gstack/bin/gstack-config

#!/usr/bin/env bash
# gstack-config — read/write ~/.gstack/config.yaml
#
# Usage:
#   gstack-config get <key>          — read a config value (falls back to DEFAULTS)
#   gstack-config has <key>          — exit 0 iff the key is literally present in the
#                                      config file (get returns DEFAULTS for absent keys,
#                                      so callers that need provenance use this instead)
#   gstack-config set <key> <value>  — write a config value
#   gstack-config list               — show all config (values + defaults)
#   gstack-config defaults           — show just the defaults table
#
# Env overrides (for testing):
#   GSTACK_STATE_ROOT — override ~/.gstack state directory (highest priority,
#                       matches D16 cathedral isolation convention)
#   GSTACK_HOME       — override ~/.gstack state directory (aligns with writer scripts)
#   GSTACK_STATE_DIR  — legacy alias for GSTACK_HOME (kept for backwards compat)
set -euo pipefail

STATE_DIR="${GSTACK_STATE_ROOT:-${GSTACK_HOME:-${GSTACK_STATE_DIR:-$HOME/.gstack}}}"
CONFIG_FILE="$STATE_DIR/config.yaml"

# Swap a freshly-rendered tmp dir into the live render location (#2569
# hardening). Installed skills SYMLINK into the live dir, so it is only ever
# replaced AFTER a successful render — a failed render leaves the previous
# render (and every link into it) fully intact. Keep in sync with setup's
# _swap_in_render (same contract, both pinned by
# test/user-render-out-dir-install.test.ts).
_swap_in_render() {
  local render_dir="$1" render_tmp="$2"
  local render_old="$render_dir.old.$$"
  rm -rf "$render_old"
  if [ -e "$render_dir" ] || [ -L "$render_dir" ]; then mv "$render_dir" "$render_old"; fi
  mv "$render_tmp" "$render_dir"
  rm -rf "$render_old"
}

# Annotated header for new config files. Written once on first `set`.
# Default semantics: DEFAULTS table below is the canonical source. Header text
# is documentation that must stay in sync with DEFAULTS.
CONFIG_HEADER='# gstack configuration — edit freely, changes take effect on next skill run.
# Docs: https://github.com/garrytan/gstack
#
# ─── Behavior ────────────────────────────────────────────────────────
# proactive: true           # Auto-invoke skills when your request matches one.
#                           # Set to false to only run skills you type explicitly.
#
# routing_declined: false   # Set to true to skip the CLAUDE.md routing injection
#                           # prompt. Set back to false to be asked again.
#
# ─── Telemetry ───────────────────────────────────────────────────────
# telemetry: off            # off | anonymous | community
#                           #   off       — no data sent, no local analytics (default)
#                           #   anonymous — counter only, no device ID
#                           #   community — usage data + stable device ID
#
# ─── Updates ─────────────────────────────────────────────────────────
# auto_upgrade: false       # true = silently upgrade on session start
# update_check: true        # false = suppress version check notifications
#
# ─── Skill naming ────────────────────────────────────────────────────
# skill_prefix: false       # true = namespace skills as /gstack-qa, /gstack-ship
#                           # false = short names /qa, /ship
#
# ─── Checkpoint ──────────────────────────────────────────────────────
# checkpoint_mode: explicit # explicit | continuous
#                           #   explicit   — commit only when you run /ship or /checkpoint
#                           #   continuous — auto-commit after each significant change
#                           #                with WIP: prefix + [gstack-context] body
#
# checkpoint_push: false    # true = push WIP commits to remote as you go
#                           # false = keep WIP commits local only (default)
#                           # Pushing can trigger CI/deploy hooks — opt in carefully.
#
# ─── Writing style (V1) ──────────────────────────────────────────────
# explain_level: default    # default = jargon-glossed, outcome-framed prose
#                           #           (V1 default — more accessible for everyone)
#                           # terse   = V0 prose style, no glosses, no outcome-framing layer
#                           #           (for power users who know the terms)
#                           # Unknown values default to "default" with a warning.
#                           # See docs/designs/PLAN_TUNING_V1.md for rationale.
#
# ─── Artifacts sync (renamed from gbrain_sync_mode in v1.27.0.0) ─────
# artifacts_sync_mode: off  # off | artifacts-only | full
#                           #   off            — no sync (default)
#                           #   artifacts-only — sync plans/designs/retros/learnings only
#                           #                    (skip behavioral data: question-log,
#                           #                    developer-profile, timeline)
#                           #   full           — sync everything allowlisted
#                           # Set by the first-run privacy stop-gate. See docs/gbrain-sync.md.
#
# artifacts_sync_mode_prompted: false
#                           # Set to true once the privacy gate has asked the user.
#                           # Flip back to false to be re-prompted.
#
# ─── Timeline Stop hook ──────────────────────────────────────────────
# timeline_stop_hook: yes   # Controls whether ./setup registers the timeline
#                           #   Stop hook (closes dangling session entries).
#                           #   yes — register on every setup (default)
#                           #   no  — never register; setup also removes a
#                           #         live registration (persistent opt-out;
#                           #         --no-team stays a one-shot teardown, #2677)
#
# ─── Plan-tune hooks ─────────────────────────────────────────────────
# plan_tune_hooks: prompt   # Controls whether ./setup installs the plan-tune
#                           #   Claude Code hooks (PostToolUse capture +
#                           #   PreToolUse preference enforcement).
#                           #   prompt — ask on a real TTY, skip otherwise (default)
#                           #   yes    — install non-interactively
#                           #   no     — skip non-interactively
#                           # Override per-run: ./setup --plan-tune-hooks /
#                           #   --no-plan-tune-hooks, or env GSTACK_PLAN_TUNE_HOOKS.
#
# ─── Memorable recall bridge (opt-in, third party) ──────────────────
# memorable_recall: off     # The gstack-side consent gate for the Memorable
#                           #   UserPromptSubmit bridge (bin/gstack-memorable).
#                           #   off — the hook does nothing, spawns nothing (default)
#                           #   on  — the hook hands each prompt to the local
#                           #         `memorable` CLI, receipted as memorable-recall
#                           # Written by `gstack-memorable enable|disable`. An
#                           # invalid value is REJECTED and the stored value kept:
#                           # a typo must never flip a third-party consent.
#                           # The vendor capture consent (`memorable enable`)
#                           # is separate; gstack never sets it.
#
# ─── Advanced ────────────────────────────────────────────────────────
# codex_reviews: enabled    # Workflow outside review (Codex or Claude Code by harness).
#                           #   enabled: /review, /ship, /document-release, plan reviews,
#                           #   and /autoplan use their existing external + fallback rules.
#                           #   disabled: /review, /ship, /autoplan keep native passes;
#                           #   plan/document reviews skip the entire extra review step.
#                           #   Office hours/design/spec/manual wrappers keep their own
#                           #   opt-in/skip controls. Invalid values preserve the old value.
# design_detector_install_prompted: false
#                           #   true once you answered the one-time offer from the
#                           #   design skills to download the impeccable engine with
#                           #   "never ask again"; flip back to false to be asked again.
# design_detector: auto     # Deterministic design pre-pass through a user-installed
#                           #   impeccable engine (/design-review, /review, /ship,
#                           #   /design-html). auto = use the engine when the probe
#                           #   finds one (gstack never installs or downloads it);
#                           #   off = no probe, no scan, no hint, no /impeccable
#                           #   handoff lines. An invalid value is REJECTED (existing
#                           #   value preserved) so a typo cannot silently disable it.
# gstack_contributor: false # true = file field reports when gstack misbehaves
# skip_eng_review: false    # true = skip eng review gate in /ship (not recommended)
#
# ─── Workspace-aware ship ────────────────────────────────────────────
# workspace_root: $HOME/conductor/workspaces  # Where /ship looks for sibling
#                           # Conductor worktrees when picking a VERSION slot.
#                           # Set to "null" to disable sibling scanning entirely.
#                           # Non-Conductor users can point this at any directory
#                           # that holds parallel worktrees of the same repo.
#
'

# DEFAULTS table — canonical default values for known keys.
# `get <key>` returns DEFAULTS[key] when the key is absent from the config file
# AND the env override is not set. Keep in sync with the CONFIG_HEADER comments.
lookup_default() {
  case "$1" in
    proactive) echo "true" ;;
    routing_declined) echo "false" ;;
    telemetry) echo "off" ;;
    auto_upgrade) echo "false" ;;
    update_check) echo "true" ;;
    skill_prefix) echo "false" ;;
    checkpoint_mode) echo "explicit" ;;
    checkpoint_push) echo "false" ;;
    explain_level) echo "default" ;;
    codex_reviews) echo "enabled" ;;
    design_detector) echo "auto" ;; # auto | off — impeccable engine pre-pass in the design skills
    design_detector_install_prompted) echo "false" ;; # true once the user answered the one-time engine install offer with "never ask again"
    gstack_contributor) echo "false" ;;
    skip_eng_review) echo "false" ;;
    workspace_root) echo "$HOME/conductor/workspaces" ;;
    cross_project_learnings) echo "" ;; # intentionally empty → unset triggers first-time prompt
    artifacts_sync_mode) echo "off" ;;
    artifacts_sync_mode_prompted) echo "false" ;;
    plan_tune_hooks) echo "prompt" ;; # prompt | yes | no — controls ./setup plan-tune hook install
    timeline_stop_hook) echo "yes" ;; # yes | no — controls ./setup timeline Stop hook registration (#2677)

    redact_repo_visibility) echo "" ;; # empty → fall through to gh/glab detection
    redact_prepush_hook) echo "false" ;;
    pair_agent) echo "off" ;; # remote tunnel consent — fail-closed until /pair-agent asks
    memorable_recall) echo "off" ;; # on | off — Memorable bridge gate, fail-closed until `gstack-memorable enable`
    founder_resources) echo "true" ;; # office-hours resource pitch — #538 permanent opt-out sets false
    # Brain-aware planning (v1.48 / T5+T10+T16). Defaults documented inline:
    #   brain_trust_policy@<endpoint-id>  — unset on fresh install; setup-gbrain
    #                                writes 'personal' for local engines,
    #                                asks the user for remote-ambiguous.
    #   salience_allowlist          — empty falls through to
    #                                SALIENCE_DEFAULT_ALLOWLIST (D9).
    #   user_slug_at_<endpoint-id>  — empty triggers resolve-user-slug
    #                                fallback chain (D4 A3) on first call.
    brain_trust_policy*) echo "unset" ;;
    salience_allowlist) echo "" ;;
    user_slug_at_*) echo "" ;;
    # Read by skill preambles but missing from this table, so they fell through
    # to the catch-all and came back "" with exit 0. Values below are the ones
    # the callers already assume in their own `|| echo "<default>"` fallback.
    question_tuning) echo "false" ;;
    team_mode) echo "false" ;;
    transcript_ingest_mode) echo "off" ;;
    # repo_mode: EMPTY is load-bearing — gstack-repo-mode treats any non-empty
    # answer as a user override and skips its own classification entirely, so
    # a synthesized "unknown" default turns the classifier into dead code.
    # Empty + exit 0 = "no override set, go classify".
    repo_mode) echo "" ;;
    # Unknown key: exit non-zero instead of printing "". The fallback pattern
    # the preambles use,
    #   VAR=$(gstack-config get <key> 2>/dev/null || echo "<default>")
    # only fires on a non-zero exit, so a catch-all echoing "" with exit 0 left
    # VAR empty and the written default unreachable.
    # Deliberately *only* the unknown-key path: the keys above whose default is
    # intentionally empty (cross_project_learnings, salience_allowlist,
    # user_slug_at_*, redact_repo_visibility) keep exit 0, because "" is their
    # real answer and their callers rely on it.
    *) return 1 ;;
  esac
}

# ──────────────────────────────────────────────────────────────────────
# Brain-integration helpers (T5+T10+T16)
# ──────────────────────────────────────────────────────────────────────

# Compute sha8 of a string. Used for endpoint hashing.
# shasum is macOS/perl; most Linux distros ship only coreutils sha256sum —
# resolve whichever exists (same fallback chain as the codex-probe timeout
# wrapper). Without this, any Linux user with a git email hit exit 127 in
# resolve-user-slug's Layer-3 fallback.
sha8_of() {
  if command -v sha256sum >/dev/null 2>&1; then
    printf '%s' "$1" | sha256sum | cut -c1-8
  else
    printf '%s' "$1" | shasum -a 256 | cut -c1-8
  fi
}

# Detect the active brain endpoint hash. Reads ~/.claude.json for the gbrain
# MCP server URL. Falls back to the literal 'local' when no MCP is configured.
endpoint_hash() {
  _claude_json="$HOME/.claude.json"
  if [ -f "$_claude_json" ] && command -v jq >/dev/null 2>&1; then
    _url=$(jq -r '.mcpServers.gbrain.url // .mcpServers.gbrain.transport.url // empty' "$_claude_json" 2>/dev/null)
    if [ -n "$_url" ] && [ "$_url" != "null" ]; then
      sha8_of "$_url"
      return 0
    fi
  fi
  printf '%s' "local"
}

# Detect endpoint hash collisions. When two distinct endpoints share the same
# sha8 prefix (rare but possible), escalate to sha16 by emitting the longer
# hash. Detection: scan config file for existing brain_trust_policy@<hash> or
# user_slug_at_<hash> keys; if any non-active hash equals the active sha8 but
# would differ at sha16, the active endpoint needs sha16.
endpoint_hash_with_collision_check() {
  _active=$(endpoint_hash)
  if [ "$_active" = "local" ]; then
    printf '%s' "$_active"
    return 0
  fi
  # If a different endpoint (different URL) shares this sha8, escalate.
  # We only catch this when the config has another endpoint recorded.
  _matching=$(grep -E "^(brain_trust_policy|user_slug_at)@${_active}" "$CONFIG_FILE" 2>/dev/null | head -1 || true)
  _claude_json="$HOME/.claude.json"
  if [ -n "$_matching" ] && [ -f "$_claude_json" ] && command -v jq >/dev/null 2>&1; then
    _url=$(jq -r '.mcpServers.gbrain.url // .mcpServers.gbrain.transport.url // empty' "$_claude_json" 2>/dev/null)
    if command -v sha256sum >/dev/null 2>&1; then
      _sha16=$(printf '%s' "$_url" | sha256sum | cut -c1-16)
    else
      _sha16=$(printf '%s' "$_url" | shasum -a 256 | cut -c1-16)
    fi
    # Look for any sha16-namespaced key that conflicts. If a stored sha16 exists
    # and differs from current sha16, that's the collision evidence; emit sha16.
    _stored16=$(grep -E "^(brain_trust_policy|user_slug_at)@${_sha16}" "$CONFIG_FILE" 2>/dev/null | head -1 || true)
    if [ -n "$_stored16" ]; then
      printf '%s' "$_sha16"
      return 0
    fi
  fi
  printf '%s' "$_active"
}

# Resolve the user-slug per D4 A3 chain:
#   1. mcp__gbrain__whoami.client_name (best effort via gbrain CLI shell-out)
#   2. $USER env
#   3. sha8($(git config user.email))
#   4. anonymous-<sha8(hostname)>
# Persists result via gstack-config set user_slug_at_<endpoint-hash> on first call.
resolve_user_slug() {
  _hash=$(endpoint_hash_with_collision_check)
  _stored=$(grep -E "^user_slug_at_${_hash}:" "$CONFIG_FILE" 2>/dev/null | tail -1 | awk '{print $2}' | tr -d '[:space:]' || true)
  if [ -n "$_stored" ]; then
    printf '%s' "$_stored"
    return 0
  fi

  _slug=""

  # Layer 1: gbrain whoami
  if command -v gbrain >/dev/null 2>&1; then
    _whoami=$(gbrain whoami --json 2>/dev/null || true)
    if [ -n "$_whoami" ] && command -v jq >/dev/null 2>&1; then
      _client_name=$(printf '%s' "$_whoami" | jq -r '.client_name // .token_name // empty' 2>/dev/null || true)
      if [ -n "$_client_name" ] && [ "$_client_name" != "null" ]; then
        _slug=$(printf '%s' "$_client_name" | tr '[:upper:] ' '[:lower:]-' | tr -dc '[:alnum:]-')
      fi
    fi
  fi

  # Layer 2: $USER
  if [ -z "$_slug" ] && [ -n "${USER:-}" ]; then
    _slug=$(printf '%s' "$USER" | tr '[:upper:] ' '[:lower:]-' | tr -dc '[:alnum:]-')
  fi

  # Layer 3: sha8 of git email
  if [ -z "$_slug" ]; then
    _email=$(git config user.email 2>/dev/null || true)
    if [ -n "$_email" ]; then
      _slug="email-$(sha8_of "$_email")"
    fi
  fi

  # Layer 4: anonymous-<sha8(hostname)>
  if [ -z "$_slug" ]; then
    _slug="anonymous-$(sha8_of "$(hostname 2>/dev/null || echo unknown)")"
  fi

  # Persist via direct file write (avoid recursion into gstack-config set)
  mkdir -p "$STATE_DIR"
  if [ ! -f "$CONFIG_FILE" ]; then
    printf '%s' "$CONFIG_HEADER" > "$CONFIG_FILE"
  fi
  if ! grep -qE "^user_slug_at_${_hash}:" "$CONFIG_FILE" 2>/dev/null; then
    echo "user_slug_at_${_hash}: ${_slug}" >> "$CONFIG_FILE"
  fi

  printf '%s' "$_slug"
}

read_config_value() {
  local key="$1"
  if [ ! -f "$CONFIG_FILE" ]; then
    return 0
  fi
  grep -E "^${key}:" "$CONFIG_FILE" 2>/dev/null \
    | tail -1 \
    | sed -E "s/^${key}:[[:space:]]*//; s/[[:space:]]+$//"
}

case "${1:-}" in
  get)
    KEY="${2:?Usage: gstack-config get <key>}"
    # Validate key (alphanumeric + underscore + optional @<endpoint-id> suffix for
    # endpoint-namespaced keys introduced by the brain-aware planning layer).
    # Endpoint ids are sha8/sha16 hex for remote MCP URLs, or the literal
    # "local" for stdio/PGLite engines (see endpoint_hash).
    if ! printf '%s' "$KEY" | LC_ALL=C grep -qE '^[a-zA-Z0-9_]+(@[a-zA-Z0-9]+)?$'; then
      echo "Error: key must contain only alphanumeric characters, underscores, and an optional @<endpoint-id> suffix" >&2
      exit 1
    fi
    VALUE=$(read_config_value "$KEY" || true)
    if [ -z "$VALUE" ]; then
      # lookup_default exits non-zero for a key it does not know. Propagate
      # that, so the caller's `|| echo "<default>"` can fire. A known key whose
      # default is empty still exits 0 and prints "".
      if ! VALUE=$(lookup_default "$KEY"); then
        exit 1
      fi
    fi
    printf '%s' "$VALUE"
    ;;
  has)
    KEY="${2:?Usage: gstack-config has <key>}"
    if ! printf '%s' "$KEY" | LC_ALL=C grep -qE '^[a-zA-Z0-9_]+(@[a-zA-Z0-9]+)?$'; then
      echo "Error: key must contain only alphanumeric characters, underscores, and an optional @<endpoint-id> suffix" >&2
      exit 1
    fi
    grep -qE "^${KEY}:" "$CONFIG_FILE" 2>/dev/null
    ;;
  set)
    KEY="${2:?Usage: gstack-config set <key> <value>}"
    VALUE="${3:?Usage: gstack-config set <key> <value>}"
    # Validate key (alphanumeric + underscore + optional @<endpoint-id> suffix).
    # Accepts hex hashes and the literal "local" from endpoint_hash.
    if ! printf '%s' "$KEY" | LC_ALL=C grep -qE '^[a-zA-Z0-9_]+(@[a-zA-Z0-9]+)?$'; then
      echo "Error: key must contain only alphanumeric characters, underscores, and an optional @<endpoint-id> suffix" >&2
      exit 1
    fi
    # Validate brain_trust_policy value domain (D4 / D11)
    if printf '%s' "$KEY" | grep -qE '^brain_trust_policy(@|$)' && \
       [ "$VALUE" != "personal" ] && [ "$VALUE" != "shared" ] && [ "$VALUE" != "unset" ]; then
      echo "Warning: brain_trust_policy '$VALUE' not recognized. Valid values: personal, shared, unset. Using unset." >&2
      VALUE="unset"
    fi
    # V1: whitelist values for keys with closed value domains. Unknown values warn + default.
    if [ "$KEY" = "explain_level" ] && [ "$VALUE" != "default" ] && [ "$VALUE" != "terse" ]; then
      echo "Warning: explain_level '$VALUE' not recognized. Valid values: default, terse. Using default." >&2
      VALUE="default"
    fi
    if [ "$KEY" = "artifacts_sync_mode" ] && [ "$VALUE" != "off" ] && [ "$VALUE" != "artifacts-only" ] && [ "$VALUE" != "full" ]; then
      echo "Warning: artifacts_sync_mode '$VALUE' not recognized. Valid values: off, artifacts-only, full. Using off." >&2
      VALUE="off"
    fi
    # redact_repo_visibility: a LOCAL override for repos gh/glab can't read (e.g.
    # self-hosted GitLab). It lives in ~/.gstack/config.yaml (never committed), so
    # it can't be used to weaken the gate repo-wide for other contributors.
    if [ "$KEY" = "redact_repo_visibility" ] && [ "$VALUE" != "public" ] && [ "$VALUE" != "private" ] && [ "$VALUE" != "unknown" ]; then
      echo "Warning: redact_repo_visibility '$VALUE' not recognized. Valid values: public, private, unknown. Using unknown." >&2
      VALUE="unknown"
    fi
    if [ "$KEY" = "redact_prepush_hook" ] && [ "$VALUE" != "true" ] && [ "$VALUE" != "false" ]; then
      echo "Warning: redact_prepush_hook '$VALUE' not recognized. Valid values: true, false. Using false." >&2
      VALUE="false"
    fi
    if [ "$KEY" = "pair_agent" ] && [ "$VALUE" != "on" ] && [ "$VALUE" != "off" ]; then
      echo "Warning: pair_agent '$VALUE' not recognized. Valid values: on, off. Using off." >&2
      VALUE="off"
    fi
    if [ "$KEY" = "founder_resources" ] && [ "$VALUE" != "true" ] && [ "$VALUE" != "false" ]; then
      echo "Warning: founder_resources '$VALUE' not recognized. Valid values: true, false. Using true." >&2
      VALUE="true"
    fi
    if [ "$KEY" = "plan_tune_hooks" ] && [ "$VALUE" != "prompt" ] && [ "$VALUE" != "yes" ] && [ "$VALUE" != "no" ]; then
      echo "Warning: plan_tune_hooks '$VALUE' not recognized. Valid values: prompt, yes, no. Using prompt." >&2
      VALUE="prompt"
    fi
    if [ "$KEY" = "timeline_stop_hook" ] && [ "$VALUE" != "yes" ] && [ "$VALUE" != "no" ]; then
      echo "Warning: timeline_stop_hook '$VALUE' not recognized. Valid values: yes, no. Using yes." >&2
      VALUE="yes"
    fi
    # codex_reviews controls workflow outside CLI calls. Unlike the warn-and-default keys above,
    # an invalid value is REJECTED and the existing setting is left unchanged — a typo
    # must never silently flip the switch and turn paid Codex calls on or off.
    if [ "$KEY" = "codex_reviews" ] && [ "$VALUE" != "enabled" ] && [ "$VALUE" != "disabled" ]; then
      echo "Error: codex_reviews '$VALUE' not recognized. Valid values: enabled, disabled. Existing value left unchanged." >&2
      exit 1
    fi
    # design_detector_install_prompted records "never ask again" for the one-time
    # engine install offer. Rejecting a typo keeps the offer from silently coming
    # back (or never coming back) because of a mistyped value.
    if [ "$KEY" = "design_detector_install_prompted" ] && [ "$VALUE" != "true" ] && [ "$VALUE" != "false" ]; then
      echo "Error: design_detector_install_prompted '$VALUE' not recognized. Valid values: true, false. Existing value left unchanged." >&2
      exit 1
    fi
    # design_detector gates a third-party binary the user installed. Reject a typo
    # rather than coerce it: "of" must not silently re-enable or disable the scan.
    if [ "$KEY" = "design_detector" ] && [ "$VALUE" != "auto" ] && [ "$VALUE" != "off" ]; then
      echo "Error: design_detector '$VALUE' not recognized. Valid values: auto, off. Existing value left unchanged." >&2
      exit 1
    fi
    # cross_project_learnings: empty get is the first-run prompt sentinel.
    # Skills enable only on the literal "true". A typo must not persist — that
    # keeps the feature off and suppresses the prompt. Reject, like
    # codex_reviews; do not coerce (a stored default still kills the sentinel).
    if [ "$KEY" = "cross_project_learnings" ] && [ "$VALUE" != "true" ] && [ "$VALUE" != "false" ]; then
      echo "Error: cross_project_learnings '$VALUE' not recognized. Valid values: true, false. Existing value left unchanged." >&2
      exit 1
    fi
    # memorable_recall is a CONSENT key: `on` lets a Claude Code hook hand every
    # prompt to a third-party binary. Reject like codex_reviews -- a typo must
    # never flip consent in either direction, so nothing is coerced or stored.
    if [ "$KEY" = "memorable_recall" ] && [ "$VALUE" != "on" ] && [ "$VALUE" != "off" ]; then
      echo "Error: memorable_recall '$VALUE' not recognized. Valid values: on, off. Existing value left unchanged." >&2
      exit 1
    fi
    mkdir -p "$STATE_DIR"
    # Write annotated header on first creation
    if [ ! -f "$CONFIG_FILE" ]; then
      printf '%s' "$CONFIG_HEADER" > "$CONFIG_FILE"
    fi
    # Drop embedded newlines, then escape sed replacement metacharacters.
    SAFE_VALUE="$(printf '%s' "$VALUE" | head -1)"
    ESC_VALUE="$(printf '%s' "$SAFE_VALUE" | sed 's/[&/\]/\\&/g')"
    if grep -qE "^${KEY}:" "$CONFIG_FILE" 2>/dev/null; then
      # Portable in-place edit (BSD sed uses -i '', GNU sed uses -i without arg)
      _tmpfile="$(mktemp "${CONFIG_FILE}.XXXXXX")"
      sed "/^${KEY}:/s/.*/${KEY}: ${ESC_VALUE}/" "$CONFIG_FILE" > "$_tmpfile" && mv "$_tmpfile" "$CONFIG_FILE"
    else
      echo "${KEY}: ${SAFE_VALUE}" >> "$CONFIG_FILE"
    fi
    # Auto-relink skills when prefix setting changes (skip during setup to avoid recursive call)
    if [ "$KEY" = "skill_prefix" ] && [ -z "${GSTACK_SETUP_RUNNING:-}" ]; then
      GSTACK_RELINK="$(dirname "$0")/gstack-relink"
      [ -x "$GSTACK_RELINK" ] && "$GSTACK_RELINK" || true
    fi
    ;;
  list)
    if [ -f "$CONFIG_FILE" ]; then
      cat "$CONFIG_FILE"
    fi
    echo ""
    echo "# ─── Active values (including defaults for unset keys) ───"
    for KEY in proactive routing_declined telemetry auto_upgrade update_check \
               skill_prefix checkpoint_mode checkpoint_push explain_level \
               codex_reviews gstack_contributor skip_eng_review workspace_root \
               artifacts_sync_mode artifacts_sync_mode_prompted plan_tune_hooks \
               timeline_stop_hook design_detector design_detector_install_prompted memorable_recall; do
      VALUE=$(read_config_value "$KEY" || true)
      SOURCE="default"
      if [ -n "$VALUE" ]; then
        SOURCE="set"
      else
        VALUE=$(lookup_default "$KEY")
      fi
      printf '  %-24s %s (%s)\n' "$KEY:" "$VALUE" "$SOURCE"
    done
    ;;
  defaults)
    echo "# gstack-config defaults"
    for KEY in proactive routing_declined telemetry auto_upgrade update_check \
               skill_prefix checkpoint_mode checkpoint_push explain_level \
               codex_reviews gstack_contributor skip_eng_review workspace_root \
               artifacts_sync_mode artifacts_sync_mode_prompted plan_tune_hooks \
               timeline_stop_hook design_detector design_detector_install_prompted memorable_recall; do
      printf '  %-24s %s\n' "$KEY:" "$(lookup_default "$KEY")"
    done
    ;;
  endpoint-hash)
    # Brain integration helper (T10): print active brain endpoint sha8
    endpoint_hash_with_collision_check
    ;;
  resolve-user-slug)
    # Brain integration helper (T16 / D4 A3): resolve + persist user-slug
    resolve_user_slug
    ;;
  gbrain-refresh)
    # Brain integration helper: re-detect gbrain installation state and
    # persist to ~/.gstack/gbrain-detection.json. gen-skill-docs reads this
    # file (when invoked with --respect-detection) to decide whether to
    # render GBRAIN_CONTEXT_LOAD and GBRAIN_SAVE_RESULTS blocks in
    # generated SKILL.md files.
    #
    # Run this after installing or uninstalling gbrain so your locally
    # generated SKILL.md files match your installation state.
    SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
    DETECT_BIN="$SCRIPT_DIR/gstack-gbrain-detect"
    DETECTION_FILE="$STATE_DIR/gbrain-detection.json"
    mkdir -p "$STATE_DIR"
    if [ ! -x "$DETECT_BIN" ]; then
      echo "gstack-gbrain-detect not found at $DETECT_BIN" >&2
      exit 1
    fi
    if ! "$DETECT_BIN" > "$DETECTION_FILE.tmp" 2>/dev/null; then
      printf '{"gbrain_on_path":false,"gbrain_local_status":"no-cli"}\n' > "$DETECTION_FILE.tmp"
    fi
    mv "$DETECTION_FILE.tmp" "$DETECTION_FILE"

    # Summarize for the user. Use python (already required elsewhere) to
    # parse the JSON portably; fall back to grep if python is unavailable.
    PYTHON_CMD=$(command -v python3 || command -v python || true)
    if [ -n "$PYTHON_CMD" ]; then
      STATUS=$("$PYTHON_CMD" -c "import json,sys; d=json.load(open('$DETECTION_FILE')); print(d.get('gbrain_local_status','unknown'))" 2>/dev/null || echo unknown)
      VERSION=$("$PYTHON_CMD" -c "import json,sys; d=json.load(open('$DETECTION_FILE')); print(d.get('gbrain_version') or 'unknown')" 2>/dev/null || echo unknown)
    else
      STATUS=$(grep -o '"gbrain_local_status":[[:space:]]*"[^"]*"' "$DETECTION_FILE" | sed 's/.*"\([^"]*\)"$/\1/')
      VERSION=$(grep -o '"gbrain_version":[[:space:]]*"[^"]*"' "$DETECTION_FILE" | sed 's/.*"\([^"]*\)"$/\1/')
      [ -z "$STATUS" ] && STATUS=unknown
      [ -z "$VERSION" ] && VERSION=unknown
    fi

    case "$STATUS" in
      ok|timeout|thin-client|engine-locked)
        # "timeout" = slow-but-healthy engine (#1964); "thin-client" =
        # remote-HTTP MCP brain, no local engine by design (#2051);
        # "engine-locked" = same class (#2456): PGLite is single-writer, so a
        # live `gbrain serve` (typically an MCP server) holds the embedded DB.
        # gbrain is installed and healthy; a transient lock must not strip
        # brain blocks out of every SKILL.md. All get the same treatment as
        # "ok", matching gstack-gbrain-detect --is-ok and gen-skill-docs.
        echo "Detected gbrain v$VERSION (local-status: $STATUS)."
        # Render brain-aware blocks into an UNTRACKED out-dir (#2569) and
        # repoint the installed skills at it — the old in-place render wrote
        # into TRACKED files of the global install checkout, so the checkout
        # stayed permanently dirty and every upgrade grew a redundant stash.
        # Guards (never mutate an arbitrary directory): the install must
        # exist, not be a symlink (a symlinked install points at a dev
        # worktree — bin/dev-setup owns that flow), and look like a real
        # gstack clone.
        INSTALL_DIR="$HOME/.claude/skills/gstack"
        RENDER_DIR="${GSTACK_USER_RENDER_DIR:-${GSTACK_HOME:-$HOME/.gstack}/render/claude}"
        if [ ! -d "$INSTALL_DIR" ]; then
          echo "No global install at $INSTALL_DIR — nothing to render. (Dev workspaces get blocks via bin/dev-setup.)"
        elif [ -L "$INSTALL_DIR" ]; then
          echo "Skip: $INSTALL_DIR is a symlink (likely a dev worktree). Run bin/dev-setup in that worktree instead."
        elif [ ! -f "$INSTALL_DIR/VERSION" ] || [ ! -f "$INSTALL_DIR/package.json" ]; then
          echo "Skip: $INSTALL_DIR doesn't look like a gstack clone (missing VERSION/package.json) — refusing to modify it."
        elif ! command -v bun >/dev/null 2>&1; then
          echo "Skip: bun not on PATH — can't render. Install bun, then re-run 'gstack-config gbrain-refresh'."
        else
          # Render into a tmp dir and swap it in only on SUCCESS. Installed
          # skills SYMLINK into $RENDER_DIR (gstack-relink prefers it), so
          # wiping it before the render meant one transient failure (bun
          # error, disk full, broken template) left every brain-aware
          # SKILL.md link dangling — the whole skill set vanished from
          # Claude Code until a successful re-render. A failed render now
          # leaves the previous render fully intact.
          RENDER_TMP="$RENDER_DIR.tmp.$$"
          rm -rf "$RENDER_TMP"
          if ( cd "$INSTALL_DIR" && bun run gen:skill-docs:user --host claude --out-dir "$RENDER_TMP" --link-root "$RENDER_DIR" >/dev/null 2>&1 ); then
            _swap_in_render "$RENDER_DIR" "$RENDER_TMP"
            # Repoint installed skills at the render — gstack-relink prefers
            # the render dir when present.
            "$INSTALL_DIR/bin/gstack-relink" >/dev/null 2>&1 || true
            echo "Rendered brain-aware blocks into $RENDER_DIR — now live across all your projects' Claude sessions."
            echo "The install checkout stays clean: upgrades no longer stash generated render dirt (#2569)."
          else
            rm -rf "$RENDER_TMP"
            echo "Warning: render failed — previous render (if any) left in place, links stay valid."
            echo "Run 'cd $INSTALL_DIR && bun run gen:skill-docs:user --host claude --out-dir $RENDER_DIR' manually to see the error."
          fi
        fi
        ;;
      *)
        echo "gbrain not detected (local-status: $STATUS) → brain-aware blocks will be suppressed in planning-skill SKILL.md files."
        echo "Install gbrain (see /setup-gbrain) and re-run 'gstack-config gbrain-refresh' once it's configured."
        ;;
    esac
    ;;
  *)
    echo "Usage: gstack-config {get|set|list|defaults|endpoint-hash|resolve-user-slug|gbrain-refresh} [key] [value]"
    exit 1
    ;;
esac