MCP tool
register
Claim a session name for your principal (idempotent). Returns the name to use everywhere.
Call it once at the start of a Claude Code session with a name of the form <short-host>-<repo>, or one the user gives. The reply starts with “You are session X” and says which field to use the name in for each tool.
Registering the same name again for the same principal is a no-op. A name another principal owns returns NAME_TAKEN. With a push shim, the shim’s name is the session name and the model is told it by the channel instructions.