### Host AI Chat Application with Echo: Stored Input and Output Artifacts

**Family:** Workload recipe  
**Summary:** Deploy a AI chat application built with Echo 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 Echo: 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 AI chat application-specific behavior as your application code.

### Representative Queries
- Host AI chat application with Echo: stored input and output artifacts  
- Where can I host AI chat application built with Echo?  
- I need an input/output artifact contract, object metadata and access boundaries.

### Parent IDs
- workload:ai-chat-application  
- stack:framework-echo  
- pattern:generated-downloads  
- intent:deploy-ai-app

### 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.

### Workflow Steps
1. **Build and start**  
   CGO_ENABLED=0 go build -o app ./... then ./app on the ubuntu-24.04 template (go.sum committed for a reproducible build). The server must bind 0.0.0.0 on PORT.

2. **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.

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/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

### Limitations
- Verified on the ubuntu-24.04 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Echo major versions are not verified.  
- The AI chat application 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.

### Cost Estimate
- **Currency:** USD  
- **Monthly Amount:** 10.0  
- **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.

### Examples
- **Echo pattern fixture:** Multi-pattern Echo app whose generated downloads module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

### Success Checks
- App responds on its public URL: **HTTP GET** at path /, expect: ample canary echo patterns  
- Generated-downloads self-test: **HTTP GET** at path /p/generated-downloads, expect: export=ok rows=3 (with ?token=...; 401 without)

### Next Actions
- **[Browse the catalog index](#)**  
- **[Search published recipes by intent, stack and constraints](#)**  
- **[Prepare a side-effect-free deployment plan for an authorized project](#)**  
- **[Read the existing agent authentication setup](#)**  
- **[Browse AI chat application](#)**  
- **[Browse Echo](#)**  
- **[Browse Generated downloads](#)**  
- **[Browse Deploy AI app](#)**

### Document Links
- **[HTML Documentation](/content/recipes/ai-chat-application/echo/artifact-storage/index.html)**  
- **[Markdown Documentation](/content/recipes/ai-chat-application/echo/artifact-storage.md)**  
- **[JSON Documentation](https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Aai-chat-application%3Aecho%3Aartifact-storage)