What access to my code hosting service do you require?
You won’t need to provide CodeStream with any Git (or GitHub, Bitbucket, etc.) credentials, as the extension simply leverages your IDE’s access to Git. CodeStream uses Git to do things like automatically mention the most recent author when you comment on a block of code, and to maintain the connection between that block of code and where it’s located in the source file as the file evolves over time (and commits).
CodeStream does have integrations with GitHub, GitLab and Bitbucket to provide additional features, such as the ability to review pull requests. But, they are not needed for CodeStream's core code discussion and feedback request functionality.