Claude
Add WhyVault as a custom connector in Claude so every chat can use your memory – on the web, on desktop and on your phone.
Guide as of 26 September 2026. Tested with the OAuth flow Claude uses.
Once set up, the connection works in Claude in the browser, in the desktop app and on your phone – on every Claude plan, including Free.
Requirements
- Claude plan: any plan – Free, Pro, Max, Team or Enterprise. On Free you can add one custom connector.
- Where: claude.ai in the browser or the Claude desktop app for macOS and Windows. You add the connector there; the apps for iOS and Android then pick it up.
- Team and Enterprise: an Owner adds the connector for the whole organisation. Members only click Connect.
- WhyVault: any account, Free included. Claude signs in via OAuth – no access key needed.
- Your MCP address:
https://mcp.whyvault.io. You also find it in the app under Connect agents.
Add the custom connector
Add the connector
In Claude, open Customize → Connectors, click +, then Add custom connector. Enter WhyVault as the name and https://mcp.whyvault.io as the URL.
If Claude asks about the OAuth client, choose Register automatically – not the recommended "Use Claude's published identity". Click Add.
Sign in and approve
Claude opens the WhyVault sign-in window. Sign in and approve access. The agent can then read and write – it can only delete if you allow it. Every change shows up in your history, and you can revoke access under Connect agents at any time.
Turn it on in a chat
In the chat, click + at the bottom left → Connectors and switch WhyVault on. Try: "Read my vault and summarise what I'm currently working on."
Claude starts with vault_overview, which tells it how your vault is organised and what the rules in 9_System/ say. From then on it searches and reads specifically instead of loading everything.
On the free Claude plan you can add only one custom connector. If you already use another one there, you need to remove it for WhyVault.
Team and Enterprise: an Owner adds the connector for the organisation (Organization settings → Connectors → Add → Custom). You then click Connect under Customize → Connectors.
Mobile: connectors you added in the browser or desktop app are automatically available in the Claude app on iOS and Android.
Troubleshooting
The sign-in window doesn't open
- In the browser, Claude opens WhyVault in a new window. Allow pop-ups for claude.ai and try again.
- In the desktop app, the sign-in opens in your default browser. After approving, the browser hands you back to Claude. If it doesn't, return to Claude yourself – the connector then shows Connect again, and a second click finishes the sign-in.
Sign-in fails right after "Add"
You probably chose Use Claude's published identity. WhyVault expects clients to register themselves (Dynamic Client Registration). Remove the connector and add it again with Register automatically.
The sign-in link opens in a different browser
WhyVault sends you a link by email. If it opens in a browser other than the one with the sign-in window, enter the code from the email in the sign-in window instead – or sign in with your password if you set one.
"Add custom connector" is greyed out
On the free plan only one custom connector is possible, and another one is already there. Remove it under Customize → Connectors. On Team and Enterprise, members can't add custom connectors – your Owner does that.
WhyVault doesn't appear in the chat
The connector is added but not switched on for this chat. Click + → Connectors and turn WhyVault on. This works in project chats too.
Claude can read but not write
The connection is set to read only in WhyVault. Change it under Connect agents → Permissions. delete_note only appears once you allow deleting. Claude loads the tool list when it connects – after a change, disconnect the connector and connect it again.
The connector shows "Disconnected"
You revoked access under Connect agents, or the sign-in expired. Click Connect and approve again. A new approval starts with read and write; deleting has to be allowed again.
"Too many changes in a short time"
WhyVault slows down a connection that writes an unusual amount per minute. Wait a minute and ask Claude to combine its changes.
FAQ
Does it work on the free Claude plan?
Yes. Free allows one custom connector, and WhyVault works with it like on every other plan.
Do I have to set it up again on my phone?
No. Connectors you added on the web or desktop are available in the Claude app on iOS and Android.
Does Claude Code use the same connection?
Set up Claude Code separately with one command – see Claude Code. Both write to the same vault.
What does Anthropic see?
Whatever Claude reads from your vault is processed by Anthropic. WhyVault itself is EU-hosted (Frankfurt) and GDPR-compliant. More in the GDPR guide.
Can Claude delete my notes?
Only if you allow it for this connection – and then it moves notes to the trash, where you can restore them.