LCM-X: memory tool for Hermes Agent

LCM-X

electricsheephq/lcm-x

Lossless context memory for Hermes Agent using a SQLite-backed summary DAG

In short

LCM-X is a context engine plugin for Hermes Agent that replaces one-shot prompt compression with a SQLite-backed, DAG-based store. It keeps the live prompt bounded while letting the agent recover exact detail from compacted history.

What LCM-X does

LCM-X saves raw messages before compaction, condenses older context into depth-aware summary nodes, and assembles the live prompt from the system prompt, the highest-value summaries and a protected recent tail. Summaries keep source lineage, so detail stays recoverable. It replaces the built-in compressor's approach of summarizing older turns once, after which the active prompt no longer holds them verbatim.

The agent gets recall tools, including lcm_grep, lcm_recall, lcm_retrieve, lcm_recent, lcm_load_session and lcm_describe, to search and expand compacted material in bounded pages. A /lcm command and a bundled hermes-lcm skill complete the interface. The design is based on the LCM paper by Ehrlich and Blackman (Voltropy PBC, February 2026) and inspired by lossless-claw for OpenClaw, and the README documents importing from lossless-claw. From v0.24.0 the plugin is named hermes-lcm-x and the engine lcm-x.

Key features

SQLite message store that preserves raw messages before compaction
Hierarchical summary DAG with source lineage
Bounded paging of raw messages, child summaries and externalized payloads
lcm_* recall tools plus a /lcm command and bundled skill
Import path for OpenClaw lossless-claw data

When to use it

Keep long Hermes sessions going without losing exact earlier details
Search compacted history for a specific message or decision
Migrate an OpenClaw lossless-claw memory store to Hermes

Who it is for: Hermes Agent users with long-running sessions who need compacted context to stay recoverable.

How it fits with Hermes Agent

Built for Hermes Agent as a plugin that provides the runtime context engine lcm-x in place of the built-in compressor.

Note: From v0.24.0 the plugin was renamed hermes-lcm-x and the context engine lcm-x, which is a breaking change for existing hermes-lcm installs.

FAQ

What is LCM-X?

LCM-X is a lossless context memory plugin for Hermes Agent. It stores messages in SQLite, summarizes older context into a DAG, and gives the agent tools to recover exact detail after compaction.

Does LCM-X work with Hermes Agent?

Yes. It is built for Hermes Agent and acts as its context engine, named lcm-x, in place of the built-in compression.

Is LCM-X free and open source?

Yes. The repository is published under the MIT license.