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

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

## Prerequisites
- A Gin project that builds and starts with the documented commands (CGO_ENABLED=0 go build -o app ./... then ./app on the ubuntu-24.04 template (go.sum committed for a reproducible build))
- 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**: ubuntu-24.04
- **Runtime**: go
- **Size**: s-1vcpu-1gb
- **Build command**: CGO_ENABLED=0 go build -o app ./...
- **Start command**: ./app

## 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 Keep private data in an unpublished bucket.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 <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

## Examples
- **Gin Pattern Fixture**: Multi-pattern Gin 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**
  - **Kind**: http_get
  - **Path**: /
  - **Expect**: ample canary gin patterns
- **Generated-downloads self-test**
  - **Kind**: http_get
  - **Path**: /p/generated-downloads
  - **Expect**: export=ok rows=3 (with ?token=...; 401 without)

## Limitations
- Verified on the ubuntu-24.04 template at s-1vcpu-1gb with the example fixture; other sizes, templates, and Gin 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.