Update
inboxmcp is in review with Claude and ChatGPT
Short version: inboxmcp is now in review for both major AI-assistant directories. Once approved, you'll be able to add inboxmcp to Claude or ChatGPT with a single click, no URL to paste anywhere. Until then, the custom-connector route still works exactly the same as before.
Why directories matter
If you've added inboxmcp to Claude already, you remember the step where you paste https://mcp.inboxmcp.io into a settings dialog. It works — and our setup guide walks you through the four clicks — but a URL field in a settings panel isn't the most welcoming entry point for someone who's never heard of MCP.
Both Anthropic and OpenAI ship in-product directories where you can browse integrations the same way you browse apps on a phone. You search "email", "mailbox", "Inbox", you tap "Connect", you log in once, done. We want to be in those lists.
ChatGPT App Directory
We submitted to the ChatGPT App Directory on May 15. OpenAI is reviewing the app — same kind of security and reliability checks any app store does. The connector card on the inboxmcp landing page is currently flagged as Submitted; when approved, that flips to Live and you'll find us in the ChatGPT Apps directory under the inbox/productivity bucket.
Claude Connector Directory
Anthropic runs a similar directory inside Claude itself — open the connectors panel, search, install. We've submitted inboxmcp for inclusion. The review there focuses on the MCP protocol details (every tool needs a clear name, a description that matches its behaviour, proper read-only vs destructive annotations), plus the usual privacy and security bar. We spent a couple of late evenings making sure each of our nine tools answers cleanly to the directory checklist.
If you're curious what that review process actually looks like from the outside, Anthropic's review criteria are public.
What changes for you
For now: nothing. inboxmcp keeps working as a custom connector in Claude and (once approved) ChatGPT, with the same account, the same mailbox, the same tools. The directories are a smoother on-ramp, not a different product.
Once we're approved, the steps for a new user shrink from "paste a URL, accept the OAuth dialog" to "tap Install, accept the OAuth dialog". That's the entire difference — but those few seconds matter a lot for people who've never set up a connector before. It also gives us a permanent listing where users can find us without us hosting another link somewhere.
What we did to get here
A quick peek under the hood, in case you're building your own MCP server and wondering what the bar looks like:
- Every tool got a title field, an explicit readOnlyHint, and a destructiveHint where appropriate, so Claude knows which actions can be auto-permitted and which need user confirmation.
- The OAuth flow now serves an RFC 9728 protected-resource metadata document and includes the
resource_metadatahint in every 401 from the MCP endpoint, so Claude can auto-discover the right authorization server. - Error messages got rewritten end-to-end. Failed connections now return a structured errorCode plus a localised explanation (e.g. imap_auth_failed: "Your IMAP server rejected the username or password…") instead of the cryptic English exception text we used to leak.
- We added three pre-built MCP prompts (daily triage, weekly catch-up, draft replies) so the directory listing isn't just a list of low-level tools but a "here, try this" experience.
Try it today, without waiting
You don't have to wait for either review. The custom-connector path works on a Claude Pro, Max, Team or Enterprise plan and gives you exactly the same tools. Our step-by-step guide walks you through it in about three minutes. Sign-up is free and the first mailbox is on the free plan — no card required.
When the approvals land, we'll post here again with the one-tap install link.