Hmem MCP Server

hmem — Humanlike Memory for AI Agents

Your AI forgets everything between sessions. hmem fixes that.

One read_memory() call. 5k tokens. Your agent knows every project, every past mistake, every decision you ever made together — across sessions, devices, and AI providers. No setup per conversation. No "let me re-read the codebase." It just remembers.

---

The Problem

Every AI session starts from zero. Your agent asks the same questions, makes the same mistakes, contradicts last week's decisions, and wastes 50k tokens loading context it already processed yesterday.

You've tried workarounds — CLAUDE.md files, custom prompts, manually pasting context. They don't scale. You have 10 projects. You switch between 3 devices. You use different AI tools.

The Solution

You:    "Load project hmem"
Agent:  [calls load_project("P0048") — 700 tokens]
Agent:  "Got it. v5.0.0, TypeScript/SQLite/npm, 10 source files,
         3 open tasks, 9 ideas. Last session you implemented
         auto-checkpoints via Haiku. What's next?"

That's it. 700 tokens for a complete project briefing. The agent knows the stack, the architecture, the open bugs, the recent decisions, and exactly where you left off — even if "you" was a different AI on a different machine yesterday.

---

How It Works

Level 1  ──  One-line summary          (always loaded — ~5k tokens for 300+ entries)
  Level 2  ──  Paragraph detail        (loaded on demand)
    Level 3  ──  Full context           (loaded on demand)
      Level 4  ──  Extended detail      (loaded on demand)
        Level 5  ──  Raw/verbatim data  (loaded on demand)

At session start, the agent loads Level 1 summaries — one line per memory. When it needs detail, it drills down. Your 300-entry memory costs 5k tokens to overview. A single project costs 700.

Nothing is summarized away. Level 1 is a summary, but Levels 2-5 hold the complete original text, word for word, accessible on demand.

---

What Makes v5 Different

Automatic Session Memory

Every conversation is recorded automatically. No "save your work" prompts. No manual checkpoints.

You type  →  Agent responds  →  Stop hook fires  →  Exchange saved to O-entry
                                                  →  Linked to active project
                                                  →  Haiku auto-titles the session

Switch projects mid-session? The O-entry switches too. Start a new session on a different PC? The next agent sees every exchange from every device — the conversation never dies.

Haiku Background Checkpoints

Every 20 exchanges, a Haiku subagent wakes up in the background. It reads the recent conversation, extracts lessons learned, errors encountered, and decisions made, then writes them to long-term memory — with full MCP tool access. Your main agent is never interrupted.

The checkpoint also writes a handoff note to the project: "Here's what was done, here's what's in progress, here's the next step." The next agent — on any device, any provider — picks up exactly where you left off.

Project-Based, Not Session-Based

Sessions are meaningless. Projects are everything.

• O-entries are linked to the active project, not the session
• Checkpoint counters count project exchanges, not session messages
• 10 messages on your laptop + 10 on your server = checkpoint fires on message 20
• load_project shows recent conversations with full context — across all devices

---

Key Features

Categories

---

Quick Start

1. Install

npm install -g hmem-mcp

2. Run the interactive installer

npx hmem init

This detects your AI tools, creates the memory directory, configures MCP, and installs all 4 hooks:

3. Verify

Restart your AI tool, then:

read_memory()

Empty response = working (first run). Error = check the troubleshooting section.

Manual setup

If you prefer manual configuration over hmem init:

{
  "mcpServers": {
    "hmem": {
      "command": "/absolute/path/to/node",
      "args": ["/absolute/path/to/hmem-mcp/dist/mcp-server.js"],
      "env": {
        "HMEM_PROJECT_DIR": "/home/yourname/.hmem",
        "HMEM_AGENT_ID": "DEVELOPER"
      }
    }
  }
}

Find the paths:

echo "Node: $(which node)"
echo "Server: $(npm root -g)/hmem-mcp/dist/mcp-server.js"

{
  "mcp": {
    "hmem": {
      "type": "local",
      "command": ["/absolute/path/to/node", "/absolute/path/to/hmem-mcp/dist/mcp-server.js"],
      "environment": { "HMEM_PROJECT_DIR": "/home/yourname/.hmem" },
      "enabled": true
    }
  }
}

Edit ~/.cursor/mcp.json, ~/.codeium/windsurf/mcp_config.json, or .vscode/mcp.json:

{
  "mcpServers": {
    "hmem": {
      "command": "/absolute/path/to/node",
      "args": ["/absolute/path/to/hmem-mcp/dist/mcp-server.js"],
      "env": { "HMEM_PROJECT_DIR": "/home/yourname/.hmem" }
    }
  }
}

---

Configuration

hmem.config.json in your HMEM_PROJECT_DIR (or Agents/NAME/):

{
  "memory": {
    "maxCharsPerLevel": [200, 2500, 10000, 25000, 50000],
    "maxDepth": 5,
    "checkpointMode": "auto",
    "checkpointInterval": 20,
    "recentOEntries": 10,
    "maxTitleChars": 50,
    "prefixes": { "X": "Custom" }
  },
  "sync": {
    "serverUrl": "https://your-server/hmem-sync",
    "userId": "yourname",
    "salt": "...",
    "token": "..."
  }
}

All keys are optional. Missing keys use defaults.

---

Cross-Device Sync

Sync memories across all devices with zero-knowledge encryption.

npm install -g hmem-sync
npx hmem-sync connect     # Interactive wizard — first device creates, others join

Add HMEM_SYNC_PASSPHRASE to your MCP config for automatic sync on every read/write.

Multi-server redundancy

{
  "sync": [
    { "name": "primary", "serverUrl": "https://server1/hmem-sync", "userId": "me", "salt": "...", "token": "..." },
    { "name": "backup",  "serverUrl": "https://server2/hmem-sync", "userId": "me", "salt": "...", "token": "..." }
  ]
}

Announcements

Broadcast to all synced agents across all devices:

npx hmem-sync announce --message "Server URL changing — update your config!"

---

Troubleshooting

---

Updating

npm update -g hmem-mcp       # MCP server
npm update -g hmem-sync       # Sync (if installed)
npx hmem update-skills        # Refresh skill files

---

License

MIT