Crypto Basics

What is a Hard Fork and How Does it Work?

Discover what a hard fork is and how it works in blockchain technology. Learn about its impact and implementation in this comprehensive guide
S. Vishwa
5 Minutes
MIN

In the world of blockchain technology, a hard fork refers to a significant and radical change in a network's protocol. This change results in the creating of two separate branches, one following the previous protocol and the other following the new version. 

Unlike a soft fork, which is a minor upgrade to the protocol, a hard fork requires all nodes or users to upgrade to the latest version of the protocol software.

Understanding Blockchain and Forks

Before delving into hard forks, it's important to understand the basics of blockchain technology. A blockchain is a decentralized digital ledger that records transactions and other events in a series of blocks. 

Each block contains data and a set of instructions, known as protocols, which dictate how the blockchain network functions. Because a blockchain is decentralized, any changes to its protocol need to be voted on and approved by its community of users. 

When developers propose major changes or disagreements arise regarding the development of a blockchain, a hard fork may be initiated to create a new and separate blockchain.

How Does a Hard Fork Work?

When a hard fork occurs, the new version of the blockchain is no longer compatible with older versions. This creates a permanent divergence from the previous version of the blockchain. 

The new rules and protocols implemented through the hard fork create a fork in the blockchain, with one path following the upgraded blockchain and the other path continuing along the old one.

Miners, who play a crucial role in verifying transactions and maintaining the blockchain, must choose which blockchain to continue verifying. Holders of tokens in the original blockchain will also be granted tokens in the new fork. 

However, it's important to note that the old version of the blockchain may continue to exist even after the fork, potentially with security or performance flaws that the hard fork aimed to address.

Reasons for Hard Forks

Developers may implement a hard fork for various reasons. One common motivation is to correct significant security risks found in older versions of the software. 

Hard forks can also introduce new functionality or reverse transactions, as seen in the case of the Ethereum blockchain's hard fork to address the hack on the Decentralized Autonomous Organization (DAO).

In 2016, the Ethereum community unanimously voted in favor of a hard fork to roll back transactions that resulted in the theft of millions of dollars worth of digital currency. 

The hard fork allowed DAO token holders to retrieve their funds through a newly created smart contract. While the hard fork did not undo the network's transaction history, it enabled the recovery of stolen funds and provided failsafe protection for the organization.

Examples of Hard Forks

Hard forks have occurred in various blockchain networks, not just in Bitcoin. Bitcoin itself has witnessed several notable hard forks. 

In 2014, Bitcoin XT emerged as a hard fork to increase the number of transactions per second that Bitcoin could handle. However, the project lost interest and is no longer in use.

Another significant hard fork in the Bitcoin ecosystem took place in 2017, resulting in the creation of Bitcoin Cash. 

The hard fork aimed to increase Bitcoin's block size to improve transaction capacity. Subsequently, in 2018, Bitcoin Cash experienced another hard fork, leading to the emergence of Bitcoin Cash ABC and Bitcoin Cash SV.

Ethereum, another prominent cryptocurrency, also underwent a hard fork in response to the DAO hack mentioned earlier. The fork resulted in the creation of Ethereum Classic, which maintained the original blockchain and the updated Ethereum network.

Pros and Cons of Hard Forks

Hard forks offer several benefits to blockchain networks. They can address security issues, enhance the performance of a blockchain, and introduce new features or functionalities. 

Hard forks also provide an opportunity for participants in a blockchain community to pursue different visions for their projects and potentially resolve disagreements.

However, hard forks also come with disadvantages. They can confuse investors when a new but similar cryptocurrency is created alongside the original. 

Furthermore, hard forks may expose blockchain networks to vulnerabilities, such as 51% attacks or replay attacks. Additionally, the existence of the old version of the blockchain after a hard fork may lead to security or performance flaws that the fork aimed to fix.

Hard Forks vs. Soft Forks

While hard forks create two separate blockchains, soft forks result in a single valid blockchain. In a soft fork, the blockchain's existing code is updated, but the old version remains compatible with the new one. 

This means that not all nodes or users need to upgrade to the latest version of the protocol software. The decision to implement a hard fork or a soft fork depends on a blockchain network's specific goals and requirements. 

Hard forks are often favored when significant changes are necessary, even if a soft fork could potentially achieve the same outcome.

Conclusion

Hard forks play a significant role in the evolution of blockchain technology. They allow for radical changes to a network's protocol, creating new blockchains and potential improvements in security, performance, and functionality. 

However, hard forks also come with risks and challenges, such as confusion among investors and possibly exposing blockchain networks to vulnerabilities.

As the blockchain industry continues to evolve, it's essential for investors and stakeholders to stay informed about proposed changes and forks in their cryptocurrency holdings. 

Understanding the implications of hard forks and their potential impact on the value of crypto assets is crucial for navigating this rapidly changing landscape.

Remember, investing in cryptocurrency should be cautiously approached, especially for newcomers who are still learning how blockchain works. Stay updated, do thorough research, and seek professional advice before making investment decisions.

Disclaimer

The information provided on this website does not constitute investment advice, financial advice, trading advice, or any other advice, and you should not treat any of the website's content as such.

Token Metrics does not recommend buying, selling, or holding any cryptocurrency. Conduct your due diligence and consult your financial advisor before making investment decisions.

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Token Metrics Team
Token Metrics Team

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Research

Accessing Historical Crypto Data Using APIs: A Complete Guide

Token Metrics Team
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Understanding price trends and market dynamics is essential for researchers, developers, and analysts working in the cryptocurrency ecosystem. The demand for actionable, reliable historical crypto data has surged as more professionals seek to power apps, AI agents, and dashboards with accurate blockchain information. But how can you easily access robust historical data—from Bitcoin’s early days to today—using an API?

Why Historical Crypto Data Matters

Historical crypto data serves multiple critical roles in the blockchain and digital asset space. It is the foundation for backtesting trading algorithms, visualizing price trends, and conducting academic or business-driven research on market cycles. Given cryptocurrencies’ rapid global growth, time series data helps users:

  • Identify past market regimes and volatility periods
  • Study correlations and performance against traditional assets
  • Evaluate technology adoption over time
  • Build and validate AI models for trend detection

Yet with thousands of coins traded across dozens of exchanges since 2009, acquiring comprehensive, accurate history is challenging without programmatic tools like APIs.

APIs 101: How Crypto Data APIs Work

An Application Programming Interface (API) acts as a bridge, allowing your software to interact with data providers’ servers in real time or on demand. For historical cryptocurrency data, APIs typically offer endpoints for retrieving:

  • Daily or intraday OHLC (Open, High, Low, Close) price candles
  • Tick-by-tick trade data for specified assets
  • Market capitalization, volume, and liquidity history
  • On-chain blockchain activity metrics (transaction count, fees, supply)

Data is returned in structured formats like JSON or CSV, ideal for integration with research notebooks, dashboards, and machine learning pipelines. API providers may cover dozens or hundreds of exchanges, aggregate data, or focus on specific subsets of assets.

Choosing the Right Crypto Data API

With a crowded crypto data landscape, selecting the best API depends on your use case and quality requirements. Consider evaluating providers by:

  1. Coverage: Which coins, tokens, and exchanges are included? Do you need spot or derivatives data?
  2. Granularity & History: Does the API deliver tick-level trades, minute bars, or only daily snapshots? How far back does the data go?
  3. Reliability: Is the data validated and aggregated from trustworthy sources? What is the uptime of the API?
  4. Pricing & Limits: Are there free tiers, rate limits, or tiered plans that support your data needs?
  5. Special Features: Does the API include on-chain data, AI-assisted signals, or example code?

Token Metrics and a few other advanced platforms provide comprehensive coverage alongside AI-driven analytics that can integrate seamlessly with research or engineering workflows.

How to Fetch and Use Historical Data via an API

Fetching crypto history using an API typically involves several common steps:

  1. Sign up with a data provider to obtain your API key
  2. Review API documentation to find relevant endpoints (e.g., /historical/prices)
  3. Send HTTP GET requests (using Python, JavaScript, etc.) with parameters such as asset symbol, time range, and granularity
  4. Parse JSON or CSV responses into your application for visualization or analysis
  5. Respect API rate limits and terms of use

For example, you can retrieve daily Bitcoin OHLC data from a well-documented endpoint and use it in pandas to build price charts, calculate volatility, or feed into a machine learning model. Programmatic access ensures you can automate research, power trading dashboards, or compare assets historically without manual downloads or spreadsheet wrangling.

Leveraging AI and API Tools for Crypto Analysis

Combining robust historical data APIs with AI-powered analytics unlocks new potential for crypto research. Platforms like Token Metrics utilize large datasets not just for presenting history, but for generating intelligence: pattern recognition, trading signals, anomaly detection, and fundamental scoring. By integrating API live feeds with AI models, you can:

  • Detect market regime shifts in real time
  • Build custom alerting and signal-generation bots
  • Enrich dashboards with sentiment, on-chain, and social indicators
  • Support research with up-to-date and historical context

This workflow ensures analysts, quant researchers, and builders can move from raw blockchain data to actionable insights efficiently, while focusing on accuracy and reproducibility.

Build Smarter Crypto Apps & AI Agents with Token Metrics

Token Metrics provides real-time prices, trading signals, and on-chain insights all from one powerful API. Grab a Free API Key

Frequently Asked Questions

What types of historical crypto data can I access with an API?

APIs give you programmatic access to a variety of historical data: price OHLCV (Open, High, Low, Close, Volume), order book snapshots, tick-by-tick trades, market capitalization, on-chain metrics, and more. The granularity and range depend on the specific API provider.

Are there free APIs for historical cryptocurrency data?

Yes, several APIs (including entry-level tiers from advanced providers) offer free endpoints for historical prices and market data. However, free plans may limit data granularity, history depth, or request frequency compared to paid subscriptions.

How far back do most crypto APIs provide historical data?

APIs vary: Bitcoin data typically goes back to 2010, while Ethereum and other major coins cover several years. Full coverage for all coins and smaller assets may depend on the exchange and the API provider’s archival policies.

Can I use historical crypto data APIs for machine learning or AI models?

Absolutely. Clean, granular API feeds are essential for training, validating, and deploying machine learning models for trend detection, price prediction, and anomaly analysis. Many platforms now deliver AI-ready historical crypto data to streamline these workflows.

What programming languages work best for integrating crypto APIs?

Most APIs return data as JSON or CSV, which can be fetched and handled with Python (using requests or httpx packages), JavaScript/TypeScript, Java, or Go. Providers often supply SDKs and code examples for easy onboarding.

Disclaimer

This blog post is provided for educational and informational purposes only. It does not offer investment advice or endorse any specific assets, services, or platforms. Always conduct independent research and review provider documentation before making technical or business decisions related to APIs and crypto data.

Research

How to Find the Most Accurate Crypto Price Data via API

Token Metrics Team
6
MIN

The search for reliable, real-time cryptocurrency price data is a common challenge for developers, analysts, and researchers in the digital asset space. With hundreds of active crypto exchanges and significant price discrepancies across platforms, choosing the right API can make or break your crypto app or data-driven workflow. But which crypto API actually delivers the most accurate price data?

Why Crypto Price Data Accuracy Matters

Whether you're building an app for portfolio tracking, algorithmic trading, DeFi analytics, or AI-powered crypto agents, precision in price feeds is critical. Inaccurate or delayed data can lead to flawed models, missed opportunities, or even compliance issues for institutional players. Since the crypto market is decentralized and fragmented, no single exchange houses the universally accepted price for Bitcoin or any other token. As a result, APIs aggregate data differently—some provide an average price across several exchanges, while others pick a primary source. How an API compiles and updates prices determines its accuracy and reliability.

The Main Types of Crypto Price APIs

Not all crypto price APIs are created equal. Understanding the different types can help you match your needs with the right provider:

  • Single-Exchange APIs: These offer prices directly from their own platform (e.g., Binance API). They deliver real-time trade data but reflect only that exchanges market.
  • Aggregator APIs: Providers like CoinGecko, CoinMarketCap, and Token Metrics collect and average prices from dozens (sometimes hundreds) of exchanges. This approach can minimize outliers and boost overall reliability, but latency or exchange coverage gaps may affect accuracy.
  • Premium APIs: Platforms focused on institutional users (e.g., Token Metrics, Kaiko, CryptoCompare) often offer robust methodologies for handling outliers, wash trading, and thin liquidity. These APIs tend to document their data curation processes more thoroughly.

When choosing a crypto price API, consider whether you need spot pricing, historical data, liquidity-weighted averages, or normalized feeds for your use case.

Evaluating API Price Accuracy: Key Criteria

Comparing API providers involves more than just looking at their exchange list. Here are the most important variables to assess:

  1. Data Sources and Coverage: Does the API include top-tier global exchanges, and how frequently is this list updated as markets evolve?
  2. Aggregation and Calculation Methods: Is the price simply the last trade, a weighted average, or an advanced formula that discounts unreliable exchanges or outliers?
  3. Update Frequency / Latency: How close is the reported price to real-time market activity? Lower latency is crucial for traders and automated agents.
  4. Transparency: Are methodologies documented? Can you verify how average prices are computed or how data integrity is ensured?
  5. Auditability and Error Handling: Does the API have systems to flag and fix suspicious data or sudden anomalies?

Many serious projects also look for compliance features, such as market surveillance and anti-manipulation policies, though this is more relevant for enterprise integrations than hobby projects.

Leading Crypto APIs for Accurate Price Data

Based on public documentation, developer feedback, and recent reliability tests, here are five of the most widely used crypto price APIs and how they address accuracy:

  • Token Metrics API: Offers real-time prices across thousands of cryptocurrencies, with liquidity-weighted methodologies and AI-enhanced outlier detection. Provides transparency through robust API docs and supports custom integrations for advanced users.
  • CoinGecko API: A popular free-to-use aggregator, drawing prices from more than 800 exchanges. Employs volume- and liquidity-weighted averages to offer a reasonably accurate view of the market.
  • CoinMarketCap API: One of the oldest aggregators, it pulls data from major global exchanges, filtering for reliability. Offers both free and paid tiers.
  • CryptoCompare API: Geared towards institutions, with configurable price aggregation formulas and high-tier exchange sources.
  • Kaiko API: Provides institutional-grade data with sophisticated error handling, audit trails, and low-latency feeds—ideal for enterprise AI models and trading systems.

No single provider is the "ultimate source"—trade-offs between speed, coverage, and cost exist. For most AI, DeFi, or advanced analytics projects, combining a trusted aggregator (like the Token Metrics API) with cross-references from single-exchange feeds offers a best-practice approach to price accuracy.

Tips for Using Crypto APIs in Your Projects

To ensure the highest price accuracy in your crypto app or data science workflow, keep these best practices in mind:

  • Cross-Verify Price Feeds: Dont rely on a single API for critical operations. Compare outputs from multiple top providers, especially during volatile market swings.
  • Understand Latency Constraints: Even the fastest APIs can be delayed by network latency or exchange downtime. For algorithmic trading, look for WebSocket feeds over basic REST endpoints.
  • Monitor API Status: Use dashboard tools and status pages to watch for outages or updates to exchange listings, both of which can temporarily affect price accuracy.
  • Leverage AI/ML Tools: Consider APIs that integrate machine learning, not just for data aggregation but also for anomaly detection, order book analytics, and risk reporting.
  • Review Documentation: Always delve into the providers API docs and update policies; transparent documentation signals a commitment to quality.

Ultimately, the API you choose should align with your use case—whether that's an AI-powered agent making split-second decisions, a portfolio dashboard for long-term holders, or a research tool tracking historical price shifts at scale.

Build Smarter Crypto Apps & AI Agents with Token Metrics

Token Metrics provides real-time prices, trading signals, and on-chain insights all from one powerful API. Grab a Free API Key

What is a crypto price API?

A crypto price API is a programmatic interface that allows apps and tools to access up-to-date digital asset price data from exchanges and aggregators. Developers use these APIs to retrieve spot prices, historical data, and market statistics, improving the responsiveness and accuracy of crypto-enabled products.

How do crypto APIs ensure price accuracy?

Most aggregator APIs use liquidity- and volume-weighted averages from multiple exchanges to provide representative prices. Leading providers employ filters to exclude abnormal data, detect outliers, and update the source list regularly to reflect top-performing exchanges. Documentation should always be reviewed for each provider's methodology.

Which API is best for research versus trading?

For research, broad coverage and rich historical data (e.g., CoinGecko, Token Metrics) are important. For trading, prioritized speed, low-latency feeds (such as those from Token Metrics, Kaiko, or direct exchange APIs), and advanced analytics/tooling are key. Many professionals use both types: one for research, and one for live trading signals.

Are free crypto price APIs reliable?

Free APIs can provide reasonably accurate prices, especially for widely traded assets like Bitcoin and Ethereum. However, they may offer lower rate limits, slower updates, or less historical depth than premium options. For critical or business applications, upgrading to a paid plan with greater support and data guarantees is advisable.

How frequently are prices updated on most APIs?

Update frequency varies: some APIs refresh data every few seconds, while others provide real-time data through streaming (WebSocket) feeds. For fast-moving markets, always check the provider's documentation for precise update intervals.

Disclaimer

This article is for informational and educational purposes only and does not constitute financial or investment advice. Always conduct your own research and consult a qualified professional for guidance specific to your situation.

Research

Exploring Crypto APIs: Types of Data You Can Access

Token Metrics Team
4
MIN

The explosion of digital assets has fueled a new era of on-demand data analysis, making crypto APIs essential for enthusiasts, developers, and analysts alike. But what kinds of information can you actually unlock using a crypto API, and how can this data power smarter apps or research?

Real-Time Crypto Prices and Market Snapshots

One of the most popular uses for a crypto API is accessing real-time pricing data. APIs enable you to pull the latest prices for thousands of cryptocurrencies across multiple exchanges instantly. This information is foundational for market analysis, digital asset tracking, and powering portfolio dashboards.

  • Spot Prices: The current buy and sell price for a cryptocurrency.
  • Volume: The amount traded within a particular time period.
  • Market Cap: Calculated by multiplying the price by circulating supply.
  • Highs/Lows: Highest and lowest prices over different intervals (e.g., 24-hour range).

Most leading APIs, such as the Token Metrics API, offer live pricing feeds for efficient decision-making and data integration.

Deep-Dive: Historical Price and Volume Data

Reliable historical data is key to uncovering trends, backtesting strategies, and building machine learning models. Crypto APIs typically allow you to pull:

  • Tick-level Data: Every trade or price change, often down to milliseconds.
  • OHLCV Data: Open, High, Low, Close, Volume over set intervals (minute, hour, day, etc.).
  • Aggregated Statistics: Average prices, moving averages, and other calculated metrics.

Historical endpoints help quant researchers and developers build accurate visualizations and statistical models. For instance, analyzing 365 days of closing prices can reveal volatility patterns or market cycles.

Order Book Depth and Market Liquidity Insights

Order book data provides the pulse of live trading activity, revealing granular details about market depth and liquidity. With a crypto API, you can access:

  • Bid/Ask Orders: See active buy (bid) and sell (ask) orders, including sizes and prices.
  • Order Book Snapshots: Full snapshots of orders at a moment in time or real-time streaming updates.
  • Depth Charts: Visualize how deep the market is at different price levels.

Order book access is crucial for algorithmic trading, slippage estimates, and evaluating liquidity. Some APIs even support aggregated order books across several exchanges for more complete market intelligence.

Live Trades, Transactions, and Ticker Data

In addition to static prices, many crypto APIs deliver real-time trade and ticker data. This includes:

  • Ticker Streams: Continuous feeds of price and volume changes for multiple assets.
  • Trades Feed: A chronological record of every executed trade—useful for volume analysis and pattern recognition.
  • Trade Metadata: Additional details like trade size, buyer/seller side, and unique trade IDs.

Use cases range from powering trading bots to feeding AI-driven analytics or anomaly detection systems. This granularity allows a deeper understanding of real-time market sentiment.

Access to On-Chain and Blockchain Analytics

Beyond market data, advanced crypto APIs now offer direct access to blockchain or on-chain data. Developers and analysts gain the ability to:

  • Monitor Wallet Balances & Activity: Track transactions, wallet holdings, and token movements.
  • Analyze Smart Contracts: Fetch function calls, execution outcomes, and contract metrics.
  • Identify Network Metrics: Including block times, hash rates, gas fees, and validator stats.

Such on-chain analytics underpin advanced research, compliance processes, and fraud detection strategies. APIs that aggregate insights across multiple blockchains add significant value for multi-asset and multi-chain projects.

Build Smarter Crypto Apps & AI Agents with Token Metrics

Token Metrics provides real-time prices, trading signals, and on-chain insights all from one powerful API. Grab a Free API Key

Frequently Asked Questions

What is the most common data provided by crypto APIs?

Most crypto APIs supply real-time prices, trading volume, order books, and historical price/volume data. Some also cover blockchain transactions and wallet-level insights—useful for a range of research and app development scenarios.

Can I get data from multiple exchanges with one API?

Leading crypto APIs aggregate data from various exchanges, allowing developers and analysts to access consolidated prices, order books, and liquidity. Aggregated APIs minimize discrepancies and broaden coverage.

How far back does historical crypto data go in APIs?

The available historical depth varies; top APIs like Token Metrics offer years of daily price data, with some offering tick-level data spanning months or years. Always review documentation for specific asset or interval support.

Why is programmatic access to crypto data important?

APIs allow for automated retrieval, filtering, and analysis of large datasets—enhancing research, powering trading robots, building dashboards, or supporting AI-driven models with up-to-date, reliable information.

What are practical uses for on-chain data from APIs?

On-chain data enables compliance monitoring, wallet tracking, DeFi analytics, NFT research, contract auditing, and forensic investigations. Modern APIs help analysts and businesses stay agile amid evolving blockchain trends.

Disclaimer

This article is for informational purposes only and does not constitute investment, financial, legal, or tax advice. Cryptocurrency markets are volatile and involve risks. Always conduct your own research before making decisions or building applications based on crypto data.

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