## The short version

Deploy an event registration built with Spring Boot on Ample using the transactional workflows pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, a managed PostgreSQL 16 database is auto-provisioned and injected as DATABASE_URL.

## WHAT WAS VERIFIED

Verified on Spring Boot: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected).

## 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.)

## PREREQUISITES

## Before you start

- A Spring Boot project that builds and starts with the documented commands (`./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 (auto-provisioned when omitted, or supplied with `--env`)
- An Ample account token with `servers:write`, `databases:read`

## STEP BY STEP

## How to do it

1. 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. 2

### Implement the pattern on PostgreSQL

The fixture's module implements transactional workflows: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected). Copy the approach into your schema; keep migrations idempotent and run them with `--release-command`.

3. 3

### Deploy

Run the synchronous deploy once and read the result (exit 0 live, 1 failed, 2 blocked). Re-running with no change is a no-op.

```
ample deploy . --name <app-name> --public
```

4. 4

### Verify

Fetch the live URL and the pattern self-test route(s) (`/p/transactional-workflows`) from the example; then run your own checks. On failure read `ample logs <deployment_id> --kind build` then `--kind runtime`.

```
ample logs <deployment_id> --kind build
```

## EXAMPLES

## Tested examples

- **Spring Boot pattern fixture** (`tests/deploy-canaries/spring-boot-patterns`): Multi-pattern Spring Boot app whose transactional workflows module was checked live; the module is under `tests/deploy-canaries/_pattern-modules`.

## SUCCESS CHECKS

## How to know it worked

- app responds on its public URL (`/` on the live URL, expect ample canary spring boot patterns)
- transactional-workflows self-test (`/p/transactional-workflows` on the live URL, expect tx=ok history=2 conflict=rejected)

## 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); checks passed for transactional-workflows and configuration-secrets. Pattern proof: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected). (expires 2027-03-20T02:34:39Z)
- canary_run on 2026-09-20T22:49:19Z at revision `af6f45adea26 (CLI af6f45a)`: The same Spring Boot app deployed with a `--release-command` migration; the marker it created was readable after activation. (expires 2027-03-19T22:49:19Z)

## 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`.

## 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 Event registration (`GET /v1/catalog/nodes/workload%3Aevent-registration` 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 Transactional workflows (`GET /v1/catalog/nodes/pattern%3Atransactional-workflows` on the api origin; authentication not required, approval not required)
- Browse Deploy web app (`GET /v1/catalog/nodes/intent%3Adeploy-web-app` on the api origin; authentication not required, approval not required)

## ABOUT THIS RECIPE

## Identifiers and status

Recipe `page:recipes:event-registration:spring-boot:relational-workflow`. Revision r1.

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

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