page:recipes:rest api:echo:artifact storage
Host rest api with Echo: stored input and output artifacts
Deploy a rest api 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 rest api-specific behavior as your application code.
Representative Queries
- Host rest api with Echo: stored input and output artifacts
- Where can I host REST API built with Echo?
- I need an input/output artifact contract, object metadata and access boundaries.
Resource Requirements
- Compute
- PostgreSQL
- S3-compatible object storage
Infrastructure Requirements
- Compute
Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes. - 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. - S3-compatible object storage
Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.
Workflow Steps
- 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. - 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. - 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 Keep private data in an unpublished bucket. - 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.ample deploy . --name --public --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=... - 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 readample logs --kind buildthen--kind runtime.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 rest api 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: $10.00
- Basis: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
- Components:
- App server (s-1vcpu-1gb): $5.00
- Managed PostgreSQL database (s-1vcpu-1gb): $5.00
- 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
Expected:ample canary echo patterns
Path:/ - Generated-downloads self-test
Expected:export=ok rows=3 (with ?token=...; 401 without)
Path:/p/generated-downloads
Example
Echo pattern fixture
Description: Multi-pattern Echo app whose generated downloads module was checked live; the module is under tests/deploy-canaries/_pattern-modules.
Source Ref: tests/deploy-canaries/echo-patterns
Next Actions
- Browse Catalog
Browse the catalog index - Search Recipes
Search published recipes by intent, stack and constraints - Prepare Deployment Plan
Prepare a side-effect-free deployment plan for an authorized project - Read Existing Agent Authentication Setup
Read the existing agent authentication setup - Browse REST API
Browse REST API - Browse Echo
Browse Echo - Browse Generated Downloads
Browse Generated downloads - Browse Deploy API
Browse Deploy API