page:recipes:ai chat application:echo:artifact storage

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

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