How to Use the Brex MCP in Mastra AI

Q: How do I register the Brex MCP tools inside a Mastra AI agent?

Install @mastra/mcp and instantiate the client with your Vinkius server URL. Use mcpClient.listTools() to retrieve the tools, then spread them directly into your agent's tool configuration array.

Q: Can Mastra AI automatically retry a failed Brex payment?

Yes, you can wrap brexpayvendor in a Mastra workflow step with custom retry logic. If the Brex API returns a rate limit or temporary error, the workflow backs off and retries automatically.

Q: How does Mastra AI handle human-in-the-loop approvals for Brex card creation?

You can use Mastra's requireToolApproval setting on the brexcreatecard tool. This pauses the workflow and waits for an admin signature before the virtual card is generated.

Q: How does Mastra AI keep my Brex transaction histories secure?

All financial data fetched via brexlisttransactions is processed in memory during the workflow execution. Vinkius secures the gateway with token-based authentication, ensuring no transaction details are stored or logged outside your private environment.

Build autonomous Mastra AI workflows that auto-retry failed Brex payments and manage budgets with strict conditional branching.

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Connect Brex MCP to Mastra AI

Create your Vinkius account to connect Brex to Mastra AI and route execution through our secure gateway. The platform manages server hosting, runtime updates, and security layers. Configuration requires no manual server provisioning.

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Setup Brex with Mastra AI

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Fail-safe vendor payments via Mastra AI workflows

`brex_pay_vendor` executes within a structured workflow, letting you build complex payment pipelines that handle failures gracefully. If a transaction fails, Mastra's engine automatically retries with exponential backoff. You can write logic that checks `brex_get_balance` before sending cash. If the balance is too low, the workflow branches to alert an administrator instead of failing silently.

Conditional employee onboarding using this MCP Server

`brex_create_user` joins your automated HR onboarding flows to get new hires set up instantly. The agent checks if the user exists via `brex_list_users` before issuing the invite. Once the user is created, the workflow automatically assigns them to a budget using `brex_list_budgets`. This turns a multi-step manual HR task into a single autonomous run.

Automated budget auditing and card tracking

`brex_list_cards` sweeps your entire company's active plastic through this MCP integration to flag unassigned or over-budget accounts. The Mastra engine schedules this check to run nightly without human intervention. The agent compares active cards against `brex_list_transactions` to find anomalous spend. Any discrepancy triggers an automated Slack notification or a locked card event.

Setup guide

Set up Brex MCP in Mastra AI

Prerequisites

Node.js 18+ and a TypeScript project
@mastra/mcp + @mastra/core packages
Active Vinkius subscription with a valid endpoint token

1

Install dependencies
Run npm install @mastra/mcp @mastra/core plus your preferred model provider (e.g. @ai-sdk/openai).
2

Configure the MCPClient
Create an MCPClient with your Vinkius endpoint as a URL object. Replace [YOUR_TOKEN_HERE] with your token from cloud.vinkius.com.
3

Discover and inject tools
Call mcpClient.listTools() and spread the result into your agent's tools object. All Brex tools become native Mastra tools.
4

Run with any model
Swap openai("gpt-4o") for any AI SDK-compatible provider. Call agent.generate() and the agent routes tool calls through MCP automatically.

agent.ts

import { MCPClient } from "@mastra/mcp";
import { Agent } from "@mastra/core/agent";
import { openai } from "@ai-sdk/openai";

const mcpClient = new MCPClient({
  id: "brex-mcp-client",
  servers: {
    "brex-mcp": {
      url: new URL(
        "https://edge.vinkius.com/[YOUR_TOKEN_HERE]/mcp"
      ),
    },
  },
});

const agent = new Agent({
  name: "Brex Agent",
  model: openai("gpt-4o"),
  instructions: "You have access to Brex tools.",
  tools: {
    ...(await mcpClient.listTools()),
  },
});

const result = await agent.generate(
  "List recent Brex transactions"
);
console.log(result.text);

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Independent Platform Disclaimer: Vinkius is an independent platform and is not affiliated with, endorsed by, sponsored by, verified by, or otherwise authorized by Brex. All third-party trademarks, logos, and brand names are the property of their respective owners. Their use on this website is strictly for informational purposes to identify service compatibility and interoperability.

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Common questions about Brex MCP in Mastra AI

Install `@mastra/mcp` and instantiate the client with your Vinkius server URL. Use `mcpClient.listTools()` to retrieve the tools, then spread them directly into your agent's tool configuration array.

Yes, you can wrap `brex_pay_vendor` in a Mastra workflow step with custom retry logic. If the Brex API returns a rate limit or temporary error, the workflow backs off and retries automatically.

You can use Mastra's `requireToolApproval` setting on the `brex_create_card` tool. This pauses the workflow and waits for an admin signature before the virtual card is generated.

Yes. Mastra lets you deploy your entire agentic setup, including the server integrations, to any cloud provider instantly. The Vinkius endpoint handles the secure connection to Brex.

All financial data fetched via `brex_list_transactions` is processed in memory during the workflow execution. Vinkius secures the gateway with token-based authentication, ensuring no transaction details are stored or logged outside your private environment.

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