Crypto Basics

NFTs Explained: What Are Non-Fungible Tokens?

A definitive guide to explain NFTs, or non-fungible tokens.
Token Metrics Team
7 minutes
MIN

NFTs, or non-fungible tokens, are gaining widespread popularity in the market for digital art and collectibles. In recent years, NFTs have become a cultural phenomenon, attracting the attention of crypto enthusiasts, digital art creators, and celebrities alike. As the Web 3.0 ecosystem continues to grow and adoption increases, many believe that NFTs will play a key role in the ownership of assets online.

So what are NFTs? Let's find out.

‍NFT Basics

NFTs, or non-fungible tokens, are a type of digital asset that represents ownership of something on the blockchain.

NFTs can be anything such as art, collectibles, music, profile pictures or PFP, DAO memberships, event tickets, gaming assets, virtual land, domain names, and so on. They can represent either completely digital assets or tokenized versions of assets that exist in the real world. Currently, there is a lot of excitement around using NFTs to sell virtual art.

Characteristics of NFTs

  • Ownership: NFT represents digital ownership of an item on a blockchain
  • Permanent: NFTs have data permanently stored within the token. This information includes images, messages, signatures, or any other data
  • Programmable: An NFT can be programmed to do anything. For example, an NFT artwork might be programmed to pay the artist royalties on every secondary sale of that artwork
  • Unique: NFTs are unique, and that uniqueness can be confirmed on a blockchain

How to Make an NFT

To create an NFT, or non-fungible token, you will need to first prepare your media file. NFTs can support a wide range of file types, including audio, images, and even 3D files. Some popular file types that are supported by NFTs include MP3, JPG, PNG, and GIF. You can also use 3D file formats like GLB to create NFTs that represent unique, digital objects.

Once your media is ready, you will need to set up a non-custodial wallet to securely store the cryptocurrency that you will use to buy, sell, and create NFTs. Non-custodial wallets are important because they allow you to retain control of your private keys, which are needed to access your cryptocurrency and make transactions. There are many different wallet options available, so it is important to do your research and choose one that is secure and user-friendly.

Once you have set up your wallet, you will need to buy Ethereum, or other fungible tokens depending on the blockchain being used, to cover the cost of minting your NFT. Ethereum is the most commonly used blockchain for NFTs, and it is typically the easiest to get started with. You can buy Ethereum using a variety of methods, including through a cryptocurrency exchange or from other individuals who are willing to sell.

Once you have your Ethereum, you will need to connect your wallet to an NFT marketplace like Rarible or OpenSea. These platforms allow you to easily create and mint your NFT, as well as trade and purchase NFTs created by others. To connect your wallet, simply tap the "Connect" button in the top right corner of the marketplace's website. This will create an account for you on the platform and allow you to begin creating your NFT.

To create your NFT, upload your media file to the platform and provide a description of your asset. You can choose to create a standalone piece, or create multiple NFTs of the same piece, each with its own unique characteristics. You can also set rules around royalties and other aspects of your NFT to ensure that you are fairly compensated for your work.

Once you are ready to mint your NFT, the process will require you to pay a small amount of ETH for transaction fees. This is necessary to get your NFT added to the blockchain and verified as unique. Once your NFT is minted, it will be available for trade and purchase on the marketplace. You can monitor the progress of your NFT and track its sales through your wallet or the marketplace's website.

NFT Secondary Markets

Creators make NFTs using blockchain-based minting platforms to retain more control over their creative output. Once NFTs are minted on a non-custodial wallet-compatible website, collectors and traders can sell these assets on the secondary market.

Here is a list of the most used NFT marketplaces:

  • OpenSea: OpenSea is the first and largest marketplace for NFTs. OpenSea is building tools that allow consumers to trade their items, creators to launch new digital works, and developers to build rich, integrated marketplaces for their digital items. It recently announced the support for Solana-based NFTs.
  • Coinbase NFT: Coinbase, a cryptocurrency exchange, recently launched its NFT marketplace in beta version to the public. This marketplace acts as a social media platform in which users can not only buy and sell NFTs but also interact with and showcase their collections using user profiles, likes, and comments.
  • Solanart: Solanart is the first and largest fully-fledged NFT marketplace on Solana. Users can get quick and easy access to digital collectibles, and explore, buy, and sell NFTs that run on the Solana blockchain.
  • Rarible: Rarible is a do-it-yourself NFT marketplace where you can mint NFTs when and how you please. Creators are highly favorable towards Rarible, as the minting process is free, easy, and unrestricted. Rarible’s native governance token “RARI” is used to incentivize platform users and give the community members a voice.
  • Nifty Gateway: Nifty Gateway is owned by the Gemini crypto exchange and has become one of the most known NFT marketplaces lately. They focus on viral drops from artists like Beeple, Trevor Jones, Pak, and more.
  • SuperRare: SuperRare (SR) is one of Ethereum’s debut crypto-art NFT marketplaces. Artists must be accepted to the platform before they can list their assets.

Notable NFT Projects

NFT-based companies have seen significant growth in recent years. Some notable examples include:

  • Yuga Labs: a blockchain technology company that creates Ethereum-based NFTs and digital collectibles. Yuga's most valuable NFT collection is Bored Ape Yacht Club, which has seen a floor price of over 150 ETH at its all-time high. In addition to apes, Yuga has also created dog NFTs, mutant apes, and deeds for its Metaverse. The company recently acquired Larva Labs, bringing high-value projects like Cryptopunks and Meebits under the Yuga brand. Yuga is backed by investors like Coinbase, Samsung, and Mark Cuban.
  • Doodles: a collection of 10,000 Ethereum-based NFTs created by artist BurntToast. The Doodles collection includes a wide range of visual traits, heads, costumes, and colorways. Owners of Doodles NFTs have exclusive access to new experiences like Space Doodles and Dooplicator.
  • Okay Bears: a collection of 10,000 Solana-based NFTs. Ownership of an Okay Bear grants access to a community of collectors and exclusive products, merchandise, and events.

Investing in NFTs

NFTs, or non-fungible tokens, provide many benefits as an investment vehicle.

One of the main advantages of NFTs is that they allow physical objects, such as artwork, to be tokenized.

Additionally, NFTs offer greater liquidity for investors, making it easier to trade and sell their assets.

The Future of NFTs

NFTs offer a new way to represent and prove ownership of assets on the blockchain.

This technology has already been used for digital art, collectibles, and in-game assets, but it has the potential to be applied to a wide range of other industries as well. For example, tokenized real estate could provide a way for people to invest in property without the barriers to entry that currently exist.

High-end fashion brands like Louis Vuitton have also expressed interest in using NFTs to track the ownership of luxury items.

Additionally, NFTs can be used to tokenize certifications, degrees, and licenses, providing a way to securely track and maintain this sensitive data on the blockchain.

Overall, the potential applications for NFTs are nearly limitless.

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How Crypto APIs Enable Automatic Trade Execution

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Imagine triggering a cryptocurrency trade in milliseconds—automatically, precisely, and on your schedule. Behind much of today’s algorithmic and automated crypto trading lies a powerful tool: the crypto API. But how exactly do APIs let you execute trades, and what are the fundamentals users need to understand before getting started? This guide unpacks the essentials of using crypto APIs for trade execution, including how these interfaces work, real-world applications, risks, and practical integration tips.

What Are Crypto Trading APIs?

APIs, or Application Programming Interfaces, are software intermediaries that enable different applications to communicate. In the context of cryptocurrencies, a crypto trading API allows users, developers, or institutions to connect directly to a crypto exchange’s backend systems. This connection makes it possible to request live data, place and manage orders, check balances, and retrieve trade history—all programmatically.

Common examples include Binance, Coinbase Pro, Kraken, and Bybit APIs, all of which support crucial trading functions. These APIs typically support REST (for single requests) and WebSocket (for real-time updates) protocols. API access levels and capabilities often depend on your account permissions and security settings at the exchange.

How Do You Execute Trades Using a Crypto API?

Executing trades via a crypto API requires a step-by-step process that generally includes:

  1. API Key Generation: Users generate API keys (and often API secrets) through their exchange account dashboard, configuring permissions such as trading and withdrawal rights.
  2. Authentication: Every API request must be securely authenticated, usually with the key/secret and sometimes additional security protocols like IP whitelisting.
  3. Order Placement: By sending properly formatted HTTP requests (e.g., POST /order) or WebSocket messages, users can initiate buy or sell orders. The API parameters define order type, price, amount, and other specifics.
  4. Order Management: Once placed, trades can be monitored, modified, or cancelled via subsequent API commands, allowing for dynamic strategy execution.

These automated processes underpin trading bots, portfolio managers, and sophisticated AI-driven trading agents—turning manual strategies into efficient, round-the-clock executions, all without a traditional front-end user interface.

Real-World Applications of Crypto API Trading

API-based trading is central to a variety of modern crypto workflows, powering:

  • Trading Bots: Automated systems that scan markets and react to pre-programmed signals, sometimes integrating machine learning for strategy optimization.
  • Portfolio Rebalancing: Programmatically adjusting crypto portfolios at set intervals or according to defined thresholds, minimizing manual intervention.
  • Arbitrage: Exploiting price differences between exchanges in real time, something only possible with split-second API commands.
  • Institutional Trading: Large desks and funds use APIs to execute high-frequency strategies, where speed and accuracy are paramount.
  • Custom Dashboards & Alerts: Developers create bespoke monitoring or trading tools that interact with exchange APIs for data, order placement, and notifications.

AI-powered platforms are increasingly integrating advanced analytics and signals directly into their API workflows, letting traders and developers access sophisticated research and data-driven triggers with minimal manual effort. Token Metrics is a notable example of a service blending advanced crypto analytics with API accessibility for builders and traders alike.

Security Best Practices for API-Based Trading

While crypto APIs are powerful, they also introduce unique security considerations:

  • Scope Permissions: Only enable required actions (e.g., trade, read-only) and never allow withdrawal permissions unless absolutely necessary.
  • IP Whitelisting: Restrict API access to only trusted IP addresses.
  • Key Management: Store API secrets securely, using encrypted environment variables or dedicated key management services.
  • Monitor Usage: Regularly audit API logs to identify unauthorized or suspicious activity promptly.
  • Rotate Keys: Periodically regenerate and update API keys and secrets as a precautionary measure.

Responsible API usage helps minimize exposure to hacking, credential leaks, or account abuse—especially as trading volumes and automation scale.

Getting Started with Crypto Trading APIs

To integrate and utilize a crypto trading API effectively:

  • Choose your exchange(s): Research exchanges supporting the required API features, such as order types, rate limits, and supported assets.
  • Read API Documentation: Exchange documentation details request formats, security practices, error handling, and best practices.
  • Code Your Integration: Use supported programming languages (such as Python, JavaScript, or Go) along with official SDKs or open-source libraries for streamlined development.
  • Simulate Before Going Live: Many APIs offer sandbox environments for testing. Confirm strategies perform as expected before deploying with real funds.
  • Consider Third-Party Tools: Analytics and trading signal providers, such as Token Metrics, offer APIs that can supplement exchange data with actionable insights for strategy development.

Building with APIs requires a combination of technical skills and operational caution, but unlocks the full potential of programmable trading in crypto markets.

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Can anyone use crypto trading APIs?

Most major crypto exchanges offer trading APIs accessible to users with verified accounts. However, each platform sets its own requirements regarding API access levels, regional restrictions, and compliance, which users should review before starting.

Are crypto trading APIs secure?

Crypto APIs are designed with robust security features, but safety also depends on user practices. Limiting API key permissions, restricting access via IP, and keeping keys private are essential for minimizing risks.

Can I automate trading strategies using APIs?

Yes, APIs are the main mechanism for building automated trading systems (bots) and integrating algorithmic trading strategies. This allows for uninterrupted operation and rapid reaction to market signals based on predefined logic.

What skills do I need to use crypto APIs?

At minimum, familiarity with programming (such as Python or JavaScript), API communication (HTTP/websocket), and basic security practices are required to use crypto APIs effectively and safely.

What are some common limits of crypto APIs?

Most APIs enforce rate limits to control the number of allowed requests within specific time frames. They may also restrict order types or trading pairs and require periodic re-authentication or API key refreshes.

Disclaimer

This article is for informational and educational purposes only. It does not provide investment advice or endorse specific assets, platforms, or trading strategies. Always perform your own research and consult with qualified professionals before making technical or financial decisions related to cryptocurrency trading or API integration.

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Mastering API Rate Limits: Strategies for Developers and Crypto Pros

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APIs power the data-driven revolution in crypto and beyond, but nothing derails innovation faster than hitting a rate limit at a critical moment. Whether you’re building trading bots, AI agents, portfolio dashboards, or research tools, understanding and managing API rate limits is essential for reliability and scalability.

What Are API Rate Limits?

Most API providers, especially in crypto, impose rate limits to protect their infrastructure and ensure fair resource usage among clients. A rate limit defines the maximum number of requests your app can make within a specific timeframe—say, 100 requests per minute or 10,000 per day. Exceeding these limits can result in errors, temporary bans, or even long-term blocks, making robust rate management not just a courtesy, but a necessity for uninterrupted access to data and services.

Why Do Crypto APIs Enforce Rate Limits?

The explosive growth of crypto markets and real-time analytics means data APIs face enormous loads. Providers implement rate limits for several key reasons:

  • Stability: Throttling prevents spikes that could crash servers or degrade performance for all users.
  • Fair Use: It ensures that no single client monopolizes resources, maintaining equal access for everyone.
  • Security: Rate limits help detect and mitigate misuse, such as DDoS attacks or automated scraping.

This is especially critical in crypto, where milliseconds count and data volumes can be extreme. Services like trading execution, real-time quotes, and on-chain analytics all rely on consistent API performance.

Detecting and Interpreting Rate Limit Errors

When your app exceeds rate limits, the API usually responds with a specific HTTP status code, such as 429 Too Many Requests or 403 Forbidden. Along with the status, APIs often return structured error messages detailing the violation, including which limit was breached and when new requests will be allowed.

Common fields and headers to look for:

  • X-RateLimit-Limit: the current quota
  • X-RateLimit-Remaining: requests left in the window
  • X-RateLimit-Reset: UNIX timestamp when quota resets

Proper error handling—such as parsing these headers and logging retry attempts—is the foundation for any robust API integration.

Best Practices for Handling API Rate Limits

Successfully managing API rate limits ensures both smooth user experiences and API provider goodwill. Here are essential best practices:

  1. Understand the Documentation: Review each API’s rate limit policy (per key, user, endpoint, IP, etc.), as these can vary significantly.
  2. Throttle Requests Client-Side: Build in logic to pace outbound traffic, using techniques like token bucket algorithms or leaky buckets to smooth bursty behavior.
  3. Implement Automated Backoff: If you hit a limit, respect the Retry-After or X-RateLimit-Reset values and back off request attempts accordingly.
  4. Aggregate Requests Smartly: Wherever possible, use batch endpoints or design your workflow to minimize redundant calls.
  5. Monitor Usage Analytics: Continuously track API consumption trends to anticipate bottlenecks or the need to request a higher quota.
  6. Graceful Error Handling: Use robust error handling to avoid cascading failures in your application in the event of limit breaches.

The combination of proactive client design and real-time monitoring is the best defense against hitting hard limits, whether you’re scaling a single app or orchestrating a fleet of decentralized AI agents.

Advanced Strategies for Developers and Quant Teams

As your infrastructure grows—handling multiple APIs, high-frequency trading signals, or deep analytics—you’ll need even more sophisticated approaches, such as:

  • Centralized Rate Limiters: Use middleware or reverse proxies (such as Redis-based limiters) to coordinate requests across servers and services.
  • Distributed Queuing: Implement job queues (RabbitMQ, Kafka, etc.) to control throughput at scale, balancing real-time needs against quota constraints.
  • Adaptive Algorithms: Employ dynamic algorithms that adjust polling rates based on remaining quota, market volatility, or business urgency.
  • API Key Rotation: For enterprise cases (where allowed), rotating across authorized keys can help balance traffic and stay within limits.
  • Rate Limit Forecasting: Use analytics and AI modeling to predict traffic bursts and optimize usage proactively—tools like Token Metrics can help analyze trends and automate parts of this process.

Planning for scalability, reliability, and compliance with provider guidelines ensures you remain agile as your crypto project or trading operation matures.

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FAQ: What Happens If I Exceed an API Rate Limit?

Exceeding rate limits typically results in HTTP 429 errors and temporary suspension of requests. Many APIs automatically block requests until your quota resets, so continual violation may lead to longer blocks or even account suspension. Always refer to your provider’s documentation for specifics.

FAQ: How Can I Check My Current API Usage?

Most APIs include custom headers in responses detailing your remaining quota, usage window, and reset times. Some services offer dashboards to monitor usage statistics and set up alerts for approaching quota boundaries.

FAQ: Can I Request a Higher API Rate Limit?

Many API providers, especially paid plans or partners, allow you to request increased quotas. This process often involves contacting support, outlining your use case, and justifying why higher limits are needed.

FAQ: Which Crypto APIs Have Generous Rate Limits?

Rate limits vary widely by provider. Well-established platforms like Token Metrics, Binance, and CoinGecko balance fair access with high-performance quotas—always compare tiers and read docs to see which fits your scale and usage needs.

FAQ: How Does Rate Limiting Affect AI and ML Applications?

For AI/ML models reliant on real-time data (e.g., trading bots, sentiment analysis), rate limiting shapes data availability and latency. Careful scheduling, data caching, and quota awareness are key to model reliability in production environments.

Disclaimer

This content is for educational and informational purposes only. It does not constitute investment, legal, or financial advice of any kind. Crypto services and APIs are subject to provider terms and legal compliance requirements. Readers should independently verify policies and consult professionals as necessary before integrating APIs or automated solutions.

Research

Understanding Public vs Private Crypto APIs: Key Differences Explained

Token Metrics Team
5
MIN

APIs power much of the innovation in the crypto space, but developers and analysts often face a key technical crossroads: Should you use a public or a private crypto API? Each API type serves different use cases and comes with its own set of advantages, limitations, and security requirements. Understanding these differences is critical for building effective crypto platforms, bots, and research tools.

What Are Crypto APIs?

Crypto APIs (Application Programming Interfaces) are sets of rules that let software applications interact with blockchain data, exchanges, wallets, or analytical tools. APIs bring order to a decentralized landscape, making it possible to access real-time prices, submit transactions, retrieve on-chain activity, or gather analytics—often without manually interacting with the blockchain itself.

There are two primary categories of crypto APIs:

  • Public APIs – Open, broadly accessible interfaces providing non-sensitive data or public blockchain information.
  • Private APIs – Restricted endpoints requiring authentication and permissions, allowing access to user-specific or sensitive operations.

But how do these two categories truly differ, and why does it matter for crypto application development and data consumption?

Public Crypto APIs: Open Access to Blockchain Data

Public crypto APIs typically provide access to information that is either non-sensitive or already visible on public blockchains. Examples include:

  • Market prices and trading volume
  • Blockchain explorer data (transactions, blocks, network statistics)
  • Token metadata and listings
  • General protocol or exchange status

Key traits of public APIs:

  • No login required: Most public APIs are accessible without authentication, although rate limits may be enforced to prevent abuse.
  • Great for data feeds: Ideal for researchers, portfolio trackers, or analytics dashboards needing large-scale, up-to-date datasets.
  • Limited functionality: Public APIs do not let you interact with personal accounts, make trades, or perform actions that expose user data.

For instance, if you want to build a website displaying the latest Bitcoin price or trending DeFi projects, you’d usually rely on public crypto APIs.

Private Crypto APIs: Secure, Authenticated Endpoints

Private crypto APIs open the door to more sensitive and powerful functionality, but require strict controls. They are generally used for:

  • Accessing user-specific account balances
  • Placing, modifying, or cancelling trades on an exchange
  • Transferring funds or managing API keys
  • Retrieving private analytics, custom watchlists, or signals

Key characteristics include:

  • Authentication required: Commonly via API keys, OAuth tokens, or signatures. This protects user data and controls access.
  • Security and privacy orientations: Implemented with strict rate limiting, encryption in transit, and granular permissions.
  • Risk of exposure: Poorly managed private keys or API credentials can lead to loss of control over accounts or assets.

Developers building personal portfolio management tools, automated trading bots, or custodial dashboards integrate private crypto APIs to enable a customized, authenticated user experience.

Key Differences: Public vs Private Crypto APIs

Understanding the distinctions helps teams design more robust crypto products:

  • Access & Security: Public APIs are low-risk and have minimal restrictions, whereas private APIs can expose user or financial data if mishandled.
  • Rate Limiting: Public APIs have moderate limits to ensure fair usage, while private endpoints often get higher quotas based on trust and verification.
  • Functional Scope: Public endpoints only relay general data; private endpoints enable actionable operations like trading or transferring assets.
  • Use Case Alignment: Public APIs suit real-time charts, analytics, and research, while private APIs drive account-specific dashboards, bots, and custom integrations.

The choice often comes down to your project requirements: If you just need publicly available blockchain data or market feeds, public APIs suffice. If your solution needs to modify user data or interact on behalf of a user, private APIs with strong authentication are mandatory.

Choosing the Right API for Secure Crypto Development

Several factors help determine whether a public or private crypto API is appropriate:

  1. Data Sensitivity: Is the data or action user-specific or can it be safely shared with the public?
  2. Application Purpose: Are you building an analytics dashboard (public API) or a trading bot (private API)?
  3. Security Posture: Does your team have processes for securely storing and rotating API keys?
  4. API Provider Reputation: Evaluate available documentation, historical uptime, and support—especially with private APIs.

Following best practices for handling API credentials—such as storing secrets off-chain, using environment variables, and enforcing minimal permission scopes—can greatly reduce risk.

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Frequently Asked Questions: Public vs Private Crypto APIs

What can I build with public crypto APIs?

Public crypto APIs help developers launch apps like price tickers, market dashboards, blockchain explorers, and analytics tools that require broadly accessible, non-sensitive data. They are ideal for gathering real-time feeds or tracking on-chain activity without user authentication.

How do private crypto APIs handle security?

Private crypto APIs protect endpoints with authentication mechanisms like API keys, OAuth, or digital signatures. This ensures only authorized clients can fetch sensitive information or perform actions like trading or withdrawals. API providers also employ rate limits and monitor usage for suspicious behavior.

Are rate limits different for public vs private APIs?

Yes. Public APIs often have stricter rate limits to prevent abuse, since anyone can access them. Private API users, once authenticated, may receive higher quotas, prioritizing account-specific operations.

What are the risks of using private API keys in crypto?

Exposed, leaked, or improperly stored private API keys can allow malicious actors to access accounts, make unauthorized trades, or withdraw funds. Always use environment variables, restrict permissions, and rotate keys periodically.

How do I choose the best crypto API provider?

Look for reliability, comprehensive documentation, secure authentication, supportive developer communities, and transparent pricing. Solutions like Token Metrics combine robust data coverage and AI-powered insights for flexible crypto app development.

Disclaimer

This article is for informational purposes only and does not constitute financial or investment advice. Always perform your own research and implement strong security practices when developing crypto applications or integrating APIs.

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