About
Lossless memory for long sessions: LCM-X keeps every turn in a local store instead of compacting it away, and the agent can search and expand it. The store is local SQLite (lcm.db) with a recoverable DAG of summaries over it and 16 lcm_* tools for search, recall and expansion (lcm_memory only with LCM_ENTITIES_ENABLED=1). Select it with context.engine: lcm-x. Upgrading from hermes-lcm (breaking in v0.24.0): stop Hermes, then in plugins.enabled replace hermes-lcm with hermes-lcm-x and run exactly one LCM copy (the install script prints the steps; the old engine name lcm still resolves with a deprecation warning); lcm.db and the lcm: config block are unchanged. Summaries use the model Hermes is configured with. Disclosure — local semantic recall is on by default once its dependency companion is installed (hermes plugins install electricsheephq/lcm-x/companions/hermes-lcm-x-local-embeddings --ref <the LCM-X commit>; it carries fastembed): summaries and message chunks are embedded in-process with BAAI/bge-small-en-v1.5 after a one-time model download, in the background, and stay on the machine. Without the companion, recall answers from full text and lcm_doctor prints the install command; on hosts with 2 or fewer effective CPUs the default answers from full text unless LCM_EMBEDDINGS_ENABLED=true; LCM_EMBEDDINGS_ENABLED=false turns semantic recall off. Cloud embedding providers (Voyage via VOYAGE_API_KEY, an OpenAI-compatible endpoint, or a local Ollama) send message text to that provider and run only with LCM_EMBEDDINGS_ENABLED=true and an explicit model. For known cloud providers the provider-bound copy is privacy-transformed by default (LCM_EMBEDDING_PRIVACY_ENABLED=false opts out), while lcm.db keeps the raw text. Every turn (user, assistant and tool output) is stored in plaintext in lcm.db (secret redaction at rest is opt-in); on gateway platforms the sender's platform user ID is recorded with each user message by default (LCM_SENDER_CAPTURE=0 turns it off), and oversized tool outputs are by default written as plaintext files under HERMES_HOME/lcm-large-outputs and replaced in the model's context by recoverable references. The engine also reads Hermes' state.db read-only for session lineage, reads private AIAgent attributes via the call stack on Hermes builds without subagent hooks, and runs git on its own install directory for lcm_status/lcm_doctor; tiktoken may fetch its BPE file on first use.
LCM-X for Hermes
LCM-X keeps the live context bounded, preserves raw conversation history, and
provides cited retrieval across sessions. This is the runtime catalog payload.
hermes plugins install hermes-lcm-x
hermes plugins enable hermes-lcm-x
Set context.engine: lcm-x in your Hermes configuration, then restart Hermes.
Local semantic recall needs the companion below; without it, recall uses full text.
hermes plugins install electricsheephq/lcm-x/companions/hermes-lcm-x-local-embeddings --ref 3a4a08ff501347a79669fab51444c471b09b551d
README from the reviewed commit 984a400; it updates when the author re-pins.