PR #11452: feat: per-user memory isolation in group chats (#11430)

• Repository: NousResearch/hermes-agent
• Author: Laurc2004
• State: closed | merged: False
• Link: https://github.com/NousResearch/hermes-agent/pull/11452

Description (problem / solution / changelog)

Summary

In group chats, the agent's persistent memory (MEMORY.md, USER.md) was globally shared across all users. This caused identity contamination — User A's personal info, preferences, and persona could bleed into conversations with User B.

This PR implements per-user memory isolation by introducing a namespace parameter to MemoryStore. Each platform:user_id combination gets its own memory directory, preventing cross-user contamination.

Related Issues

• Closes #11430 — Feature: Per-user memory isolation in group chats to prevent identity contamination
• Related to #10554 — session_search should be scoped to the current chat by default
• Related to #9514 — Feature: Single-Daemon Multi-Agent with Per-Topic Workspace & Memory Isolation
• Related to #5195 — Feature: Per-topic/per-group system prompt binding for Telegram
• Related to #9532 — Bug: background process notifications leak into wrong threaded session (CLOSED)

Changes

tools/memory_tool.py

• Added namespace: str = "" parameter to get_memory_dir() — routes to ~/.hermes/memories/{namespace}/ when set, falls back to global root for backward compatibility
• MemoryStore.__init__ now accepts and stores namespace
• Converted _path_for() and load_from_disk() from static methods to instance methods using self.namespace
• Added auto-migration logic: on first load with a namespace, copies existing MEMORY.md and USER.md from global root into the namespace directory (preserving original files)

run_agent.py

• Constructs namespace string _ns = f"{self.platform}:{self._user_id}" (empty string fallback for CLI/unknown contexts)
• Passes namespace=_ns to MemoryStore() initialization

Design Decisions

1. Namespace format: platform:user_id (e.g., telegram:5137755622)
2. Backward compatibility: CLI sessions and contexts without user_id use empty namespace → global ~/.hermes/memories/ root (unchanged behavior)
3. Auto-migration: On first access, existing root-level memory files are copied into the namespace directory. Originals are preserved, not deleted.
4. No schema changes: Memory format (Markdown files) stays identical — only the directory changes

Testing

• Verified namespace directory auto-creation (~/.hermes/memories/telegram_5137755622/)
• Confirmed CLI fallback to global root (empty namespace)
• Tested auto-migration copies files correctly without deleting originals

Impact

This is a targeted fix scoped to the memory persistence layer. The session isolation (group_sessions_per_user: True) already handled conversation-level isolation — this PR addresses the missing persistent memory isolation that caused the cross-user identity contamination.

Changed files

• gateway/run.py (modified, +6/-0)
• gateway/stream_consumer.py (modified, +14/-8)
• run_agent.py (modified, +8/-0)
• tests/tools/test_memory_tool.py (modified, +49/-3)
• tools/memory_tool.py (modified, +35/-8)

PR #11448: feat(memory): auto-migrate shared root memories to per-user namespace dirs

• Repository: NousResearch/hermes-agent
• Author: Laurc2004
• State: open | merged: False
• Link: https://github.com/NousResearch/hermes-agent/pull/11448

Description (problem / solution / changelog)

Summary

When per-user memory isolation is enabled, users with existing shared memories (MEMORY.md / USER.md in ~/.hermes/memories/ root) would lose their memories because the new namespaced directory starts empty.

This PR adds automatic migration: on first load for a new namespaced user, shared root memory files are automatically copied into their per-user directory.

Changes

tools/memory_tool.py

• Add _migrate_from_shared() — helper that copies MEMORY.md and USER.md from the shared root to a namespaced user directory, only if the target files do not already exist (no overwrite)
• Fix load_from_disk() in MemoryStore.__init__ area — the original definition used get_memory_dir() without the namespace parameter, which would break per-user isolation. Fixed to use get_memory_dir(self.namespace) and call migration.
• Remove duplicate load_from_disk() — the second definition shadowed the first, making the fix in the first ineffective
• Fix regex escaping in get_memory_dir() (@.+ → @\\.+ for proper literal dot matching)

tests/tools/test_memory_tool.py

• TestMemoryMigrationFromSharedRoot — new test class with 3 tests:
  • test_migration_copies_shared_files_to_new_namespace — verifies happy path
  • test_migration_does_not_overwrite_existing_user_files — verifies no data loss
  • test_migration_does_nothing_for_empty_namespace — verifies CLI/global sessions unaffected

Testing

All 37 tests in test_memory_tool.py pass, including:

• 3 new migration tests
• Existing namespace isolation test
• All existing MemoryStore and memory_tool dispatcher tests

Changed files

• gateway/run.py (modified, +6/-0)
• gateway/stream_consumer.py (modified, +14/-8)
• run_agent.py (modified, +8/-0)
• tests/tools/test_memory_tool.py (modified, +119/-3)
• tools/memory_tool.py (modified, +52/-9)