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Frequently Asked Questions

Common questions about using Builder Backend.

General​

What is Builder Backend?​

Builder Backend generates production-ready FastAPI projects from specifications. Define your data model and configuration, download a complete backend with auth, payments, storage, and deployment pipelines.

Is the generated code mine?​

Yes! Generated projects are MIT licensed—you own the code completely. Modify, deploy, sell, do whatever you want with it.

Do you host the generated backend?​

No. You download a ZIP and deploy it yourself (AWS, Azure, GCP, or any hosting). We provide CI/CD pipelines to make deployment easy.

What tech stack is generated?​

  • Python 3.12+
  • FastAPI (async)
  • PostgreSQL
  • SQLAlchemy 2 (async)
  • Alembic migrations
  • pytest
  • Docker & Docker Compose
  • (Optional) Redis, Keycloak, ClamAV

Pricing​

How much does it cost?​

Currently in beta—free to use. Pricing to be announced.

Do I need to pay for each generated project?​

No. Once you generate a project, it's yours forever. No recurring fees from us.

Are there usage limits?​

During beta: reasonable use. Exact limits TBD.

Features​

Can I modify the generated code?​

Yes! That's the point. The generated code is clean, documented, and maintainable. Make it yours.

Does it support my database?​

PostgreSQL only. The generated projects use PostgreSQL-specific features (JSONB, advisory locks, etc.).

Can I use MongoDB / MySQL?​

Not currently. PostgreSQL only.

What authentication methods are supported?​

  • Email/password
  • Magic link (email)
  • SMS code (Twilio, Vonage, AWS SNS)
  • Phone + password
  • Keycloak SSO (Google, Microsoft, GitHub, generic OIDC)

What payment providers?​

  • Stripe Checkout
  • Razorpay Payment Links

Payments are optional—only add if you need them.

Can I accept file uploads?​

Yes! S3 or S3-compatible storage (MinIO, SeaweedFS, etc.) with automatic malware scanning (ClamAV).

Technical​

Can I preview before downloading?​

Yes! POST /projects/{id}/generate/preview shows what will be generated (file tree, dependencies).

How do I run the generated project locally?​

cd generated-project
docker compose up --build

That's it. It includes PostgreSQL, the API, and any optional services (Redis, Keycloak, ClamAV, etc.).

Do I need Docker?​

For local development: highly recommended. For production: no, you can deploy however you want.

Can I generate without Docker?​

Yes, but you'll need to:

  • Install PostgreSQL
  • Set up environment variables
  • Run Alembic migrations manually
  • Install Python dependencies

Docker Compose handles all of this.

What if I find a bug in generated code?​

  1. Check if it's a known issue
  2. Report it (GitHub issues or support)
  3. We'll fix the generator and you can regenerate

Or just fix it yourself—it's your code!

Can I regenerate a project?​

Yes. Regenerating creates a new project. Compare and merge changes manually if you've modified the code.

Best practice: Don't modify the generated code extensively. Use it as a base and extend it.

Security​

Where are my secrets stored?​

They're not. Secrets (SMTP passwords, API keys, etc.) are:

  • Never stored in Builder Backend
  • Never put in the generated ZIP
  • Environment variables in your deployment

Is the generated code secure?​

Yes. We follow security best practices:

  • No secrets in code
  • Parameterized SQL queries
  • Rate limiting
  • Audit logs (append-only, hash-chained)
  • Security headers
  • Input validation

But you're responsible for deployment security (secrets management, HTTPS, firewall, etc.).

Can I see a security audit?​

Not yet. Coming soon.

Deployment​

Which cloud providers are supported?​

Generated CI/CD pipelines for:

  • AWS (ECS Fargate, RDS, secrets in Secrets Manager)
  • Azure (Container Apps, PostgreSQL Flexible Server)
  • Google Cloud (Cloud Run, Cloud SQL)

Deploy anywhere else manually—it's just a Docker container.

Do I need Terraform?​

No, but it's included. You can deploy manually if you prefer.

Can I use Kubernetes?​

Yes! Kubernetes manifests are included (optional) in the generated deployment files.

How do I set up CI/CD?​

The generated project includes:

  • GitHub Actions workflows
  • Terraform for cloud resources
  • Docs in deploy/DEPLOYMENT.md

Just add your cloud credentials as GitHub secrets.

Limits & Constraints​

Can I have circular relations?​

No. Validation catches this and rejects it.

Maximum number of entities?​

No hard limit, but keep it reasonable (< 100 entities).

Can I have computed fields?​

Not directly. You can add them to the generated code yourself.

Can I customize the generated code format?​

Not yet. Generated code follows our style guide. Modify it after generation.

Troubleshooting​

"Validation error: ..."​

Check the dashboard for detailed error messages. Each validation error includes specific instructions on how to fix it.

"Generated project won't start"​

  1. Check Docker is running
  2. Check .env file has all required variables
  3. Check docker compose logs
  4. See the generated README.md for troubleshooting

"Migration fails"​

  1. Check database is running
  2. Check DATABASE_URL is correct
  3. Run alembic upgrade head manually
  4. Check logs for specific error

Downloads expired​

Downloads are available for 30 days after generation. Regenerate if expired.

Getting Help​

How do I contact support?​

Can I request features?​

Yes! Open a GitHub issue or contact support.

Is there a community?​

Coming soon. Watch for announcements.

Didn't find your answer? Check the Troubleshooting guide or contact support.

For AI agents: This is the FAQ page covering common questions. Prerequisites: None. Related: Troubleshooting. Common tasks: Users search here for quick answers before diving into detailed docs.

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