# Migrate Railway app: FastAPI

Move FastAPI compute from Railway app 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: Export variables from the Railway service (Variables tab or `railway variables`) into an env file kept out of the repository. Not migrated automatically: Railway cron schedules, volumes and private 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 Railway target, keep the Railway service until verified, then remove it. Rollback: keep the source untouched until you confirm; nothing at the source is changed or deleted by this guide.

## Workflow Steps
1. **Inventory the source**: List what Railway app provides beyond the component you are moving. Out of scope here: Railway cron schedules, volumes and private networking are not migrated; persistent data belongs in a managed database, a bucket or an Ample volume.
2. **Source step 1**: Export variables from the Railway service (Variables tab or `railway variables`) into an env file kept out of the repository.
3. **Source step 2**: Translate `railway.json`/Nixpacks settings into the repository's build and start commands; Ample detects Node and Python builds itself.
4. **Source step 3**: Note Railway-only features in use: cron schedules, volumes, private networking, templates.
5. **Deploy on Ample in parallel**: pip install into .ample/python from requirements.txt, then uvicorn from run.py reading PORT on the python-3.12 template. Pass the exported variables with --env; keep the source running.
   
   Command: `ample deploy . --name  --public --start "python3 run.py" --env-file .env.production`
6. **Validate before cutover**: Run the app's own checks and, for data, compare counts and checksums; the example checks are the pattern self-tests (/p/configuration-secrets, /p/relational-records).
7. **Cut over**: Add the custom domain with `ample domain add`, update DNS from the Railway target, keep the Railway service until verified, then remove it.
8. **Rollback**: Point DNS or configuration back to the source. The source was never modified; deletion is a separate, user-executed step after validation.

## Examples
- **FastAPI pattern fixture (destination)**: Verified destination basis: FastAPI compute.

## Success Checks
- Destination app responds on its public URL.
- Configuration-secrets check from the destination example.
- Relational-records check from the destination example.
- Data or object counts and checksums match the source.

## Limitations
- Documentation only: nothing is executed automatically and no execution binding is offered.
- The source-side procedure is documented from Railway app's standard tooling and was not executed in this catalog's evidence; the destination side was verified with the pattern fixture.
- No full source-product parity is claimed: Railway cron schedules, volumes and private networking are not migrated; persistent data belongs in a managed database, a bucket or an Ample volume.

## Cost Estimate
Monthly Amount: $10.00
Basis: Size prices from pricing.toml (loaded by the API)
- **Components**:
    - App server: s-1vcpu-1gb x1.0: $5.00
    - Managed PostgreSQL database: s-1vcpu-1gb x1.0: $5.00
Note: Destination always-on monthly price of the tested sizes; apps auto-pause when idle.

## Evidence Summary
Destination side verified: the FastAPI pattern fixture deployed on Ample and its checks passed. The source-side export from Railway app is documented from the vendor's standard tooling and was not executed by this catalog's evidence.

## Last Verified At
2026-09-21T01:14:18Z

---  
**Next Actions**:
- **Browse the catalog index**: GET /v1/catalog
- **Search published recipes by intent, stack and constraints**: POST /v1/catalog/search
- **Prepare a side-effect-free deployment plan for an authorized project**: POST /v1/catalog/plan
- **Read the existing agent authentication setup**: GET /mcp/setup
- **Browse Railway app**: GET /v1/catalog/nodes/migration%3Arailway-app
- **Browse FastAPI**: GET /v1/catalog/nodes/stack%3Aframework-fastapi
- **Browse Migrate compute**: GET /v1/catalog/nodes/intent%3Amigrate-compute.