### Configure S3-compatible access for Sinatra

#### Summary
Object storage client for a Sinatra app on Ample. Verified on Sinatra: bucket credentials delivered as encrypted S3_* environment variables and a validated PutObject/GetObject round-trip linked to a database row (upload=ok linked=ok). Build and start: bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via `rackup` (config.ru) reading PORT on the ruby-3.4 template.

#### Representative Queries
- Configure S3-compatible access for Sinatra
- Where can I host Configure S3-compatible access built with Sinatra?
- I need exact S3 endpoint, credentials, operation requirements and an upload/download verification.

#### Prerequisites
- A Sinatra project (bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via `rackup` (config.ru) reading PORT on the ruby-3.4 template)
- A bucket from `ample bucket create` with credentials passed as encrypted S3_* environment variables
- An Ample account token with servers:write, buckets:read

#### Workflow Steps
1. **Build and start**  
   bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via `rackup` (config.ru) reading PORT on the ruby-3.4 template; 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.  
   Command: `ample deploy . --name --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...`

3. **Verify**  
   Fetch the live URL and /p/browser-file-uploads on the example; on failure read the build and runtime logs.  
   Command: `ample logs --kind build`

#### Success Checks
- app responds on its public URL
- browser-file-uploads check from the example

#### Limitations
- Verified on the ruby-3.4 template at s-1vcpu-1gb; other sizes and Sinatra major versions are not verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- PutObject and GetObject with path-style addressing are verified; other S3 operations are not.

#### Cost Estimate
- **Currency**: USD  
- **Monthly Amount**: 5.0  
- **Basis**: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty  
- **Components**:  
  - name: app server  
    size: s-1vcpu-1gb  
    quantity: 1.0  
    monthlyAmount: 5.0

#### Evidence Summary
- **Summary**: Sinatra pattern fixture deployed on Ample (bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via `rackup` (config.ru) reading PORT on the ruby-3.4 template); for this guide: bucket credentials delivered as encrypted S3_* environment variables and a validated PutObject/GetObject round-trip linked to a database row (upload=ok linked=ok).
- **Observed At**: 2026-09-20T23:45:31Z

#### Tested Configuration
- **Template**: ruby-3.4
- **Runtime**: ruby
- **Size**: s-1vcpu-1gb
- **Install**: bundle config set --local path vendor/bundle && bundle config set --local without 'development test' && bundle install
- **Start**: bundle exec rackup -o 0.0.0.0 -p $PORT

#### Input Schema
- **Required**: env, name, path  
- **Properties**:  
  - env: Encrypted environment variables (max 50 items, pattern: ^[A-Z][A-Z0-9_]*=.*$)
  - name: App name (1-63 characters, pattern: ^[a-z0-9-]+$)
  - path: Project directory or ample.toml service (1-512 characters)  
  - release_command: Migration command run before activation (max 512 characters)