page:recipes:graphql api:starlette:response streaming

Host GraphQL API with Starlette: Streamed Responses

Deploy a GraphQL API built with Starlette 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 Starlette: a Server-Sent Events endpoint read incrementally through the public HTTPS gateway: five one-second chunks arrived spread over time with the first within seconds (not buffered), a 70-second stream of 36 chunks completed past common 60-second idle timeouts, and a client that disconnected after two chunks was observed and recorded by the server (disconnected=true). Not separately tested: your event schema, reconnection strategy, and any per-request duration ceiling beyond the 70 seconds measured; treat the graphql api-specific behavior as your application code.

Representative Queries

• Host graphql api with Starlette: streamed responses
• Where can I host GraphQL API built with Starlette?
• I need a tested end-to-end streaming transport, timeout behavior, and client disconnect handling.

Resource Requirements

• Compute
• Postgres

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.

Prerequisites

• A Starlette project that builds and starts with the documented commands (pip install into .ample/python from requirements.txt, then uvicorn from run.py reading PORT on the python-3.12 template).
• A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env).
• An Ample account token with servers:write, databases:read.

Workflow Steps

1. Build and Start: pip install into .ample/python from requirements.txt, then uvicorn from run.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 streaming response service...
3. Deploy: Run the synchronous deploy once and read the result...
4. Verify: Fetch the live URL and the pattern self-test route(s) from the example; then run your own checks.

Success Checks

• App responds on its public URL.
• Streaming-response-service self-test.

Limitations

• Verified on the python-3.12 template at s-1vcpu-1gb with the example fixture; other sizes, templates, and Starlette major versions are not verified.
• The GraphQL API itself (your event schema, reconnection strategy, and any per-request duration ceiling beyond the 70 seconds measured) is application code and was not separately tested.

Cost Estimate

• Monthly Amount: $10.00
• 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.

Evidence Summary

• Starlette pattern fixture deployed on Ample...

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.