How to Connect ChatGPT to Public
Last updated November 2026
Short answer
Public now runs its own official AI connector for Public accounts only. The other route is a connector that reaches Public through Walnut's own connection, which can hold several brokers in one connection, signing in at Public's own screen so no tool handles your password. ChatGPT's built-in Finances feature can also link many US brokerages through Plaid to read holdings, depending on what the institution shares, but it is US only and cannot place trades. ChatGPT accepts custom connectors in Developer Mode on a paid plan. You add the connector URL in settings, authorise once, and the tools appear inside the conversation. Once connected, ChatGPT is reading your actual account. Walnut's own app and assistant also place buys you approve at Public, and at E*Trade, tastytrade, Webull and other brokers, not only reading. Walnut is informational and is not an investment adviser.
Asking ChatGPT how your Public portfolio is doing gets a generic answer unless you have linked accounts through its Finances feature, because otherwise it has no access to your positions. ChatGPT is the assistant most people already have open, which is why this is the most common version of the question. Once the account is connected, its answers are about what you actually hold.
How the connection works
ChatGPT accepts custom connectors in Developer Mode on a paid plan. You add the connector URL in settings, authorise once, and the tools appear inside the conversation.
Behind it, you authenticate at Public's own screen, Walnut receives scoped access, and the assistant reads through it. Your login is never handled by the assistant, and access is revocable from either end.
Walnut reads Public and places buys you approve there. Public enforces a $5 minimum per fractional order, so each leg of a small basket has to clear that. Public also hosts its own connector at mcp.public.com/mcp for Public accounts only; Walnut adds analysis across your other brokers and baskets with target weights.
How to set it up, step by step
These steps use Walnut, which connects Public and any other brokers you add in one place. Setup takes a few minutes, and there is nothing to download.
1. Create a free Walnut account
Sign up with an email address or a phone number. Nothing is connected yet, and nothing is shared.
2. Connect Public inside Walnut
Open the brokerage screen and pick Public. You sign in at Public's own screen, through Walnut's own connection, so Walnut never sees your password. Your positions appear once the first sync finishes.
3. Add Walnut to ChatGPT
Turn on Developer Mode in ChatGPT's settings (it needs a paid plan), go to Settings, then Apps, choose Create app, and add the server URL https://walnutinvest.com/api/connector/mcp.
4. Sign in to Walnut and approve access
ChatGPT sends you to Walnut to sign in, and you approve what it can use. The connector reads; it does not place trades. Buys at Public are approved in Walnut's own app, one order at a time.
5. Check that it is reading the right account
Ask ChatGPT to list your Public positions with their weights. If the list matches what Public shows, the connection is live. If it answers in generalities, the connector is not attached to that conversation yet. The full walkthrough is in how to connect Walnut to ChatGPT.
Public's own AI connector
Public hosts its own official MCP server at mcp.public.com/mcp, part of the Agentic Brokerage it launched on March 31, 2026. Its setup docs list Claude, ChatGPT, Codex, Perplexity, Grok and Meta Muse, and it can read a Public account and place orders. It works with Public accounts only.
That makes it the direct route if Public is the only account you want an assistant to see. Walnut covers a different case: one connection across several brokers, including brokers with no connector of their own, read-only by default, with baskets of target weights on top, and buys placed only when you approve each one.
ChatGPT Finances, the built-in option
Since mid-2026, ChatGPT has a Finances feature that links US accounts through Plaid, including many brokerages, depending on what each institution shares. It launched as a Pro preview on May 15, 2026, reached Plus on June 25, 2026, and has been rolling out to Free and Go since October 2, 2026. Once linked, it can show balances, net worth and a market update on equity holdings, including daily change, current value and position size.
It is read-only and US only. It cannot place trades, and some institutions share balances but not holdings. What Walnut adds is buys you approve at Public (and at E*Trade, tastytrade, Webull and other brokers), baskets with target weights and a suggested rebalance, each holding framed against the S&P 500, and the same connection inside Claude as well as ChatGPT.
What it can and cannot see
| Data | Available? |
|---|---|
| Positions and quantities | Yes, once connected. This is the base of any analysis |
| Average cost per position | Not through Walnut, which receives no cost basis from brokers, so returns are measured as price change over a period |
| Account balances | Yes |
| Placing an order | Buys, yes, with your approval on each order, from Walnut's app and assistant |
| Your tax position and goals | No. Nothing knows this unless you say it |
| Accounts at other providers | Only if you connect those too |
Whether orders can be placed depends on the broker and on Walnut, not on the assistant. Walnut places buys you approve at Public, and at E*Trade, tastytrade, Webull and other brokers, and reads every other connected broker in full, so the analysis can cover all your accounts while each buy goes to a broker that takes them.
Get a recommendation for your situation
Walnut is the AI that knows your portfolio: ask anything in plain English, research any fund, and get an honest second opinion. On the broker you already use, read-only, and you approve every trade. Walnut is not a registered investment adviser.
What to ask about your Public account
First ask the assistant to list your positions, so you know what it can see. These questions are useful on a Public account in particular.
What trades would bring this basket back to its target weights?
Public takes buys you approve through Walnut. The assistant lists the trades, and nothing reaches Public until you approve the specific order.
Does every leg of this plan clear Public's $5 minimum?
Public requires at least $5 per fractional order, so the smallest target weight in a basket, not the number of holdings, decides the smallest amount that works.
How has each holding done against the S&P 500 over the past year?
Walnut measures each holding as price change over the period against the index, because brokers send no cost basis, so it shows how each holding performed, not your profit or loss on it.
You may not need ChatGPT for this
If the goal is to ask questions about your own portfolio and get answers based on what you hold, the assistant you use is a matter of preference.
Walnut connects Public and has its own built-in assistant, so the conversation works whether or not ChatGPT ever supports connectors. For people who would rather stay in the assistant they already use, Walnut also exposes an MCP connector that Claude and ChatGPT accept. Both routes read the same account.
Related: connecting Public to an AI assistant covers this broker in depth, and AI portfolio analysis covers what you can learn from reading the account alone.
FAQ
Can ChatGPT connect to Public?
Yes, in three ways: Public's own official connector, for Public accounts only; the built-in Finances feature, which links many US brokerages through Plaid to read holdings (depending on what the institution shares) and cannot trade; Walnut's connector, which reads Public alongside your other brokers in one connection and adds analysis across them, while Walnut's app places buys you approve at Public. Once connected, ChatGPT reads your real positions inside the conversation rather than answering from what you paste in.
Does ChatGPT see my real Public holdings?
Only through a connection you set up and authorise, either a Finances link (US only, and some institutions share balances but not holdings) or a connector. Without one it knows nothing about your account and answers in general terms. With one, it reads your actual positions.
Can ChatGPT place trades in my Public account?
Walnut's own app and built-in assistant place buys you approve at Public, and nothing reaches the broker until you approve the specific order. Approving and placing are separate steps, and each approval covers one specific order. Public's own connector is a second route for orders, limited to Public accounts. ChatGPT's Finances feature cannot place trades either.
Is it safe to connect Public to an AI assistant?
The safe shape is the same regardless of assistant: you sign in at Public's own screen so no tool handles your password, access is scoped and revocable, and you can end it from the broker's side as well as the app's. Check those before you connect.
What can it not do?
It does not know your tax position, your goals, or any account you have not connected, so advice depending on those is guessing unless you supply them. It also cannot see accounts at other providers unless you connect those too.
Do I need ChatGPT at all?
No. Walnut has its own built-in assistant that reads a connected Public account directly, so you can ask about your portfolio without ChatGPT or any other client supporting connectors. Using ChatGPT is optional.
Which brokers can an AI assistant actually trade?
Through Walnut, buys you approve are placed at Public first, and also at E*Trade, tastytrade, Webull (US and Canada), moomoo, Questrade, Wealthsimple, Trading 212 and Stake (Australia). Every other connected broker, including Robinhood, Fidelity, Schwab, Vanguard and Interactive Brokers, is read in full for tracking and analysis. Separately, several brokers now run their own official AI connectors for their own accounts, including Robinhood, Interactive Brokers (which drafts orders for you to submit), Webull and Public.
How do I disconnect Public?
From the app that holds the connection. In Walnut, the brokerage screen has a disconnect that removes the authorization, so nothing can read Public through it any more, including ChatGPT. Removing the Walnut connector from ChatGPT's settings ends the assistant's side as well. You can also review and revoke connected apps from Public's own account settings.
Is connecting Public to ChatGPT free?
Walnut is free to start, including connecting Public and adding the connector to ChatGPT. Walnut Plus, $9.99 a month on the web, removes the session limit on the assistant. Custom connectors in ChatGPT need a paid ChatGPT plan with Developer Mode turned on. Pricing changes, so check the current plans before you rely on this.
What should I ask once it is connected?
Ask it to list your positions and their weights, sorted by value. That shows what it can see and how concentrated the account is. Then ask how each holding has done against the S&P 500.
More on Public
Connect your broker to an AI assistant
Step-by-step guides for each major broker, plus the general setup guides for ChatGPT and Claude, which brokers have an AI assistant built in, and Walnut's MCP connector.
Related articles
Walnut is informational and is not an investment adviser, and nothing here is investment advice. Assistant connector support and broker integrations both change; the positions described were checked again in October 2026 and may have changed since.