How to Connect ChatGPT to External Memory

ChatGPT has built-in memory, but it is limited to a single account and cannot be shared with other AI tools. HippoDid gives ChatGPT access to a shared, structured memory system that also works with Claude, Gemini, Codex, and OpenClaw.

What you will get

After connecting HippoDid to ChatGPT:

• ChatGPT can store facts to the same memory database used by your other AI tools
• ChatGPT can recall memories written by Claude Code, Cursor, or any MCP client
• Memories are organized by character, category, and salience — not just a flat list

Requirements

• ChatGPT Business, Enterprise, or Edu plan — developer mode is required
• A HippoDid account with at least one character

How it works

ChatGPT connects to HippoDid via OAuth 2.1 with PKCE. The flow is fully automatic:

1. You provide the MCP server URL: https://api.hippodid.com/mcp
2. ChatGPT discovers the OAuth configuration automatically and requests the profile and email scopes
3. You authorize on the Clerk consent screen (your existing HippoDid login)
4. ChatGPT sends a Bearer token on every tool call — no API key needed

Step 1 — Enable developer mode

In your ChatGPT workspace, an admin must enable developer mode. Go to Settings > Workspace > Developer mode and toggle it on.

Step 2 — Create the app

1. Go to Settings > Apps > Create
2. Enter the MCP server URL: https://api.hippodid.com/mcp
3. ChatGPT will discover the OAuth flow and prompt you to authorize
4. Sign in with your HippoDid account on the Clerk consent screen

Step 3 — Use it

Ask ChatGPT:

What HippoDid tools do you have?

Then try:

Use HippoDid to search for: project preferences

If you previously stored preferences in Claude Code, they will appear here.

Limitations

• Setup must be done on the web — mobile ChatGPT can use the app after it has been linked on web
• Organization context required — your HippoDid account must belong to an organization
• Company Knowledge mode is read-only — search/fetch only, no writes

Cross-platform memory in practice

The power of HippoDid with ChatGPT is cross-platform recall:

1. In Claude Code: remember: the API uses pagination with cursor-based tokens
2. In ChatGPT: recall: how does the API handle pagination?

The memory written by Claude is instantly available in ChatGPT, and vice versa.

Next steps

• MCP Setup — setup guides for all supported clients
• What is Persistent AI Memory? — how it works under the hood
• Tiers & Limits — feature availability by plan