### Generate Client Token in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/ClientTokenGateway.md

Basic and customer-specific token generation examples.

```csharp
// Basic client token
string clientToken = gateway.ClientToken.Generate();

// Client token for specific customer
var request = new ClientTokenRequest
{
    CustomerId = "customer_id"
};
string clientToken = gateway.ClientToken.Generate(request);
```

--------------------------------

### Initialize BraintreeGateway and Process a Transaction

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/BraintreeGateway.md

Demonstrates the standard setup for the BraintreeGateway and executing a basic sale transaction. Ensure valid sandbox credentials are provided before execution.

```csharp
using System;
using Braintree;

namespace BraintreeExample
{
    class Program
    {
        static void Main(string[] args)
        {
            var gateway = new BraintreeGateway
            {
                Environment = Environment.SANDBOX,
                MerchantId = "the_merchant_id",
                PublicKey = "a_public_key",
                PrivateKey = "a_private_key"
            };

            var request = new TransactionRequest
            {
                Amount = 100.00M,
                PaymentMethodNonce = "nonce_from_client"
            };

            Result<Transaction> result = gateway.Transaction.Sale(request);

            if (result.IsSuccess())
            {
                Console.WriteLine("Success! Transaction ID: " + result.Target.Id);
            }
            else
            {
                Console.WriteLine("Error: " + result.Message);
            }
        }
    }
}
```

--------------------------------

### Quick Start: Braintree Gateway Transaction Sale

Source: https://github.com/braintree/braintree_dotnet/blob/master/README.md

This example demonstrates how to initialize the Braintree Gateway in sandbox mode and process a transaction sale using a payment method nonce. It includes error handling for successful transactions and various failure scenarios.

```csharp
using System;
using Braintree;

namespace BraintreeExample
{
    class Program
    {
        static void Main(string[] args)
        {
            var gateway = new BraintreeGateway
            {
                Environment = Braintree.Environment.SANDBOX,
                MerchantId = "the_merchant_id",
                PublicKey = "a_public_key",
                PrivateKey = "a_private_key"
            };

            TransactionRequest request = new TransactionRequest
            {
                Amount = 1000.00M,
                PaymentMethodNonce = nonceFromTheClient,
                Options = new TransactionOptionsRequest
                {
                    SubmitForSettlement = true
                }
            };

            Result<Transaction> result = gateway.Transaction.Sale(request);

            if (result.IsSuccess())
            {
                Transaction transaction = result.Target;
                Console.WriteLine("Success!: " + transaction.Id);
            }
            else if (result.Transaction != null)
            {
                Transaction transaction = result.Transaction;
                Console.WriteLine("Error processing transaction:");
                Console.WriteLine("  Status: " + transaction.Status);
                Console.WriteLine("  Code: " + transaction.ProcessorResponseCode);
                Console.WriteLine("  Text: " + transaction.ProcessorResponseText);
            }
            else
            {
                foreach (ValidationError error in result.Errors.DeepAll())
                {
                    Console.WriteLine("Attribute: " + error.Attribute);
                    Console.WriteLine("  Code: " + error.Code);
                    Console.WriteLine("  Message: " + error.Message);
                }
            }
        }
    }
}
```

--------------------------------

### Install Braintree NuGet Package

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/README.md

Use the .NET CLI to add the Braintree package to your project.

```bash
dotnet add package Braintree
```

--------------------------------

### Search Credit Cards Usage Example

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/CreditCardGateway.md

Demonstrates searching for credit cards by customer ID and expiration date, then iterating through the results.

```csharp
var cards = gateway.CreditCard.Search(search =>
{
    search.CustomerId().Is("customer_id");
    search.ExpirationDate().Is("12/2025");
});

foreach (CreditCard card in cards.Fetch(0, 25))
{
    Console.WriteLine(card.MaskedNumber);
}
```

--------------------------------

### SubmitForSettlement Usage Example

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/TransactionGateway.md

Demonstrates submitting a transaction for settlement and checking the result status.

```csharp
Result<Transaction> result = gateway.Transaction.SubmitForSettlement("transaction_id");
if (result.IsSuccess())
{
    Console.WriteLine("Status: " + result.Target.Status);
}
```

--------------------------------

### Perform 3D Secure Lookup

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/ThreeDSecureGateway.md

Example of initiating a lookup request and handling the result to check if authentication is required.

```csharp
var request = new ThreeDSecureLookupRequest
{
    Amount = 100.00M,
    Nonce = "payment_method_nonce"
};

Result<ThreeDSecureLookup> result = gateway.ThreeDSecure.Lookup(request);
if (result.IsSuccess())
{
    ThreeDSecureLookup lookup = result.Target;
    if (lookup.Threaded)
    {
        Console.WriteLine("3DS authentication required");
        // Redirect user to authentication
    }
}
```

--------------------------------

### SubmitForPartialSettlement Usage Example

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/TransactionGateway.md

Demonstrates submitting a partial settlement using a TransactionRequest object.

```csharp
var request = new TransactionRequest { Amount = 50.00M };
Result<Transaction> result = gateway.Transaction.SubmitForPartialSettlement("txn_id", request);
```

--------------------------------

### AdjustAuthorization Usage Example

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/TransactionGateway.md

Demonstrates adjusting the authorized amount of a transaction.

```csharp
Result<Transaction> result = gateway.Transaction.AdjustAuthorization("txn_id", 150.00M);
```

--------------------------------

### Initialize Configuration with Environment and Keys

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Creates a configuration using an explicit Environment object and API keys.

```csharp
public Configuration(
    Environment environment, 
    string merchantId, 
    string publicKey, 
    string privateKey
)
```

--------------------------------

### Build and Test with .NET CLI on Windows

Source: https://github.com/braintree/braintree_dotnet/blob/master/DEVELOPMENT.md

Restore dependencies, build the project, and run tests using the dotnet CLI on a Windows environment.

```bash
dotnet restore
dotnet build
dotnet test .
```

--------------------------------

### Configure Gateway with API Keys

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Initializes the gateway using explicit environment, merchant ID, public key, and private key.

```csharp
var configuration = new Configuration(
    Environment.SANDBOX,
    "your_merchant_id",
    "your_public_key",
    "your_private_key"
);

var gateway = new BraintreeGateway(configuration);
```

--------------------------------

### Initialize Configuration with String Environment

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Creates a configuration using a string-based environment name and API keys.

```csharp
public Configuration(
    string environment, 
    string merchantId, 
    string publicKey, 
    string privateKey
)
```

--------------------------------

### Configure Gateway with String Environment

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Initializes the gateway using a string representation for the environment.

```csharp
var configuration = new Configuration(
    "sandbox",
    "your_merchant_id",
    "your_public_key",
    "your_private_key"
);

var gateway = new BraintreeGateway(configuration);
```

--------------------------------

### Retrieve and Paginate Plans

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/PlanGateway.md

Demonstrates how to fetch all plans and iterate through them using pagination with the Fetch method.

```csharp
var plans = gateway.Plan.All();

// Fetch first 25 plans
foreach (Plan plan in plans.Fetch(0, 25))
{
    // Process plan
}

// Fetch plans 25-50
foreach (Plan plan in plans.Fetch(25, 50))
{
    // Process plan
}
```

--------------------------------

### Initialize BraintreeGateway with Environment and Keys

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/BraintreeGateway.md

Creates a gateway instance using explicit environment and API credential parameters.

```csharp
public BraintreeGateway(Environment environment, string merchantId, string publicKey, string privateKey)
```

```csharp
var gateway = new BraintreeGateway(
    Environment.SANDBOX,
    "your_merchant_id",
    "your_public_key",
    "your_private_key"
);
```

--------------------------------

### Configure Gateway with Client Credentials

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Initializes the gateway using client ID and client secret.

```csharp
var configuration = new Configuration("client_id", "client_secret");
var gateway = new BraintreeGateway(configuration);
```

--------------------------------

### List Available Plans in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/PlanGateway.md

Retrieves all plans from the gateway and iterates through them to display basic plan information and trial details.

```csharp
var plans = gateway.Plan.All();

Console.WriteLine("Available Plans:");
foreach (Plan plan in plans.Fetch(0, 50))
{
    Console.WriteLine($"- {plan.Name}: ${plan.Price}/month");
    if (plan.TrialPeriod == true)
    {
        Console.WriteLine($"  Trial: {plan.TrialDuration} {plan.TrialDurationUnit}(s)");
    }
}
```

--------------------------------

### Initialize Configuration with Client Credentials

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Creates a configuration using OAuth 2.0 client ID and client secret.

```csharp
public Configuration(string clientId, string clientSecret)
```

--------------------------------

### Initialize Configuration with Access Token

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Creates a configuration using an OAuth 2.0 access token, which automatically parses the merchant ID and environment.

```csharp
public Configuration(string accessToken)
```

--------------------------------

### Create Subscription with Add-ons and Discounts in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/PlanGateway.md

Creates a subscription request that includes specific add-ons and discounts by their inherited IDs.

```csharp
var request = new SubscriptionRequest
{
    PaymentMethodToken = "token",
    PlanId = "plan_id"
};

// Add add-ons
var addOns = new List<AddAddOnRequest>();
addOns.Add(new AddAddOnRequest { InheritedFromId = "addon_id_1" });
addOns.Add(new AddAddOnRequest { InheritedFromId = "addon_id_2" });
request.AddOns = addOns;

// Add discounts
var discounts = new List<AddDiscountRequest>();
discounts.Add(new AddDiscountRequest { InheritedFromId = "discount_id" });
request.Discounts = discounts;

Result<Subscription> result = gateway.Subscription.Create(request);
```

--------------------------------

### Initialize Configuration with Default Constructor

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Creates an empty configuration instance requiring manual property assignment.

```csharp
public Configuration()
```

--------------------------------

### Initialize BraintreeGateway with API Keys

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/README.md

Use this method for standard server-side integration using sandbox or production credentials.

```csharp
new BraintreeGateway(Environment.SANDBOX, merchantId, publicKey, privateKey)
```

--------------------------------

### Configure Gateway with Access Token

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Initializes the gateway using an access token for authentication.

```csharp
var configuration = new Configuration("access_token_value");
var gateway = new BraintreeGateway(configuration);
```

--------------------------------

### Initialize BraintreeGateway with Configuration Object

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/BraintreeGateway.md

Creates a gateway instance from an existing Configuration object.

```csharp
public BraintreeGateway(Configuration configuration)
```

--------------------------------

### Manage Subscription in .NET

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/workflow-patterns.md

Demonstrates how to retrieve subscription details, check status, retry failed charges, update subscription attributes, and cancel an existing subscription.

```csharp
// Find subscription
Subscription subscription = gateway.Subscription.Find("subscription_id");

// Check status
if (subscription.Status == "Active")
{
    Console.WriteLine("Subscription is active");
}
else if (subscription.DaysPastDue > 0)
{
    Console.WriteLine("Subscription is " + subscription.DaysPastDue + " days past due");
    
    // Retry failed payment
    Result<Transaction> retryResult = gateway.Subscription.RetryCharge("subscription_id");
}

// Update subscription
var updateRequest = new SubscriptionRequest
{
    Price = 39.99M  // New price
};
Result<Subscription> updateResult = gateway.Subscription.Update("subscription_id", updateRequest);

// Cancel subscription
Result<Subscription> cancelResult = gateway.Subscription.Cancel("subscription_id");
```

--------------------------------

### Build Docker Image with .NET Core 3.1

Source: https://github.com/braintree/braintree_dotnet/blob/master/DEVELOPMENT.md

Use this command to build a Docker image with .NET Core 3.1 for development.

```bash
make core3
```

--------------------------------

### Initialize BraintreeGateway with Environment Variables

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Retrieves Braintree credentials from system environment variables to avoid hardcoding sensitive information. Throws a ConfigurationException if required variables are missing.

```csharp
var environment = System.Environment.GetEnvironmentVariable("BRAINTREE_ENV") ?? "sandbox";
var merchantId = System.Environment.GetEnvironmentVariable("BRAINTREE_MERCHANT_ID");
var publicKey = System.Environment.GetEnvironmentVariable("BRAINTREE_PUBLIC_KEY");
var privateKey = System.Environment.GetEnvironmentVariable("BRAINTREE_PRIVATE_KEY");

if (string.IsNullOrEmpty(merchantId) || string.IsNullOrEmpty(publicKey) || string.IsNullOrEmpty(privateKey))
{
    throw new ConfigurationException("Missing required Braintree credentials in environment variables");
}

var gateway = new BraintreeGateway(environment, merchantId, publicKey, privateKey);
```

--------------------------------

### Create Subscription in .NET

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/workflow-patterns.md

Requires a customer ID and a vaulted payment method token. The process involves creating a customer, vaulting their credit card, and then initiating the subscription request.

```csharp
// Step 1: Create customer
var customerRequest = new CustomerRequest
{
    FirstName = "Jane",
    LastName = "Smith",
    Email = "jane@example.com"
};
Result<Customer> customerResult = gateway.Customer.Create(customerRequest);
string customerId = customerResult.Target.Id;

// Step 2: Vault payment method
var cardRequest = new CreditCardRequest
{
    CustomerId = customerId,
    Number = "4111111111111111",
    ExpirationDate = "12/2025"
};
Result<CreditCard> cardResult = gateway.CreditCard.Create(cardRequest);
string cardToken = cardResult.Target.Token;

// Step 3: Create subscription
var subscriptionRequest = new SubscriptionRequest
{
    CustomerId = customerId,
    PaymentMethodToken = cardToken,
    PlanId = "plan_id",
    Price = 29.99M
};

Result<Subscription> subResult = gateway.Subscription.Create(subscriptionRequest);
if (subResult.IsSuccess())
{
    Subscription subscription = subResult.Target;
    Console.WriteLine("Subscription ID: " + subscription.Id);
    Console.WriteLine("Status: " + subscription.Status);
    Console.WriteLine("Next billing: " + subscription.NextBillingDate);
}
```

--------------------------------

### Initialize BraintreeGateway with Default Constructor

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/BraintreeGateway.md

Creates a new gateway instance with an empty configuration that requires manual property assignment.

```csharp
public BraintreeGateway()
```

```csharp
var gateway = new BraintreeGateway
{
    Environment = Environment.SANDBOX,
    MerchantId = "merchant_id",
    PublicKey = "public_key",
    PrivateKey = "private_key"
};
```

--------------------------------

### Create a customer in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/CustomerGateway.md

Initializes a CustomerRequest object and submits it to the gateway to create a new customer record.

```csharp
var request = new CustomerRequest
{
    FirstName = "John",
    LastName = "Doe",
    Email = "john@example.com",
    Phone = "555-1234",
    Company = "Acme Corp"
};

Result<Customer> result = gateway.Customer.Create(request);
if (result.IsSuccess())
{
    Console.WriteLine("Customer ID: " + result.Target.Id);
}
```

--------------------------------

### Initialize BraintreeGateway with direct properties

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Configures the gateway instance using direct property assignment for environment and API credentials.

```csharp
var gateway = new BraintreeGateway
{
    Environment = Environment.SANDBOX,
    MerchantId = "merchant_id",
    PublicKey = "public_key",
    PrivateKey = "private_key"
};
```

--------------------------------

### Configure Braintree Gateway

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/README.md

Initialize the BraintreeGateway with your sandbox or production credentials.

```csharp
using Braintree;

var gateway = new BraintreeGateway
{
    Environment = Environment.SANDBOX,
    MerchantId = "your_merchant_id",
    PublicKey = "your_public_key",
    PrivateKey = "your_private_key"
};
```

--------------------------------

### Create Subscription from Plan in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/PlanGateway.md

Creates a new subscription using a plan ID, with an optional override for the plan price.

```csharp
Plan plan = gateway.Plan.Find("annual_plan");

var request = new SubscriptionRequest
{
    PaymentMethodToken = "credit_card_token",
    PlanId = plan.Id,
    Price = plan.Price  // Can override plan price if needed
};

Result<Subscription> result = gateway.Subscription.Create(request);
if (result.IsSuccess())
{
    Subscription subscription = result.Target;
    Console.WriteLine("Subscription created: " + subscription.Id);
    Console.WriteLine("Next billing: " + subscription.NextBillingDate);
}
```

--------------------------------

### Configure Gateway Environment

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/BraintreeGateway.md

Sets the execution environment to either SANDBOX or PRODUCTION.

```csharp
public virtual Environment Environment { get; set; }
```

--------------------------------

### Initialize BraintreeGateway with String Environment

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/BraintreeGateway.md

Creates a gateway instance using a string-based environment identifier.

```csharp
public BraintreeGateway(string environment, string merchantId, string publicKey, string privateKey)
```

--------------------------------

### Initialize BraintreeGateway with Client Credentials

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/BraintreeGateway.md

Creates a gateway instance using OAuth 2.0 client ID and secret.

```csharp
public BraintreeGateway(string clientId, string clientSecret)
```

--------------------------------

### Transaction Search Usage

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/TransactionGateway.md

Demonstrates how to configure search criteria using a delegate and iterate through the resulting paginated collection.

```csharp
var transactions = gateway.Transaction.Search(search =>
{
    search.Id().Is("transaction_id");
    search.Status().IncludedIn(TransactionStatus.SETTLED);
    search.CreatedAt().Between(startDate, endDate);
});

foreach (Transaction txn in transactions.Fetch(0, 50))
{
    Console.WriteLine(txn.Id);
}
```

--------------------------------

### All()

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/PlanGateway.md

Retrieves all billing plans with pagination support.

```APIDOC
## All()

### Description
Retrieves all billing plans with pagination support.

### Method
public virtual ResourceCollection<Plan> All()

### Returns
ResourceCollection<Plan> - Paginated collection of all plans

### Usage Example
var plans = gateway.Plan.All();
foreach (Plan plan in plans.Fetch(0, 100))
{
    Console.WriteLine("Plan ID: " + plan.Id);
    Console.WriteLine("Price: $" + plan.Price);
    Console.WriteLine("Billing Frequency: " + plan.BillingFrequency + " months");
}
```

--------------------------------

### Construct development environment URL

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Retrieves gateway host and port from environment variables with fallback defaults for local development.

```csharp
var host = System.Environment.GetEnvironmentVariable("GATEWAY_HOST") ?? "localhost";
var port = System.Environment.GetEnvironmentVariable("GATEWAY_PORT") ?? "3000";
var url = $"http://{host}:{port}";
```

--------------------------------

### Create a Transaction Sale in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/TransactionGateway.md

Executes an immediate charge using a payment method nonce. Ensure SubmitForSettlement is set to true if the transaction should be captured immediately.

```csharp
var request = new TransactionRequest
{
    Amount = 100.00M,
    PaymentMethodNonce = "nonce_from_client",
    Options = new TransactionOptionsRequest
    {
        SubmitForSettlement = true
    }
};

Result<Transaction> result = gateway.Transaction.Sale(request);
if (result.IsSuccess())
{
    Console.WriteLine("Transaction ID: " + result.Target.Id);
}
```

--------------------------------

### Display Plan Details with Add-ons and Discounts in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/PlanGateway.md

Finds a specific plan by ID and iterates through its associated add-ons and discounts to display their details.

```csharp
Plan plan = gateway.Plan.Find("standard_plan");

Console.WriteLine("Plan: " + plan.Name);
Console.WriteLine("Price: $" + plan.Price);
Console.WriteLine("Billing Frequency: Every " + plan.BillingFrequency + " months");

if (plan.AddOns != null && plan.AddOns.Length > 0)
{
    Console.WriteLine("Available Add-ons:");
    foreach (AddOn addOn in plan.AddOns)
    {
        Console.WriteLine($"  + {addOn.Name}: ${addOn.Amount}");
    }
}

if (plan.Discounts != null && plan.Discounts.Length > 0)
{
    Console.WriteLine("Available Discounts:");
    foreach (Discount discount in plan.Discounts)
    {
        Console.WriteLine($"  - {discount.Name}: ${discount.Amount}");
        if (discount.NumberOfBillingCycles.HasValue)
        {
            Console.WriteLine($"    (Applies for {discount.NumberOfBillingCycles} cycles)");
        }
    }
}
```

--------------------------------

### Initialize BraintreeGateway with Access Token

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/BraintreeGateway.md

Creates a gateway instance using an OAuth 2.0 access token.

```csharp
public BraintreeGateway(string accessToken)
```

```csharp
var gateway = new BraintreeGateway("access_token_value");
```

--------------------------------

### Create

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/AddressGateway.md

Creates a new address for a specified customer.

```APIDOC
## Create

### Description
Creates a new address for a customer.

### Signature
`public virtual Result<Address> Create(string customerId, AddressRequest request)`

### Parameters
- **customerId** (string) - Required - Customer identifier
- **request** (AddressRequest) - Required - Address details

### Returns
`Result<Address>` - Result containing the created address or validation errors

### Throws
- `NotFoundException` if customer not found
```

--------------------------------

### Create Subscription in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/SubscriptionGateway.md

Initializes a new subscription using a SubscriptionRequest object. Check the Result object for success before accessing the target subscription.

```csharp
var request = new SubscriptionRequest
{
    PaymentMethodToken = "credit_card_token",
    PlanId = "plan_id",
    Price = 29.99M
};

Result<Subscription> result = gateway.Subscription.Create(request);
if (result.IsSuccess())
{
    Console.WriteLine("Subscription ID: " + result.Target.Id);
    Console.WriteLine("Status: " + result.Target.Status);
}
```

--------------------------------

### Handle ConfigurationException

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/errors.md

Catch errors related to invalid or incomplete gateway configuration settings.

```csharp
try
{
    var gateway = new BraintreeGateway(
        "invalid_env",
        "merchant_id",
        "public_key",
        "private_key"
    );
}
catch (ConfigurationException ex)
{
    Console.WriteLine("Configuration error: " + ex.Message);
    // Verify configuration properties
}
```

--------------------------------

### Generate Token with Verification Options

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/ClientTokenGateway.md

Configuring card verification and default payment method settings during token generation.

```csharp
var request = new ClientTokenRequest
{
    CustomerId = "customer_id",
    Options = new ClientTokenOptionsRequest
    {
        VerifyCard = true,
        MakeDefault = true
    }
};
string clientToken = gateway.ClientToken.Generate(request);
```

--------------------------------

### Manage Payment Methods

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/QUICK_REFERENCE.md

Handle credit card creation and payment method lifecycle management.

```csharp
// Create credit card
Result<CreditCard> result = gateway.CreditCard.Create(new CreditCardRequest
{
    CustomerId = "customer_id",
    Number = "4111111111111111",
    ExpirationDate = "12/2025"
});

// Find payment method
PaymentMethod method = gateway.PaymentMethod.Find("token");

// Update payment method
Result<PaymentMethod> update = gateway.PaymentMethod.Update("token", new PaymentMethodRequest
{
    Options = new PaymentMethodOptionsRequest { MakeDefault = true }
});

// Delete payment method
Result<PaymentMethod> delete = gateway.PaymentMethod.Delete("token");
```

--------------------------------

### gateway.Plan.All()

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/PlanGateway.md

Retrieves a list of all available plans configured in the Braintree control panel.

```APIDOC
## gateway.Plan.All()

### Description
Retrieves a collection of all plans available in the Braintree environment.

### Usage
```csharp
var plans = gateway.Plan.All();
foreach (Plan plan in plans.Fetch(0, 50)) {
    Console.WriteLine($"- {plan.Name}: ${plan.Price}/month");
}
```
```

--------------------------------

### Build Docker Image with Mono

Source: https://github.com/braintree/braintree_dotnet/blob/master/DEVELOPMENT.md

Use this command to build a Docker image that includes Mono for development.

```bash
make mono
```

--------------------------------

### Client-Side Integration

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/ClientTokenGateway.md

Initializing the Braintree client using the generated token.

```html
<script src="https://js.braintreegateway.com/web/3.88.0/braintree.min.js"></script>
<script>
  braintree.client.create({
    authorization: '<CLIENT_TOKEN>'
  }, function (err, clientInstance) {
    // Use clientInstance for Hosted Fields, 3D Secure, etc.
  });
</script>
```

--------------------------------

### All

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/CustomerGateway.md

Retrieves all customers (with pagination support).

```APIDOC
## All

### Description
Retrieves all customers (with pagination support).

### Returns
- **ResourceCollection<Customer>** - Paginated collection of all customers
```

--------------------------------

### Execute a Transaction

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/README.md

Create a sale transaction using a payment method nonce.

```csharp
var request = new TransactionRequest
{
    Amount = 100.00M,
    PaymentMethodNonce = "nonce_from_client"
};

Result<Transaction> result = gateway.Transaction.Sale(request);

if (result.IsSuccess())
{
    Console.WriteLine("Success! Transaction ID: " + result.Target.Id);
}
```

--------------------------------

### Configuration Check Methods

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Methods to check the current authentication configuration state.

```APIDOC
## IsClientCredentials

### Description
Returns true if configured with OAuth 2.0 client credentials.

## IsAccessToken

### Description
Returns true if configured with OAuth 2.0 access token.
```

--------------------------------

### Implement Async Operations for Transactions and Customers

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/workflow-patterns.md

Demonstrates handling asynchronous gateway calls with retry logic for timeouts and conditional creation of customer records.

```csharp
public async Task ProcessTransactionAsync(TransactionRequest request)
{
    try
    {
        Result<Transaction> result = await gateway.Transaction.SaleAsync(request);
        
        if (result.IsSuccess())
        {
            Console.WriteLine("Transaction: " + result.Target.Id);
        }
    }
    catch (GatewayTimeoutException)
    {
        // Retry logic
        await Task.Delay(1000);
        await ProcessTransactionAsync(request);
    }
}

public async Task<Customer> GetOrCreateCustomerAsync(string email)
{
    try
    {
        // Attempt to find existing customer
        var customers = gateway.Customer.Search(s => s.Email().Is(email));
        var existing = customers.Fetch(0, 1).FirstOrDefault();
        
        if (existing != null)
        {
            return existing;
        }
    }
    catch (NotFoundException)
    {
        // Not found - create new
    }

    var request = new CustomerRequest { Email = email };
    Result<Customer> result = await gateway.Customer.CreateAsync(request);
    return result.Target;
}
```

--------------------------------

### Import Braintree Namespaces

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/README.md

Include these namespaces to access the main SDK functionality and exception handling types.

```csharp
using Braintree;                    // Main SDK
using Braintree.Exceptions;         // Exception types
```

--------------------------------

### Retrieve all billing plans

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/PlanGateway.md

Fetches a paginated collection of all available billing plans.

```csharp
public virtual ResourceCollection<Plan> All()
```

```csharp
var plans = gateway.Plan.All();
foreach (Plan plan in plans.Fetch(0, 100))
{
    Console.WriteLine("Plan ID: " + plan.Id);
    Console.WriteLine("Price: $" + plan.Price);
    Console.WriteLine("Billing Frequency: " + plan.BillingFrequency + " months");
}
```

--------------------------------

### Create

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/SubscriptionGateway.md

Creates a new subscription using the provided request details.

```APIDOC
## Create

### Description
Creates a new subscription.

### Method
SubscriptionGateway.Create(SubscriptionRequest request)

### Parameters
- **request** (SubscriptionRequest) - Required - Subscription details including plan ID and payment method

### Returns
Result<Subscription> - Result containing the created subscription or validation errors
```

--------------------------------

### Create

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/CustomerGateway.md

Creates a new customer record in the vault.

```APIDOC
## Create

### Description
Creates a new customer record in the vault.

### Parameters
#### Parameters
- **request** (CustomerRequest) - Optional - Customer details

### Returns
- **Result<Customer>** - Result containing the created customer or validation errors
```

--------------------------------

### Generate Token for New Customer

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/ClientTokenGateway.md

Standard token generation for a new customer session.

```csharp
string clientToken = gateway.ClientToken.Generate();
// Pass token to client-side JavaScript/mobile app
```

--------------------------------

### Handle AuthenticationException

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/errors.md

Catch authentication errors resulting from invalid credentials or environment mismatches.

```csharp
try
{
    var transaction = gateway.Transaction.Find("txn_id");
}
catch (AuthenticationException ex)
{
    Console.WriteLine("Authentication failed: " + ex.Message);
    // Check credentials and environment configuration
}
```

--------------------------------

### Configuration Constructors

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Methods to initialize the Braintree Configuration object for SDK connectivity.

```APIDOC
## Configuration Constructors

### Description
Initializes a new instance of the Configuration class to establish a connection to the Braintree gateway.

### Constructors

#### Default Constructor
`public Configuration()`
Creates an empty configuration object.

#### OAuth Access Token
`public Configuration(string accessToken)`
Creates configuration from an OAuth 2.0 access token.
- **accessToken** (string) - Required - OAuth 2.0 access token.

#### Client Credentials
`public Configuration(string clientId, string clientSecret)`
Creates configuration from OAuth 2.0 client credentials.
- **clientId** (string) - Required - OAuth 2.0 client ID.
- **clientSecret** (string) - Required - OAuth 2.0 client secret.

#### Environment and Keys
`public Configuration(Environment environment, string merchantId, string publicKey, string privateKey)`
Creates configuration with explicit environment and API keys.
- **environment** (Environment) - Required - Gateway environment instance.
- **merchantId** (string) - Required - Merchant account ID.
- **publicKey** (string) - Required - Public API key.
- **privateKey** (string) - Required - Private API key.

#### String Environment
`public Configuration(string environment, string merchantId, string publicKey, string privateKey)`
Creates configuration with environment specified as a string.
- **environment** (string) - Required - Environment name: "sandbox", "production", "qa", or "development".
- **merchantId** (string) - Required - Merchant account ID.
- **publicKey** (string) - Required - Public API key.
- **privateKey** (string) - Required - Private API key.
```

--------------------------------

### Create Payment Method from Nonce

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/PaymentMethodGateway.md

Creates a new payment method for a customer using a nonce and optional configuration settings.

```csharp
var request = new PaymentMethodRequest
{
    CustomerId = "customer_id",
    PaymentMethodNonce = "nonce_from_client",
    Options = new PaymentMethodOptionsRequest
    {
        MakeDefault = true,
        VerifyCard = true
    }
};

Result<PaymentMethod> result = gateway.PaymentMethod.Create(request);
if (result.IsSuccess())
{
    var method = result.Target;
    Console.WriteLine("Created: " + method.Token);
}
```

--------------------------------

### Manage Customers

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/QUICK_REFERENCE.md

Create, retrieve, update, and delete customer records.

```csharp
// Create customer
Result<Customer> result = gateway.Customer.Create(new CustomerRequest
{
    FirstName = "John",
    LastName = "Doe",
    Email = "john@example.com"
});

// Find customer
Customer customer = gateway.Customer.Find("customer_id");

// Update customer
Result<Customer> update = gateway.Customer.Update("customer_id", new CustomerRequest
{
    Email = "newemail@example.com"
});

// Delete customer
Result<Customer> delete = gateway.Customer.Delete("customer_id");
```

--------------------------------

### Retrieve all customers in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/CustomerGateway.md

Fetches a paginated collection of all customers stored in the vault.

```csharp
var customers = gateway.Customer.All();
foreach (Customer customer in customers.Fetch(0, 50))
{
    Console.WriteLine(customer.FirstName + " " + customer.LastName);
}
```

--------------------------------

### Generate Client Tokens

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/QUICK_REFERENCE.md

Generate tokens for client-side SDK initialization, optionally scoped to a specific customer.

```csharp
// Generate client token
string clientToken = gateway.ClientToken.Generate();

// With customer
string token = gateway.ClientToken.Generate(new ClientTokenRequest
{
    CustomerId = "customer_id"
});
```

--------------------------------

### Create Credit Card in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/CreditCardGateway.md

Initializes a CreditCardRequest object and submits it to the gateway to create a new payment method.

```csharp
var request = new CreditCardRequest
{
    Number = "4111111111111111",
    ExpirationDate = "12/2025",
    CVV = "123",
    CardholderName = "John Doe",
    CustomerId = "customer_id"
};

Result<CreditCard> result = gateway.CreditCard.Create(request);
if (result.IsSuccess())
{
    Console.WriteLine("Token: " + result.Target.Token);
    Console.WriteLine("Masked Number: " + result.Target.MaskedNumber);
}
```

--------------------------------

### Parse Environment by Name

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Use ParseEnvironment to retrieve an Environment instance from a string. Throws a ConfigurationException if the provided name is invalid.

```csharp
public static Environment ParseEnvironment(string environment)
```

--------------------------------

### Search Credit Card Methods

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/CreditCardGateway.md

Synchronous and asynchronous method signatures for searching credit cards using a search delegate.

```csharp
public virtual ResourceCollection<CreditCard> Search(SearchDelegate searchDelegate)
public virtual async Task<ResourceCollection<CreditCard>> SearchAsync(SearchDelegate searchDelegate)
```

--------------------------------

### gateway.Plan.All()

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/PlanGateway.md

Retrieves a collection of all plans associated with the merchant account. The returned collection supports pagination via the Fetch method.

```APIDOC
## gateway.Plan.All()

### Description
Retrieves a collection of all plans defined in the control panel. The returned ResourceCollection allows for paginated access to the plans.

### Method
Method call

### Parameters
None

### Returns
- **ResourceCollection<Plan>** - A collection of plan objects that can be iterated or paginated using the Fetch(int, int) method.

### Example
```csharp
var plans = gateway.Plan.All();

// Fetch first 25 plans
foreach (Plan plan in plans.Fetch(0, 25))
{
    // Process plan
}
```
```

--------------------------------

### Check configuration status properties

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

Boolean properties to determine if the gateway is configured via client credentials or an access token.

```csharp
public bool IsClientCredentials { get; }
```

```csharp
public bool IsAccessToken { get; }
```

--------------------------------

### Create Address

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/AddressGateway.md

Creates a new address for a customer using an AddressRequest object. Throws a NotFoundException if the specified customer does not exist.

```csharp
public virtual Result<Address> Create(string customerId, AddressRequest request)
public virtual async Task<Result<Address>> CreateAsync(string customerId, AddressRequest request)
```

```csharp
var request = new AddressRequest
{
    FirstName = "John",
    LastName = "Doe",
    StreetAddress = "123 Main St",
    ExtendedAddress = "Suite 100",
    Locality = "Chicago",
    Region = "IL",
    PostalCode = "60622",
    CountryCodeAlpha2 = "US"
};

Result<Address> result = gateway.Address.Create("customer_id", request);
if (result.IsSuccess())
{
    Console.WriteLine("Address ID: " + result.Target.Id);
}
```

--------------------------------

### Configure OAuth 2.0 Credentials

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/BraintreeGateway.md

Properties for OAuth 2.0 authentication. Setting the AccessToken automatically populates MerchantId and Environment.

```csharp
public virtual string AccessToken { get; set; }
```

```csharp
public virtual string ClientId { get; set; }
```

```csharp
public virtual string ClientSecret { get; set; }
```

--------------------------------

### Search Resources

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/QUICK_REFERENCE.md

Use search criteria builders to query transactions, customers, or subscriptions.

```csharp
// Search transactions
var transactions = gateway.Transaction.Search(search =>
{
    search.Status().Is(TransactionStatus.SETTLED);
    search.CreatedAt().Between(start, end);
});

// Search customers
var customers = gateway.Customer.Search(search =>
{
    search.Email().Is("email@example.com");
});

// Search subscriptions
var subscriptions = gateway.Subscription.Search(search =>
{
    search.Status().Is("Active");
    search.DaysPastDue().Min(0);
});
```

--------------------------------

### gateway.Plan.Find(string planId)

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/PlanGateway.md

Retrieves the details of a specific plan by its unique identifier, including its associated add-ons and discounts.

```APIDOC
## gateway.Plan.Find(string planId)

### Description
Fetches a single plan object by its ID. This object contains metadata such as price, billing frequency, and lists of available add-ons and discounts.

### Parameters
- **planId** (string) - Required - The unique identifier of the plan to retrieve.

### Usage
```csharp
Plan plan = gateway.Plan.Find("standard_plan");
Console.WriteLine("Plan: " + plan.Name);
```
```

--------------------------------

### Vault Customer and Execute Transaction

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/workflow-patterns.md

Creates a customer, adds a credit card, and processes a transaction using the vaulted payment method token.

```csharp
// Step 1: Create customer
var customerRequest = new CustomerRequest
{
    FirstName = "John",
    LastName = "Doe",
    Email = "john@example.com"
};

Result<Customer> customerResult = gateway.Customer.Create(customerRequest);
if (!customerResult.IsSuccess())
{
    foreach (ValidationError error in customerResult.Errors.DeepAll())
    {
        Console.WriteLine(error.Message);
    }
    return;
}

string customerId = customerResult.Target.Id;

// Step 2: Create payment method for customer
var cardRequest = new CreditCardRequest
{
    CustomerId = customerId,
    Number = "4111111111111111",
    ExpirationDate = "12/2025",
    CVV = "123"
};

Result<CreditCard> cardResult = gateway.CreditCard.Create(cardRequest);
string cardToken = cardResult.Target.Token;

// Step 3: Use vaulted card for transaction
var transactionRequest = new TransactionRequest
{
    Amount = 100.00M,
    PaymentMethodToken = cardToken,
    Options = new TransactionOptionsRequest
    {
        SubmitForSettlement = true
    }
};

Result<Transaction> txnResult = gateway.Transaction.Sale(transactionRequest);
```

--------------------------------

### Create

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/CreditCardGateway.md

Creates a new credit card payment method in the vault.

```APIDOC
## Create

### Description
Creates a new credit card payment method.

### Method
public virtual Result<CreditCard> Create(CreditCardRequest request)

### Parameters
- **request** (CreditCardRequest) - Required - Credit card details

### Returns
Result<CreditCard> - Result containing the created credit card or validation errors
```

--------------------------------

### Create

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/PaymentMethodGateway.md

Creates a new payment method in the vault.

```APIDOC
## Create

### Description
Creates a new payment method (credit card, PayPal, etc.).

### Signature
`public virtual Result<PaymentMethod> Create(PaymentMethodRequest request)`
`public virtual async Task<Result<PaymentMethod>> CreateAsync(PaymentMethodRequest request)`

### Parameters
- **request** (PaymentMethodRequest) - Required - Payment method details

### Returns
`Result<PaymentMethod>` - Result containing the created payment method or validation errors
```

--------------------------------

### Define Braintree Environments

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/configuration.md

The Environment class provides static instances for Sandbox, Production, QA, and Development environments.

```csharp
public static class Environment
{
    public static Environment SANDBOX = new Environment(
        "sandbox",
        "https://api.sandbox.braintreegateway.com:443",
        "https://auth.sandbox.venmo.com",
        "https://payments.sandbox.braintree-api.com/graphql"
    );

    public static Environment PRODUCTION = new Environment(
        "production",
        "https://api.braintreegateway.com:443",
        "https://auth.venmo.com",
        "https://payments.braintree-api.com/graphql"
    );

    public static Environment QA = new Environment(
        "qa",
        "https://gateway.qa.braintreepayments.com",
        "https://auth.qa.venmo.com",
        "https://payments-qa.dev.braintree-api.com/graphql"
    );

    public static Environment DEVELOPMENT = new Environment(
        "development",
        "http://localhost:3000",  // Uses GATEWAY_HOST and GATEWAY_PORT env vars
        "http://auth.venmo.dev:9292",
        "http://graphql.bt.local:8080/graphql"
    );
}
```

--------------------------------

### Restore Dependencies for .NET Core 3.1 Tests

Source: https://github.com/braintree/braintree_dotnet/blob/master/DEVELOPMENT.md

Restore project dependencies before running tests on a Unix-like system with .NET Core 3.1.

```bash
dotnet restore
dotnet test . -f netcoreapp3.1
```

--------------------------------

### gateway.PaymentMethod.Create(PaymentMethodRequest request)

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/PaymentMethodGateway.md

Creates a new payment method for a customer using a nonce.

```APIDOC
## gateway.PaymentMethod.Create(PaymentMethodRequest request)

### Description
Creates a new payment method in the vault using a payment method nonce. Requires a PaymentMethodRequest object.

### Parameters
- **request** (PaymentMethodRequest) - Required - The request object containing CustomerId, PaymentMethodNonce, and optional configuration.

### Response
- **Result<PaymentMethod>** (object) - A result object containing the created payment method or error details.
```

--------------------------------

### Iterating Validation Errors in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/errors.md

Demonstrates how to check for operation failure and iterate through all validation errors using DeepAll().

```csharp
var request = new CustomerRequest
{
    Email = "invalid_email"
};

Result<Customer> result = gateway.Customer.Create(request);

if (!result.IsSuccess())
{
    foreach (ValidationError error in result.Errors.DeepAll())
    {
        Console.WriteLine("Field: " + error.Attribute);
        Console.WriteLine("Code: " + error.Code);
        Console.WriteLine("Message: " + error.Message);
    }
}
```

--------------------------------

### Search for customers in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/CustomerGateway.md

Uses a search delegate to filter customers based on specific criteria like name or creation date.

```csharp
var customers = gateway.Customer.Search(search =>
{
    search.FirstName().StartsWith("John");
    search.CreatedAt().Between(startDate, endDate);
});

foreach (Customer customer in customers.Fetch(0, 100))
{
    Console.WriteLine(customer.Id);
}
```

--------------------------------

### Create a Credit Transaction in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/TransactionGateway.md

Issues a refund to a customer's original payment method.

```csharp
var request = new TransactionRequest
{
    Amount = 50.00M,
    PaymentMethodNonce = "nonce_from_client"
};

Result<Transaction> result = gateway.Transaction.Credit(request);
```

--------------------------------

### Search and Paginate Resources

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/README.md

Search for resources and iterate through paginated results using ResourceCollection.

```csharp
var transactions = gateway.Transaction.Search(search => 
{
    search.Status().Is(TransactionStatus.SETTLED);
});

foreach (Transaction txn in transactions.Fetch(0, 50))
{
    // Process transaction
}
```

--------------------------------

### Search and Paginate Transactions

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/workflow-patterns.md

Shows how to filter transactions using search criteria and iterate through paginated results.

```csharp
// Search transactions
var transactions = gateway.Transaction.Search(search =>
{
    search.Status().Is(TransactionStatus.SETTLED);
    search.CreatedAt().Between(
        DateTime.Now.AddMonths(-1),
        DateTime.Now
    );
    search.Amount().Between(100M, 500M);
});

// Paginate results
int pageSize = 100;
int totalProcessed = 0;

foreach (Transaction txn in transactions.Fetch(0, pageSize))
{
    Console.WriteLine(txn.Id + ": $" + txn.Amount);
    totalProcessed++;
}

Console.WriteLine("Processed " + totalProcessed + " transactions");
```

--------------------------------

### Iterate Over ResourceCollection

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/types.md

Use the Fetch method to retrieve specific pages of items from a resource collection.

```csharp
var customers = gateway.Customer.All();
foreach (Customer customer in customers.Fetch(0, 100))
{
    Console.WriteLine(customer.Id);
}
```

--------------------------------

### Lookup Method Signatures

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/ThreeDSecureGateway.md

Synchronous and asynchronous method signatures for performing a 3D Secure lookup.

```csharp
public virtual Result<ThreeDSecureLookup> Lookup(ThreeDSecureLookupRequest request)
public virtual async Task<Result<ThreeDSecureLookup>> LookupAsync(ThreeDSecureLookupRequest request)
```

--------------------------------

### Find Payment Method

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/PaymentMethodGateway.md

Retrieves a payment method by its token. Throws a NotFoundException if the token does not exist.

```csharp
public virtual PaymentMethod Find(string token)
public virtual async Task<PaymentMethod> FindAsync(string token)
```

```csharp
PaymentMethod method = gateway.PaymentMethod.Find("payment_method_token");
Console.WriteLine("Type: " + method.GetType().Name);
```

--------------------------------

### Authorize and Settle Transactions in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/workflow-patterns.md

Workflow for capturing funds after an initial authorization. Useful for scenarios where settlement must wait for order fulfillment.

```csharp
// Step 1: Authorize transaction (does not charge yet)
var authRequest = new TransactionRequest
{
    Amount = 100.00M,
    PaymentMethodNonce = "nonce",
    Options = new TransactionOptionsRequest
    {
        SubmitForSettlement = false  // Just authorize, don't settle yet
    }
};

Result<Transaction> authResult = gateway.Transaction.Sale(authRequest);
if (!authResult.IsSuccess())
{
    // Handle authorization failure
    return;
}

string transactionId = authResult.Target.Id;
Console.WriteLine("Authorized: " + transactionId);

// Step 2: Perform some operation (prepare shipment, etc.)
// ...

// Step 3: Submit for settlement (after shipment)
Result<Transaction> settleResult = gateway.Transaction.SubmitForSettlement(transactionId);
if (settleResult.IsSuccess())
{
    Console.WriteLine("Settled: " + settleResult.Target.Status);
}
```

--------------------------------

### Execute Sale with Payment Nonce in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/workflow-patterns.md

Standard flow for processing a transaction using a client-side generated nonce. Requires a client token generated on the server and optional device data for fraud protection.

```csharp
// Server: Create client token
string clientToken = gateway.ClientToken.Generate();
// Send clientToken to client

// Client: Generate payment nonce via JavaScript SDK
// var nonce = result.nonce; // from Drop-in UI or Hosted Fields

// Server: Create transaction with nonce
var request = new TransactionRequest
{
    Amount = 100.00M,
    PaymentMethodNonce = "nonce_from_client",
    Options = new TransactionOptionsRequest
    {
        SubmitForSettlement = true  // Automatically submit for settlement
    },
    DeviceData = "device_data_from_client",  // Optional fraud tools data
    OrderId = "order_123"
};

Result<Transaction> result = gateway.Transaction.Sale(request);

if (result.IsSuccess())
{
    Transaction transaction = result.Target;
    Console.WriteLine("Transaction ID: " + transaction.Id);
    Console.WriteLine("Status: " + transaction.Status);
    
    // Transaction is settled if SubmitForSettlement was true
}
else if (result.Transaction != null)
{
    // Processor declined or gateway rejected
    Console.WriteLine("Status: " + result.Transaction.Status);
    Console.WriteLine("Code: " + result.Transaction.ProcessorResponseCode);
    Console.WriteLine("Text: " + result.Transaction.ProcessorResponseText);
}
else
{
    // Validation errors
    foreach (ValidationError error in result.Errors.DeepAll())
    {
        Console.WriteLine(error.Attribute + ": " + error.Message);
    }
}
```

--------------------------------

### Verify(string challenge)

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/WebhookNotificationGateway.md

Verifies a webhook challenge string and returns the verification response.

```APIDOC
## Verify(string challenge)

### Description
Verifies a webhook challenge string and returns the verification response.

### Parameters
- **challenge** (string) - Required - Challenge string from Braintree (hex-encoded, 20-32 chars)

### Returns
- **string** - Challenge response in format "public_key|digest"

### Throws
- **InvalidChallengeException** - if challenge format is invalid
```

--------------------------------

### SubmitForSettlement Method Signatures

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/TransactionGateway.md

Defines the synchronous and asynchronous methods for submitting authorized transactions for settlement.

```csharp
public virtual Result<Transaction> SubmitForSettlement(string id)
public virtual Result<Transaction> SubmitForSettlement(string id, decimal amount)
public virtual Result<Transaction> SubmitForSettlement(string id, TransactionRequest request)
public virtual async Task<Result<Transaction>> SubmitForSettlementAsync(string id)
public virtual async Task<Result<Transaction>> SubmitForSettlementAsync(string id, decimal amount)
public virtual async Task<Result<Transaction>> SubmitForSettlementAsync(string id, TransactionRequest request)
```

--------------------------------

### ReleaseFromEscrow

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/SubscriptionGateway.md

Releases a subscription payment from escrow.

```APIDOC
## ReleaseFromEscrow(string id)

### Description
Releases a subscription payment from escrow.

### Parameters
- **id** (string) - Required - Subscription identifier

### Returns
- **Result<Subscription>** - Result containing the subscription
```

--------------------------------

### Manage Subscriptions

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/QUICK_REFERENCE.md

Create, find, update, and cancel recurring billing subscriptions.

```csharp
// Create subscription
Result<Subscription> result = gateway.Subscription.Create(new SubscriptionRequest
{
    PlanId = "plan_id",
    PaymentMethodToken = "token"
});

// Find subscription
Subscription sub = gateway.Subscription.Find("subscription_id");

// Update subscription
Result<Subscription> update = gateway.Subscription.Update("subscription_id", new SubscriptionRequest
{
    Price = 39.99M
});

// Cancel subscription
Result<Subscription> cancel = gateway.Subscription.Cancel("subscription_id");
```

--------------------------------

### Search Subscriptions in C#

Source: https://github.com/braintree/braintree_dotnet/blob/master/_autodocs/api-reference/SubscriptionGateway.md

Queries subscriptions based on specific criteria using a search delegate. Returns a paginated collection of results.

```csharp
var subscriptions = gateway.Subscription.Search(search =>
{
    search.PlanId().Is("plan_id");
    search.Status().IncludedIn(
        Subscription.Status.ACTIVE,
        Subscription.Status.PENDING
    );
    search.DaysPastDue().Min(0);
});

foreach (Subscription sub in subscriptions.Fetch(0, 50))
{
    Console.WriteLine("ID: " + sub.Id + ", Status: " + sub.Status);
}
```