MCP Guide
MCP connectors let Claude reach outside its context window — pulling from your own data, calling external tools, or maintaining a memory that persists between conversations. Adding one takes about two minutes.
This guide covers the exact steps for Claude.ai (the web app). If you're using Claude Desktop, the setup is in a config file — but the concepts are the same.
MCP stands for Model Context Protocol — an open standard that lets Claude talk to external servers in real time. When you add a connector, you're giving Claude a URL it can call during a conversation to fetch data, write records, or run tools.
The practical result: Claude can pull in fresh information that isn't in its training data, remember things you told it last week, or interact with your own databases — without you pasting anything into the chat.
Common things people connect:
You need:
https://yourserver.example.com/mcpMCP connectors only work on claude.ai and Claude Desktop right now. They don't work via the API or in Claude's mobile apps.
Sign in, then click your profile photo in the top-right corner. Select Settings from the dropdown menu.
On desktop, you'll see a left sidebar inside Settings. Click Connectors. On narrower screens it may appear lower in the list — scroll down if you don't see it immediately.
A dialog opens with a URL field and a name field.
Paste the HTTPS URL the server gave you (ends in /mcp for most servers). Give it a short name — this is just your label. Click Save.
If the server requires authentication, Claude will open a sign-in popup automatically. Complete the sign-in flow (usually Google OAuth or a token). Once done, the connector shows as Connected in your settings.
Connectors are active by default in new chats. Start a fresh conversation and ask Claude to use the tool — for example, "call context() from my Stash" or whatever the server's first tool does.
After adding the connector, open a new chat. You should see a small indicator that the connector is available (usually a tool icon in the chat bar).
Ask Claude directly to use the tool. Something like:
"What tools do you have from [connector name]?"
Claude will list the available tools. Call one — and you'll see it reach out to the server and pull back a real response.
If the tool call succeeds, you're connected. If it fails, see the troubleshooting section below.
The connector shows an error or "disconnected" — the server may be down or the URL may be wrong. Double-check the URL you pasted: it should be exactly what the server gave you, starting with https://.
Claude says it can't find the tool — you may need to explicitly mention the connector in your message ("use my Stash connector" or similar) if Claude is confused about which tools are available. Some tools only appear when the connector is called.
The sign-in popup didn't appear / closed too fast — remove the connector from Settings and re-add it. The popup should open as soon as you save. Make sure pop-up blockers aren't blocking it.
redirect_uri_mismatch error during sign-in — this is a server-side configuration issue, not yours. Contact the server provider; they need to register their callback URL in their OAuth app.
The connector works but Claude isn't using it — connectors are on by default in each chat, but you can check with the tool indicator in the chat bar. In some chats Claude may need to be prompted: "please use the [name] connector to look that up."
If you want to test MCP connectors without setting anything up, Stash is a hosted record store with a free tier — no card required, sign in with Google.
What it does: stores lists, notes and context, searches them back to Claude in milliseconds. The main use case people reach for first is loading standing context (your role, projects, preferences) at the start of every conversation — so Claude already knows you without you pasting anything.
Connector URL:
https://app.stashlite.com/mcp
Paste that into Claude Settings → Connectors. Sign in with Google when prompted. Then ask Claude to call context() — it'll tell you what to add first.
If you're using Claude Desktop (the Mac/Windows app), MCP connectors are configured via a JSON config file rather than a UI. The location:
~/Library/Application Support/Claude/claude_desktop_config.json%APPDATA%\Claude\claude_desktop_config.jsonAdd a mcpServers section:
{
"mcpServers": {
"stash": {
"type": "sse",
"url": "https://app.stashlite.com/mcp"
}
}
}
Save the file and restart Claude Desktop. The connector will be available in all new chats.
MCP connectors are still a relatively new feature — the ecosystem is expanding fast. The most useful ones do something simple: they give Claude a place to read and write data that persists beyond the conversation. That's the pattern that makes them worth adding.