mem0/mem0-plugin/scripts/on_session_start.sh

#!/usr/bin/env bash
# Hook: SessionStart (matcher: startup|resume|compact)
#
# Bootstraps mem0 context at the start of every session.
# Output becomes part of Claude's context so it calls mem0 MCP tools.
#
# Input:  JSON on stdin with session_id, source, transcript_path, model, cwd
# Output: Text injected into Claude's context (exit 0)

# Intentionally omit -e so the script always outputs a bootstrap prompt
# even if jq is missing or stdin is malformed.
set -uo pipefail

if [ -n "${MEM0_DEBUG:-}" ]; then
  mkdir -p "$HOME/.mem0" && exec 2>>"$HOME/.mem0/hooks.log"
fi

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
# shellcheck source=_identity.sh
. "$SCRIPT_DIR/_identity.sh"

# Initialize session stats tracker
python3 "$SCRIPT_DIR/session_stats.py" init 2>/dev/null || true

INPUT=$(cat)
SOURCE=$(echo "$INPUT" | jq -r '.source // "startup"' 2>/dev/null || echo "startup")

# Skip bootstrap if no API key — still show banner but with "no key" status.
if [ -z "${MEM0_API_KEY:-}" ]; then
  echo "## Mem0 Inactive"
  echo ""
  echo "\`user=${MEM0_RESOLVED_USER_ID:-$USER} | project=${MEM0_PROJECT_ID:-unknown} | branch=${MEM0_BRANCH:-unknown} | api_key=NOT_SET\`"
  echo ""
  echo "IMPORTANT: In your FIRST response to the user, you MUST display the status banner exactly as shown below (copy-paste it as your opening line before any other output):"
  echo ""
  echo '```'
  echo "Mem0 Inactive | user=${MEM0_RESOLVED_USER_ID:-$USER} | project=${MEM0_PROJECT_ID:-unknown} | branch=${MEM0_BRANCH:-unknown} | api_key=NOT_SET"
  echo '```'
  echo ""
  echo "Set MEM0_API_KEY to enable persistent memory. Get a key at https://app.mem0.ai/dashboard/api-keys"
  exit 0
fi

# Check for failed dependency installation and warn the user
_DATA_DIR="${CLAUDE_PLUGIN_DATA:-$HOME/.mem0/plugin-data}"
if [ -f "${_DATA_DIR}/.install-failed" ]; then
  echo ""
  echo "⚠️ mem0 SDK installation failed. Some features may not work."
  echo "Run: ${CLAUDE_PLUGIN_ROOT:-$SCRIPT_DIR/..}/scripts/ensure_deps.sh"
  echo ""
fi

# Fetch project-scoped memory count (best-effort, don't block on failure, 5s timeout)
MEM0_COUNT="?"
if command -v python3 >/dev/null 2>&1; then
  MEM0_COUNT=$(python3 -c "
import json, os, urllib.request, urllib.error
api_key = os.environ.get('MEM0_API_KEY', '')
user_id = os.environ.get('MEM0_RESOLVED_USER_ID', 'default')
app_id = os.environ.get('MEM0_PROJECT_ID', '')
body = json.dumps({'filters': {'user_id': user_id, 'app_id': app_id}}).encode()
req = urllib.request.Request(
    'https://api.mem0.ai/v3/memories/?page=1&page_size=1',
    headers={'Authorization': f'Token {api_key}', 'Content-Type': 'application/json'},
    data=body,
    method='POST',
)
try:
    with urllib.request.urlopen(req, timeout=5) as r:
        data = json.loads(r.read())
        if isinstance(data, dict) and 'count' in data:
            print(data['count'])
        elif isinstance(data, list):
            print(len(data))
        else:
            print('?')
except Exception:
    print('?')
" 2>/dev/null || echo "?")
fi

# Identity line is emitted before every bootstrap variant so the agent
# uses the same user_id the hooks resolved. Without this, the agent's
# search_memories/add_memory MCP calls may bind to a different bucket
# than what the hooks write to.
echo "## Mem0 Active"
echo ""
echo "\`user=$MEM0_RESOLVED_USER_ID | project=$MEM0_PROJECT_ID | branch=$MEM0_BRANCH | memories=$MEM0_COUNT\`"
echo ""
echo "IMPORTANT: In your FIRST response to the user, you MUST display the identity banner exactly as shown below (copy-paste it as your opening line before any other output):"
echo ""
echo '```'
echo "Mem0 Active | user=$MEM0_RESOLVED_USER_ID | project=$MEM0_PROJECT_ID | branch=$MEM0_BRANCH | memories=$MEM0_COUNT"
echo '```'
echo ""
echo "Always include \`user_id\` + \`app_id\` in every \`search_memories\` filter and \`add_memory\` call:"
echo "- user_id: \`$MEM0_RESOLVED_USER_ID\`"
echo "- app_id: \`$MEM0_PROJECT_ID\` (project scope — passed as top-level \`app_id\`, NOT in metadata)"
echo ""

# Load mem0.md project config if present (best-effort, non-blocking)
MEM0_PROJECT_CONFIG=""
MEM0_CWD_RESOLVED=$(echo "$INPUT" | jq -r '.cwd // "."' 2>/dev/null || echo ".")
if command -v python3 >/dev/null 2>&1; then
  MEM0_PROJECT_CONFIG=$(python3 "$SCRIPT_DIR/parse_mem0_config.py" --full "$MEM0_CWD_RESOLVED" 2>/dev/null || echo "{}")
fi
if [ -n "$MEM0_PROJECT_CONFIG" ] && [ "$MEM0_PROJECT_CONFIG" != "{}" ]; then
  _CONFIG_KEYS=$(echo "$MEM0_PROJECT_CONFIG" | python3 -c "import sys,json; d=json.load(sys.stdin); print(len(d))" 2>/dev/null || echo "?")
  echo "### Project Config (mem0.md)"
  echo "\`mem0.md loaded (${_CONFIG_KEYS} sections configured)\`"
  if [ -n "${MEM0_DEBUG:-}" ]; then
    echo "\`\`\`json"
    echo "$MEM0_PROJECT_CONFIG"
    echo "\`\`\`"
  fi
  echo ""
fi

if [ "$SOURCE" = "startup" ]; then
  # First-run detection: auto-trigger onboarding for new projects
  _SAFE_PID=$(printf '%s' "$MEM0_PROJECT_ID" | tr '/:' '--')
  _ONBOARD_MARKER="$HOME/.mem0/.onboarded_${_SAFE_PID}"
  if [ ! -f "$_ONBOARD_MARKER" ]; then
    mkdir -p "$HOME/.mem0" 2>/dev/null || true
    touch "$_ONBOARD_MARKER"
    cat <<'EOF'
## Mem0 First Run — Automatic Onboarding

This is the first time mem0 is running for this project. You MUST run the onboarding wizard NOW before doing anything else.

Execute the `/mem0:onboard` skill immediately. This will:
1. Verify the API key
2. Detect and import project files (CLAUDE.md, AGENTS.md, .cursorrules, etc.)
3. Install coding categories optimized for development
4. Show a summary of what was set up

Do NOT skip this. Do NOT ask the user if they want to onboard. Just run `/mem0:onboard` now.
EOF
  else
    cat <<'EOF'
## Mem0 Session Bootstrap

You have access to persistent memory via the mem0 MCP tools. Before doing anything else:

1. Call `search_memories` with a query related to the current project or user request to load relevant context.
2. Review the returned memories to understand what has been learned in prior sessions.
3. If appropriate, call `get_memories` to browse all stored memories for this user.

IMPORTANT: Do NOT skip this step. Always bootstrap context first.
EOF
  fi

  # Detect native Claude Code auto-memory for THIS project
  _PROJ_KEY=$(printf '%s' "$MEM0_CWD_RESOLVED" | tr '/' '-')
  _MEMORY_MD="$HOME/.claude/projects/${_PROJ_KEY}/memory/MEMORY.md"
  if [ -f "$_MEMORY_MD" ] && [ -s "$_MEMORY_MD" ]; then
    cat <<MEMEOF

### Native auto-memory detected

Found \`$_MEMORY_MD\`. The mem0 plugin handles all memory storage.
To avoid two parallel memory systems:
- Add \`"autoMemoryEnabled": false\` to \`~/.claude/settings.json\`
- Or run \`/mem0:import\` to migrate existing MEMORY.md content into mem0

MEMEOF
  fi

  # Auto-import declarative project files in background
  MEM0_CWD="$(echo "$INPUT" | jq -r '.cwd // "."' 2>/dev/null || echo ".")" \
    python3 "$SCRIPT_DIR/auto_import.py" 2>/dev/null &

elif [ "$SOURCE" = "resume" ]; then
  cat <<'EOF'
## Mem0 Session Resumed

This is a resumed session. Your prior context is already loaded. Before continuing:

1. Call `search_memories` with a query related to the current task to refresh relevant memories.
2. If significant time has passed, search for recent project-wide updates.

Continue where you left off.
EOF

elif [ "$SOURCE" = "compact" ]; then
  cat <<'EOF'
## Mem0 Post-Compaction Recovery

Context was just compacted. Reload your context from mem0.

1. Call `search_memories` to reload context, layering up to three angles:
   - `metadata.type=session_state` -- the pre-compaction summary you wrote before compaction
   - `metadata.type=decision` / `anti_pattern` -- specific facts you stored during the session
2. Continue working from the recovered context.
EOF
fi

# Telemetry (background, fire-and-forget)
python3 "$SCRIPT_DIR/telemetry.py" session_start --source="$SOURCE" --memory_count="${MEM0_COUNT:-0}" 2>/dev/null &

exit 0