Known issues

Contract

1. Using transaction hashes as resource IDs is not user- and URL- friendly, and will create issues if bulk create endpoints are introduced. An alternative approach would be to use an ID generator and provide the IDs in the response body. Seems like this will require assigning IDs prior to actually sending transactions.
2. Have to figure out a means to use URL templates with path variables, as using parent resource IDs (such as lot ID in bid placement) as query string or request entity body parameters looks like a poor contract definition.

Implementation

1. Since ServiceApiBuilder wires endpoints to static methods, a single blocking endpoint and the after_commit callback synchronize on a global state. While the attempt was to make it as safe as possible, this is still unsafe...
2. The same blocking endpoint blocks indefinitely since pub-sub does not provide a timed wait API, and it seems there is little use in launching a thread for this since there's no way to terminate a thread externally.
3. Integration tests should be more deterministic and use some means of thread communication instead of a fixed delay before block commits.