page:recipes:mcp server:flask:response streaming

Host mcp server with Flask: streamed responses

Summary

Deploy a mcp server built with Flask on Ample using the streaming response service 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. Verified on Flask: a Server-Sent Events endpoint read incrementally through the public HTTPS gateway.

Representative Queries

• Host mcp server with Flask: streamed responses
• Where can I host MCP server built with Flask?
• I need a tested end-to-end streaming transport, timeout behavior and client disconnect handling.

Resource Requirements

• primitive:compute
• primitive:postgres

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.
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.

Prerequisites

• A Flask project that builds and starts with the documented commands.
• A PostgreSQL driver reading DATABASE_URL at runtime.
• An Ample account token with servers:write, databases:read.

Workflow Steps

1. Build and start
   Command: 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
   Description: The fixture's module implements streaming response service.

3. Deploy
   Command: ample deploy . --name --public --start "python3 app.py"

4. Verify
   Command: ample logs --kind build

Cost Estimate

• Currency: USD
• Monthly Amount: $10.00
• Components:
  • App server
    • Size: s-1vcpu-1gb
    • Monthly Amount: $5.00
  • Managed PostgreSQL database
    • Size: s-1vcpu-1gb
    • Monthly Amount: $5.00

Success Checks

1. App responds on its public URL

   • Kind: http_get
   • Path: /
   • Expect: ample canary flask patterns

2. Streaming-response-service self-test

   • Kind: http_get
   • Path: /p/streaming-response-service
   • Expect: an SSE stream: data: id=, ... done=true|false

Examples

• Flask pattern fixture: Multi-pattern Flask app whose streaming response service module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

Limitations

• Verified on the python-3.12 template at s-1vcpu-1gb with the example fixture.
• Other sizes, templates and Flask major versions are not verified.
• Apps auto-pause when idle and wake on the next request.

Evidence Summary

1. Canary run: Flask pattern fixture deployed on Ample.
   • Observed At: 2026-09-21
   • Summary: All checks passed.

Last Verified At

2026-09-21