Hermes + Mnemosyne: give the cheap agent a local memory

The Stack

Steps

1. 1

   Register Mnemosyne as a Hermes MCP server, then prove the round-trip

   Add an mcp_servers.mnemosyne block to config.yaml (command: mnemosyne, args: [mcp]) so Hermes launches it. Then install Mnemosyne and run a real store → recall round-trip with the mnemosyne CLI; without the embedding extra it falls back to FTS5 keyword retrieval, which is fully offline. CI runs exactly this, no key. (Confirm the launch command against the repo's Hermes integration doc, since entrypoints can change between versions.)

   python3 -m venv .venv
   .venv/bin/pip install -q "mnemosyne-memory==3.7.0" pyyaml
   cat > config.yaml <<'YAML'
   mcp_servers:
     mnemosyne:
       command: mnemosyne
       args: ["mcp"]
   YAML
   .venv/bin/python - <<'EOF'
   import yaml
   cfg = yaml.safe_load(open("config.yaml"))
   srv = cfg["mcp_servers"]["mnemosyne"]
   assert srv["command"] == "mnemosyne", f"bad command {srv.get('command')}"
   assert srv["args"] == ["mcp"], f"bad args {srv.get('args')}"
   print("config OK: mcp_servers.mnemosyne -> command 'mnemosyne' args ['mcp']")
   EOF
   .venv/bin/mnemosyne store "User prefers dark mode interfaces" preference 0.9 >/dev/null
   OUT=$(.venv/bin/mnemosyne recall "interface preferences" 3)
   if printf '%s' "$OUT" | grep -q "dark mode"; then
     echo "mnemosyne round-trip OK: recalled the stored fact in keyword mode"
   else
     echo "recall missed the stored fact: $OUT"; exit 1
   fi

2. 2

   Turn on semantic recall (the model step, not checked by CI)

   Install the embedding extra (pip install "mnemosyne-memory[all]") for semantic search and sleep-cycle consolidation. Those run embeddings, which are non-deterministic, so CI never claims them.