Improved session state management in hooks

CHANGELOG.md

@@ -8,6 +8,11 @@ Migration details for `/agent-memory update` live in [`skills/agent-memory/vendo
 
 ## [Unreleased]
 
+### Fixed
+
+- Hooks: `_rebind_session_state_unlocked` preserves `session_binding_host` from `.hook-sync-state` when `AGENT_MEMORY_HOST` is unset; sync harness configs now set `AGENT_MEMORY_HOST` on checkpoint commands (re-run hooks installer to pick up).
+- Hooks: `refresh_branch_cache` updates `branch` and clears `session_touched_files` under one lock; fail-open skips both (no path wipe without branch update).
+
 ## [0.1.1] - 2026-07-31
 
 ### Added

hooks/agent-memory-hooks/agent-memory-common.sh

@@ -250,6 +250,9 @@ _rebind_session_state_unlocked() {
   local host="${AGENT_MEMORY_HOST:-}"
   local day tmp
   day=$(_today_ymd)
+  if [ -z "$host" ]; then
+    host=$(read_state session_binding_host "")
+  fi
   case "$sid" in
     *$'\n'* | *$'\r'*)
       printf 'agent-memory: write_session_binding refused newline in sid\n' >&2
@@ -377,13 +380,25 @@ reset_session_state_if_changed() {
 
 refresh_branch_cache() {
   [ -n "${cwd:-}" ] || return 0
-  local b last
+  local b
   b=$(git -C "$cwd" branch --show-current 2>/dev/null || true)
   [ -n "$b" ] || return 0
+  agent_memory_with_state_lock _refresh_branch_cache_unlocked "$b"
+}
+
+_refresh_branch_cache_unlocked() {
+  local b=$1 last
+  if [ "${AGENT_MEMORY_LOCK_ACQUIRED:-0}" != "1" ]; then
+    printf 'agent-memory: skip branch cache refresh (lock not held)\n' >&2
+    return 0
+  fi
   last=$(read_state branch "")
-  write_state branch "$b"
-  if [ -n "$last" ] && [ "$last" != "$b" ]; then
-    _clear_session_path_state
+  if [ "$last" = "$b" ]; then
+    return 0
+  fi
+  _write_state_unlocked branch "$b"
+  if [ -n "$last" ]; then
+    _write_state_unlocked session_touched_files ""
   fi
 }
 

hooks/agent-memory-hooks/agent-memory-sync.sh

@@ -6,6 +6,9 @@
 #
 # Reads harness stdin JSON when present (session_id, cwd).
 # Session ID also from AGENT_MEMORY_SESSION_ID env or state.
+# Set AGENT_MEMORY_HOST to the harness name when possible (cursor | claude |
+# codex | copilot | opencode | gemini); when omitted, rebind preserves
+# session_binding_host from .hook-sync-state.
 #
 # Set AGENT_MEMORY_EVENT (any host naming):
 #   afterAgentResponse | Stop | agentStop | AfterAgent — end of turn

hooks/claude-code/settings.json

@@ -17,7 +17,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "AGENT_MEMORY_EVENT=Stop .claude/hooks/agent-memory-sync.sh",
+            "command": "AGENT_MEMORY_HOST=claude AGENT_MEMORY_EVENT=Stop .claude/hooks/agent-memory-sync.sh",
             "timeout": 15
           }
         ]
@@ -29,7 +29,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "AGENT_MEMORY_EVENT=PreCompact .claude/hooks/agent-memory-sync.sh",
+            "command": "AGENT_MEMORY_HOST=claude AGENT_MEMORY_EVENT=PreCompact .claude/hooks/agent-memory-sync.sh",
             "timeout": 15
           }
         ]

hooks/codex/config.toml.snippet

@@ -17,14 +17,14 @@
 #   [[hooks.Stop]]
 #     [[hooks.Stop.hooks]]
 #     type    = "command"
-#     command = ["sh", "-c", "AGENT_MEMORY_EVENT=Stop .codex/hooks/agent-memory-sync.sh"]
+#     command = ["sh", "-c", "AGENT_MEMORY_HOST=codex AGENT_MEMORY_EVENT=Stop .codex/hooks/agent-memory-sync.sh"]
 #     timeout = 15
 #
 #   [[hooks.PreCompact]]
 #   matcher = "auto|manual"
 #     [[hooks.PreCompact.hooks]]
 #     type    = "command"
-#     command = ["sh", "-c", "AGENT_MEMORY_EVENT=PreCompact .codex/hooks/agent-memory-sync.sh"]
+#     command = ["sh", "-c", "AGENT_MEMORY_HOST=codex AGENT_MEMORY_EVENT=PreCompact .codex/hooks/agent-memory-sync.sh"]
 #     timeout = 15
 #
 # After adding project hooks, run `/hooks` in the Codex TUI to trust them.

hooks/codex/hooks.json

@@ -17,7 +17,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "AGENT_MEMORY_EVENT=Stop .codex/hooks/agent-memory-sync.sh",
+            "command": "AGENT_MEMORY_HOST=codex AGENT_MEMORY_EVENT=Stop .codex/hooks/agent-memory-sync.sh",
             "timeout": 15
           }
         ]
@@ -29,7 +29,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "AGENT_MEMORY_EVENT=PreCompact .codex/hooks/agent-memory-sync.sh",
+            "command": "AGENT_MEMORY_HOST=codex AGENT_MEMORY_EVENT=PreCompact .codex/hooks/agent-memory-sync.sh",
             "timeout": 15
           }
         ]

hooks/copilot/agent-memory.json

@@ -11,14 +11,14 @@
     "agentStop": [
       {
         "type": "command",
-        "bash": "AGENT_MEMORY_EVENT=agentStop .github/hooks/agent-memory-sync.sh",
+        "bash": "AGENT_MEMORY_HOST=copilot AGENT_MEMORY_EVENT=agentStop .github/hooks/agent-memory-sync.sh",
         "timeoutSec": 15
       }
     ],
     "preCompact": [
       {
         "type": "command",
-        "bash": "AGENT_MEMORY_EVENT=preCompact .github/hooks/agent-memory-sync.sh",
+        "bash": "AGENT_MEMORY_HOST=copilot AGENT_MEMORY_EVENT=preCompact .github/hooks/agent-memory-sync.sh",
         "timeoutSec": 15
       }
     ]

hooks/cursor/hooks.json

@@ -9,13 +9,13 @@
     ],
     "afterAgentResponse": [
       {
-        "command": "AGENT_MEMORY_EVENT=afterAgentResponse .cursor/hooks/agent-memory-sync.sh",
+        "command": "AGENT_MEMORY_HOST=cursor AGENT_MEMORY_EVENT=afterAgentResponse .cursor/hooks/agent-memory-sync.sh",
         "timeout": 15
       }
     ],
     "preCompact": [
       {
-        "command": "AGENT_MEMORY_EVENT=preCompact .cursor/hooks/agent-memory-sync.sh",
+        "command": "AGENT_MEMORY_HOST=cursor AGENT_MEMORY_EVENT=preCompact .cursor/hooks/agent-memory-sync.sh",
         "timeout": 15
       }
     ]

hooks/gemini/settings.json

@@ -17,7 +17,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "AGENT_MEMORY_EVENT=AfterAgent .gemini/hooks/agent-memory-sync.sh",
+            "command": "AGENT_MEMORY_HOST=gemini AGENT_MEMORY_EVENT=AfterAgent .gemini/hooks/agent-memory-sync.sh",
             "timeout": 15000
           }
         ]
@@ -28,7 +28,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "AGENT_MEMORY_EVENT=PreCompress .gemini/hooks/agent-memory-sync.sh",
+            "command": "AGENT_MEMORY_HOST=gemini AGENT_MEMORY_EVENT=PreCompress .gemini/hooks/agent-memory-sync.sh",
             "timeout": 15000
           }
         ]

tests/hooks-checkpoint.sh

@@ -318,6 +318,72 @@ grep -q 'session_binding=s-new' .agents/memory/.hook-sync-state ||
 ! grep -q 'stale-session.txt' .agents/memory/.hook-sync-state ||
   fail "distinct cursor sessions must clear session_touched_files"
 
+# --- sync without AGENT_MEMORY_HOST preserves session_binding_host ---
+printf '%s\n' \
+  'session_binding=s-old-host' \
+  'session_binding_host=cursor' \
+  "session_binding_day=$today" \
+  'session_touched_files=host-preserve-test.txt' \
+  >.agents/memory/.hook-sync-state
+printf '{"session_id":"s-new-host","cwd":"%s"}\n' "$TMP" |
+  AGENT_MEMORY_PROJECT_DIR="$TMP" \
+  AGENT_MEMORY_EVENT=afterAgentResponse AGENT_MEMORY_SESSION_ID=s-new-host \
+  ./agent-memory-sync.sh >/dev/null
+grep -q 'session_binding=s-new-host' .agents/memory/.hook-sync-state ||
+  fail "sync without host should rebind session"
+grep -q 'session_binding_host=cursor' .agents/memory/.hook-sync-state ||
+  fail "sync without AGENT_MEMORY_HOST must preserve session_binding_host from state"
+! grep -q 'host-preserve-test.txt' .agents/memory/.hook-sync-state ||
+  fail "distinct session without host must still clear paths"
+
+# --- explicit AGENT_MEMORY_HOST overrides preserved host ---
+printf '%s\n' \
+  'session_binding=s-old-override' \
+  'session_binding_host=cursor' \
+  "session_binding_day=$today" \
+  'session_touched_files=override-test.txt' \
+  >.agents/memory/.hook-sync-state
+printf '{"session_id":"s-new-override","cwd":"%s"}\n' "$TMP" |
+  AGENT_MEMORY_HOST=opencode AGENT_MEMORY_PROJECT_DIR="$TMP" \
+  AGENT_MEMORY_EVENT=Stop AGENT_MEMORY_SESSION_ID=s-new-override \
+  ./agent-memory-sync.sh >/dev/null
+grep -q 'session_binding_host=opencode' .agents/memory/.hook-sync-state ||
+  fail "explicit AGENT_MEMORY_HOST must override session_binding_host"
+
+# --- branch cache refresh fail-open skips branch + path clear ---
+current_branch=$(git branch --show-current)
+fake_branch="stale-branch-name"
+printf '%s\n' \
+  'session_binding=s-branch' \
+  "branch=$fake_branch" \
+  'session_touched_files=branch-atomic-keep.txt' \
+  >.agents/memory/.hook-sync-state
+mkdir -p .agents/memory/.hook-sync-state.lock
+printf '%s\n' "$$" >.agents/memory/.hook-sync-state.lock/pid
+printf '{"session_id":"s-branch","cwd":"%s"}\n' "$TMP" |
+  AGENT_MEMORY_HOST=cursor AGENT_MEMORY_PROJECT_DIR="$TMP" \
+  AGENT_MEMORY_EVENT=afterAgentResponse AGENT_MEMORY_SESSION_ID=s-branch \
+  ./agent-memory-sync.sh >/dev/null 2>"$TMP/branch-lock.err" || true
+grep -qi 'skip branch cache\|fail-open\|lock busy' "$TMP/branch-lock.err" ||
+  fail "branch refresh under lock contention should log skip/fail-open"
+grep -q "branch=$fake_branch" .agents/memory/.hook-sync-state ||
+  fail "fail-open branch refresh must not update branch"
+grep -q 'branch-atomic-keep.txt' .agents/memory/.hook-sync-state ||
+  fail "fail-open branch refresh must not clear paths without updating branch"
+[[ -d .agents/memory/.hook-sync-state.lock ]] ||
+  fail "branch fail-open must not remove foreign lock"
+rm -rf .agents/memory/.hook-sync-state.lock
+
+# Successful branch refresh after lock release updates branch + clears paths
+printf '{"session_id":"s-branch","cwd":"%s"}\n' "$TMP" |
+  AGENT_MEMORY_HOST=cursor AGENT_MEMORY_PROJECT_DIR="$TMP" \
+  AGENT_MEMORY_EVENT=afterAgentResponse AGENT_MEMORY_SESSION_ID=s-branch \
+  ./agent-memory-sync.sh >/dev/null
+grep -q "branch=$current_branch" .agents/memory/.hook-sync-state ||
+  fail "unlocked branch refresh should update branch to git head"
+! grep -q 'branch-atomic-keep.txt' .agents/memory/.hook-sync-state ||
+  fail "branch change must clear session_touched_files"
+
 # --- sync without session id keeps existing binding/paths (e.g. pre-commit) ---
 printf '%s\n' \
   'session_binding=s-active' \

tests/hooks-merge.sh

@@ -23,7 +23,7 @@ cat >"$TMP/src.json" <<'EOF'
       { "command": "AGENT_MEMORY_HOST=cursor .cursor/hooks/agent-memory-session.sh" }
     ],
     "afterAgentResponse": [
-      { "command": "AGENT_MEMORY_EVENT=afterAgentResponse .cursor/hooks/agent-memory-sync.sh" }
+      { "command": "AGENT_MEMORY_HOST=cursor AGENT_MEMORY_EVENT=afterAgentResponse .cursor/hooks/agent-memory-sync.sh" }
     ]
   }
 }
@@ -77,7 +77,7 @@ cat >"$TMP/src-n.json" <<'EOF'
     "Stop": [
       {
         "hooks": [
-          { "type": "command", "command": "AGENT_MEMORY_EVENT=Stop .claude/hooks/agent-memory-sync.sh" }
+          { "type": "command", "command": "AGENT_MEMORY_HOST=claude AGENT_MEMORY_EVENT=Stop .claude/hooks/agent-memory-sync.sh" }
         ]
       }
     ]