What Is the Walnut Connector, and What Does It Actually Do?
Last updated August 2026
Short answer
The Walnut connector is a read-only bridge between the brokerage account you already have and an AI assistant. You add one URL to Claude, ChatGPT or another MCP-capable client, sign in with your Walnut account, and the assistant can answer questions about your real holdings at current prices instead of a portfolio you described to it. It never receives your broker password, cannot place an order, cannot move money, and sees only the accounts you connect. It is free. Walnut is informational and is not an investment adviser.
The confusing thing about this category is that four different products are described with overlapping words: aggregators, APIs, robo-advisors and connectors. They do genuinely different jobs, and knowing which one you are looking at answers most of the questions people arrive with, including the security ones.
The four links in the chain
- Your broker. Holds your money and your positions. Nothing about the connector changes that, and your account stays exactly where it is.
- A secure connection to the broker. Walnut links to the account through a regulated connection where your broker login stays with your broker. Walnut never sees or stores that password, so there is nothing to leak downstream.
- Walnut. Reads the positions, fetches live prices, and computes the things a holdings list alone cannot tell you: performance against the market, concentration, drift from your targets.
- The assistant. Claude, ChatGPT or any client supporting remote MCP servers calls Walnut as a tool and gets the answer. It authenticates to Walnut with your Walnut account, never to your broker.
The security question people actually mean is answered by link two. Your broker password stays at your broker, so Walnut does not hold it, so there is nothing to pass to an assistant even in principle. The assistant is two steps removed from your brokerage login and never touches it.
What it exposes, and what it does not
| Exposed? | |
|---|---|
| Positions and share counts | Yes |
| Live prices for what you hold | Yes |
| Performance against the S&P 500 | Yes |
| Drift from your target weights | Yes |
| Portfolios you built in Walnut | Yes |
| Your Walnut order history | Yes |
| Your broker username or password | No, and it never has them |
| The ability to place an order | No. The connector is read-only |
| The ability to move money | No, and Walnut never takes custody |
| Accounts you have not connected | No |
The last four rows are the boundary. Read-only is the default and not a setting you toggle, so an assistant with the connector attached has no mechanism to buy, sell or move anything, however it is asked.
What it is not
| Not a... | Because |
|---|---|
| An aggregator | Aggregators are the plumbing that reaches brokers. The connector uses one; it is not one, and it adds the analysis an aggregator does not do |
| A brokerage API | A broker API is built for developers writing code. The connector needs no code, no key and no server |
| A robo-advisor | A robo-advisor takes custody and makes decisions. The connector reads an account you keep and decides nothing |
| A trading bot | It places no orders at all. Trading in Walnut happens on the web with an explicit confirmation for each order |
| A data feed | Market-data servers supply prices and news about the market. This supplies facts about your portfolio |
The distinction that matters most in practice is the last one. A market-data server tells an assistant about the market, which it can already discuss reasonably well. A portfolio connector tells it about you, which is the part it cannot guess and the reason the answers change character.
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 changes once it is connected
The clearest way to describe the difference is by the questions that become answerable. Before, an assistant can tell you what a company does and what diversification means. After, it can tell you that a single position is 22% of what you own, that three of your funds hold substantially the same companies, and that your portfolio has trailed the index by a specific amount over a specific window.
None of that is a better model. It is the same model with the right inputs, and it is why the question shifts from “is this a good stock” to “what has this done for me, and how much of my portfolio is it now”.
Why it is read-only by default
Read-only is not a conservative setting we chose and could relax; it is what the connector is. Analysis needs to read positions and nothing more, and giving an assistant the ability to trade solves no problem that reading does not already solve.
Trading does exist in Walnut, and it deliberately lives somewhere else: in Walnut's own assistant on the web, where an order is previewed in full, stated plainly as spending real money, and confirmed by you before anything is placed. The preview mints a one-time token and the order will not run without that exact token from that exact preview, so an order cannot be assembled out of a conversation.
Keeping those two capabilities in separate places is the point. The thing you add to a third-party assistant cannot spend your money, whatever anyone types into it.
The question people actually mean by “is it safe”
Usually one of three, and they have different answers. Can the AI company see my portfolio? It sees what the assistant fetches during your conversation, in the same way it sees anything else you discuss with it, which is worth knowing and is a different question from broker access.
Can someone take my money? Not through the connector, which cannot move money or place orders and never holds your broker credentials.
What if I change my mind? Remove the connector in the assistant, or disconnect the broker in Walnut to revoke everything at the source at once. Neither requires contacting anyone. Longer treatment in is it safe to connect your brokerage to an AI.
Setting it up
The URL is https://walnutinvest.com/api/connector/mcp, and setup is adding it as a custom connector then signing in.
Step-by-step: Claude, ChatGPT, or the full connector reference for every supported client. For the whole capability including the confirmation step before any order, see how Walnut works.
FAQ
Why is the connector read-only rather than configurable?
Because that is what it is rather than a setting we chose. Analysis needs to read positions and nothing more. Trading exists in Walnut and deliberately lives elsewhere, in Walnut's own web assistant, where every order is previewed and confirmed and the preview mints a one-time token the order cannot run without.
Can the AI company see my portfolio?
It sees what the assistant fetches during your conversation, in the same way it sees anything else you discuss with it. That is a real question worth knowing the answer to, and it is a different question from whether anyone gains access to your broker, which they do not.
What happens if I change my mind after connecting?
Remove the connector in the assistant's settings to stop that client, or disconnect the broker inside Walnut to revoke the underlying access at the source regardless of which assistant is asking. Neither requires contacting anyone or waiting.
What is the Walnut connector?
A read-only bridge between the brokerage account you already have and an AI assistant. You add one URL to Claude, ChatGPT or another MCP-capable client, sign in with your Walnut account, and the assistant can then answer questions about your real holdings instead of a portfolio you described to it.
What does the connector actually expose?
Your positions and share counts, live prices for them, performance against the S&P 500, drift from target weights, the portfolios you have built in Walnut, and your Walnut order history. It does not expose your broker credentials, cannot place an order, cannot move money, and cannot see accounts you have not connected.
Does the connector have my broker password?
No, and this is structural rather than a policy. The link to your broker runs through a secure connection where the login stays with the broker, so Walnut never receives that password and therefore cannot pass it on. The assistant authenticates to Walnut with your Walnut account, which is a separate credential entirely.
Is the Walnut connector an aggregator?
No. Aggregators are the regulated plumbing that reaches brokerage accounts, and the connector uses one to make the link. The difference is what sits on top: an aggregator hands over raw positions, while the connector computes the things a raw holdings list cannot tell you, such as performance against the market and concentration once you look inside the funds.
How is it different from a brokerage API?
A broker API is built for people writing software: you hold keys, you run something, and you handle the integration. The connector is a URL and a sign-in with nothing to maintain. The trade is control against effort, and for most people who want to ask questions about their own portfolio the effort is the wrong thing to be spending.
Is it a robo-advisor?
No, and it is close to the opposite. A robo-advisor takes custody of your money and makes the investing decisions for you. The connector reads an account that stays yours, at a broker you chose, and makes no decisions at all. Nothing is under management, which is also why there is no percentage-of-assets fee.
Which assistants can use it?
Claude, in the desktop app, the browser and Claude Code. ChatGPT, with Developer Mode on a paid plan. Codex and the Codex CLI, Cursor, and any client that supports remote MCP servers. The same URL works in all of them and each authenticates separately.
What is MCP?
The Model Context Protocol, an open standard for letting an AI assistant call external tools and read external data. It is what allows one connector URL to work across several different assistants rather than needing a separate integration for each, and it is the reason setup is a paste rather than a build.
Does it cost anything?
No. The connector is free and needs a Walnut account, which is also free. There is no percentage-of-assets fee because nothing is under management, and no separate charge for connecting an assistant.
Can I revoke it?
Two ways. Remove the connector in the assistant's settings, which stops that client. Or disconnect the broker inside Walnut, which revokes the underlying access regardless of which assistant is asking. The second is the one to use if you want everything cut at once.
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Walnut is informational and is not an investment adviser, and nothing here is investment advice. Broker support and third-party client capabilities change; the connector URL above is current.