1. A method for tracking a transaction flow in a distributed environment comprising at least one computer system, comprising: responsive to transactional middleware for a particular domain processing a particular transaction instance at a particular processing point specified in transaction telemetry standards as a tracking point along a flow of the particular transaction instance from a requesting domain to a requestee domain, determining, by at least one facility of the transactional middleware, whether a token with correlation data comprising a unique identifier for the particular transaction instance available to both the requesting domain and the requestee domain is passed to the particular domain in compliance with transaction telemetry standards, wherein the transaction telemetry standards specify a same set of standards for application by each separate transactional middleware instance of a plurality of middleware instances of a composite application through each of the different types of facilities of each separate middleware instance; responsive to the at least one facility of the transactional middleware not detecting the token with correlation data, generating the token with generated correlation data accessible to the particular domain comprising the unique identifier for the particular transaction instance accessible to each of the requesting domain and the requestee domain in accordance with transaction telemetry standards; and passing, by the at least one facility of the transactional middleware, the token to at least one subsequent transactional middleware instance of the plurality of middleware instances of the composite application along the flow of the particular transaction instance to uniquely identify the particular transaction instance.