Claude Code gives a session a new session_id at /clear, with nothing
naming the earlier one, so keying claude_code_wait's state by session id
lost a session's waits the moment it cleared. ADR 0490 changes ADR 0489
§1: waits are now kept under the caller's name and node (by, who@node);
every op also takes session, the caller's current id, and the module
keeps a binding of the name to the session that last called for it. An
unbound name is claimed by the first call for it; a session whose own
id no longer matches the binding is refused on every op, naming the
session that holds it, until it calls the new op adopt, which always
takes the name over at once (no bound protects a recent call) and tells
the earlier session so on its own next call.
The mirrored file a hook reads stays keyed by session id (a hook only
ever has that), holding whichever name's waits are currently bound to
it; adopting rewrites both the old id's file (emptied) and the new id's
(filled) in the same call. A second mirrored file, the node-wide index,
lists every name on the node with an open wait; the SessionStart hook
now also reads it, on every start, and prints the exact adopt call for
each name, so a session with a brand new id can find and reclaim its
own waits without calling back into the module.
A session id reaching the Stop and SessionStart hooks was only checked
for blank, so "../../x" or "a/b" could read or write outside the waits
directory; both hooks now hold every session id to waitSessionID before
building any path, and allow (saying why) rather than fail on a bad one.
claude_code_wait's list/watched/done/said held only add to that same
check, letting a malformed id through as an ordinary, always-empty key;
they all refuse it now.
The Stop hook's three-strikes cap could be bypassed forever if its
counter file could not be written on a refusal: it now allows instead,
saying so, so a wait can never hold a turn open indefinitely. Its advice
offered mesh_wait on a wait's event family unconditionally, ignoring
that the session's tool runner may not be granted it (ADR 0367 §2); it
now offers mesh_wait only "if this session's tool runner is granted it,
otherwise start a watcher", and drops the family entirely when a wait
has none.
Both hooks' fail-open and let-through notices were said only on stderr,
which Claude Code does not show the operator on an allowed (exit 0)
outcome; they now also print the same words as a "systemMessage" JSON
object on stdout, which Claude Code does show.
A session is never told its session id by any tool, only by a hook's
stdin, so it cannot name itself to claude_code_wait. The plugin's
SessionStart hook (claude-code session-start <waits-dir>) prints the id
and how to give it, plus the session's still-open waits after a /clear,
reading the waits file claude_code_wait mirrors directly rather than
calling back into this module. Carries the Stop hook's command and the
GuardFiles.WaitsDir plumbing MarketplaceWith needs for both (issue 1743
wires the Stop hook's dispatch next).
jochen