What data moves?

Connection direction does not tell you what data moves. A deployment can open every connection and still send commands, results, logs, errors, and telemetry to your hosted product.

hosted product              deployment
      │  command input          │
      ├────────────────────────▶│
      │◀────────────────────────┤ command result
      │◀────────────────────────┤ logs and telemetry

Path	Examples
Sent to the deployment	command inputs, HTTP requests, events
Returned to your application	command results, HTTP responses, errors
Reported to Alien	health, status, logs, telemetry

Write down the contents of each message before promising that data stays in one environment. A command that returns database rows moves those rows. A log that includes a request body moves that body.

For each path, decide what happens when the deployment cannot be reached: fail the request, retry it, or use a hosted fallback. Test that decision with the remote side unavailable.

Related: AI Gateway, Encryption Gateway, and Commands.