We are trying to verify, in a read-only way, that all processes capable of accessing a Volume-backed service have terminated before starting a scheduled data collection job.

Using Railway's API, environment.deployments returned hasNextPage=false, but it did not include a previous REMOVED deployment that was still retrievable directly by deployment ID.

We confirmed:

The current deployment has a RUNNING instance.

The immediately previous deployment's instance is REMOVED and deploymentStopped=true.

We are not trying to modify deployment state or database records; we only need to understand the scope and guarantees of Railway's read APIs.

Could you clarify:

What are the default filters and retention scope of environment.deployments? Is there a supported API/query that reliably enumerates all currently running or terminating deployments/instances for a service?

For a service with a Railway Volume attached, does Railway's single-active-mount protection guarantee that processes from a previous deployment or one-off execution can no longer access the Volume before a new deployment becomes active? Please distinguish Volume unmounting from process termination if they are separate.

Without changing configuration or restarting the service, what is the recommended read-only method to verify all current execution actors/instances and their termination state?

We are not asking Railway to determine whether our application-level collection job completed, and we are not requesting any database changes. We only want to understand the platform-level observability and guarantees.