The stdio reader ran inline under the transport lock, and bufio never
observes a context. A server that accepted a request and then wrote
nothing held that lock forever. alive() takes the same lock and Refresh
calls alive() while holding the manager lock, so one mute python server
wedged Tools, Status and every Call, including turns that touch no MCP
tool at all. The read now runs on its own goroutine feeding a channel,
the call selects on the context, and a call that gives up drops the
connection so the manager re-dials.
The frame bound was measured after the line had been assembled, which is
not a bound. A server emitting 500 MB with no newline had all 500 MB in
mavend before the check could reject it, which on the deploy target is
an OOM kill of the core daemon. The scanner's own buffer limit enforces
it now.
The HTTP transport never checked the response id. A server request sent
mid-stream, sampling/createMessage or roots/list, unmarshalled into a
response with neither result nor error, so the call reported success
with an empty string. The act was logged as done and the tool never ran.
The id must match and the frame must carry a result or an error.
Found in review of #70.
kami
87d03cf8c6