(Microsoft) GitHub Copilot already builds a semantic index of your solution in a cloud cache, which is used to give higher code intelligence than what you can get from Claude Code alone or LLM interfaces which don't have native support for the Roslyn API like GitHub Copilot does.

GitHub Copilot's semantic index can work for any SaaS repo provider (GitLab, Bitbucket, etc.) or any local repos but this requires you to opt into the feature. Repos hosted in GitHub and Azure DevOps do NOT require opting into it since Microsoft already has your code.