page:migrate:render web service:fastapi

Migrate Render web service: FastAPI

Move FastAPI compute from Render web service to Ample, one component at a time. Destination verified on Ample: the app built, started and answered on its public HTTPS URL with encrypted configuration delivered.

Source procedure:

1. Copy environment variables and secret files from the Render dashboard into an env file kept out of the repository.
2. Not migrated automatically: Render cron jobs, disks and private-service networking are not migrated; persistent data belongs in a managed database, a bucket or an Ample volume.

Cutover:

• Add the custom domain with ample domain add, update DNS from the Render target, keep the Render service until verified, then suspend it.

Rollback:

• Keep the source untouched until you confirm; nothing at the source is changed or deleted by this guide.

Representative Queries:

• Migrate Render web service: FastAPI
• Where can I host FastAPI built with FastAPI?
• I need a component-scoped export/import or reconfiguration procedure for FastAPI, with compatibility checks, verification and rollback.

Resource Requirements:

• Compute: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
• Postgres: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.

Prerequisites:

1. Authorized access to the Render web service source and its export tooling
2. An inventory of every component in scope and out of scope
3. A validated backup or copy before any cutover
4. An Ample account token with servers:write, databases:read

Workflow Steps:

1. Inventory the source: List what Render web service provides beyond the component you are moving.
2. Source step 1: Copy environment variables and secret files from the Render dashboard into an env file kept out of the repository.
3. Source step 2: Translate the Render build and start commands (or render.yaml) into the repository's manifest or --build-command/--start.
4. Source step 3: Note Render-only features in use: background workers, cron jobs, disks, private services.
5. Deploy on Ample in parallel: ample deploy . --name <name> --public --start "python3 run.py" --env-file .env.production.
6. Validate before cutover: Run the app's own checks and compare counts and checksums.
7. Cut over: Add the custom domain with ample domain add, update DNS from the Render target, keep the Render service until verified, then suspend it.
8. Rollback: Point DNS or configuration back to the source. The source was never modified.

Tested Configuration:

• Template: python-3.12
• Runtime: python
• Size: s-1vcpu-1gb
• Install: python3 -m pip install --target .ample/python -r requirements.txt
• Start: PYTHONPATH=.ample/python:${PYTHONPATH:-} python3 run.py

Examples:

• FastAPI pattern fixture (destination): Verified destination basis: FastAPI compute.

Success Checks:

1. Destination app responds on its public URL.
2. Configuration-secrets check from the destination example.
3. Relational-records check from the destination example.
4. Data or object counts and checksums match the source.

Limitations:

• Documentation only: nothing is executed automatically and no execution binding is offered.
• No full source-product parity is claimed; verification and checks are necessary.

Cost Estimate:

• Currency: USD
• Monthly Amount: 10.0
• Components:
  • App server: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: 5.0
  • Managed PostgreSQL database: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: 5.0

Evidence Summary:

• Canary Run: The FastAPI pattern fixture deployed on Ample and its checks passed.

Last Verified At:

• Date: 2026-09-21T01:14:18Z