Market Data - Starter Guide

Welcome to the CoinAPI developer documentation. This document should contain all the information required to properly implement applications using our API.

Overview of the APIs

3 main interfaces can be used to access CoinAPI:

API	Data	Communication	Description
RESTful	Live and Historical	Request-response	Stateless API provides the widest range of data, not capable of streaming, only pooling.
WebSocket V1	Live	Publish-subscribe	Stateful API providing streaming of real-time market data. Using a single connection, clients are able to subscribe to multiple data sources.
WebSocket DS	Live	Publish-subscribe	Newly introduced, stateful API providing streaming of real-time market data with direct connections to each data source for optimized performance and reliability.
FIX	Live	Publish-subscribe	Stateful API providing streaming of real-time market data, widely adopted by the finance industry. Using single connection client is able to subscribe to multiple data sources.

Comparison: REST vs. Streaming Protocols (WebSocket & FIX)

Understanding the differences between REST and streaming protocols like WebSocket and FIX is essential for developers when designing and implementing financial applications. Here's a detailed comparison to guide your choice.

Feature	REST API	WebSocket & FIX
Communication Model	Request-response model, where the client sends a request and the server responds	Continuous, bidirectional communication allowing for real-time data streaming
Use Case	Ideal for operations that do not require real-time updates, such as retrieving historical data	Suited for applications requiring real-time market data updates and trading operations
Complexity	Generally simpler to implement due to the stateless nature of HTTP requests	More complex due to the need for handling continuous connections and real-time data management
Data Freshness	Data is only as fresh as the last request made by the client	Data is continuously updated in real-time, providing the latest market information
Scalability	Can be more easily scaled using standard web infrastructure	Scaling requires careful management of connection resources and data throughput
Latency	Higher latency due to the overhead of making HTTP requests	Lower latency, optimized for real-time data delivery and trading activities
State Management	Stateless, with each request being independent	Stateful, maintaining a continuous connection state

Key Takeaways

• REST API is straightforward and effective for operations that can tolerate the latency inherent in the request-response model. It's widely used for accessing historical data, account management, and other non-time-sensitive operations.
• WebSocket & FIX are tailored for real-time applications, such as live market data feeds, trading platforms, and other scenarios where immediate data access is crucial. They offer lower latency and continuous data streams but come with added complexity in implementation and resource management.

Choosing between REST and streaming protocols depends on your application's specific needs regarding data freshness, real-time updates, and the complexity you're prepared to manage.

Comparison: WebSocket APIs vs. FIX API

Understanding the differences between WebSocket APIs (both V1 and DS) and the FIX API is crucial for developers and financial institutions looking to integrate real-time market data and trading capabilities. Here's a detailed comparison to guide your choice.

Feature	WebSocket APIs	FIX API
Protocol Nature	Publish-subscribe model, designed for real-time data streaming	Session-based protocol, widely used for trading and order management
Use Case	Best suited for applications requiring real-time market data updates	Primarily used for trading, order submission, and execution reports
Complexity	Relatively simple to implement and use	More complex due to its extensive use in trading operations
Data Types	Primarily focused on market data (quotes, trades, book data)	Supports a wide range of financial information including order entries, executions, and market data
Latency	Low latency, especially with WebSocket DS API optimized for high-frequency data	Generally low latency, with performance depending on the implementation and network infrastructure
Reliability	High reliability with TCP-based delivery ensuring message order and integrity	Extremely high reliability and considered the industry standard for trading activities
Authorization	HTTP based authorization methods	Uses session-based logins with possible additional security measures
Flexibility	High flexibility in subscribing to specific data types and exchanges	High degree of customization and control over trading operations and data exchange

Key Takeaways

• WebSocket APIs are ideal for applications that require efficient, real-time access to market data. They offer simplicity in implementation and flexibility in data subscription, making them suitable for a wide range of applications beyond trading, such as analytics and monitoring tools.
• FIX API is the go-to protocol for trading operations, offering robustness, reliability, and a wide range of functionalities tailored to the needs of traders and financial institutions. Its complexity and capabilities make it the standard for order management and execution in the financial industry.

Choosing between WebSocket APIs and the FIX API depends on your specific requirements, whether you're focusing on real-time data streaming for various applications or engaging in complex trading operations.

Comparison: WebSocket V1 vs. WebSocket DS API

When choosing between WebSocket V1 and WebSocket DS API, it's important to understand their key differences and how they cater to different needs. Here's a comparison to help you decide which API suits your project requirements better.

Feature	WebSocket V1 API	WebSocket DS API
Connection Type	Possible to acquire the data from multiple data sources using single connection	Separate data sources need separate connection
Routing	GeoDNS for regional routing to nearest infrastructure	Optimized DNS for more direct connection per specific data source
Data types	trade, quote, orderbooks, ohlcv, exchange rates, metadata	trade, quote, orderbooks
Authorization	In protocol authorization, query-string, URL path, header, or JWT	query-string, URL path, header, or JWT
Symbol Filtering	Flexible symbol filtering	Requires precise symbol identifiers for improved data accuracy
Symbology	CoinAPI Symbol identifiers	CoinAPI or Exchange symbols identifiers

Key Takeaways

• WebSocket V1 is versatile and user-friendly, making it suitable for a wide range of applications that require real-time market data.
• WebSocket DS API is tailored for scenarios demanding high data volumes and low latency, such as high-frequency trading platforms. Its direct routing and exchange-specific connections provide a more efficient data stream with reduced latency.

Choosing the right API depends on your specific needs regarding data volume, latency sensitivity, and the complexity of your data subscription requirements. Both APIs continue to be supported, ensuring that you can select the one that best fits your project's needs.

SDK

Our Software Development Kit (SDK) is available on GitHub at https://github.com/coinapi/coinapi-sdk. If possible then we are strongly recommending using our tested libraries available on GitHub, rather than creating new ones. However, if you decide to create your implementation or to change the existing one, then we encourage you to create a Pull Request to our main repository with the proposed changes, we will able to include your code in our official repository for use by other users, effectively creating collaboration.

In the repository, you can find libraries or examples for languages or environments like:

• Python
• R
• Matlab
• C#
• C++
• .NET
• Java
• Ruby
• Go
• JavaScript
• TypeScript
• Node.js
• PHP
• Haskell
• Objective-C
• Swift

Security

The use of encryption is optional, and the decision to use it is on you. On the encrypted endpoints, we are using protocols that are considered the best security practices.

tip

You should assume that we are always providing certificates signed by the Trusted Certification Authority.

Standards and conventions

This section represents used standards and conventions across all documents and API's.

info

The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.

Variables naming

All variables are named using the Snake case (or snake_case) naming convention. This means that words are separated by a single underscore _ character, no spaces are used, and letters are lowercase.

Asset codes

ISO 4217 currency code standard is used for fiat money identifications. Cryptocurrency assets are identified using codes used by the general public or adopted by the majority of exchanges.

Exchange codes

Exchange on our platform is identified by the specific exchange API and the matching engine behind it. When the example exchange has multiple separate APIs, e.g., for different products SPOT, OPTIONS, or to cover other regions, we will expose these symbols from these respective APIs on different exchange identifiers. Below are examples of BINANCE (multiple APIs, multiple regions) and DERIBIT (single API, single region). A full listing of exchanges can be queried using the Market Data REST API.

BINANCE Exchange IDs	Website	Description
BINANCE	https://www.binance.com/	Binance
BINANCEDEX	https://www.binance.org/	Binance DEX
BINANCEFTS	https://www.binance.com/	Binance Futures (USDT/dapi)
BINANCEFTSC	https://www.binance.com/	Binance Futures (Coin/fapi)
BINANCEFTSCUAT	https://www.binance.com/	Binance Futures Testnet (Coin/fapi)
BINANCEFTSUAT	https://www.binance.com/	Binance Futures Testnet (USDT/dapi)
BINANCEJE	https://www.binance.je/	Binance Jersey
BINANCEJEX	https://www.jex.com/en	Binance JEX
BINANCEKR	https://www.binance.kr/	Binance Korea
BINANCEOPTV	https://www.binance.com/	Binance Options Vanilla (vapi)
BINANCEOPTVUAT	https://www.binance.com/	Binance Options Vanilla Testnet (vapi)
BINANCEUAT	https://www.binance.com/	Binance Testnet
BINANCEUG	https://www.binance.co.ug/	Binance Uganda
BINANCEUS	https://www.binance.us/	Binance US

DERIBIT Exchange IDs	Website	Description
DERIBIT	https://www.deribit.com/	Deribit

Numbers precision

Numbers in our platform can have a maximum of 19 digits overall, but no more than 9 decimal places. In cases when the number represents aggregate value then we allow 38 digits overall, but still no more than 9 decimal places.

Time

For all input and output time values ISO 8601 standard is used.

Format specifier	Description
yyyy	The year is a four-digit number.
MM	The month, from 01 through 12.
dd	The day of the month, from 01 through 31.
HH	The hour, using a 24-hour clock from 00 to 23.
mm	The minute, from 00 through 59.
ss	The second, from 00 through 59.
fff	The milliseconds in a date and time value.
fffffff	The ten-millionths of a second in a date and time value.

Input time values are parsed using the following formats as far as possible:

• yyyy-MM-ddTHH:mm:ss.fffffff
• yyyy-MM-ddTHH:mm:ss.fff
• yyyy-MM-ddTHH:mm:ss
• yyyy-MM-ddTHH:mm
• yyyy-MM-ddTHH
• yyyy-MM-dd
• yyyyMMddTHHmmssfffffff
• yyyyMMddTHHmmssfff
• yyyyMMddTHHmmss
• yyyyMMddTHHmm
• yyyyMMddTHH
• yyyyMMdd

info

When time zone information is not supplied, we will assume the UTC zone.

Output time values are formatted using the following patterns:

1. yyyy-MM-ddTHH:mm:ss.fffffffZ
2. yyyy-MM-dd

info

All time values we provide are UTC zones. Do not assume otherwise.

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