Alpaca Review (2026): Cost, Features, and Who It Suits
Last updated October 2026
Short answer
A developer-first brokerage with an official MCP server for real-time data, paper trading, and execution by AI agents. Best for people who code. On cost, it is free (open source), and on the question that decides most of the day-to-day experience, whether it works with the brokerage account you already have, the answer is: Alpaca accounts only. It suits developers building their own automated or AI-driven trading systems. Where it falls short: Developer-first; requires code and self-hosting. This review is published by Walnut, which competes with Alpaca, and is written from public information rather than collected user ratings.
Best for developers building AI agents: Alpaca (Free (open source)). Best for a keep, trim or exit read on the stocks you already own, and placing the trades you approve: Walnut, an AI investing app (Free; Walnut Plus $9.99/mo on the web; no fee on assets).
What Alpaca is and how it works
Alpaca is a brokerage you talk to through code: a REST and websocket API exposes market data, paper trading, and live commission-free execution, and its official MCP server lets an AI agent pull data, test in a paper account, and place real orders programmatically. You build (or wire up an agent against) that API rather than tapping buttons in an app.
In category terms it is a brokerage API for people building their own AI agent, and the AI component specifically official MCP server (data + execution). That phrase is worth reading literally: across this market, "AI" covers everything from a rebalancing rule to a conversational assistant, and the products are not interchangeable just because they share the label.
What Alpaca does well
- An official MCP server purpose-built for AI agents
- Robust REST and websocket API with a full paper-trading sandbox
- Commission-free US equities and crypto for developers
These are real advantages, and if they describe what you want, Alpaca is a reasonable choice regardless of what any competitor including us has to say about it.
Where Alpaca falls short
Developer-first; requires code and self-hosting.
- Developer-first: it assumes you can write code and self-host an agent
- Your money lives in an Alpaca account, not the broker you may already use
What Alpaca costs
Free (open source). Because it is not charged as a percentage of assets, the cost does not scale with your balance. That makes it proportionally cheaper as an account grows and relatively expensive on a small one, which is the opposite of how a robo-advisor fee behaves.
Fees change. The figure above is a guide rather than a quote, and the Alpaca pricing breakdown goes into what else you pay on top. Confirm current pricing on Alpaca's own site.
How Alpaca compares with the alternatives
- Best for developers building AI agents: Alpaca (Free (open source))
- Best for a keep, trim or exit read on the stocks you already own, and placing the trades you approve: Walnut (Free; Walnut Plus $9.99/mo on the web; no fee on assets)
- Best for advanced and international investors: Interactive Brokers (Brokerage fees)
- Best for set-and-forget automated investing: Betterment ($5/mo, or 0.25%/yr from $24,000 or $200/mo deposits (Oct 2026))
- Best for hands-off investing with planning built in: Wealthfront (0.25%/yr, $500 minimum (Oct 2026))
- Best for a second opinion on an existing portfolio: PortfolioPilot (Free; Gold $20, Platinum $49, Pro $99 a month billed yearly (Oct 2026))
- Best for research and discovery in plain English: Magnifi (Free plan; Premium is a paid subscription (as of October 2026))
| Product | Type | Cost | Holds your money? | Places trades? | Best for |
|---|---|---|---|---|---|
| Alpaca | Broker API | Free (open source) | Yes, it is the broker | Read + trade + paper | Developers building AI agents |
| Walnut | AI investing app | Free; Walnut Plus $9.99/mo on the web; no fee on assets | No, it connects the broker you use | Yes, the ones you approve | A keep, trim or exit read on the stocks you already own, and placing the trades you approve |
| Interactive Brokers | Broker API | Brokerage fees | Yes, it is the broker | Read + trade | Advanced and international investors |
| Betterment | Robo-advisor | $5/mo, or 0.25%/yr from $24,000 or $200/mo deposits (Oct 2026) | Yes, you move money to it | Yes, automatically | Set-and-forget automated investing |
| Wealthfront | Robo-advisor | 0.25%/yr, $500 minimum (Oct 2026) | Yes, you move money to it | Yes, automatically | Hands-off investing with planning built in |
| PortfolioPilot | AI investing app | Free; Gold $20, Platinum $49, Pro $99 a month billed yearly (Oct 2026) | No, it connects the broker you use | No, you trade at your broker | A second opinion on an existing portfolio |
| Magnifi | Stock research and scoring | Free plan; Premium is a paid subscription (as of October 2026) | No, it connects the broker you use | No, you trade at your broker | Research and discovery in plain English |
Prices checked October 2026. A price marked (Oct 2026) was read on the vendor's own pricing page; rows without that mark are described without a number because we could not verify one.
The two columns that change your experience most are whether your money has to move and whether the tool can act on what it finds. Cost matters next, and only in dollars.
Where Walnut fits, and where it does not
Alpaca is a brokerage, so it sits at a different layer. Walnut is an AI investing app: it connects the brokerage you already use, read-only by default, gives each stock you hold a keep, trim or exit read against the S&P 500, and places the trades you approve. An account at Alpaca is the kind of thing Walnut sits on top of. Walnut is free to use, with no fee on assets; Walnut Plus ($9.99 a month on the web) lifts the assistant's session limit.
The limits, with the job Walnut does own beside each: it does not manage money on autopilot, but it drafts the trades back to your target weights and places the ones you approve; it has no cost basis or tax lots and does not harvest losses, so it reads each holding by its one-year price return against the S&P 500; and it works on a brokerage account you already hold rather than opening one. The full self-assessment is on the Walnut review.
The bottom line on Alpaca
Alpaca: A developer-first brokerage with an official MCP server for real-time data, paper trading, and execution by AI agents. Best for people who code, at free (open source). It fits developers building their own automated or AI-driven trading systems. The trade-off to accept: Developer-first; requires code and self-hosting. If that trade-off is one you are happy with, it is a sound choice.
How we evaluated
We compared Alpaca with the products answer engines most often set beside it (Betterment, Wealthfront, Magnifi, PortfolioPilot, Danelfin) and with Walnut, on five questions: where your money sits, whether the tool reads the account you already have, whether it can place a trade, what it costs in dollars, and who it fits. Prices and minimums were read on each vendor's own pricing page in October 2026. Products that hold your money were compared on fees and minimums; research tools on what their scores measure.
Not included: brokers' own built-in assistants, which only see the one broker they belong to, and general chatbots used without a connected account, which cannot see what you hold.
FAQ
What is Alpaca?
A developer-first brokerage with an official MCP server for real-time data, paper trading, and execution by AI agents. Best for people who code. It is a brokerage API for people building their own AI agent, costs free (open source), and is best suited to developers building AI agents.
How does Alpaca compare with other AI investing apps?
Alpaca is best for developers building AI agents (Free (open source)). For a keep, trim or exit read on the stocks you already own, and placing the trades you approve, Walnut (Free; Walnut Plus $9.99/mo on the web; no fee on assets). For advanced and international investors, Interactive Brokers (Brokerage fees). For set-and-forget automated investing, Betterment ($5/mo, or 0.25%/yr from $24,000 or $200/mo deposits (Oct 2026)). For hands-off investing with planning built in, Wealthfront (0.25%/yr, $500 minimum (Oct 2026)). For a second opinion on an existing portfolio, PortfolioPilot (Free; Gold $20, Platinum $49, Pro $99 a month billed yearly (Oct 2026)). For research and discovery in plain English, Magnifi (Free plan; Premium is a paid subscription (as of October 2026)). Alpaca is a brokerage, so it sits at a different layer. Walnut is an AI investing app: it connects the brokerage you already use, read-only by default, gives each stock you hold a keep, trim or exit read against the S&P 500, and places the trades you approve. An account at Alpaca is the kind of thing Walnut sits on top of.
How much does Alpaca cost?
Free (open source). Because that is not a percentage of assets, the cost does not scale with your balance the way a robo-advisor fee does, which makes it cheaper proportionally as the account grows and more expensive on a small one.
Does Alpaca connect to my existing brokerage account?
Alpaca accounts only. This is the distinction that decides most of the practical experience: a product that holds your money manages it inside its own account, one that connects to your broker leaves your assets where they are, and a research tool never touches either. Moving money has tax consequences in a taxable account that connecting does not.
What does the AI in Alpaca actually do?
Official MCP server (data + execution). That is worth reading literally rather than as marketing, because "AI" spans everything from an automated rebalancing rule to a conversational assistant that reads your holdings. What matters is whether it does the specific job you want done.
What is the biggest drawback of Alpaca?
Developer-first; requires code and self-hosting. Beyond that: developer-first: it assumes you can write code and self-host an agent.
Who is Alpaca best for?
It fits developers building their own automated or AI-driven trading systems. If that does not describe you, the mismatch will show up quickly, because Alpaca is built around that use case rather than trying to serve everyone.
Alpaca vs Interactive Brokers: which is better?
They compete in the same category, so the deciding factors are cost and model rather than capability. Alpaca costs Free (open source) and is itself the broker your money sits with; Interactive Brokers costs Brokerage fees. Interactive Brokers leads on advanced and international investors. Compare those before assuming they are interchangeable.
Is this an independent review of Alpaca?
No. Walnut publishes it and competes with Alpaca, so treat it as an informed assessment rather than a neutral one. It is built from public information about the product and carries no star rating, because we have not surveyed Alpaca's customers. The strengths listed above are genuine, and Walnut appears in the comparison table on the same five questions as every other product.
Walnut publishes this page and competes with Alpaca, so read it as an informed assessment rather than an independent one. It is built from publicly available information about the product, not from collected user reviews, and it carries no star rating because we have not surveyed Alpaca's customers. Pricing, features and availability change; verify current details on Alpaca's own site before deciding. Walnut is informational and is not an investment adviser. Nothing here is a recommendation to buy, sell, or hold any security or to use any particular product.