Hooks

Where it lives

• hooks/mempal_hook_run.shGitHub ↗
  Read the script

  #!/bin/bash
  # Runs `mempalace hook run "$@"`, stdin included, through the first of
  # $MEMPAL_PYTHON, `mempalace` on PATH, python3, or python that can import
  # mempalace.
  #
  # This file is shared by every hook wrapper. The Claude Code and Codex plugins
  # install from their own folders, so each carries a byte-identical copy
  # (.claude-plugin/hooks/, .codex-plugin/hooks/); tests/test_hook_resolver.py
  # keeps the copies in step. Edit this file and copy it over.
  #
  # When no interpreter can import mempalace, the hook prints the empty reply
  # and exits 0 so the harness carries on. A leading --on-missing=error makes it
  # exit 1 with the message instead, for harnesses that should show the failure.
  set -uo pipefail
  
  on_missing=empty
  if [ "${1:-}" = "--on-missing=error" ]; then
      on_missing=error
      shift
  fi
  
  # Hooks run in the user's project directory, which may be untrusted. Python puts
  # that directory first on sys.path for `-c` and `-m`, so a project holding
  # mempalace/ or mempalace.py would run instead of the installed package.
  # PYTHONSAFEPATH stops that on Python 3.11+, for this hook and the mines it
  # spawns; the probe and launch below also drop the empty entry `-c` adds, which
  # covers 3.9 and 3.10. The working directory itself stays put.
  export PYTHONSAFEPATH=1
  drop_cwd='import sys
  if sys.path and sys.path[0] == "": del sys.path[0]'
  probe="${drop_cwd}
  import mempalace"
  launch="${drop_cwd}
  import runpy
  runpy.run_module(\"mempalace\", run_name=\"__main__\", alter_sys=True)"
  
  if [ -n "${MEMPAL_PYTHON:-}" ] && "${MEMPAL_PYTHON}" -c "${probe}" </dev/null >/dev/null 2>&1; then
      exec "${MEMPAL_PYTHON}" -c "${launch}" hook run "$@"
  fi
  if command -v mempalace >/dev/null 2>&1; then
      exec mempalace hook run "$@"
  fi
  for python_bin in python3 python; do
      if command -v "${python_bin}" >/dev/null 2>&1 \
          && "${python_bin}" -c "${probe}" </dev/null >/dev/null 2>&1; then
          exec "${python_bin}" -c "${launch}" hook run "$@"
      fi
  done
  
  echo "MemPalace hook error: could not find a runnable mempalace command or module; set MEMPAL_PYTHON" >&2
  if [ "$on_missing" = error ]; then
      exit 1
  fi
  printf '{}'
  

• hooks/mempal_precompact_hook.shGitHub ↗
  Read the script

  #!/bin/bash
  # Legacy Claude Code PreCompact hook. `mempalace hook run` does the mining;
  # mempal_hook_run.sh picks the interpreter. The supported install is the
  # Claude Code plugin (.claude-plugin/); see hooks/README.md.
  exec bash "$(dirname "$0")/mempal_hook_run.sh" --hook precompact --harness claude-code
  

• hooks/mempal_save_hook.shGitHub ↗
  Read the script

  #!/bin/bash
  # Legacy Claude Code Stop hook. `mempalace hook run` does the counting,
  # mining and saving; mempal_hook_run.sh picks the interpreter. The supported
  # install is the Claude Code plugin (.claude-plugin/); see hooks/README.md.
  exec bash "$(dirname "$0")/mempal_hook_run.sh" --hook stop --harness claude-code
  

• hooks/mempal_session_end_hook.shGitHub ↗
  Read the script

  #!/bin/bash
  # MemPalace SessionEnd Hook — final save on clean exit.
  #
  # Claude Code documents a default SessionEnd hook timeout of 1.5s; a per-hook
  # "timeout" in settings.local.json can raise it (up to 60s), but a
  # plugin-provided timeout cannot (https://code.claude.com/docs/en/hooks). A cold
  # `mempalace` start alone can exceed 1.5s, so we background the hook and return
  # immediately; the detached child finishes the save after the session has
  # exited. All logic lives in mempalace.hooks_cli for cross-harness extensibility;
  # mempal_hook_run.sh picks the interpreter (MEMPAL_PYTHON first).
  hook_run="$(dirname "$0")/mempal_hook_run.sh"
  
  # Capture stdin (the SessionEnd JSON) before backgrounding — the parent's
  # stdin is gone once we return. Forward it to the detached worker, which runs
  # the final mine on its own time and outlives this process.
  payload="$(cat)"
  (
    printf '%s' "$payload" | bash "$hook_run" --hook session-end --harness "${MEMPALACE_HOOK_HARNESS:-claude-code}"
  ) >/dev/null 2>&1 </dev/null &
  disown 2>/dev/null || true
  
  # Return immediately so the harness never blocks on session exit.
  printf '{}'
  

Read the script before you install anything that runs on your machine. This is the one part of a plugin that acts without being asked.