API BRICKS SDK is a C#-based collection of client SDKs and data-processing samples for the CoinAPI and FinFeedAPI product families, released under the MIT licence for developers who need to consume cryptocurrency market data, exchange rates, indexes, execution management, stock, SEC and prediction-market feeds from their own applications.

What it is

API BRICKS SDK is a single repository that bundles the vendor-supplied software development kits and sample code for two commercial data product families. The coinapi family covers the CoinAPI Market Data API across REST, WebSocket and FIX protocols, the Execution Management System through an EMS Cloud Management SDK for managed cloud REST access plus EMS Gateway REST and FIX SDKs, the Indexes API and the Exchange Rates API in REST and WebSocket variants, and a set of Flat Files API processing samples for GZIP+CSV data. The finfeedapi family covers the FinFeedAPI Stock API, SEC API, Currencies Realtime API, Currencies Historical API and Prediction Markets API, all exposed over REST.

The concrete problem it solves is the integration work that normally sits between an application and a market data vendor. Without it, a C# team consumes raw REST endpoints, maintains its own WebSocket or FIX session handling, and writes bespoke parsing for compressed historical dumps. This repository supplies generated client libraries for each endpoint family and, in the case of the Flat Files API, working examples for the GZIP+CSV format, so the transport and deserialisation layers come from the repository rather than from each consuming team. It sits in the C# and .NET tooling ecosystem, next to the vendor documentation hubs rather than inside any general-purpose package registry.

Key capabilities

• Market Data API SDK covering REST, WebSocket and FIX connectivity to CoinAPI market data.
• EMS Gateway SDKs in both REST/WS and FIX forms, plus the EMS Cloud Management SDK for the managed cloud REST API.
• Indexes API and Exchange Rates API SDKs, each available in REST and WebSocket variants.
• Flat Files API processing samples demonstrating work with GZIP+CSV historical files.
• FinFeedAPI SDKs for Stock API, SEC API, Currencies Realtime API, Currencies Historical API and Prediction Markets API, all REST-based.
• Directory layout mirroring the product catalogue, for example coinapi/market-data-api-rest, coinapi/ems-api-fix, finfeedapi/sec-api-rest and finfeedapi/currencies-api-rest-historical.
• MIT-licensed source, with 532 stars, 195 forks and 16 open issues.

Who uses it and how

• C# trading and market-data developers who need CoinAPI feeds inside an existing .NET application and prefer a shipped client over hand-written HTTP calls.
• Teams requiring low-latency streaming, where the WebSocket and FIX SDKs under coinapi/market-data-api-* are the relevant entry points.
• Quantitative and data engineering groups that load historical cryptocurrency datasets, using the GZIP+CSV flat-file processing samples as a starting pattern.
• Fintech and financial-data developers working on the equities and filings side, who use the finfeedapi Stock API and SEC API SDKs.
• Back-office and analytics teams that need reference data such as exchange rates or indexes, selecting from the REST or WebSocket Exchange Rates SDK directories.

Getting started

The README does not publish an install command, NuGet package name, Docker image or compose file; it directs readers to clone the repository, pick the subdirectory for the target API and consult the CoinAPI documentation hub at docs.coinapi.io or the FinFeedAPI hub at docs.finfeedapi.com for usage detail.

How it compares

No list of paid products that this project replaces is provided, and the facts name no comparable open-source SDK collections. It therefore stands alone in this registry.

When to use it — and when not to

Choose it when the target stack is C# and the data sources are CoinAPI or FinFeedAPI, because the repository is a direct vendor client rather than a general abstraction. Avoid it if the project is written in another language, since only C# SDKs are present, and treat the README as incomplete: it contains no build or install instructions, describes some directory purposes as "TBC" or "potentially redundant", and lists overlapping exchange-rates-api paths that a reader must disambiguate. Teams expecting a maintained changelog or per-package release notes will need the vendor documentation hubs instead.