# Jeremylongshore Claude Code Plugins Plus Skills Replit Architecture Variants > Replit Architecture Variants - Skill: `tomevault-io/jeremylongshore-claude-code-plugins-plus-skills-replit-archi` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/jeremylongshore-claude-code-plugins-plus-skills-replit-archi` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/jeremylongshore-claude-code-plugins-plus-skills-replit-archi/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/jeremylongshore-claude-code-plugins-plus-skills-replit-archi --- # Replit Architecture Variants ## Overview Application architectures on Replit at three scales: single-file prototype, modular production app, and multi-service architecture. Each matches Replit's container model, built-in services, and deployment types. ## Prerequisites - Replit account - Understanding of deployment types (Static, Autoscale, Reserved VM) - Familiarity with Replit's storage options ## Architecture Decision Matrix | Factor | Single-File | Modular App | Multi-Service | |--------|------------|-------------|---------------| | **Users** | Prototype, < 100/day | 100-10K/day | 10K+/day | | **Database** | Replit KV (50 MiB) | PostgreSQL | PostgreSQL + cache | | **Storage** | Local + KV | Object Storage | Object Storage + CDN | | **Persistence** | Ephemeral OK | Durable required | Durable required | | **Deployment** | Repl Run / Autoscale | Autoscale / Reserved VM | Multiple Reserved VMs | | **Cost** | Free-$7/mo | $7-25/mo | $25+/mo | | **Always-on** | No (free), Yes (deploy) | Yes (deployment) | Yes (deployment) | ## Instructions ### Variant A: Single-File Script (Prototype) **Best for:** Bots, scripts, learning, hackathon projects. ```python # main.py — everything in one file from flask import Flask, request, jsonify from replit import db import os app = Flask(__name__) # KV Database for simple state @app.route('/') def home(): count = db.get("visits") or 0 db["visits"] = count + 1 return f"Visit #{count + 1}" @app.route('/api/notes', methods=['GET', 'POST']) def notes(): if request.method == 'POST': note = request.json notes = db.get("notes") or [] notes.append(note) db["notes"] = notes return jsonify(note), 201 return jsonify(db.get("notes") or []) app.run(host='0.0.0.0', port=int(os.environ.get('PORT', 3000))) ``` ```toml # .replit run = "python main.py" [nix] channel = "stable-24_05" [deployment] run = ["python", "main.py"] deploymentTarget = "autoscale" ``` **Limitations:** 50 MiB data, files lost on restart, cold starts. Upgrade to Variant B when you need structured data or durability. --- ### Variant B: Modular App with PostgreSQL (Production) **Best for:** Web apps, APIs, SaaS MVPs with 100-10K daily users. ``` my-app/ ├── .replit ├── replit.nix ├── package.json ├── src/ │ ├── index.ts # Express entry point │ ├── config.ts # Environment + secrets validation │ ├── routes/ │ │ ├── api.ts # Business logic │ │ ├── auth.ts # Replit Auth integration │ │ └── health.ts # Health check │ ├── services/ │ │ ├── db.ts # PostgreSQL pool │ │ ├── kv.ts # KV for cache/sessions │ │ └── storage.ts # Object Storage for files │ └── middleware/ │ ├── auth.ts # Auth header extraction │ └── rateLimit.ts # Rate limiting └── tests/ ``` ``` Architecture: Client → Replit Proxy (Auth) → Express Server │ ┌─────────────────┤ │ │ PostgreSQL KV Database (structured) (cache/sessions) │ Object Storage (file uploads) ``` **Key decisions:** - PostgreSQL for all structured data (users, posts, orders) - KV Database for cache and session data only - Object Storage for user uploads and backups - Single Deployment (Autoscale or Reserved VM) --- ### Variant C: Multi-Service (Scale) **Best for:** Production services with 10K+ daily users, background jobs, or real-time features. ``` Architecture: CDN (Cloudflare) → Replit Deployment 1: API Server │ PostgreSQL (Replit) Redis (Upstash — external) │ Replit Deployment 2: Worker │ Queue (Upstash Kafka — external) │ Replit Deployment 3: Static Frontend ``` **Implementation:** ```markdown Repl 1: my-app-api - Express/Fastify API server - Reserved VM deployment (always-on) - Handles authentication, CRUD operations - Publishes events to queue Repl 2: my-app-worker - Background job processor - Reserved VM deployment (always-on) - Consumes events from queue - Handles: email sending, image processing, reports Repl 3: my-app-frontend - React/Next.js frontend - Static deployment (free, CDN-backed) - Calls API server for data Communication: - API to Worker: Upstash Kafka/Redis queues - Frontend to API: REST/GraphQL over HTTPS - Shared state: PostgreSQL + Redis ``` **When to use external services:** | Service | Replit-native | External (Recommended at Scale) | |---------|---------------|--------------------------------| | Database | Replit PostgreSQL | Neon, Supabase, PlanetScale | | Cache | Replit KV (50 MiB limit) | Upstash Redis | | Queue | None built-in | Upstash Kafka, BullMQ | | Storage | Object Storage | Cloudflare R2, AWS S3 | | Search | None built-in | Algolia, Meilisearch | --- ### Variant D: Static + API Split **Best for:** Frontend-heavy apps with a lightweight API backend. ``` Architecture: Client → Replit Static Deployment (React/Vue/Svelte) │ └──→ Replit Autoscale Deployment (API) │ PostgreSQL ``` ```toml # Frontend Repl .replit [deployment] deploymentTarget = "static" publicDir = "dist" build = ["sh", "-c", "npm ci && npm run build"] ``` ```toml # API Repl .replit [deployment] deploymentTarget = "autoscale" run = ["sh", "-c", "node dist/index.js"] build = ["sh", "-c", "npm ci && npm run build"] ``` **Benefit:** Frontend is free (Static deployment), API only charges when receiving requests (Autoscale). ## Growth Path ``` Single-File → Modular App → Multi-Service │ │ │ │ Add PostgreSQL Add Worker + Queue │ Add Auth Add CDN │ Add Storage Add Redis │ Split frontend ``` ## Error Handling | Issue | Cause | Solution | |-------|-------|----------| | KV database full | Over 50 MiB limit | Migrate to PostgreSQL | | Container sleeping | Free plan / no deployment | Use Autoscale or Reserved VM | | Cross-service latency | Multiple Repls communicating | Use external queue, not HTTP polling | | Static deploy stale | Cache not cleared | Redeploy or add cache-busting | ## Resources - [Replit Deployments](https://docs.replit.com/hosting/deployments) - [Replit Database Options](https://docs.replit.com/category/storage-and-databases) - [Upstash (Redis/Kafka)](https://upstash.com) - [Neon (PostgreSQL)](https://neon.tech) ## Next Steps For known pitfalls at each scale, see `replit-known-pitfalls`. --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/jeremylongshore) — claim your Tome and manage your conversions.