Broker MCP Server

What You Can Do

• Ask questions against Broker API data. In live, use read operations to look up accounts, inspect account status and profile details, review trading account state, check buying power and cash, list positions, pull portfolio history, review activities, and inspect transfers.
• Discover the right endpoint and schema. Built-in OpenAPI discovery lets an assistant search Broker API operations, inspect required parameters, and call endpoints with structured inputs.
• Get documentation-aware answers. Curated Alpaca docs and API-reference lookup tools answer integration questions about guides, endpoint behavior, request shapes, response fields, and sample usage.
• Test full broker workflows in sandbox. Sandbox exposes read and write operations for account opening, funding, transfers, trading, watchlists, documents, options, rebalancing, journals, instant funding, and IPOs.
• Create synthetic sandbox accounts quickly. The create_sandbox_account tool generates test accounts with valid defaults and optional KYC or account-status fixture outcomes for demos, QA, and integration testing.

Who Can Use It (Super Users)

The Broker MCP connects to your firm's Broker API through an OAuth authorization in the Broker Dashboard. Approving that authorization requires the manage_keys entitlement, which today is held only by the Superuser role.

Before inviting a teammate to test, confirm whether they can actually authorize the connection within your team.

Environments

There are two hosted endpoints. Each maps to a distinct correspondent and uses its own OAuth client — sandbox and live credentials are not interchangeable. Use sandbox to test writes, account creation, orders, and funding.

Setup

Connect from any MCP client that supports remote (OAuth) servers. Every client authorizes through the same OAuth flow: you start the connection, a super user approves the consent request in the Broker Dashboard, and the client is then authorized.

Cursor

An Alpaca plugin is available for Cursor:

1. Open the command palette: Cmd + Shift + P (macOS) / Ctrl + Shift + P (Windows/Linux).
2. Type Open Customize and select the matching option.
3. Click Browse Marketplace.
4. Click Add Marketplace, then choose Import from GitHub from the dropdown on the right of the search bar.
5. Enter the plugins repository URL: https://github.com/alpacahq/agentic

Claude Code (CLI)

A Claude Code plugin is also available. Add the marketplace:

claude plugin marketplace add alpacahq/agentic

To install the MCP server:

1. Start a new session with claude, then run /plugin.
2. Open the Marketplaces tab and select alpaca-plugins.
3. Choose Browse plugins, select alpaca-broker, and install it.
4. Run /reload-plugins to load it.
5. Run /plugin again, open the Installed tab, and confirm alpaca-broker is listed.

To enable the servers, run /mcp in the chat. You'll see plugin:alpaca-broker:alpaca-broker and plugin:alpaca-broker:alpaca-broker-sandbox; selecting either starts its OAuth flow.

ChatGPT (Web)

1. Go to Settings → Apps → Advanced Settings and enable developer mode.
2. In the same panel, click Create App and fill in the form with the MCP URL (live or sandbox).
3. Click Connect and sign in through the OAuth flow.

VS Code

Add either or both servers in .vscode/mcp.json:

{
  "servers": {
    "alpaca-broker-mcp": {
      "type": "http",
      "url": "https://broker-api.alpaca.markets/mcp"
    },
    "alpaca-broker-mcp-sandbox": {
      "type": "http",
      "url": "https://broker-api.sandbox.alpaca.markets/mcp"
    }
  }
}

Then open the command palette (Cmd + Shift + P / Ctrl + Shift + P), run MCP: List Servers, select alpaca-broker-mcp or alpaca-broker-mcp-sandbox, and click Start Server to trigger the OAuth flow.

Verify

After connecting, ask your assistant:

"Find the account for [email protected] and summarize its status, buying power, positions, and recent activity."

If you get an API-backed summary, the server is connected.

How It Works

Rather than loading thousands of endpoint tools into the model's context, the server uses a CodeMode discovery flow. The assistant:

1. search — finds the relevant Broker API operation(s) from intent.
2. get_schema — inspects required parameters, types, and response shape.
3. execute — calls the endpoint with structured inputs (subject to the environment's read/write policy).

This keeps tool selection accurate and reduces context bloat.

Available Tools

The server is synced to the public Broker OpenAPI spec from docs.alpaca.markets. Streaming and redirect/download operations are excluded because they don't function as request/response tools.

Example Prompts

Control-plane (operate on accounts):

• "Find the account for [email protected] and summarize its status, buying power, positions, and recent activity."
• "Show this account's portfolio history for the last month."
• "Check recent transfers for this account and summarize anything pending or failed."
• "Create a sandbox account that lands in an action-required KYC state for a demo."
• "In sandbox, create a test account and then retrieve its status."

Data-plane (understand the API):

• "Which endpoint should I use to create an ACH relationship, and what fields are required?"
• "Show me the endpoint and required fields to create a Broker API account."
• "What is the minimal curl for creating a sandbox account, based on the docs?"
• "Search for the endpoint that retrieves account documents, inspect the schema, and explain the response."

Safety & Environment Policy

• Revoking access. Authorizations can be reviewed and revoked from the Broker Dashboard (Team Management). Removing a user's role also revokes their access on the next token refresh.
• API key security. The connection uses OAuth — never paste API keys or secrets into chat.
• Review AI-suggested actions. Where writes are enabled in either environment, confirm any mutating operation before it runs.

Known Limitations (Beta)

• IP filters. If your correspondent has IP filters configured, the hosted MCP connection will not work yet. This is a known limitation we plan to address.
• Super-user-only authorization. Broader role-based authorization (mapping consent to existing roles) is planned; today only super users can authorize.
• Production is read-only. Allowing write operations is planned in the near-future.

Resources

• Broker API documentation
• Broker API reference
• Alpaca Broker Skills for partner workflows
• Alpaca Support

Disclosure

Insights generated by our MCP server and connected AI agents are for educational and informational purposes only and should not be taken as investment advice. Please conduct your own due diligence and review any AI-suggested actions before confirming them.