## The short version

CDN assets for a Spring Boot app on Ample.

## WHAT WAS VERIFIED

Verified on Spring Boot: a versioned, immutable-cached asset uploaded to a published bucket and served from the CDN URL. 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.)
- [CDN](/content/discover/primitive/cdn/index.html): verified (A published bucket's objects are served at its `public_url`. It does not front app compute and is not a cache or key-value store.)

## 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 bucket from `ample bucket create` with credentials passed as encrypted `S3_*` environment variables
- An Ample account token with `servers:write`, `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. **Publish a bucket for public assets**  
   Publish only the asset bucket; upload versioned keys with an immutable Cache-Control header and build URLs from its public URL.  
   ```
   ample bucket publish <bucket-name>
   ```

3. **Verify**  
   Fetch the live URL and `/p/versioned-static-assets` 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 CDN assets 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)
- versioned-static-assets check from the example (`/p/versioned-static-assets` on the live URL, expect see the pattern fixture checks)

## COST

### Cost estimate

Estimated 5.00 USD per month (size prices from pricing.toml at build revision ca0b484a7a9957c573a88d3a32dc603c3c10135a).

- app server 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 versioned, immutable-cached asset uploaded to a published bucket and served from the CDN URL. (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`, `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 Add CDN (`GET /v1/catalog/nodes/intent%3Aadd-cdn` on the api origin; authentication not required, approval not required)
- Browse Versioned static assets (`GET /v1/catalog/nodes/pattern%3Aversioned-static-assets` 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:cdn-assets`. Revision r1.

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

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