Coinbase .NET Core Library

Overview

The Coinbase .NET Core Library (CoinbaseSdk.Core) is the foundational building block for Coinbase .NET SDKs. It provides a standardized, robust, and thread-safe infrastructure for building API clients, handling authentication, HTTP communication, and serialization.

This library is primarily intended for internal use by Coinbase SDKs but is also available for advanced users building custom integrations requiring a standardized base.

Key Features

• Base Client Architecture: Abstract CoinbaseClient managing request lifecycles with extensible hooks (BuildRequest, ConfigureRequest, ValidateResponse).
• Resilient HTTP Communication: Wrapper around System.Net.Http.HttpClient with built-in Polly retry policies for transient failure handling.
• Robust Serialization: JsonUtility wrapper around System.Text.Json featuring:
  • NullOnUnknownEnumConverter: Graceful handling of new/unknown enum members.
  • UtcIso8601DateTimeOffsetConverter: Standardized ISO-8601 date/time processing.
  • Thread-safe initialization using Lazy<T>.
• Centralized Configuration: HttpClientDefaults and RetryPolicyDefaults ensuring consistent default behavior across SDKs.
• Standardized Error Handling: Hierarchy of exceptions (CoinbaseException, CoinbaseClientException) for uniform error reporting.

HTTP Client & Retries

The library uses SystemNetHttpClient to execute requests. By default, it performs a single attempt. You can enable retries using CallOptions, which leverages Polly's decorrelated jitter backoff strategy to handle transient failures (like rate limits or 5xx errors) without causing retry storms.

Retries can be configured at two levels:

1. Per-Client: Set default behavior for all requests made by a client instance.
2. Per-Request: Override behavior for a specific API call.

Configuration Examples

Per-Request Configuration:

var callOptions = new CallOptions
{
    MaxRetries = 2,
    ShouldRetryOnStatusCodes = true,
    RetryableStatusCodes = new HashSet<HttpStatusCode> { HttpStatusCode.TooManyRequests }
};

// options are passed to the SendRequestAsync method
var response = await client.SendRequestAsync<MyResponse>(..., callOptions);

Per-Client Configuration:

var httpClient = new SystemNetHttpClient(
    defaultCallOptions: new CallOptions
    {
        MaxRetries = 3,
        ShouldRetryOnStatusCodes = true,
        RetryableStatusCodes = new HashSet<HttpStatusCode> { HttpStatusCode.TooManyRequests }
    });

var client = new MyCoinbaseClient(credentials, httpClient: httpClient);

Retry Configuration Options

Option	Default	Description
MaxRetries	0	Maximum number of retry attempts (0 disables retries).
MedianFirstRetryDelay	500ms	Target median delay for the first retry (subject to jitter).
MaxRetryDelay	1s	Maximum delay cap for any retry attempt.
ShouldRetryOnStatusCodes	false	Whether to retry on specific HTTP status codes.
RetryableStatusCodes	empty	Set of status codes to retry (e.g., 429, 503).

Note: Retry attempts honor the CancellationToken provided to the request. If canceled, pending retries are aborted.

Installation

dotnet add package CoinbaseSdk.Core

License

This project is licensed under the Apache License, Version 2.0.