> ## Documentation Index > Fetch the complete documentation index at: https://docs.mx.com/llms.txt > Use this file to discover all available pages before exploring further. # Legacy Connectivity Guides This section contains integration guides for legacy Platform API versions (before v20250224). These guides cover the essential workflows for connecting end users to their financial institutions and retrieving various types of financial data. **IMPORTANT** If you're starting a new integration, follow the [current connectivity guides](/products/connectivity/overview/connectivity-integration-guides/) for the most up-to-date instructions and best practices. ## Integration Approaches Your use case and technology determines which method of integration you should use. Use the following table to decide which integration method is the best for you. | Method | Description | When to Use | | ------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Connect Widget** | The [Connect Widget](/connect) is a pre-built, client-facing component that's presented to end users. It allows them to select and connect to their accounts.

You can use the Connect Widget for Web and Mobile applications. SDKs are available for Web and React Native. | You want to use our ready-made connection experience that handles: | | **API Only** | Use API endpoints to connect to an end user's account and fetch data, using a non-MX UI connection experience.

You’ll have to manage connection statuses, webhooks, and more manually with this integration. | You want to build your own end-user facing connection experience instead of using our Connect Widget, or you’re looking to build a customized verification solution within your application. | ## Available Guides **PREREQUISITES** Before following any of these guides, ensure you have: * Signed up for Platform API access and obtained your development API keys from the [MX Dashboard](https://dashboard.mx.com) * Retrieved your `client_id` and `api_key` for authentication * Whitelisted your IP addresses * Configured all requests to use HTTPS with TLSv1.2 encryption or higher ### Connect Widget Integrations These guides use the Connect Widget to simplify the integration process with pre-built UI components and automatic connection management: * [Configure Your Connect Widget](/other/legacy-connectivity-guides/configure-your-connect-widget) — Configure widget URL requests, widget options, and data aggregation settings for different use cases * [Fetch Account and Routing Numbers with Connect](/other/legacy-connectivity-guides/fetch-account-routing-number-connect) — Retrieve account and routing numbers for ACH transfers * [Fetch Account and Transaction Data with Connect](/other/legacy-connectivity-guides/fetch-account-transaction-data-connect) — Retrieve up to 90 days of transaction history ### API-Only Integrations These guides provide complete control over the user experience by using API endpoints directly: * [Fetch Account Owner Data](/other/legacy-connectivity-guides/fetch-account-owner-data) — Retrieve Account Owner Identification (AOI) data * [Fetch Account and Routing Numbers with the API](/other/legacy-connectivity-guides/fetch-account-routing-number-api) — Retrieve account and routing numbers for ACH transfers * [Fetch Account and Transaction Data with the API](/other/legacy-connectivity-guides/fetch-account-transaction-data-api) — Retrieve up to 90 days of transaction history * [Fetch Extended Transaction Data](/other/legacy-connectivity-guides/fetch-extended-history) — Retrieve up to 24 months of transaction history * [Fetch Real Time Balance Data](/other/legacy-connectivity-guides/fetch-real-time-balance) — Get current account balances without transaction data * [Fetch Statements](/other/legacy-connectivity-guides/fetch-statements) — Download account statements in PDF format ### Use Case Guides These guides show how to build specific business use cases using MX connectivity products: #### Deposit Account Opening Verify identity, link funding accounts, and gather financial information when opening new deposit accounts: * [Connect Widget Integration](/other/legacy-connectivity-guides/use-case-deposit-account-opening-connect-widget) — Use the Connect Widget to capture credentials and manage connections * [API-Only Integration](/other/legacy-connectivity-guides/use-case-deposit-account-opening-api) — Build a custom solution using API endpoints directly #### Payment Verification Verify account details, balances, and owner information before initiating payments via ACH, RTP, or FedNow: * [Connect Widget Integration](/other/legacy-connectivity-guides/use-case-payment-verification-connect-widget-integration) — Use the Connect Widget to gather credentials and fetch payment verification data * [API-Only Integration](/other/legacy-connectivity-guides/use-case-payment-verification-api) — Build a custom solution using API endpoints directly