Claude Code memory

It gets smarterEvery correction sticks. It stops making the same mistake in every new conversation, because the fix outlives the chat.

It costs fewer tokensStop pasting the same context into every session. It fetches the one fact it needs instead of re-reading all of them.

It actually remembersYour conventions, decisions and preferences persist across sessions, machines and clients.

What it looks like

you     remember that we deploy with `make ship`, never git push --force
claude  Stored 'deploy command'. It will be available in future conversations.

--- next week, new session, different laptop ---

you     how do I deploy this?
claude  make ship. You told me never to use git push --force here.

Connecting it

Connect to Claude Code

That signs you in, makes a key, and hands you the finished command with the key already in it. Paste it into a terminal and restart Claude Code.

Prefer to do it by hand, or using Claude Desktop or Cursor? The manual steps are below.

By hand

Needs Python 3.9 or newer, which macOS and most Linux systems already have. Nothing to install beyond that — the server uses only the standard library.

macOS and Linux

mkdir -p ~/.hebb && curl -fsSL https://hebb-site.pages.dev/mcp/hebb_mcp.py -o ~/.hebb/hebb_mcp.py

claude mcp add hebb -s user -e HEBB_KEY=hebb_live_your_key -- python3 ~/.hebb/hebb_mcp.py

Windows (PowerShell) — the command is python rather than python3, which is the usual reason this fails there:

mkdir -Force "$env:USERPROFILE\.hebb" | Out-Null
curl.exe -fsSL https://hebb-site.pages.dev/mcp/hebb_mcp.py -o "$env:USERPROFILE\.hebb\hebb_mcp.py"

claude mcp add hebb -s user -e HEBB_KEY=hebb_live_your_key -- python "$env:USERPROFILE\.hebb\hebb_mcp.py"

If python is not found, try py, or install Python from python.org and tick Add to PATH.

Codex CLI

Codex keeps MCP servers in ~/.codex/config.toml, and the CLI writes it for you:

codex mcp add hebb --env HEBB_KEY=hebb_live_your_key -- python3 ~/.hebb/hebb_mcp.py

Or write it yourself:

[mcp_servers.hebb]
command = "python3"
args = ["/absolute/path/to/.hebb/hebb_mcp.py"]
env = { HEBB_KEY = "hebb_live_your_key" }

Use an absolute path: Codex does not expand ~ inside args.

Claude Desktop and Cursor

claude_desktop_config.json — ~/Library/Application Support/Claude/ on macOS, %APPDATA%\Claude\ on Windows. For Cursor the same block goes in .cursor/mcp.json.

{
  "mcpServers": {
    "hebb": {
      "command": "python3",
      "args": ["/absolute/path/to/.hebb/hebb_mcp.py"],
      "env": { "HEBB_KEY": "hebb_live_your_key" }
    }
  }
}

Restart the client, then ask what do you remember? to check.

Or skip the editor entirely

hebb is Claude in your terminal with the same memory behind it — one file, no dependencies, for a server or a CI box where installing an editor is not the plan. It needs an Anthropic key of your own; the model is theirs, the memory is yours.

curl -fsSL https://hebb-site.pages.dev/cli/hebb -o /usr/local/bin/hebb && chmod +x /usr/local/bin/hebb
export ANTHROPIC_API_KEY=sk-ant-...   # console.anthropic.com
export HEBB_KEY=hebb_live_...         # your dashboard
hebb

› remember that we deploy with make ship
  · remember: Stored 'deploy command'.

Noted, and it will still be there next week.

› hebb --memories
  deploy command: make ship

The four tools it gains

Tool	What it does
`remember`	Store a fact under a name. Storing the same name again revises it, so correcting a fact is just storing it again.
`recall`	Look it up. By name is exact; by question is a search, and the answer says which fact it matched.
`list_memories`	Everything currently stored.
`forget`	Delete one fact and get a receipt confirming it is gone.

Worth knowing before you install it

Nothing is recorded unless the assistant chooses to store it. There is no background capture and no transcript upload. It calls remember or nothing happens.

Do not store secrets. No passwords, no keys, no tokens. The tool tells the model the same thing, but a model is not a control.

One key, one memory. Every client using the same key sees the same facts, which is the point — your editor and your terminal know the same things. Use a second key for a separate set.

Free plan: 10,000 lookups and 500 new facts a month, 50 facts stored.

If it does not connect

Your client shows a failed server’s error output, which is where this prints.

Message	Fix
`HEBB_KEY is not set`	the env block is missing or misspelled
`That API key was not accepted`	copy it again, or check it is not revoked
tools never get used	say remember that ... once; some clients wait to be shown
`python3: command not found`	on Windows use `python` or `py`

Not affiliated with Anthropic or Cursor. Product names and marks belong to their owners and are used to say what this connects to.

Your coding agent forgets everything when you switch projects