maltego-trx is the legacy Python SDK for building Maltego transforms (the OSINT/graph investigation platform), now explicitly archived and superseded by the actively maintained maltego-transforms SDK. In production it runs as a Flask HTTP server: the Maltego desktop client POSTs an XML transform request to /run/<transform_name>/, the server parses it into a MaltegoMsg, dispatches to a registered transform class, and serializes the resulting MaltegoTransform response back as XML. Transform classes are auto-discovered from the project's local `transforms` package (class name must match the filename and subclass DiscoverableTransform). The package also ships a CLI (`maltego-trx start`/`init`) that scaffolds new transform projects from a template directory, plus a project-level CLI (`project.py runserver/list/local`) implemented in handler.py.