Host form collection with SvelteKit: file attachments

Deploy a form collection built with SvelteKit on Ample using the browser file uploads 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 SvelteKit: content-type and size validation that rejects disallowed files, an object written to a private bucket and a row linking the record to the object key (reject=ok upload=ok linked=ok). Not separately tested: your upload UI, allowed types, size limits and virus scanning; treat the form collection-specific behavior as your application code.

Representative Queries

• Host form collection with SvelteKit: file attachments
• Where can I host Form collection built with SvelteKit?
• I need a restricted upload flow, file validation and record-to-object linkage.

Resource Requirements

• primitive:compute
• primitive:postgres
• primitive:s3-compatible-object-storage

Infrastructure Requirements

1. Compute: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
2. Postgres: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.
3. S3-compatible object storage: Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.

Prerequisites

• A SvelteKit project that builds and starts with the documented commands (vite build with @sveltejs/adapter-node then node build on the node-22 template)
• A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env)
• A bucket from ample bucket create with its credentials passed as encrypted S3_* environment variables
• An Ample account token with servers:write, databases:read, buckets:read

Tested Configuration

• Template: node-22
• Runtime: node
• Size: s-1vcpu-1gb
• Install: npm install
• Build: npm run build --if-present
• Start: npm run start

Workflow Steps

1. Build and start: vite build with @sveltejs/adapter-node then node build on the node-22 template. The server must bind 0.0.0.0 on PORT.
2. Implement the pattern on PostgreSQL: The fixture's module implements browser file uploads: content-type and size validation that rejects disallowed files, an object written to a private bucket and a row linking the record to the object key (reject=ok upload=ok linked=ok). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.
3. 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.
4. 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=...
5. Verify: Fetch the live URL and the pattern self-test route(s) (/p/browser-file-uploads) from the example; then run your own checks. On failure read ample logs --kind build then --kind runtime. Command: ample logs --kind build

Examples

SvelteKit pattern fixture

Description: Multi-pattern SvelteKit app whose browser file uploads module was checked live; the module is under tests/deploy-canaries/_pattern-modules. Source Ref: tests/deploy-canaries/sveltekit-patterns

Success Checks

1. App responds on its public URL: Kind: http_get, Path: /, Expect: ample canary sveltekit patterns
2. Browser-file-uploads self-test: Kind: http_get, Path: /p/browser-file-uploads, Expect: reject=ok upload=ok linked=ok

Limitations

• Verified on the node-22 template at s-1vcpu-1gb with the example fixture; other sizes, templates and SvelteKit major versions are not verified.
• The form collection itself (your upload UI, allowed types, size limits and virus scanning) 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
• 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, monthlyAmount: 5.0
  • Managed PostgreSQL database: size: s-1vcpu-1gb, quantity: 1.0, monthlyAmount: 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.

Next Actions

• Browse the catalog index: method: GET, relativePath: /v1/catalog
• Search published recipes: method: POST, relativePath: /v1/catalog/search
• Prepare a deployment plan: method: POST, relativePath: /v1/catalog/plan
• Read existing authentication setup: method: GET, relativePath: /mcp/setup
• Browse Form collection: method: GET, relativePath: /v1/catalog/nodes/workload%3Aform-collection
• Browse SvelteKit: method: GET, relativePath: /v1/catalog/nodes/stack%3Aframework-sveltekit
• Browse Browser file uploads: method: GET, relativePath: /v1/catalog/nodes/pattern%3Abrowser-file-uploads
• Browse Deploy web app: method: GET, relativePath: /v1/catalog/nodes/intent%3Adeploy-web-app