Module fsproto 

The file protocol between srv and agentmux-remote serve --stdio (SPEC_REMOTE_TERMINALS_AND_DURABLE_SESSIONS_2026_10_02.md §6.1, §6.3), carried over one ssh -T host -- agentmux-remote serve --stdio per connection. Shared by both ends, so they can never disagree on it.

A message is [len: u32 big-endian][body: len bytes]. A request body is [id: u32][op: u8][fields], a reply body [id: u32][status: u8][fields]; the reply carries its request’s id. Strings and byte runs are [len: u32][bytes]; numbers are big-endian. Binary, not JSON lines: the helper stays dependency-free (a few hundred KB on the host), and a file’s bytes need no escaping.

Structs

Entry

PaneFrame

The answer to Request::PaneProcs. Absent values are ones the host’s OS wouldn’t give, never zeros.

ProcFrame

The answer to Request::Procs.

ProcRow

One process in a ProcFrame. Absent values are ones the host’s OS wouldn’t give without elevation, never zeros.

Splitter

Splits a byte stream that arrives in arbitrary pieces into message bodies.

Enums

ErrKind

Why a request failed, for srv to report the way a local error would be.

Kind

What kind of thing an entry is (a symlink is reported as what it points to, with Entry::symlink set).

PaneFound

How Request::PaneProcs found the pane’s processes.

Reply

The answer to one request.

Request

What a request asks for.

Constants

MAX_MESSAGE

Largest message accepted; a longer length means a broken stream.

MAX_READ

Largest Read answered at once: a bigger file is read in ranges.

MAX_WRITE

Largest file Write takes in one message.

PROTOCOL

The protocol version both ends must share (Hello). 2 added Procs, 3 PaneProcs.