Setup

Straddle Setup

This skill covers first-time setup for working with Straddle. Follow the sections in order for a complete setup, or jump to the section you need.

MCP Server Connection

Straddle provides an MCP server that gives AI agents direct access to the Straddle API. Straddle supports three connection methods depending on your environment.

1. Remote OAuth (default)

The simplest method. Uses Straddle's hosted MCP server with OAuth authentication. Best for interactive development.

Claude Code:

claude mcp add --transport http straddle https://mcp.straddle.com/mcp

Cursor / VS Code (mcp.json):

{
  "mcpServers": {
    "straddle": {
      "url": "https://mcp.straddle.com/mcp"
    }
  }
}

On first use, the server initiates an OAuth flow in your browser to authenticate with Straddle.

2. API Key (for agents and CI/CD)

For automated environments where interactive OAuth isn't available. Uses a separate endpoint that accepts API key authentication through a header.

Claude Code:

claude mcp add --transport http straddle https://straddle.stlmcp.com/ \
  --header "Authorization: Bearer $STRADDLE_API_KEY"

Cursor / VS Code (mcp.json):

{
  "mcpServers": {
    "straddle": {
      "url": "https://straddle.stlmcp.com",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

Replace YOUR_API_KEY with your actual Straddle API key. Do not commit this configuration to version control.

3. Local npx (offline)

Runs the MCP server locally via npx. Useful for offline development or for inspecting traffic.

Claude Code:

claude mcp add straddle -- npx -y @straddlecom/straddle-mcp@latest

Requires the STRADDLE_API_KEY environment variable to be set in your shell.

Cursor / VS Code (mcp.json):

{
  "mcpServers": {
    "straddle": {
      "command": "npx",
      "args": ["-y", "@straddlecom/straddle-mcp@latest"],
      "env": {
        "STRADDLE_API_KEY": "YOUR_API_KEY"
      }
    }
  }
}

Straddle CLI

The Straddle CLI gives you full API access from the terminal. Every resource available through the SDKs (customers, paykeys, charges, payouts, bridge, embed) is available as a CLI command.

brew install straddleio/tools/straddle

Set your API key and confirm it works:

export STRADDLE_API_KEY=your_sandbox_key
straddle charges create --help

The --help flag shows available parameters for any command. Use it to explore the API surface:

straddle --help
straddle paykeys --help

Use --format json for structured output and --debug to see the full HTTP request and response when troubleshooting.

The CLI uses the same API keys and environments as the SDKs.

API Keys

Straddle API keys are opaque strings. Get them from the Straddle Dashboard:

Dashboard: https://dashboard.straddle.com

Each environment (sandbox, production) has its own set of keys. Keys aren't interchangeable between environments.

Rules:

• Never commit API keys to version control
• Store keys in environment variables (STRADDLE_API_KEY) or a secrets manager
• Rotate keys immediately if exposed
• Sandbox keys only work against the sandbox environment; production keys only work against production

Environments

Environment	Base URL	Purpose
Sandbox	https://sandbox.straddle.com	Testing and development. No real money moves.
Production	https://production.straddle.com	Live payments. Real money moves.

Use sandbox for all development and testing. Switch to production only when you are ready to process real payments.

SDK clients accept an environment parameter:

import Straddle from '@straddlecom/straddle';

const client = new Straddle({
  apiKey: process.env.STRADDLE_API_KEY,
  environment: 'sandbox',  // or 'production'
});

Integration Type

Ask the user what they are building:

• Direct account: A single business collecting or sending payments. No sub-merchants, no embedded accounts. This is the simplest integration.
• SaaS platform: Software with embedded payments for your clients. Your clients (embedded accounts) own their customers in the Straddle API. Examples: loan servicing, property management, subscription billing software.
• Marketplace: A platform connecting buyers with multiple sellers. The platform owns customer relationships directly. Examples: e-commerce marketplace, gig economy, rental platform.

Write the answer to the plugin's .local.md file:

---
platform_type: account
---

Valid values: account, saas, marketplace.

If .local.md already exists with a platform_type, show the current value and ask if they want to change it.

Verification

After setup, verify everything works with these checks:

1. Test a code tool

Ask your AI agent:

List my Straddle customers

This confirms the straddle MCP server is connected and authenticated. Expect a response from the Straddle API (even if the customer list is empty in sandbox).

2. Test CLI (if installed)

Run:

straddle charges create --help

This confirms the CLI is installed and working. The output should show the full list of parameters for creating a charge.

If any check fails, verify the MCP server is registered (claude mcp list in Claude Code) and that your API key is set correctly for the environment you are targeting.

Next steps

Based on integration type:

Direct account:

• Ask to plan your integration, or run /sandbox-test to test payment flows
• Ask about specific payment operations (charges, payouts, Bridge)

SaaS platform or marketplace:

• Ask to plan your integration -- the plan covers Embed onboarding, customer management, and payment flows
• Run /sandbox-test embed-onboarding to test the merchant onboarding flow

Troubleshooting

OAuth flow does not open a browser

Headless environment (CI, SSH, containers). Switch to the API key connection method:

claude mcp add --transport http straddle https://straddle.stlmcp.com/ \
  --header "Authorization: Bearer $STRADDLE_API_KEY"

401 Unauthorized after initial setup

OAuth token expired. Remove and re-add the MCP server:

claude mcp remove straddle
claude mcp add --transport http straddle https://mcp.straddle.com/mcp

Connection timeout

Firewall or proxy blocking the connection. Try the local npx method:

claude mcp add straddle -- npx -y @straddlecom/straddle-mcp@latest

MCP server registered but tools not appearing

Restart the editor. MCP servers load on session start.

• Claude Code: start a new session
• Cursor: Developer > Reload Window
• Codex: restart the CLI

Wrong environment (sandbox vs production)

API keys are JWT bearer tokens. The same key format works for both environments. The environment is determined by the base URL, not the key. If API calls return unexpected results, verify the environment URL matches the dashboard where the key was generated:

• Sandbox: https://sandbox.straddle.com
• Production: https://production.straddle.com

CLI returns "command not found"

Homebrew did not add the binary to PATH. Run:

brew link straddleio/tools/straddle

Or install with Go:

go install 'github.com/straddleio/straddle-cli/cmd/straddle@latest'