> ## Documentation Index
> Fetch the complete documentation index at: https://docs.younegotiate.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Third Party APIs

> External services used by the platform to support communications, identity verification, address validation, payment security, and payment processing.

## Purpose

Third-party APIs provide critical infrastructure services that support account onboarding, communications, payment processing, compliance, and creditor identity verification.

## Twilio

### Purpose

Provides SMS messaging services and inbound text processing.

### Uses

* Consumer SMS notifications
* Campaign SMS delivery
* Reminder notifications
* Negotiation notifications
* Payment notifications
* STOP / START processing
* SMS delivery tracking

### Key Functions

* Outbound SMS delivery
* Inbound SMS processing
* Opt-out management
* Delivery status callbacks

## SendGrid

### Purpose

Provides email delivery and engagement tracking.

### Uses

* Consumer email notifications
* Creditor email notifications
* Campaign emails
* CFPB delivery notifications
* Secure EcoLetter notifications

### Key Functions

* Email delivery
* Open tracking
* Delivery tracking
* Bounce management
* Event callbacks

## Basis Theory

### Purpose

Provides PCI-compliant payment vaulting and tokenization.

### Uses

* Consumer payment methods
* Bill Pay Wallet
* Payment plan payment methods
* Settlement payment methods
* Creditor membership billing methods

### Key Functions

* Payment tokenization
* Secure payment storage
* PCI compliance
* Vault management

### Key Rule

The platform stores payment tokens and payment metadata only.
Raw payment credentials are never stored by the platform.

## Smarty

### Purpose

Provides address validation and address enrichment services.

### Uses

* Consumer address validation
* Creditor address validation
* Address auto-population
* Mail delivery optimization

### Key Functions

* Address verification
* Address standardization
* Address enrichment

## Middesk

### Purpose

Provides business identity verification (KYB).

### Uses

* Creditor onboarding
* Federal TIN verification
* Business validation
* ECO Address verification

### Key Functions

* Business identity verification
* TIN validation
* Business registration verification

### Key Rule

Verified creditor identity becomes the permanent ECO Address used throughout the platform.

## Merchant Processor Gateways

### Supported Gateways

* Stripe
* USAePay
* Authorize.Net

### Purpose

Provides ACH and Credit Card payment processing.

### Uses

* Settlement payments
* Payment plan payments
* Membership billing
* Platform billing

### Key Functions

* ACH processing
* Credit card processing
* Payment authorization
* Payment settlement