SessionStartHook to set persistent variables for getting around Claude Code's inability to remember its project work dir.

hooks.json

{
  "hooks": {
    "SessionStart": [
      {
        "hooks": [
          {
            "type": "command",
            "command": "${CLAUDE_PLUGIN_ROOT}/scripts/workdir-persistence.sh",
            "timeout": 10
          }
        ]
      }
    ]
  }
}

workdir-persistence.sh

#!/bin/bash
# workdir-persistence.sh
# Persists PROJECT_WORK_DIR and additional directories as environment variables
# Called by SessionStart hook
#
# Exports:
#   PROJECT_WORK_DIR - Main project directory ($CLAUDE_PROJECT_DIR)
#   ADDITIONAL_DIR_1, ADDITIONAL_DIR_2, etc. - From additionalDirectories in settings.local.json
#   SHARED_DIR_100, SHARED_DIR_101, etc. - From additionalDirectories in settings.json

if [ -z "$CLAUDE_ENV_FILE" ]; then
    exit 0  # Not in a Claude session context
fi

# Always set PROJECT_WORK_DIR to the main project directory
echo "export PROJECT_WORK_DIR=\"$CLAUDE_PROJECT_DIR\"" >> "$CLAUDE_ENV_FILE"

# Parse additionalDirectories from .claude/settings.local.json
# Export them as ADDITIONAL_DIR_1, ADDITIONAL_DIR_2, etc.
SETTINGS_FILE="${CLAUDE_PROJECT_DIR}/.claude/settings.local.json"
if [ -f "$SETTINGS_FILE" ]; then
    python3 -c "
import json
try:
    with open('$SETTINGS_FILE') as f:
        data = json.load(f)
    dirs = data.get('permissions', {}).get('additionalDirectories', [])
    for i, d in enumerate(dirs, 1):
        print(f'export ADDITIONAL_DIR_{i}=\"{d}\"')
except:
    pass
" >> "$CLAUDE_ENV_FILE"
fi

# Also check shared settings.json
SHARED_SETTINGS="${CLAUDE_PROJECT_DIR}/.claude/settings.json"
if [ -f "$SHARED_SETTINGS" ]; then
    python3 -c "
import json
try:
    with open('$SHARED_SETTINGS') as f:
        data = json.load(f)
    dirs = data.get('permissions', {}).get('additionalDirectories', [])
    # Start numbering from 100 to avoid conflicts with local settings
    for i, d in enumerate(dirs, 100):
        print(f'export SHARED_DIR_{i}=\"{d}\"')
except:
    pass
" >> "$CLAUDE_ENV_FILE"
fi

# Output context message (shown to Claude via SessionStart additionalContext)
echo "Environment variables persisted for session:"
echo "  PROJECT_WORK_DIR=$CLAUDE_PROJECT_DIR"
exit 0