or buttons?
2. State: Stateless, SQLite, or PostgreSQL?
3. Integrations: LLM, payments, external APIs?
4. Delivery: Webhooks or polling?

Patterns

• Start with polling (simpler), switch to webhooks for prod
• FSM (finite state machine) for dialogs
• Inline keyboards for navigation
• Rate limit user requests

Stack

[dependencies]
teloxide = { version = "0.13", features = ["macros"] }
tokio = { version = "1", features = ["full"] }
sqlx = { version = "0.8", features = ["runtime-tokio", "sqlite"] }  # if DB
serde = { version = "1", features = ["derive"] }

Example Structure

src/
  main.rs          # Bot setup
  lib.rs           # Command handlers
  handlers/
    commands.rs    # /start, /help, etc
    callbacks.rs   # Button callbacks
  state.rs         # FSM states (if dialog)
  db.rs            # Database (if needed)

Key Considerations

• Store bot token in env var: TELOXIDE_TOKEN
• Handle /start and /help commands
• Graceful shutdown for webhook mode

---

Discord Bot

Discovery Questions

1. Type: Slash commands, prefix commands, or both?
2. Scope: Single server or multi-server?
3. Features: Moderation, games, integrations?
4. State: In-memory, SQLite, or PostgreSQL?

Patterns

• Use slash commands (modern)
• Respect rate limits
• Handle guild joins/leaves
• Shard for 2500+ servers

Stack

[dependencies]
serenity = { version = "0.12", features = ["framework", "standard_framework"] }
tokio = { version = "1", features = ["full"] }
sqlx = { version = "0.8", features = ["runtime-tokio", "sqlite"] }  # if DB

---

Mobile App

Discovery Questions

1. Platforms: iOS, Android, or both?
2. Offline: Offline-first or online-only?
3. Push: Push notifications needed?
4. Native: Camera, GPS, sensors?

Patterns

• Consider Flutter for cross-platform
• Local storage with Hive/SQLite
• Deep linking support
• App store submission requirements

Stack Options

• Flutter: Dart, single codebase
• React Native: JS/TS, web dev friendly
• Native: Swift/Kotlin for full control

Key Considerations

• Design for both platforms (different UX conventions)
• Handle offline gracefully
• Consider app size
• Test on real devices

---

Data Pipeline

Discovery Questions

1. Trigger: Schedule, event, or manual?
2. Volume: How much data? How often?
3. Sources: APIs, databases, files?
4. Output: Database, files, API?

Patterns

• Idempotent operations
• Checkpointing for resumability
• Structured logging
• Alerting on failures

Stack

[dependencies]
tokio = { version = "1", features = ["full"] }
reqwest = { version = "0.12", features = ["json"] }
sqlx = { version = "0.8", features = ["runtime-tokio", "postgres"] }
serde = { version = "1", features = ["derive"] }
chrono = "0.4"

---

Browser Extension

Discovery Questions

1. Browser: Chrome, Firefox, or both?
2. Permissions: What site access?
3. UI: Popup, sidebar, or page action?
4. Storage: Local or sync?

Patterns

• Manifest V3 for Chrome
• Content scripts for page interaction
• Background service workers
• Careful with permissions (minimal)

Stack

• TypeScript for type safety
• Vite for bundling
• Chrome Extension APIs

Example Structure

src/
  background.ts    # Service worker
  content.ts       # Content script
  popup/           # Popup UI
  options/         # Options page
manifest.json

---

Quick Selection Guide

Need CLI tool?
  → Rust + clap

Need API?
  → REST: Rust + axum
  → GraphQL: Rust + async-graphql

Need Web UI?
  → Simple: Rust + HTMX
  → Complex SPA: Consider separate frontend

Need Bot?
  → Telegram: Rust + teloxide
  → Discord: Rust + serenity

Need Mobile?
  → Cross-platform: Flutter
  → Web skills: React Native

Need Data Processing?
  → Batch: Rust or Python
  → Stream: Rust + Tokio