# ChatGPT + Pear MCP guide

<!-- MCP_HOST_IDS: chatgpt-custom-app -->
<!-- MCP_HOST_COMPATIBILITY:START -->
## Connection and authentication

Use the authentication method shown for each client surface.

| Client surface | Authentication | Setup guide |
| --- | --- | --- |
| ChatGPT custom app | OAuth client metadata document | Setup guide available |
<!-- MCP_HOST_COMPATIBILITY:END -->

Use Pear with ChatGPT Developer Mode and MCP apps.

Pear server URL:

```text
https://pearmcp.com/api/mcp
```

## Setup

1. Create a Pear account.
2. Connect Apple iCloud or Microsoft 365.
3. In ChatGPT, enable Developer Mode if your plan/workspace supports it.
4. Create a custom app and enter the Pear remote MCP server URL.
5. Choose OAuth and complete the Pear sign-in flow.
6. Scan tools and enable the app in a chat.

ChatGPT prefers a Client ID Metadata Document (CIMD) when an authorization
server advertises it, as Pear does. Pear intentionally exposes no Dynamic Client
Registration (DCR) endpoint. If a client attempts DCR, the flow stops before a
Pear login screen because the registration method is incompatible; do not treat
that as an invalid Pear password or a generic OAuth outage.

Developer Mode eligibility depends on plan, workspace role, and admin policy. Pro
currently supports custom MCP apps with read/fetch actions; full write/modify MCP is
currently limited to eligible Business, Enterprise, and Edu workspaces. The tools and
actions ChatGPT can use also depend on app permissions, Pear account state, connected
providers, and any confirmation required for the requested action. Check OpenAI's
[current Developer Mode requirements](https://help.openai.com/en/articles/12584461)
if the Apps controls are not visible.

## Use cases

- Summarize Outlook or iCloud Mail, draft a reply, and send after confirmation.
- Check free time, create a calendar event, and write the attendee follow-up.
- Turn chat notes into Microsoft To Do tasks, or use Apple only when legacy CalDAV reminder data meets the workflow.

## Apple Reminders compatibility

Pear's hosted CalDAV connection cannot access Apple's upgraded Reminders store. Apple
may return compatibility tombstones instead of current reminder data; reconnecting or
replacing the App-Specific Password cannot change that protocol limit. Microsoft To Do
uses Microsoft Graph and is unaffected. See the full
[Apple Reminders compatibility note](./apple-reminders-compatibility.md).