A memory provider plugin for Hermes Agent (v0.7.0+) that replaces the default flat memory layer with workspace-scoped, vector-searchable hierarchical memory.
Uses ChromaDB for vector similarity search and SQLite for relational storage. A lightweight local embedding model (all-MiniLM-L6-v2, ~50MB) keeps everything fast and offline.
- Workspace isolation — memories in Project A never bleed into Project B
- Explicit-first ranking — deliberate user instructions always surface above auto-extracted context
- Dual-store architecture — SQLite for canonical data, ChromaDB for semantic search
- Zero config — storage paths derive from
$HERMES_HOME, no API keys needed - Non-blocking — turn sync runs in a background thread
Memories are organized into a two-level hierarchy:
Wings (scope) Rooms (priority)
├── Global_User ──► ├── Explicit (user instructions, preferences)
│ └── Implicit (auto-extracted context)
└── Workspace_[ID] ──► ├── Explicit
└── Implicit
Search queries hit the current workspace wing + the global wing, with explicit results always ranked before implicit ones.
| Tool | Purpose |
|---|---|
mempalace_remember_explicit |
Store a deliberate user instruction or preference (high priority) |
mempalace_store_implicit |
Store extracted project context or environment details (lower priority) |
mempalace_recall |
Semantic search across memory with explicit-first ranking |
git clone https://github.com/neilharding/hermes_memorypalace.git
cd hermes_memorypalace
./scripts/deploy.sh
hermes gateway restart
hermes doctor# 1. Install dependencies
pip install chromadb sentence-transformers
# 2. Clone and symlink into Hermes plugins
git clone https://github.com/neilharding/hermes_memorypalace.git
ln -sf "$(pwd)/hermes_memorypalace/mempalace" \
~/.hermes/hermes-agent/plugins/memory/mempalace
# 3. Activate
hermes config set memory.provider mempalace
# 4. Verify
hermes gateway restart
hermes doctorAll data is stored locally under $HERMES_HOME/mempalace/:
| Backend | Default Path | Override Env Var |
|---|---|---|
| SQLite | $HERMES_HOME/mempalace/mempalace.db |
MEMPALACE_DB_PATH |
| ChromaDB | $HERMES_HOME/mempalace/chroma_storage/ |
MEMPALACE_CHROMA_PATH |
# Run tests (uses the Hermes venv for access to the MemoryProvider ABC)
~/.hermes/hermes-agent/venv/bin/python -m pytest tests/ -v
# 37 tests: 11 store, 22 provider, 4 E2E integrationThe plugin implements Hermes's MemoryProvider ABC and hooks into the agent lifecycle:
| Lifecycle Hook | What MemPalace Does |
|---|---|
initialize() |
Bootstraps SQLite schema + ChromaDB collection with embedding model |
system_prompt_block() |
Injects L1 summary (global profile + workspace explicit memories) |
prefetch(query) |
Runs vector search, returns priority-ranked results before each turn |
sync_turn(user, assistant) |
Background thread stores conversation as implicit context |
on_memory_write(action, target, content) |
Mirrors built-in MEMORY.md writes to MemPalace global wing |
handle_tool_call(name, args) |
Dispatches the 3 memory tools |
MIT
