page:recipes:mcp server:flask:artifact storage

Host MCP Server with Flask: Stored Input and Output Artifacts

Summary

Deploy a mcp server built with Flask 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 Flask: 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 mcp server-specific behavior as your application code.

Representative Queries

Resource Requirements

Infrastructure Requirements

  1. 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.
    • More Info: Compute
  2. 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.
    • More Info: Postgres
  3. 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.
    • More Info: S3

Prerequisites

Tested Configuration

Workflow Steps

  1. Build and start
    pip install into .ample/python from requirements.txt, then waitress from app.py reading PORT on the python-3.12 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 Keep private data in an unpublished bucket.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.

    ample deploy . --name <name> --public --start "python3 app.py" --env S3_ENDPOINT=<endpoint> --env S3_REGION=<region> --env S3_BUCKET=<bucket> --env S3_ACCESS_KEY_ID=<access_key> --env S3_SECRET_ACCESS_KEY=<secret_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.

    ample logs  --kind build  
    

Success Checks

  1. App Responds

    • Kind: http_get
    • Path: /
    • Expect: ample canary flask patterns
  2. Generated Downloads Self-test

    • Kind: http_get
    • Path: /p/generated-downloads
    • Expect: export=ok rows=3 (with ?token=...; 401 without)

Limitations

Cost Estimate

Cost Components

  1. App server

    • Size: s-1vcpu-1gb
    • Quantity: 1.0
    • Monthly Amount: 5.0
  2. Managed PostgreSQL database

    • Size: s-1vcpu-1gb
    • Quantity: 1.0
    • Monthly Amount: 5.0

Additional 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

Next Actions