## The short version

Private file access for a Spring Boot app on Ample.

### WHAT WAS VERIFIED

Verified on Spring Boot: a role-to-document access model with negative tests (401, 403) and an authorized private-bucket round-trip (private=ok). Build and start: `./mvnw -q -DskipTests package` (or the Gradle wrapper) producing one application jar, then `java -jar` on the jvm-21 template (Temurin JDK 21) with `server.port` read from `PORT`.

## INFRASTRUCTURE

### What it needs

- [Compute](/content/discover/primitive/compute/index.html): verified (Apps run in isolated x86_64 Firecracker microVMs; sizes are the priced VM sizes.)
- [Postgres](/content/discover/primitive/postgres/index.html): 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](/content/discover/primitive/s3-compatible-object-storage/index.html): verified (Buckets are S3-compatible with issued credentials; `PutObject` and `GetObject` are verified by canary. Other S3 operations are not verified.)

## PREREQUISITES

### Before you start

- A Spring Boot project (`./mvnw -q -DskipTests package` (or the Gradle wrapper) producing one application jar, then `java -jar` on the jvm-21 template (Temurin JDK 21) with `server.port` read from `PORT`)
- A PostgreSQL driver reading `DATABASE_URL` at runtime
- A bucket from `ample bucket create` with credentials passed as encrypted `S3_*` environment variables
- An Ample account token with `servers:write`, `databases:read`, `buckets:read`

## STEP BY STEP

### How to do it

1. Build and start

`./mvnw -q -DskipTests package` (or the Gradle wrapper) producing one application jar, then `java -jar` on the jvm-21 template (Temurin JDK 21) with `server.port` read from `PORT`; the server must bind `0.0.0.0` on `PORT`.

2. Create the bucket and pass its credentials

Create it once with `ample bucket create`, then pass endpoint, region, bucket and keys with `--env`; use path-style addressing.
   
   ```
   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=...
   ```

3. Authorize before touching storage

Return `401` for unauthenticated requests and `403` for the wrong role; keep the bucket unpublished and stream objects through the app.

4. Verify

Fetch the live URL and `/p/private-document-library` on the example; on failure read the build and runtime logs.
   
   ```
   ample logs <deployment_id> --kind build
   ```

## EXAMPLES

### Tested examples

- **Spring Boot pattern fixture** (`tests/deploy-canaries/spring-boot-patterns`): Verified private file access on Spring Boot.

## SUCCESS CHECKS

### How to know it worked

- app responds on its public URL (`/` on the live URL, expect ample canary spring boot patterns)
- private-document-library check from the example (`/p/private-document-library` on the live URL, expect see the pattern fixture checks)

## COST

### Cost estimate

Estimated 10.00 USD per month (size prices from `pricing.toml` at build revision `ca0b484a7a9957c573a88d3a32dc603c3c10135a`).

- app server x1 `s-1vcpu-1gb`: 5.00 USD
- managed PostgreSQL database x1 `s-1vcpu-1gb`: 5.00 USD

Upper-bound monthly price of the tested sizes. Buckets are allocation-priced per quota and not included.

## EVIDENCE

### Verification evidence

- `canary_run` on `2026-09-21T02:34:39Z` at revision `1d28ae0 (CLI 0.1.21)`: Spring Boot pattern fixture deployed on Ample (./mvnw -q -DskipTests package (or the Gradle wrapper) producing one application jar, then `java -jar` on the jvm-21 template (Temurin JDK 21) with `server.port` read from `PORT`); for this guide: a role-to-document access model with negative tests (401, 403) and an authorized private-bucket round-trip (private=ok). (expires `2027-03-20T02:34:39Z`)

## EXECUTION

### Execution binding

MCP tool `ample_deploy` (registry `mcp:ample_deploy`), schema hash `876465fce906da0c` observed `2026-09-22T00:31:22.774679+00:00` at revision `e6446ceea69b`. Binding state at export: `schema_changed`. Required scopes: `servers:write`, `databases:read`, `buckets:read`.

## NEXT ACTIONS

### Typed next actions

- Browse the catalog index (`GET /v1/catalog` on the api origin; authentication not required, approval not required)
- Search published recipes by intent, stack and constraints (`POST /v1/catalog/search` on the api origin; authentication not required, approval not required)
- Prepare a side-effect-free deployment plan for an authorized project (`POST /v1/catalog/plan` on the api origin; authentication required, approval not required)
- Read the existing agent authentication setup (`GET /mcp/setup` on the api origin; authentication not required, approval not required)
- Browse Spring Boot (`GET /v1/catalog/nodes/stack%3Aframework-spring-boot` on the api origin; authentication not required, approval not required)
- Browse Connect app to storage (`GET /v1/catalog/nodes/intent%3Aconnect-app-to-storage` on the api origin; authentication not required, approval not required)
- Browse Private document library (`GET /v1/catalog/nodes/pattern%3Aprivate-document-library` on the api origin; authentication not required, approval not required)

Actions describe possible next steps. They are typed data, not commands, and grant no permission. Public discovery never provisions anything; planning requires your own authenticated token and approval happens in your client.

## ABOUT THIS RECIPE

### Identifiers and status

Recipe `page:guides:spring-boot:private-file-access`. Revision r1.

release **published** support **verified** execution **blocked (schema_changed: live tool schema differs from the recorded binding)**

Formats: [HTML](/content/guides/spring-boot/private-file-access/index.html) | [Markdown](/content/guides/spring-boot/private-file-access.md) | [JSON contract](https://api.ample.computer/v1/catalog/recipes/page%3Aguides%3Aspring-boot%3Aprivate-file-access)