n8n Workflow Builder

# 🐛 Release v1.18.1 - Template System Bugfixes **Release Date**: 2025-12-17 ## 🎯 Overview This is a bugfix release that resolves critical `UnboundLocalError` issues in the template system. These bugs prevented `generate_workflow_template` and `get_template_details` tools from functioning correctly. ## 🐛 Bug Fixes ### 1. Fixed `generate_workflow_template` UnboundLocalError **Issue**: The tool was throwing `UnboundLocalError: cannot access local variable 'WORKFLOW_TEMPLATES' where it is not associated with a value` **Root Cause**: A duplicate local import of `WORKFLOW_TEMPLATES` later in the function (line 4125) caused Python to treat the variable as local throughout the entire function scope. When the code tried to access it earlier (line 1672), the variable was not yet assigned. **Fix**: Removed the redundant local import since `WORKFLOW_TEMPLATES` is already imported at module level (line 23). **Commit**: `bb2b6fc` **Before**: ```python # Line 1672 if template_type in WORKFLOW_TEMPLATES: # ❌ UnboundLocalError ... # Line 4125 (same function) from .templates.recommender import WORKFLOW_TEMPLATES # Local import! ``` **After**: ```python # Line 23 (module level) from .templates.recommender import TemplateRecommendationEngine, WORKFLOW_TEMPLATES # Line 1672 if template_type in WORKFLOW_TEMPLATES: # ✅ Works now! ... # Line 4125 if template_id in WORKFLOW_TEMPLATES: # ✅ No duplicate import ``` --- ### 2. Fixed `get_template_details` UnboundLocalError **Issue**: Same `UnboundLocalError` when trying to get template details **Root Cause**: The function was directly accessing `WORKFLOW_TEMPLATES` without proper fallback logic, and had the same scope issue. **Fix**: Refactored to use the new template registry system with backward compatibility fallback to old templates. **Commit**: `e85f877` **Changes**: 1. Try new `template_registry` first (supports enhanced metadata) 2. Fallback to old `WORKFLOW_TEMPLATES` dict if not found 3. Enhanced output with new template metadata fields **Before**: ```python if template_id not in WORKFLOW_TEMPLATES: # ❌ UnboundLocalError available = ", ".join(WORKFLOW_TEMPLATES.keys()) return error_message template = WORKFLOW_TEMPLATES[template_id] ``` **After**: ```python # Try new registry first template = await template_registry.get_template(template_id) if not template: # Fallback to old templates if template_id in WORKFLOW_TEMPLATES: # ✅ Safe now! template_dict = WORKFLOW_TEMPLATES[template_id] # ... render old format else: return error_message # Use new template metadata with enhanced fields # - Success rate, usage count, trust metrics # - Quality indicators, external systems ``` --- ## 🎉 Improvements ### Enhanced Template Details Output The `get_template_details` tool now includes additional metadata when using templates from the new registry: **New Fields**: - ✅ **Source**: Template source (n8n_official, github, local, community) - ✅ **Complexity**: Difficulty level (beginner, intermediate, advanced) - ✅ **Node Count**: Total number of nodes in template - ✅ **Purpose**: Extracted intent/purpose of the template - ✅ **External Systems**: List of integrated services (Slack, Postgres, etc.) **Quality Indicators**: - ✅ **Error Handling**: Whether template includes error handling - ✅ **Documentation**: Whether template is documented **Trust Metrics**: - ✅ **Success Rate**: Historical success rate (0-100%) - ✅ **Usage Count**: Number of times template was used **Example Output**: ```markdown # 📄 Template Details: Daily Sales Report **Template ID:** `sales_report_daily` **Source:** github **Category:** reporting **Complexity:** beginner **Estimated Time:** 15 minutes **Node Count:** 5 ## Description Fetch sales data daily and send reports to Slack ## Purpose Automated daily reporting for sales metrics ## External Systems `Slack`, `PostgreSQL` ## Node Structure 1. **Schedule Trigger** (`n8n-nodes-base.scheduleTrigger`) 2. **Postgres Query** (`n8n-nodes-base.postgres`) 3. **Format Data** (`n8n-nodes-base.function`) 4. **Send to Slack** (`n8n-nodes-base.slack`) ## Tags `sales`, `slack`, `automation`, `daily` ## Quality Indicators ✅ Has error handling ✅ Has documentation ## Metrics - **Success Rate:** 95% - **Usage Count:** 150 ## Implementation Guide 1. Use this template as a starting point for your workflow 2. Customize node names and parameters to match your requirements 3. Configure credentials for nodes that require authentication 4. Test with sample data before deploying to production 5. Add error handling and monitoring as needed ``` --- ## 🔧 Technical Details ### Python Scope Issue Explanation The `UnboundLocalError` occurs when Python sees a variable being assigned anywhere in a function scope, making it a local variable for the entire function. Even if the assignment comes later, Python treats references earlier in the function as attempts to access an uninitialized local variable. **Problem Pattern**: ```python def my_function(): if condition: print(GLOBAL_VAR) # ❌ UnboundLocalError # Later in same function from module import GLOBAL_VAR # This makes it local! ``` **Solution**: - Import at module level, not inside functions - Or use `global` keyword explicitly ### Affected Tools **Fixed**: - ✅ `generate_workflow_template` - Now works correctly - ✅ `get_template_details` - Now works with enhanced metadata **Verified Safe** (no changes needed): - ✅ All other template tools working correctly - ✅ Template registry system functioning properly - ✅ Backward compatibility maintained --- ## 📊 Testing ### Test Cases Verified **Test 1: generate_workflow_template** ```json { "description": "Create a workflow that monitors GitHub issues and sends Slack notifications", "template_type": "custom" } ``` **Result**: ✅ Works - Generates workflow outline successfully **Test 2: get_template_details** ```json { "template_id": "api_endpoint" } ``` **Result**: ✅ Works - Returns detailed template information **Test 3: Backward Compatibility** ```json { "template_id": "sales_report_daily" } ``` **Result**: ✅ Works - Old templates still accessible --- ## 🚀 Migration Guide No migration needed - this is a pure bugfix release. All existing code continues to work. ### For Users If you encountered these errors before: - `generate_workflow_template` now works correctly - `get_template_details` now works correctly with enhanced output ### For Developers If you're building on this codebase: - Always import module-level constants at the top of files - Avoid local imports of module-level variables inside functions - Use the new `template_registry` for accessing templates when possible --- ## 📝 Files Changed **Modified**: - `src/n8n_workflow_builder/server.py` - Fixed 2 UnboundLocalError issues **Changes**: - Removed 1 duplicate import statement - Refactored 1 function to use template registry - Added 60+ lines of enhanced template detail output - Net: +61 insertions, -24 deletions --- ## 🔗 Related Issues **Closed**: - Template generation failing with UnboundLocalError - Template details failing with UnboundLocalError **Root Cause**: - Python variable scoping with local imports **Prevention**: - All module-level imports now verified - Code review checklist updated - Similar patterns checked across codebase --- ## 📚 Resources - [Python UnboundLocalError Documentation](https://docs.python.org/3/faq/programming.html#why-am-i-getting-an-unboundlocalerror-when-the-variable-has-a-value) - [Template Registry Documentation](docs/TEMPLATES.md) - [GitHub Repository](https://github.com/schimmmi/n8n-workflow-builder) --- **Version**: 1.18.1 **Release Date**: 2025-12-17 **Previous Version**: 1.18.0 🐛 **Quick Bugfix Release - Templates Now Work!**