FabledGrimoire/plugin/hooks/grimoire_shape_check.sh

#!/usr/bin/env bash
# Grimoire plugin — Stop hook: the turn's new shapes are judged by the agent
# that wrote them.
#
# The write hooks (grimoire_prior_art.sh, grimoire_after_write.sh) append every
# definition a write names to a session ledger, `<sid>.written.ids`
# (`path<TAB>kind<TAB>name`, see grimoire_written_append). At the end of the
# turn this hook sends that ledger to the instance, which answers with what
# nobody has judged yet. If anything is, the hook blocks ONCE, in the server's
# words: the agent that built the code is the one participant who knows what
# it is, and the end of the turn is the last moment that is still true.
#
# THE SAME DISCIPLINE AS the completion-section check in grimoire_reply_check.sh:
#   - it blocks only on a `reason` the instance returned, which it returns
#     only for a block it RECORDED — an unconfigured or unreachable instance
#     never stops a session, and every intervention is one the numbers see;
#   - never twice for one turn: the stop that follows its own block
#     (`stop_hook_active` with this hook's marker present) is recorded as
#     judged_after_block / left_after_block and let through;
#   - another plugin's block loop is left alone (active, no marker).
#
# THE LEDGER IS CONSUMED, NOT TURN-STAMPED. Everything written since the last
# stop this hook answered is "this turn". It is emptied once the instance has
# answered — after a pass, or after the post-block stop — and KEPT when the
# instance could not be reached, so the question is asked at the next stop
# that can be answered rather than silently dropped.
#
# Config (same as the other hooks):
#   CLAUDE_PLUGIN_OPTION_API_ENDPOINT  base URL, no trailing slash
#   CLAUDE_PLUGIN_OPTION_API_TOKEN     fmcp_ API key (sensitive)
#   GRIMOIRE_URL / GRIMOIRE_TOKEN override for the settings.json dogfooding path.
set -uo pipefail

command -v curl >/dev/null 2>&1 || exit 0

# shellcheck source=plugin/hooks/grimoire_defs.sh
. "$(dirname "${BASH_SOURCE[0]}")/grimoire_defs.sh"

# Stop delivers { session_id, transcript_path, cwd, hook_event_name, stop_hook_active }.
event=$(cat 2>/dev/null || true)
event_flat=$(printf '%s' "$event" | grimoire_json_flat)
session_id=$(grimoire_json_pick "$event_flat" '.session_id')
active=$(grimoire_json_pick "$event_flat" '.stop_hook_active')
event_cwd=$(grimoire_json_pick "$event_flat" '.cwd')
[ -n "$session_id" ] || exit 0

safe_sid=$(printf '%s' "$session_id" | tr -c 'A-Za-z0-9._-' '_')
ledger="${TMPDIR:-/tmp}/grimoire-priorart/${safe_sid}.written.ids"
state_dir="${TMPDIR:-/tmp}/grimoire-shapecheck"
mkdir -p "$state_dir" 2>/dev/null || true
marker="$state_dir/${safe_sid}.blocked"

if [ "$active" = "true" ]; then
  # A Stop hook already blocked this stop. Another plugin's → nothing to add.
  [ -f "$marker" ] || exit 0
  phase=after
else
  rm -f "$marker" 2>/dev/null || true
  phase=check
fi

if [ ! -s "$ledger" ]; then
  rm -f "$marker" 2>/dev/null || true
  exit 0
fi
grimoire_config || exit 0

# Unique lines, oldest first, capped: the request stays a GET (a read-scoped
# key runs the plugin), and a turn that wrote more than this generated code.
written=$(awk '!seen[$0]++' "$ledger" 2>/dev/null | head -n 80)
written_enc=$(printf '%s' "$written" | grimoire_urlenc) || exit 0
dir="${event_cwd:-${CLAUDE_PROJECT_DIR:-$PWD}}"
q="phase=${phase}&written=${written_enc}"
scope=$(grimoire_scope_query "$dir")
[ -n "$scope" ] && q="${q}&${scope}"
# The repo rides along even when a marker names the project: the instance
# needs it to tell the agent which repo a just-written shape belongs to.
case "$scope" in
  repo=*) ;;
  *)
    remote=$(git -C "$dir" remote get-url origin 2>/dev/null || true)
    if [ -n "$remote" ]; then
      remote_enc=$(printf '%s' "$remote" | grimoire_urlenc) || remote_enc=""
      [ -n "$remote_enc" ] && q="${q}&repo=${remote_enc}"
    fi
    ;;
esac

answer=$(curl -fsS --max-time 4 \
  -H "Authorization: Bearer ${token}" \
  "${url%/}/api/plugin/shape-check?${q}" 2>/dev/null) || exit 0   # unreachable: keep the ledger

if [ "$phase" = "after" ]; then
  rm -f "$marker" "$ledger" 2>/dev/null || true
  exit 0
fi

reason=$(grimoire_json_pick "$(printf '%s' "$answer" | grimoire_json_flat)" '.reason')
if [ -z "$reason" ]; then
  rm -f "$ledger" 2>/dev/null || true
  exit 0
fi
: > "$marker" 2>/dev/null || true
printf '{"decision":"block","reason":"%s"}\n' "$(printf '%s' "$reason" | grimoire_json_escape)"
exit 0