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Broker API Comparator

Alpaca vs IBKR vs Tradier vs Schwab vs Robinhood — auth, rate limits, order types, market data, MCP, fees. Pick the right broker before coding.

By AI Fin Hub Research. Published . Corrections.

Runs in your browser. Nothing you enter is uploaded, and no account or API key is needed.

Education, not investment advice. Past performance does not predict future results. How we check our numbers.

Best fit

Alpaca

5 of 5 brokers meet every filter; Alpaca ranks first (simplest auth among them). $0 (PFOF on equities), auth complexity 1/5.

Solo AI operator, paper-to-live parity

Ranked brokers

Alpaca ↗

Solo AI operator, paper-to-live parity

Fit-score

1/1

Auth

API Key + Secret (complexity 1/5)

Commission

$0 (PFOF on equities)

Rate limits

Trading API 200 req/min; market data 200/min free, 10,000/min on Algo Trader Plus

MCP

Official Official open-source MCP server (V2 rewrite on FastMCP/OpenAPI); data, paper and live trading

Asset classes

Stocks, Options, Crypto

Order types

Market, Limit, Stop, Stop-Limit, Trailing-Stop and 5 more

Tradier ↗

Options-first retail, multi-leg strategies

Fit-score

1/1

Auth

OAuth 2.0 (complexity 3/5)

Commission

Lite ($0/mo): $0.35/stock trade + $0.35/contract; Pro ($10/mo): $0 stocks + options

Rate limits

120 req/min standard and market data, 60 req/min trading (production)

MCP

Official Official hosted MCP server (Streamable HTTP, personal API token); market data, accounts and order placement

Asset classes

Stocks, Options

Order types

Market, Limit, Stop, Stop-Limit, OCO and 3 more

Robinhood ↗

Agent-driven trading from an existing Robinhood account; no REST API for stocks or options

Fit-score

1/1

Auth

API key (Crypto Trading API); Robinhood sign-in (Trading MCP) (complexity 3/5)

Commission

$0 (PFOF), $5/mo Gold for margin + extras

Rate limits

Not publicly documented

MCP

Official Official Robinhood Trading MCP (Agentic Trading): long equities, options and crypto, only in a dedicated agentic account; no multi-leg options

Asset classes

Stocks, Options, Crypto

Order types

Market, Limit, Stop, Stop-Limit

Schwab ↗

Established retail, post-TDA API migration

Fit-score

1/1

Auth

OAuth 2.0 (3-legged) (complexity 4/5)

Commission

$0 equities, $0.65/contract options

Rate limits

120 req/min for non-order calls per app; order writes 0-120/min per account, set at app registration

MCP

Community No official MCP; community servers wrap the Trader API (self-hosted, re-authorize when the 7-day refresh token expires)

Asset classes

Stocks, Options

Order types

Market, Limit, Stop, Stop-Limit, Trailing-Stop and 4 more

Interactive Brokers ↗

Multi-asset-class, international, scale

Fit-score

1/1

Auth

OAuth + TWS/IB Gateway (complexity 5/5)

Commission

Tiered per-share or fixed; ~$0.0035/sh tiered

Rate limits

Market-data lines / 2 requests per second (50 on the default 100 lines); small-bar history 60 requests per 10 min

MCP

Official Official IBKR Connector: remote MCP at api.ibkr.com, IBKR sign-in, one account; drafts trade instructions that you submit as orders yourself

Asset classes

Stocks, Options, Futures, Crypto, Forex, Bonds

Order types

Market, Limit, Stop, Stop-Limit, Trailing-Stop and 5 more

How this ranking works

Each broker is scored against the filters you've enabled. Fit-score is an unweighted count of matching criteria. Brokers that fail any required criterion are pushed below qualifying ones and dimmed.

Auth complexity is subjective — 1 is a plain API-key header, 5 means a persistent gateway process on your machine. Rate limits shown are vendor-published tier rates; real-world limits may be lower under concurrent load.

Data last checked 2026-10-19. Broker API terms drift; always verify on the broker's developer portal before committing.

How to use it

  1. Filter brokers by required asset coverage (options, futures, crypto), and toggle MCP-required or free-tier-required. All five brokers cover US equities, so there is no separate equity filter.
  2. Read the rate-limit table and the full feature matrix (auth method, order types, MCP status, fee strings). The tool does not include latency benchmarks.
  3. Read the fee strings. Zero-commission brokers flag PFOF as a note; strings are displayed as published, not modeled.
  4. Read the auth method and security posture. Some brokers require OAuth; others use API key.
  5. Where a broker offers paper trading, test there before committing real capital. Production latency varies with deployment region and broker traffic and is not something the tool measures.

Questions people ask

Which brokers does it cover?

Five retail brokers: Alpaca, Interactive Brokers, Tradier, Schwab, and Robinhood. Each is described by auth style, rate limits, order types, market-data access, asset classes, MCP status and fee strings. The snapshot was last checked against the brokers' developer docs on 2026-10-19 (shown under the tool); broker API terms change, so confirm on the broker's portal before you build.

How are latency numbers measured?

They are not: the tool has no latency benchmarks. What it shows is each broker's published request rate limit (per minute or per second), which caps how often a strategy can poll or place orders. Real production latency depends on your region, network path and the broker's load, which the tool does not model.

Does it model commission cost?

No — commission strings are displayed as published by each broker, not modeled arithmetically. For zero-commission brokers (Alpaca, Robinhood), the fee string notes PFOF (payment for order flow) as an effective cost; effective spread costs are not computed.

Why isn't broker X listed?

The five represent the retail-accessible US broker API landscape. Full-service brokers without a documented public trading API are excluded, and crypto-native exchanges (Coinbase, Kraken) are out of scope for this comparator.

Should I trust 'free' brokers?

Zero-commission brokerage is paid for somewhere, typically through payment for order flow on equity orders, which the commission strings note. The tool shows the published fee terms but does not estimate execution-quality costs, so for high-turnover strategies measure your realized slippage against the quote before assuming 'free' is cheapest.

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All articles

Use it from an agent or code

Any agent can run this calculator by URL: put the inputs in the query string and get JSON back, with the inputs that used defaults and a line to cite (add format=md for markdown). MCP clients reach it through https://aifinhub.io/mcp.

https://aifinhub.io/api/run/broker-api-comparator?require_options=false&require_futures=false&require_crypto=false&require_mcp=false&require_free_tier=false&max_auth_complexity=5

In code, import the same module; it runs where you import it, with no request or key.

import { compute } from "https://aifinhub.io/engines/broker-api-comparator.js";

Input and output contract and the guide for agents.