Survey of Local-First Markdown Memory Servers for AI Agents: Mem0, Hindsight, Zep, and the Newcomer Engram

A Reddit user asked for a fully local agent memory system that stores memories as readable Markdown files — not a database or cloud service. After receiving ~20 suggestions and testing them all, here is the breakdown of what each tool actually offers and where the gaps remain.

Non-Memory Systems Flagged

Several suggested tools are not memory systems: ChromaDB is a vector database; qmd is a document search engine with no write pipeline; ContextKeep does context compression; LCM preserves session context only.

Established Options

• mem0 — market leader, graph-based memory, SDKs in multiple languages, production-scale. Downsides: defaults to OpenAI, leans hosted, stores in opaque database.
• Hindsight — knowledge graph, entity resolution, handles contradictory memories. Requires Postgres + vector DB, storage is SQL — can't read files directly.
• Zep — longest track record, multi-modal memory, structured extraction. Cloud-first, similar infra requirements to Hindsight.
• Honcho — continual learning, stateful architecture, more research-grade. AGPL license + cloud dependency.

OpenClaw-Specific Options

• memory-lancedb-pro — strongest memory plugin for OpenClaw, hybrid retrieval, decay model, actively maintained. Not a standalone server.
• GBrain — MCP-first, decent OpenClaw integration, not useful outside ecosystem.

Most Interesting Newcomer: mnem

mnem is a Rust single binary, no Python/Ollama/external dependencies. Described as "git for agent memories": branch, diff, merge, revert. Uses GraphRAG. Benchmarks well against mem0. Two weeks old — thin test coverage. Storage is content-addressed graph nodes, not readable files.

The Gap and What Fills It: Engram

None of the tested tools combined fully local + human-readable file storage + smart deduplication + importance decay + standalone server with no infrastructure requirements. Engram by Obsidian68 (github.com/Obsidian68/Engram) is brand new (almost no stars) but checks all four boxes:

• Memories stored as Markdown files in a folder — openable in VS Code, editable, deletable.
• Full REST API and MCP server.
• Smart dedup on writes, importance decay for older memories.
• Runs entirely on Ollama — no API keys, no external calls, fully local.

If privacy and readability matter for your agent's knowledge, Engram is currently the only complete solution.