Use Synapse with Claude Desktop

Claude forgets everything when a conversation ends. Synapse fixes that — give Claude persistent memory in about 2 minutes. No terminal, no config files, no coding.

Recommended: one-click install

Works on macOS and Windows. No Node.js, no npm, nothing to install beforehand.

Faster path: let your agent do this

Working in Claude Code, Codex, or another coding agent? Paste this page's URL into its chat and say "implement Synapse memory using this doc." It reads the steps below, installs the extension, and wires the config — you just paste in the API key when it asks.

Step 1: Get a free API key

Sign up at synapse.by-kit.com/signup. Your key is shown once at creation — copy it somewhere safe (a password manager, not a text file) before you close that page.

Step 2: Download and open the Synapse extension

Download the extension file, then double-click it. Claude Desktop opens automatically and shows an install screen.

Download synapse-memory.mcpb

Requires Claude Desktop (not the web/browser version). If double-clicking doesn't open Claude, open Claude Desktop first, then go to Settings → Extensions → Advanced settings → Install Extension and select the downloaded file.

Step 3: Paste your API key — in the right place

The install screen asks for your Synapse API Key. Paste it into that field.

⚠️ Only paste your key into that one field.

Never paste your API key into a chat message, a schema/JSON box, or anywhere else — even if it looks similar. If you're ever unsure whether a box is the right one, stop and check this page again. A key pasted in the wrong place should be treated as compromised — rotate it from your dashboard.

Click install. Claude restarts the extension automatically — nothing else to do.

Step 4: Tell Claude to actually use it

In Claude Desktop, go to Settings → Custom instructions and paste:

You have Synapse memory tools. At the start of every conversation, call synapse_recall with query='recent context' and synapse_recent with limit=5. During conversation, whenever the user shares something important, call synapse_remember immediately. Never wait to be asked.

This tells Claude to load your memory at the start of every conversation and save important things as they come up — automatically. Without this step, the tools are installed but Claude won't use them on its own.

Test it

Start a new conversation and say something like "My name is Alex and I run a landscaping business." Then start a completely new conversation and ask "What do you know about me?" If Claude answers correctly, it's working.

What Claude can remember

  • Your name and preferences
  • Ongoing projects you're working on
  • Decisions you've made together
  • Anything you tell it — automatically saved

Advanced: manual install via npm

Only use this path if you're comfortable with a terminal and already have Node.js installed. Most people should use the one-click extension above instead.

Check you have Node.js first

Open a terminal and run node -v. If that fails with "command not found," you don't have Node.js — use the one-click extension above instead of installing Node just for this.

Install the package

npm install -g synapse-memory-mcp

Then add Synapse to your Claude Desktop config file:

  • macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
  • Windows: %APPDATA%\Claude\claude_desktop_config.json

Paste this config (replace your-key-here with your API key — nowhere else):

{
  "mcpServers": {
    "synapse": {
      "command": "synapse-memory-mcp",
      "env": { "SYNAPSE_API_KEY": "your-key-here" }
    }
  }
}

Save the file and restart Claude Desktop, then repeat Step 4 above (system prompt).

Next steps