GitHub Issue Draft: Memory Types + Tool Memory

GitHub Issue Draft: Memory Types + Tool Memory

Title

[2026NewYearChallenge] Specialized Memory Types with Tool Learning

Description

What will this task implement?

This PR enhances MemU's memory type system to support specialized memory structures with type-specific metadata and introduces Tool Memory for agent self-improvement.

Current State: MemU has a memory_type field with 5 types (profile, event, knowledge, behavior, skill) and uses different LLM prompts to extract each type. However, after extraction, all memories share the same storage schema - just summary and embedding. There's no type-specific metadata, no type-aware retrieval, and no way for agents to learn from their tool usage.

Enhancement: Extend the memory system to support:

• Type-specific metadata fields (e.g., when_to_use for smarter retrieval)
• Tool Memory type for tracking tool execution history
• Tool usage statistics for agent self-improvement
• Type-aware retrieval filtering

Key Benefits:

• Agents can learn from their own tool usage patterns
• Smarter retrieval based on memory context
• Foundation for agents that improve over time
• Better alignment with agentic application needs

Requirements

• Type-specific metadata schema with when_to_use field
• Tool Memory implementation with execution tracking
• Tool statistics (success_rate, avg_time_cost, avg_score)
• Type-aware retrieval filtering
• Tests for Tool Memory CRUD and statistics
• Documentation and usage examples

Review Criteria

• Correctness: All tests pass, no regressions
• Quality: Clean code, follows existing patterns
• DX: Clear documentation and examples
• Impact: Enables agent self-improvement use cases

Implementation Summary

Files Modified:

1. src/memu/database/models.py - Added ToolCallResult model, extended MemoryItem with when_to_use, metadata, tool_calls fields
2. src/memu/database/repositories/memory_item.py - Updated interface with new fields
3. src/memu/database/inmemory/repositories/memory_item_repo.py - Updated implementation
4. src/memu/database/postgres/repositories/memory_item_repo.py - Updated implementation
5. src/memu/database/postgres/models.py - Added JSON columns for new fields
6. src/memu/prompts/memory_type/__init__.py - Added tool type
7. src/memu/prompts/memory_type/tool.py - New prompt for tool memory extraction

Files Added:

1. tests/test_tool_memory.py - 14 unit tests for Tool Memory feature

Notes

This builds on MemU's existing memory type foundation while adding the specialized structures needed for agentic applications. The Tool Memory feature is particularly valuable for agents that need to learn which tools work best in different situations.