# Host mcp server with Spring Boot: stored input and output artifacts

Deploy a mcp server built with Spring Boot on Ample using the generated downloads 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, a private S3-compatible bucket holds objects with credentials delivered as encrypted environment variables. Verified on Spring Boot: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3). Not separately tested: your export formats, retention policy and entitlement model; treat the mcp server-specific behavior as your application code.

## Representative Queries
- Host mcp server with Spring Boot: stored input and output artifacts
- Where can I host MCP server built with Spring Boot?
- I need an input/output artifact contract, object metadata and access boundaries.

## Resource Requirements
- primitive:compute
- primitive:postgres
- primitive:s3-compatible-object-storage

## Infrastructure Requirements
### Compute
- **Status**: verified  
- **Summary**: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.

### Postgres
- **Status**: verified  
- **Summary**: 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
- **Status**: verified  
- **Summary**: Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.

## Framework
- **Spring Boot**

## Workload
- **MCP server**

## Release Status
- **Published**

## Support Status
- **Verified**

## Execution Status
- **Ready**

## Prerequisites
1. 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.
2. A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env).
3. A bucket from `ample bucket create` with its credentials passed as encrypted S3_* environment variables.
4. An Ample account token with servers:write, databases:read, buckets:read.

## Tested Configuration
- **Template**: jvm-21  
- **Runtime**: java  
- **Size**: s-1vcpu-2gb  
- **Build**: ./mvnw -q -DskipTests package  
- **Start**: java -jar $(ls target/*.jar | grep -v -- '-plain' | head -n 1)

## Workflow Steps
### 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.

### Implement the pattern on PostgreSQL
- The fixture's module implements generated downloads: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.

### Wire object storage
- Create the bucket(s), then pass endpoint, region, bucket and keys as --env values. Use path-style addressing. Keep private data in an unpublished bucket.

### 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.  
**Command**: ample deploy . --name --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...

### Verify
- Fetch the live URL and the pattern self-test route(s) (/p/generated-downloads) from the example; then run your own checks. On failure read `ample logs --kind build` then `--kind runtime`.  
**Command**: ample logs --kind build

## Examples
### Spring Boot pattern fixture
- **Description**: Multi-pattern Spring Boot app whose generated downloads module was checked live; the module is under tests/deploy-canaries/_pattern-modules.  
- **Source Ref**: tests/deploy-canaries/spring-boot-patterns

## Success Checks
- **App responds on its public URL**  
  - **Kind**: http_get  
  - **Path**: /  
  - **Expect**: ample canary spring boot patterns

- **Generated-downloads self-test**  
  - **Kind**: http_get  
  - **Path**: /p/generated-downloads  
  - **Expect**: export=ok rows=3 (with ?token=...; 401 without)

## Limitations
- Verified on the jvm-21 template at s-1vcpu-2gb with the example fixture; other sizes, templates and Spring Boot major versions are not verified.
- The mcp server itself (your export formats, retention policy and entitlement model) is application code and was not separately tested; the pattern checks are what was verified.
- 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.
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified; apps and their databases are placed together.
- PutObject and GetObject with path-style addressing are verified; multipart upload, listing, presigned URLs and lifecycle rules are not verified.

## Cost Estimate
- **Currency**: USD  
- **Monthly Amount**: 10.0  
- **Authoritative**: true  
- **Basis**: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty  
- **Components**:  
   - App server: size s-1vcpu-1gb, quantity 1.0, monthly amount 5.0  
   - Managed PostgreSQL database: size s-1vcpu-1gb, quantity 1.0, monthly amount 5.0  
- **Note**: Always-on monthly price of the tested sizes; apps and databases auto-pause when idle. Buckets are allocation-priced per quota and not included.

## Evidence Summary
- **Kind**: canary_run  
- **Summary**: 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 generated-downloads and configuration-secrets. Pattern proof: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3).
- **Observed At**: 2026-09-21T02:34:39Z
- **Implementation Revision**: 1d28ae0-dirty (CLI 0.1.21)
- **Expires At**: 2027-03-20T02:34:39Z

## Last Verified At
- 2026-09-21T02:34:39Z