# Host asset library with Phoenix: file attachments

## Summary
Deploy an asset library built with Phoenix 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 Phoenix: 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 asset library-specific behavior as your application code.

## Representative Queries
- Host asset library with Phoenix: file attachments
- Where can I host Asset library built with Phoenix?
- I need a restricted upload flow, file validation and record-to-object linkage.

## Resource Requirements
- Compute
- PostgreSQL
- 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.

## Prerequisites
- A Phoenix project that builds and starts with the documented commands (mix deps.get, MIX_ENV=prod mix compile and mix release in the builder, then the release bin script with PHX_SERVER=true on the elixir-1.18 template; PORT, DATABASE_URL and SECRET_KEY_BASE read in config/runtime.exs)
- 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

## Workflow Steps
1. **Build and start**  
   mix deps.get, MIX_ENV=prod mix compile and mix release in the builder, then the release bin script with PHX_SERVER=true on the elixir-1.18 template; PORT, DATABASE_URL and SECRET_KEY_BASE read in config/runtime.exs. 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

## Limitations
- Verified on the elixir-1.18 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Phoenix major versions are not verified.
- The asset library 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.

## 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: s-1vcpu-1gb, Quantity: 1.0, Monthly Amount: 5.0  
   - Managed PostgreSQL database: 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.

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

- **Browser-file-uploads self-test**  
   - **Kind:** http_get  
   - **Path:** /p/browser-file-uploads  
   - **Expect:** reject=ok upload=ok linked=ok

## Evidence Summary
- **Kind:** canary_run  
   **Summary:** Phoenix pattern fixture deployed on Ample (mix deps.get, MIX_ENV=prod mix compile and mix release in the builder, then the release bin script with PHX_SERVER=true on the elixir-1.18 template; PORT, DATABASE_URL and SECRET_KEY_BASE read in config/runtime.exs); checks passed for browser-file-uploads and configuration-secrets.
   - **Observed At:** 2026-09-20T23:45:31Z
   - **Implementation Revision:** 4d1511e574302f3904b75088bd4048a0975218b3-dirty (CLI 0.1.21)
   - **Expires At:** 2027-03-19T23:45:31Z

- **Kind:** canary_run  
   **Summary:** The same Phoenix app deployed with a --release-command migration; the marker it created was readable after activation.
   - **Observed At:** 2026-09-20T23:45:31Z
   - **Implementation Revision:** 4d1511e574302f3904b75088bd4048a0975218b3-dirty (CLI 0.1.21)
   - **Expires At:** 2027-03-19T23:45:31Z

## Next Actions
- **Browse the catalog index**  
   - **Action ID:** browse-catalog  
   - **Method:** GET  
   - **Relative Path:** /v1/catalog  
   - **Requires Authentication:** false

- **Search published recipes by intent, stack and constraints**  
   - **Action ID:** search-recipes  
   - **Method:** POST  
   - **Relative Path:** /v1/catalog/search  
   - **Parameters:**  
     - Body: {"limit":5,"query":"Host asset library with Phoenix: file attachments"}  
   - **Requires Authentication:** false

- **Prepare a side-effect-free deployment plan for an authorized project**  
   - **Action ID:** plan:page:recipes:asset-library:phoenix:attachments  
   - **Method:** POST  
   - **Relative Path:** /v1/catalog/plan  
   - **Requires Authentication:** true

- **Read the existing agent authentication setup**  
   - **Action ID:** auth-setup  
   - **Method:** GET  
   - **Relative Path:** /mcp/setup  
   - **Requires Authentication:** false

- **Browse Asset library**  
   - **Action ID:** browse:workload:asset-library  
   - **Method:** GET  
   - **Relative Path:** /v1/catalog/nodes/workload%3Aasset-library  
   - **Requires Authentication:** false

- **Browse Phoenix**  
   - **Action ID:** browse:stack:framework-phoenix  
   - **Method:** GET  
   - **Relative Path:** /v1/catalog/nodes/stack%3Aframework-phoenix  
   - **Requires Authentication:** false

- **Browse Browser file uploads**  
   - **Action ID:** browse:pattern:browser-file-uploads  
   - **Method:** GET  
   - **Relative Path:** /v1/catalog/nodes/pattern%3Abrowser-file-uploads  
   - **Requires Authentication:** false

- **Browse Deploy web app**  
   - **Action ID:** browse:intent:deploy-web-app  
   - **Method:** GET  
   - **Relative Path:** /v1/catalog/nodes/intent%3Adeploy-web-app  
   - **Requires Authentication:** false