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

#### Summary
Deploy an AI chat application built with NestJS 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`, and a private S3-compatible bucket holds objects with credentials delivered as encrypted environment variables. Verified on NestJS: 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).

#### Representative Queries
- Host AI chat application with NestJS: stored input and output artifacts
- Where can I host an AI chat application built with NestJS?
- 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
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.  
   (Verified)

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.  
   (Verified)

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.  
   (Verified)

#### Prerequisites
- A NestJS project that builds and starts with the documented commands (`npm install`, `nest build` (TypeScript) then `node dist/main.js` 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`

#### Workflow Steps
1. **Build and Start**  
   `npm install`, `nest build` (TypeScript) then `node dist/main.js` 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 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`

#### Success Checks
- The app responds on its public URL (`/`). Expected output: `ample canary nestjs patterns`
- Generated-downloads self-test at path `/p/generated-downloads`. Expected output: `export=ok rows=3 (with ?token=...; 401 without)`.

#### Limitations
- Verified on the `node-22` template at `s-1vcpu-1gb` with the example fixture; other sizes, templates, and NestJS 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.

#### Cost Estimate
- **Currency:** USD
- **Monthly Amount:** 10.0
- **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
- **NestJS pattern fixture** deployed on Ample (npm install, nest build (TypeScript) then node dist/main.js on the node-22 template); checks passed for generated-downloads and configuration-secrets. 
- The same NestJS app deployed with a `--release-command` migration; the marker it created was readable after activation.

### Next Actions
- **Browse the catalog index**
   - Action ID: `browse-catalog`
   - Method: `GET`
   - Relative Path: `/v1/catalog`
   - Requires Authentication: No

- **Search published recipes by intent, stack, and constraints**
   - Action ID: `search-recipes`
   - Method: `POST`
   - Relative Path: `/v1/catalog/search`
   - Requires Authentication: No

- **Prepare a side-effect-free deployment plan for an authorized project**
   - Action ID: `plan:page:recipes:ai-chat-application:nestjs:artifact-storage`
   - Method: `POST`
   - Relative Path: `/v1/catalog/plan`
   - Requires Authentication: Yes

- **Read the existing agent authentication setup**
   - Action ID: `auth-setup`
   - Method: `GET`
   - Relative Path: `/mcp/setup`
   - Requires Authentication: No

- **Browse AI chat application**
   - Action ID: `browse:workload:ai-chat-application`
   - Method: `GET`
   - Relative Path: `/v1/catalog/nodes/workload%3Aai-chat-application`
   - Requires Authentication: No