# Enforce private-file authorization for Next.js

## Summary

Enforce private-file authorization in a Next.js app on Ample. The route handler authorizes the request first, records file metadata in a managed PostgreSQL database, stores bytes in a private bucket and streams them back only to authorized callers. The bucket is never published, so objects are reachable only through the app.

## Infrastructure requirements

- **Compute**: verified (Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.)
- **Postgres**: verified (Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.)
- **S3-compatible object storage**: verified (Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.)

## Prerequisites

- An authorization check in the route handler (session, token or header) before any storage access
- pg reading DATABASE_URL and @aws-sdk/client-s3 reading the S3_* variables
- A private bucket (never `ample bucket publish`) and an auto-provisioned or supplied PostgreSQL database
- An Ample account token with servers:write, databases:read and buckets:read

## Exact tested configuration

- template: `node-22`
- runtime: `node`
- size: `s-1vcpu-1gb`
- install: `npm install`
- build: `npm run build --if-present`
- start: `npm run start`

## Steps

1. **Authorize before touching storage.** Return 401 for unauthenticated requests; never expose object keys or the bucket endpoint to the browser.
2. **Record metadata in PostgreSQL.** Keep the owner, name and object key in a table so authorization decisions come from your data, not from the bucket.
3. **Store and stream through the app.** PutObject on upload, GetObject on download, both server-side with the injected credentials.
   
   ```
   ample deploy . --name <app-name> --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=... 
   ```
4. **Test both paths.** An unauthenticated request must return 401; an authorized request must return the stored content.
5. **Verify.** Fetch the live URL and run the success checks below. On failure read the build log, then the runtime log, fix the cause and deploy again; do not blind-retry.
   
   ```
   ample logs <deployment_id> --kind build
   ```

## Tested examples

- **Next.js private files canary** (tests/deploy-canaries/next-private-files): 401 without a token; private=ok with the token after a database write and a bucket round-trip.

## Success checks

- unauthenticated request is rejected (`/files/demo` on the live URL, expect unauthorized)
- authorized request returns the private object (`/files/demo?token=<token>` on the live URL, expect private=ok)

## Limitations

- Verified on the node-22 template at s-1vcpu-1gb; other templates and sizes are not verified by this recipe.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- Apps auto-pause when idle and wake on the next request; always-on is an operator setting, not a plan feature.
- PutObject and GetObject with path-style addressing are verified; multipart upload, listing, presigned URLs and lifecycle rules are not verified.
- Bucket credentials are passed as encrypted environment variables; the catalog never creates the bucket for you (use `ample bucket create`).
- Storage is allocation-priced per bucket quota and capped by the account plan; the estimate below covers compute only.
- Authorization is application code; Ample does not provide managed end-user authentication.
- Streaming large files through the app is not verified; the fixture uses small text objects.

## Cost estimate

Estimated 10.00 USD per month (size prices from pricing.toml at build revision a1b8c38919e59cd035ebabaced73cf84ece24371).
- app server x1 `s-1vcpu-1gb`: 5.00 USD
- managed PostgreSQL database x1 `s-1vcpu-1gb`: 5.00 USD

Apps and managed databases auto-pause when idle; the estimate is the always-on monthly price of the tested sizes. Plan quotas and budgets apply.

## Verification evidence

- canary_run on 2026-09-20T01:13:26Z at revision `cc3d82057f1d5e9aa31f682cee71aabfbbbcaabe-dirty (CLI e3181f5)`: Next.js route handler that rejects unauthenticated requests with 401, records file metadata in an auto-provisioned managed PostgreSQL database, stores the bytes in a private bucket and streams them back only after authorization (private=ok). (expires 2027-03-19T01:13:26Z)
- canary_run on 2026-09-20T01:13:26Z at revision `cc3d82057f1d5e9aa31f682cee71aabfbbbcaabe-dirty (CLI e3181f5)`: ample bucket create issued credentials; PutObject and GetObject succeeded through the public S3 endpoint; publish exposed the object through the CDN host with an ETag; unpublish and delete cleaned up. (expires 2027-03-19T01:13:26Z)

Last verified: 2026-09-20T01:13:26Z

## Execution binding

MCP tool `ample_deploy` (registry `mcp:ample_deploy`), schema hash `876465fce906da0c` observed 2026-09-20T01:55:48.667900+00:00 at revision `199ff1dfd526`, binding state `current`, required scopes: servers:write, databases:read, buckets:read.