Editor context
The agent knows what you’re looking at: the file open in the editor (and your selection) rides along with the prompt, so “this method” means something without you pasting it.
The context chip
Section titled “The context chip”A chip in the composer’s toolbar, under the prompt, shows the active file and, when you have selected code, its line range. It is not there when no document is open.
Clicking the chip toggles whether that context is shared with the session; while it is off the chip dims and shows a struck-through eye. It is per pane.
What goes out
Section titled “What goes out”A trailing icon says what is going out:
| Icon | Going out |
|---|---|
| 🔖 | the position alone: file and lines |
| 🧾 | the position plus the selected code |
The second appears only with Options → Chat → Send the selected text with the message on and a live selection: an open file with no selection has no code to attach, so it stays a bookmark.
Sending the code is what makes an unsaved buffer readable, since otherwise Claude opens the file and sees the saved version; it also costs those tokens on every message.
The chip’s tooltip says the same in words: Not sent, Sent with every message: the position, not the code, or Sent with every message, selected code included.
A message that starts with / never carries the editor context: a slash command is sent as it is.
Post-edit diagnostics
Section titled “Post-edit diagnostics”After Claude edits a file, feed back the new errors/warnings that edit introduced (diffed against the Error List before the edit). The idea is to close the edit → error → fix loop without a manual build, as the VS Code extension does.
It is currently unreliable in Visual Studio: VS only analyses files open in an editor, so right
after the edit the Error List is usually still empty and Claude gets nothing. Until that’s solved,
ask Claude to read the errors; the ide_get_diagnostics MCP tool
works, because it runs once the Error List has settled.
Enable via Options → Chat → Send post-edit diagnostics.
More than context
Section titled “More than context”The chip is what the agent is told. What it can ask Visual Studio for (references, definitions, diagnostics, builds, tests, the debugger) is in MCP tools.