The Sample Environment Communication Protocol (SECoP) serves as an international standard for the communication between sample environment equipment and the experiment control software at neutron and photon sources. It eases the integration of sample environment equipment supplied by external research groups and by industrial manufacturers. SECoP is designed to be simple, inclusive and self-describing. SECoP facilitates and structures the provision of metadata which is associated with sample environment equipment. Several existing implementations of SECoP support the development of SECoP-compatible sample environment control software. This article introduces SECoP Version 1.0, the first official version of SECoP published in September 2019. It was developed during the SINE2020 project in close cooperation with the International Society for Sample Environment. The complete specifications of SECoP Version 1.0 are available on GitHub.