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replit-migration-deep-dive Execute Replit major re-architecture and migration strategies with strangler fig pattern.
Use when migrating to or from Replit, performing major version upgrades,
or re-platforming existing integrations to Replit.
Trigger with phrases like "migrate replit", "replit migration",
"switch to replit", "replit replatform", "replit upgrade major".
npx skills add jeremylongshore/claude-code-plugins-plus-skills --skill replit-migration-deep-dive ai automation claude-code devops mcp ai-agents
Replit Migration Deep Dive
Current State
!cat .replit 2>/dev/null | head -10 || echo 'No .replit found'
!cat Procfile 2>/dev/null || echo 'No Procfile (not Heroku)'
!cat Dockerfile 2>/dev/null | head -10 || echo 'No Dockerfile'
!cat railway.json 2>/dev/null || echo 'No railway.json'
Overview
Comprehensive guide for migrating existing applications to Replit from Heroku, Railway, Vercel, Render, or local development. Covers converting configuration files, migrating databases, adapting to Replit's Nix-based environment, and setting up Replit-native features.
Prerequisites
Source application with working deployment
Access to current database for export
Git repository with application code
Replit Core or Teams plan
Migration Paths
From Complexity Duration Key Changes
Local dev Low 1-2 hours Add .replit + replit.nix Heroku Medium 2-4 hours Procfile to .replit, addons to Replit services Railway Low-Medium 1-3 hours railway.json to .replit Vercel Low 1-2 hours Usually frontend-only, use Static deploy Docker Medium 3-6 hours Dockerfile to replit.nix
Instructions
Step 1: Import from GitHub 1. Go to replit.com > Create Repl > Import from GitHub
2. Paste your repository URL
3. Replit auto-detects language and creates default config
4. Review and adjust .replit and replit.nix
Step 2: Convert from Heroku # Heroku Procfile
web: npm start
worker: node worker.js
release: node migrate.js
# Equivalent .replit
run = "npm start"
entrypoint = "index.js"
[deployment]
run = ["sh", "-c", "node migrate.js && npm start"]
build = ["sh", "-c", "npm ci --production"]
deploymentTarget = "autoscale"
[env]
NODE_ENV = "production"
Heroku addons to Replit services:
Heroku Addon Replit Equivalent Heroku Postgres Replit PostgreSQL (Database pane) Heroku Redis Upstash Redis (external) or Replit KV Heroku Scheduler Replit Automations or external cron Papertrail Replit deployment logs + external SendGrid Same (use API key in Secrets) Cloudinary Replit Object Storage or same
# Export from Heroku
heroku config -s > heroku-env.txt
# Import to Replit: copy each line into Secrets tab
# Or use Replit Secrets tool (lock icon in sidebar)
Step 3: Convert from Railway // railway.json
{
"build": { "builder": "NIXPACKS" },
"deploy": {
"startCommand": "npm start",
"healthcheckPath": "/health"
}
}
# Equivalent .replit
run = "npm start"
[deployment]
run = ["sh", "-c", "npm start"]
build = ["sh", "-c", "npm ci"]
deploymentTarget = "autoscale"
Step 4: Convert from Docker Dockerfile to replit.nix:
# Dockerfile
FROM node:20-slim
RUN apt-get update && apt-get install -y python3 postgresql-client
WORKDIR /app
COPY package*.json ./
RUN npm ci --production
COPY . .
CMD ["node", "dist/index.js"]
# Equivalent replit.nix
{ pkgs }: {
deps = [
pkgs.nodejs-20_x
pkgs.python311
pkgs.postgresql
];
}
# .replit
run = "node dist/index.js"
[deployment]
run = ["sh", "-c", "node dist/index.js"]
build = ["sh", "-c", "npm ci --production && npm run build"]
deploymentTarget = "autoscale"
Step 5: Database Migration # From Heroku Postgres
heroku pg:backups:capture
heroku pg:backups:download
pg_restore -d LOCAL_DB latest.dump
# From Railway
railway run pg_dump > backup.sql
# From any PostgreSQL
pg_dump --format=custom DATABASE_URL > backup.dump
Import to Replit PostgreSQL:
# In Replit Shell, after provisioning PostgreSQL in Database pane:
# Option 1: SQL file
psql "$DATABASE_URL" < backup.sql
# Option 2: Custom format dump
pg_restore -d "$DATABASE_URL" backup.dump
# Option 3: Schema only (recreate, then migrate data app-level)
psql "$DATABASE_URL" < schema.sql
node scripts/migrate-data.js
Migrate from non-PostgreSQL (MongoDB, etc.):
// scripts/migrate-from-mongo.ts
import { MongoClient } from 'mongodb';
import { Pool } from 'pg';
const mongo = new MongoClient(process.env.MONGO_URL!);
const pg = new Pool({ connectionString: process.env.DATABASE_URL });
async function migrate() {
await mongo.connect();
const users = await mongo.db('app').collection('users').find().toArray();
await pg.query(`
CREATE TABLE IF NOT EXISTS users (
id TEXT PRIMARY KEY,
email TEXT UNIQUE,
name TEXT,
data JSONB,
created_at TIMESTAMPTZ
)
`);
for (const user of users) {
await pg.query(
'INSERT INTO users (id, email, name, data, created_at) VALUES ($1, $2, $3, $4, $5)',
[user._id.toString(), user.email, user.name, JSON.stringify(user), user.createdAt]
);
}
console.log(`Migrated ${users.length} users`);
await mongo.close();
await pg.end();
}
migrate();
Step 6: Post-Migration Checklist ## After Migration
### Configuration
- [ ] .replit configured with correct run and build commands
- [ ] replit.nix includes all system dependencies
- [ ] All env vars moved to Replit Secrets
- [ ] PORT reads from environment variable
- [ ] App listens on 0.0.0.0 (not localhost)
### Database
- [ ] PostgreSQL provisioned in Database pane
- [ ] Data imported and verified
- [ ] Connection string uses DATABASE_URL env var
- [ ] SSL configured: { rejectUnauthorized: false }
### Testing
- [ ] App runs successfully in Workspace ("Run")
- [ ] Health endpoint works: /health returns 200
- [ ] All API endpoints functional
- [ ] Auth flow works (if using Replit Auth)
- [ ] File uploads work (if using Object Storage)
### Deployment
- [ ] Deployed successfully (Autoscale or Reserved VM)
- [ ] Custom domain configured (if applicable)
- [ ] SSL certificate provisioned
- [ ] Post-deploy health check passes
### Cleanup
- [ ] Old platform deprovisioned after verification period
- [ ] DNS records updated (if custom domain)
- [ ] CI/CD updated to point to Replit
- [ ] Team notified of new deployment URL
Error Handling Issue Cause Solution Missing system package Not in replit.nix Add to deps (e.g., pkgs.openssl) Build failure Different build env Adapt build command for Replit DB connection refused Wrong SSL config Add ssl: { rejectUnauthorized: false } Port binding error Hardcoded port Read from process.env.PORT Static files not served Wrong public directory Set publicDir in deployment config
Resources
Next Steps For advanced troubleshooting after migration, see replit-advanced-troubleshooting.
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Set up and use 1Password CLI (op). Use when installing the CLI, enabling desktop app integration, signing in (single or multi-account), or reading/injecting/running secrets via op.
CLI to manage emails via IMAP/SMTP. Use `himalaya` to list, read, write, reply, forward, search, and organize emails from the terminal. Supports multiple accounts and message composition with MML (MIME Meta Language).
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Set up and use 1Password CLI (op). Use when installing the CLI, enabling desktop app integration, signing in (single or multi-account), or reading/injecting/running secrets via op.
CLI to manage emails via IMAP/SMTP. Use `himalaya` to list, read, write, reply, forward, search, and organize emails from the terminal. Supports multiple accounts and message composition with MML (MIME Meta Language).
