page:recipes:mobile backend:axum:response streaming

Host mobile backend with Axum: streamed responses

Deploy a mobile backend built with Axum 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 Axum: 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 mobile backend-specific behavior as your application code.

Representative Queries

Resource Requirements

Infrastructure Requirements

  1. Compute
    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
    Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.

Framework

Workload

Release Status

Support Status

Execution Status

Prerequisites

Tested Configuration

Workflow Steps

  1. Build and start
    cargo build --release in the rust builder image (stable toolchain, Cargo.lock committed, pure-Rust dependencies), then the release binary on the ubuntu-24.04 template reading PORT and DATABASE_URL. The server must bind 0.0.0.0 on PORT.
  2. Implement the pattern on PostgreSQL
    The fixture's module implements streaming response service: 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). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.
  3. 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
  4. Verify
    Fetch the live URL and the pattern self-test route(s) (/p/streaming-response-service) from the example; then run your own checks. On failure read ample logs --kind build then --kind runtime.
    Command: ample logs --kind build

Success Checks

  1. App responds on its public URL
    Kind: http_get
    Path: /
    Expect: ample canary axum patterns
  2. Streaming-response-service self-test
    Kind: http_get
    Path: /p/streaming-response-service
    Expect: an SSE stream: data: id=, then chunk events one interval apart (read incrementally: first chunk within seconds, chunks spread over the interval), then data: done; /status?id= reports sent=N disconnected=true|false done=true|false

Limitations

Cost Estimate

Evidence Summary

  1. Canary Run: Axum pattern fixture deployed on Ample (cargo build --release in the rust builder image (stable toolchain, Cargo.lock committed, pure-Rust dependencies), then the release binary on the ubuntu-24.04 template reading PORT and DATABASE_URL); checks passed for streaming-response-service and configuration-secrets. Pattern proof: 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).
  2. Canary Run: The same Axum app deployed with a --release-command migration; the marker it created was readable after activation.

Last Verified At

Formats

Next Actions

  1. Browse the catalog index
    Action ID: browse-catalog
    Operation ID: catalog_index
    Method: GET
    Relative Path: /v1/catalog
  2. Search published recipes by intent, stack and constraints
    Action ID: search-recipes
    Operation ID: search_recipes
    Method: POST
    Relative Path: /v1/catalog/search
    Parameters: 
    {"body":{"limit":5,"query":"Host mobile backend with Axum: streamed responses"}}
  3. Prepare a side-effect-free deployment plan for an authorized project
    Action ID: plan:page:recipes:mobile-backend:axum:response-streaming
    Operation ID: plan_deployment
    Method: POST
    Relative Path: /v1/catalog/plan
    Parameters: 
    {"body":{"inputs":{},"projectId":"","recipeId":"page:recipes:mobile-backend:axum:response-streaming","recipeRevision":"r1"}}
  4. Read the existing agent authentication setup
    Action ID: auth-setup
    Operation ID: existing_auth_setup
    Method: GET
    Relative Path: /mcp/setup
  5. Browse Mobile backend
    Action ID: browse:workload:mobile-backend
    Operation ID: browse_node
    Method: GET
    Relative Path: /v1/catalog/nodes/workload%3Amobile-backend
  6. Browse Axum
    Action ID: browse:stack:framework-axum
    Operation ID: browse_node
    Method: GET
    Relative Path: /v1/catalog/nodes/stack%3Aframework-axum
  7. Browse Streaming response service
    Action ID: browse:pattern:streaming-response-service
    Operation ID: browse_node
    Method: GET
    Relative Path: /v1/catalog/nodes/pattern%3Astreaming-response-service
  8. Browse Deploy API
    Action ID: browse:intent:deploy-api
    Operation ID: browse_node
    Method: GET
    Relative Path: /v1/catalog/nodes/intent%3Adeploy-api