What
The command and arguments for a stdio MCP server are no longer handed straight to the connection; they pass through a helper tagged mcp that can rewrite them and reports back whether the launch was deferred or capped. A per-server exemption bypasses the helper entirely.
Details
- The helper returns
pendingandcappedflags, both false in the ordinary case. - On a successful connection the server's process id gets extra bookkeeping when the launch was pending or capped, on top of the existing registration.
- Whether the helper defers the launch or wraps the command in a placement prefix is not determinable from the shipped code.
Evidence
pending: !1, capped: !1
Strings lifted out of the shipped bundle, so the claim above can be checked against them.