Research

Understanding APIs: How They Work and Why They Matter

APIs let applications communicate, fetch data, and trigger actions. Learn how APIs work, common types, evaluation criteria, and practical steps to integrate them into apps and AI pipelines.
Token Metrics Team
5
MIN

APIs are the invisible glue that connects software, data, and services. Whether you use a weather widget, log into an app with a social account, or power AI agents with external data, APIs make those interactions possible. This guide explains what an API is, how it works, common types, and practical steps to evaluate and use them effectively.

What an API Is — Core Concept

An API (Application Programming Interface) is a set of rules and definitions that lets one software program communicate with another. At a conceptual level, an API defines the inputs, outputs, and behavior expected when you request a resource or action from a service. It abstracts implementation details so developers can use functionality without needing to understand the underlying code.

Key elements:

  • Endpoints: URLs or addresses that expose resources or actions.
  • Requests & Responses: Clients send requests (often HTTP) and receive responses, typically in JSON or XML.
  • Methods/Verbs: Common operations (e.g., GET, POST, PUT, DELETE) indicate intent.
  • Contracts: Documentation specifies parameters, data formats, and error codes.

How APIs Work — Technical Overview

Most modern APIs use web protocols. RESTful APIs use standard HTTP methods and resource-oriented URLs. GraphQL exposes a single endpoint that accepts queries describing exactly what data the client needs. WebSockets and streaming APIs enable persistent connections for real-time updates, and webhooks allow services to push events to registered endpoints.

Practical components developers encounter:

  • Authentication: API keys, OAuth tokens, JWTs, and mutual TLS verify identity and scope access.
  • Rate limits: Protect providers by limiting request frequency; plan for retries and backoff.
  • Versioning: Maintain backward compatibility by versioning endpoints.
  • Schemas: OpenAPI/Swagger and GraphQL schemas document shapes and types to reduce integration friction.

Common API Use Cases and Patterns

APIs power a wide range of applications across industries. Typical use cases include:

  • Data aggregation: Combining price feeds, social metrics, or on-chain data from multiple providers.
  • Microservices: Breaking systems into modular services that communicate over APIs for scalability and maintainability.
  • Third-party integrations: Payments, identity providers, analytics, and cloud services expose APIs for developers to extend functionality.
  • AI and agents: Models use APIs to fetch external context, perform lookups, or execute actions when building intelligent applications.

Evaluating and Using an API — Practical Checklist

Choosing or integrating an API involves technical and operational considerations. Use this checklist when researching options:

  1. Documentation quality: Clear examples, error codes, SDKs, and interactive docs accelerate adoption.
  2. Latency & reliability: Test response times and uptime; review SLAs where applicable.
  3. Security & compliance: Inspect authentication schemes, encryption, data retention, and regulatory controls.
  4. Costs & limits: Understand free tiers, metering, and rate limits to model consumption and budget.
  5. Error handling: Standardized error responses and retry guidance reduce integration surprises.
  6. SDKs and tooling: Official libraries, Postman collections, and CLI tools shorten development cycles.

When testing an API, start with a sandbox or staging environment, use automated tests for core flows, and instrument monitoring for production use. For AI projects, prioritize APIs that offer consistent schemas and low-latency access to keep pipelines robust.

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FAQ: What Is an API?

Q: What is the difference between an API and a library?

A library is a collection of code you include in your project; an API describes interaction rules exposed by a service. Libraries run in-process, while APIs often operate over a network and imply a contract between client and provider.

FAQ: REST vs GraphQL — which to use?

REST is simple and cache-friendly for resource-oriented designs. GraphQL is useful when clients need flexible queries that reduce over- or under-fetching. The choice depends on payload patterns, caching needs, and team expertise.

FAQ: How do API keys and OAuth differ?

API keys are simple tokens tied to an account and scope; OAuth provides delegated access, user consent flows, and finer-grained permissions. For user-authorized actions, OAuth is typically preferable.

FAQ: Are public APIs secure?

Security depends on provider implementation. Public APIs can be secure when they enforce authentication, use HTTPS, validate inputs, and apply rate limiting. Always follow security best practices and assume any external interface could be targeted.

FAQ: Can APIs be used for real-time data?

Yes. Streaming APIs, WebSockets, server-sent events, and publish/subscribe webhooks deliver real-time data. Evaluate connection limits, reconnection logic, and message ordering guarantees for production systems.

FAQ: What is an SDK and why use one?

An SDK (Software Development Kit) wraps API calls in language-specific code, handling authentication, retries, and serialization. SDKs speed integration and reduce boilerplate, but it's still useful to understand raw API behavior.

Disclaimer

This article is for educational and informational purposes only. It does not constitute legal, financial, investment, or professional advice. Evaluate APIs and tools independently and consult appropriate professionals for specific use cases.

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Token Metrics Team
Token Metrics Team

Recent Posts

Crypto Basics

How to Store Cryptocurrency Safely in 2025 | Hot vs Cold Wallets

Token Metrics Team
6 min
MIN

Cryptocurrency offers unmatched freedom, but with that freedom comes responsibility—especially when it comes to how to store cryptocurrency securely. Unlike traditional banking, crypto is self-custodied. If you lose access to your wallet, your funds are gone forever.

This guide explains everything you need to know about storing crypto in 2025, including:

  • Why crypto storage matters
  • Types of crypto wallets
  • Hot wallets vs. cold wallets
  • Tips for securing your assets
  • How platforms like Token Metrics can help protect your investment

đŸȘ™ Why Is Storing Cryptocurrency Important?

When you buy crypto—whether it’s Bitcoin, Ethereum, or a promising moonshot altcoin—you receive private keys that give you access to your funds. Anyone with that key can spend your coins.

That’s why safe storage is critical. Without it, your assets are vulnerable to:

  • Hacks and phishing scams
  • Lost devices or forgotten passwords
  • Exchange collapses or rug pulls

You are your own bank, and your security strategy is your vault.

🔐 What Is a Crypto Wallet?

A crypto wallet is a digital tool that stores your private and public keys. It lets you send, receive, and manage your crypto.

There are two main types:

  1. Hot wallets – connected to the internet
  2. Cold wallets – offline and physically secured

Let’s explore both.

🌐 Hot Wallets: Convenience Meets Risk

Hot wallets are always online, making them easy to use for trading, DeFi, or daily transactions.

Types of Hot Wallets:

  • Web wallets (e.g., MetaMask, Trust Wallet)
  • Mobile apps (e.g., Coinbase Wallet, Phantom)
  • Desktop wallets (e.g., Exodus, Electrum)

Pros:

  • Quick access to funds
  • Easy integration with DApps and exchanges
  • Great for beginners and active traders

Cons:

  • Higher risk of hacks, malware, and phishing
  • Device or browser compromise can expose keys

Best Practices for Hot Wallets:

  • Use 2FA (Two-Factor Authentication)
  • Never store large amounts
  • Double-check URLs to avoid fake websites
  • Avoid public Wi-Fi while transacting

🧊 Cold Wallets: Ultimate Security

Cold wallets are offline storage solutions, ideal for long-term investors or large holdings.

Types of Cold Wallets:

  • Hardware wallets (e.g., Ledger Nano X, Trezor)
  • Paper wallets (QR code + private key printed on paper)
  • Air-gapped devices (old smartphones with no internet access)

Pros:

  • Immune to online hacks
  • Best for HODLing and large sums
  • You own full control

Cons:

  • Less convenient for daily use
  • Loss or damage without backups = permanent loss

Best Practices for Cold Wallets:

  • Buy hardware wallets directly from the manufacturer
  • Backup your seed phrase on metal plates or offline storage
  • Keep backups in secure, separate locations

🔄 Custodial vs. Non-Custodial Wallets

🏩 Custodial Wallets

Managed by exchanges (e.g., Binance, Coinbase). You don’t own the private keys.

Pros:

  • Easy to use
  • Ideal for beginners

Cons:

  • Not your keys, not your crypto
  • Vulnerable to hacks or platform failures

🔓 Non-Custodial Wallets

You own the keys. Wallets like MetaMask, Trust Wallet, or hardware devices.

Pros:

  • Full control and ownership
  • Safer long-term storage

Cons:

  • Losing your seed phrase = permanent loss
  • Requires more responsibility

Tip: Token Metrics recommends non-custodial wallets for storing long-term holdings and moonshot tokens.

🔐 How Token Metrics Enhances Crypto Security

Token Metrics is an AI-powered crypto research and trading platform trusted by thousands of investors. While it doesn’t store your crypto directly, it helps you manage risk and store assets wisely by:

1. Identifying Safe Assets

Token Metrics gives you AI-generated grades for tokens—helping you avoid scams and invest in credible projects worth storing long-term.

2. Trading Tools with Wallet Integration

You can explore tokens, assess moonshots, and initiate trades directly from your connected Web3 wallet without leaving the platform.

3. Portfolio Tracking with Security

Token Metrics allows you to track wallets and portfolio performance without requiring access to your private keys.

4. Educational Guidance

Through webinars, blog content, and investor resources, Token Metrics educates users on how to safely store their crypto in hot and cold wallets.

🧠 Tips to Keep Your Crypto Safe in 2025

✅ Use Hardware Wallets for Large Amounts

Your long-term Bitcoin, Ethereum, and moonshot tokens should live on a hardware wallet, not on an exchange.

✅ Store Your Seed Phrase Offline

Do NOT keep your recovery phrase in Google Docs or your phone. Use metal seed phrase storage or write it down and lock it in a safe.

✅ Use Multiple Wallets

Diversify storage:

  • Hot wallet for daily use
  • Cold wallet for savings
  • Separate wallet for DeFi

✅ Avoid Suspicious Links and Apps

Phishing is the #1 crypto threat. Double-check URLs, don’t sign unknown transactions, and avoid shady browser extensions.

✅ Monitor Wallet Activity

Use platforms like Token Metrics Alerts or Etherscan to track your wallet and get notified of suspicious activity.

đŸȘ™ How to Store Different Types of Crypto

‍

🧭 Final Thoughts

Storing cryptocurrency securely is just as important as choosing the right tokens to invest in. Whether you’re a day trader, long-term investor, or moonshot hunter, knowing when and where to store your crypto is key to protecting your wealth.

In 2025, the best strategy combines:

  • Cold wallets for large, long-term holdings
  • Hot wallets for convenience and trading
  • Non-custodial options to retain full control
  • AI tools like Token Metrics to identify trustworthy assets and avoid scams

When you store your crypto properly, you don’t just protect your assets—you gain peace of mind.

Token Metrics API

How to Build Crypto Trading Dashboard Using the Token Metrics Crypto Data API on Dune

Token Metrics Team
8 min
MIN

In today’s fast-paced crypto world, real-time data isn’t a luxury—it’s a necessity. For traders, analysts, and developers, being able to access live, actionable insights can mean the difference between profit and loss. That’s why the integration of the Token Metrics Crypto Data API with Dune is a game-changer for anyone seeking to create live dashboards backed by intelligent trading data.

In this post, we’ll walk through how to use this top crypto API to build dynamic dashboards on Dune. Whether you’re tracking bullish signals, backtesting trading strategies, or identifying top-performing tokens, this integration makes it possible—without any paid license.

Let’s dive into how you can use the best free crypto API available today to transform your trading.

What Is the Token Metrics Crypto Data API?

The Token Metrics Crypto Data API is a developer-focused gateway to powerful, AI-driven crypto data. It’s one of the top crypto APIs in 2025, giving you access to:

  • Real-time and historical trading signals
  • Proprietary trader and investor grades
  • Alpha metrics comparing trading vs. holding performance
  • Bullish and bearish token flags

This API is used by both professional quant traders and beginners seeking to automate insights. And the best part? Token Metrics provides free crypto API access to selected datasets, allowing you to create powerful dashboards without spending a dime.

Why Dune + Token Metrics API = Power Tools for Traders

Dune is a blockchain analytics platform that allows you to write SQL queries and create dashboards using on-chain and off-chain data. Now that Token Metrics datasets are available on Dune, you can combine the best of both worlds:

  • Free access to high-signal proprietary metrics
  • Real-time data visualizations via Dune’s drag-and-drop dashboard builder
  • Actionable insights based on AI-driven trading intelligence

This integration unlocks a whole new level of transparency and utility for crypto analysts, portfolio managers, and DeFi enthusiasts.

Getting Started: Accessing Token Metrics Data on Dune

To begin, create a free Dune account. Once logged in, navigate to the Token Metrics datasets. These are publicly accessible and updated regularly. You’ll find tables for:

  • trading_signals
  • trader_grades
  • investors_grades
  • tokens

Start a new SQL query and choose the dataset you want to explore. Here’s what you’ll find in the trading signals table:

‍

‍

Step-by-Step: Creating an Actionable Dashboard with Token Metrics Data

1. Query the Trading Signal Returns

Write a SQL query to calculate the average return of trading vs. holding strategies. For example:

This gives you the alpha—how much better the Token Metrics strategy performs compared to just HODLing.

In one real example, the average signal return across all tokens was 1630%, while holding returned just 400%. That’s a 12X improvement powered by this top crypto API.

2. Identify Top-Performing Tokens

Now let’s list tokens with the highest average alpha:

Tokens like BTC, ETH, BNB, and even newer ones like Virtuals stand out due to exceptional alpha performance.

3. Visualize Trader Grades vs. Alpha

The trader grade is a proprietary score from Token Metrics that predicts how favorable a token is for short-term traders.

Use a scatter plot to correlate trader grades with average alpha:

  • X-axis: Trader Grade
  • Y-axis: Average Alpha
  • Group by: Token Symbol

This helps you visually determine which tokens score high and offer exceptional returns—an essential tool for making actionable trading decisions.

4. Track the Latest Bullish Signals

Want to know which tokens are bullish right now? Here’s a query to find the most recent tokens flagged as bullish:

For example, on July 4th, tokens like BNB, XRP, and BTC were among the most recent bullish signals—perfect for immediate trade setups.

5. Build and Share Your Dashboard

Once you’ve run your queries:

  • Click “Add Visualization” in Dune
  • Choose from chart types (bar, scatter, progress bar, etc.)
  • Customize colors and filters
  • Combine multiple charts into a single dashboard

Your final product will be a real-time dashboard powered by the best crypto API, delivering insights that you—and your team—can act on instantly.

Why Token Metrics Is the Best Free Crypto API for Traders

Here’s why Token Metrics stands out among other APIs:

✅ AI-Driven Signals

Most APIs deliver raw data. Token Metrics provides curated signals, generated from machine learning models trained on market cycles, indicators, and price action.

✅ Proprietary Metrics

Access unique indicators like trader grade and investor grade, unavailable anywhere else.

✅ Real Historical Alpha

Use the API to backtest strategies. In the example shown, the AI strategy outperformed the market by over 1000X for some tokens.

✅ Seamless Integration

Whether you're using Dune, Zapier, OpenAI, or Eliza OS, Token Metrics is easy to integrate and query—making it the top crypto API for developers and analysts alike.

Final Thoughts

The combination of Token Metrics’ intelligent data and Dune’s visualization tools puts immense power in your hands. Whether you’re tracking market trends, building bots, or guiding portfolio decisions, this integration gives you everything you need to trade smarter.

With free access to real-time trading signals, alpha comparisons, and powerful visualizations, Token Metrics proves why it's the best crypto API for today’s data-driven investor.

Ready to try it out?
👉 Explore the Free Crypto API
👉 Start Building on Dune

Crypto Basics

What Is an ETF Stock? A Beginner’s Guide to Exchange-Traded Funds in 2025

Token Metrics Team
8 min
MIN

In today’s fast-moving financial markets, Exchange-Traded Funds, or ETF stocks, have emerged as one of the most popular investment vehicles for beginners and professionals alike. But what exactly is an ETF stock, how does it work, and why is it considered a smart way to invest?

This guide will walk you through everything you need to know about ETF stocks in 2025—including how they work, their benefits and risks, and how AI platforms like Token Metrics are changing the way people research and trade ETFs in both traditional and crypto markets.

📌 What Is an ETF Stock?

An ETF stock refers to a share of an Exchange-Traded Fund—a type of investment fund that trades on stock exchanges, much like individual company stocks. Each ETF holds a basket of underlying assets such as:

  • Stocks (e.g., S&P 500 companies)
  • Bonds
  • Commodities (like gold or oil)
  • Currencies
  • Cryptocurrencies (Bitcoin, Ethereum, etc.)

When you buy an ETF stock, you’re buying a fractional share of the entire portfolio of assets held by that ETF.

🔍 How Does an ETF Stock Work?

ETF stocks work like this:

  1. Creation: An asset management company (like BlackRock, Vanguard, or Fidelity) creates an ETF that tracks a specific index, sector, or asset type.
  2. Listing: The ETF is listed on a stock exchange such as the NYSE or Nasdaq.
  3. Trading: Investors can buy and sell ETF shares throughout the trading day, just like they would a stock like Apple or Tesla.
  4. Price Movement: The price of an ETF stock fluctuates during the day based on the Net Asset Value (NAV) of its holdings and supply-demand dynamics in the market.

This model provides a liquid, transparent, and low-cost way for investors to gain diversified exposure to entire markets or sectors.

📊 Example of an ETF Stock

A good example is the SPDR S&P 500 ETF Trust (SPY), which tracks the performance of the S&P 500 index. When you buy a share of SPY, you gain exposure to 500 of the largest U.S. companies—without needing to buy each stock individually.

✅ Benefits of ETF Stocks

ETF stocks offer numerous advantages for investors in 2025:

1. Diversification

Instead of buying individual assets, ETF stocks offer instant diversification by holding dozens or hundreds of securities in a single share.

2. Liquidity

ETFs are traded on exchanges, making them highly liquid. You can buy or sell them at market prices during normal trading hours.

3. Lower Costs

ETFs typically have low expense ratios (as low as 0.03%), especially compared to mutual funds or actively managed portfolios.

4. Transparency

Most ETFs disclose their holdings daily, giving investors a clear view into what they’re buying.

5. Flexibility

You can use ETFs for long-term investing, short-term trading, hedging, or generating income through dividends.

⚠ Risks of ETF Stocks

Despite their many benefits, ETF stocks do come with some risks:

1. Market Risk

ETF stocks are still subject to market volatility. If the underlying assets decline in value, so will the ETF.

2. Tracking Error

Some ETFs may not perfectly replicate the performance of their index due to fees, slippage, or illiquid assets.

3. Overexposure

Because ETFs make it easy to invest, some investors may unknowingly become overexposed to a particular sector or strategy.

4. Liquidity Risk

Not all ETFs are created equal. Low-volume ETFs may have wider bid-ask spreads, increasing trading costs.

đŸȘ™ Crypto ETFs: The New Frontier

In 2025, crypto ETF stocks have become a hot trend. These funds allow investors to gain exposure to digital assets without managing private keys, wallets, or blockchain protocols.

Types of crypto ETFs include:

  • Spot ETFs: Hold actual crypto assets (e.g., Bitcoin, Ethereum).
  • Futures ETFs: Track the price of crypto futures contracts.

Popular examples in 2025 include:

  • IBIT (BlackRock Bitcoin ETF)
  • FBTC (Fidelity Bitcoin ETF)
  • ETHX (Ethereum Spot ETF)

Crypto ETFs have opened the door for institutional and traditional investors to gain exposure to the crypto market in a regulated and simplified manner.

đŸ€– How Token Metrics Helps You Trade ETF Stocks Smarter

Whether you're interested in traditional ETF stocks or crypto ETFs, Token Metrics provides the AI-powered insights you need to make better investment decisions.

🔎 1. AI-Powered Ratings

Token Metrics assigns each token or ETF a Trader Grade and Investor Grade based on price trends, volume, volatility, and technical strength—making it easy to spot outperformers.

📈 2. Bullish and Bearish Signals

AI-driven signals show when it’s time to buy or sell based on real-time metrics like ETF inflows, exchange balances, and market sentiment.

📊 3. Price Forecasts

Get access to predictive models that estimate where Bitcoin, Ethereum, and major crypto ETFs are headed—based on 80+ factors.

🔔 4. Smart Alerts

Set custom alerts for ETF stock signals, price movements, or grade changes so you never miss an opportunity.

By combining ETF investing with Token Metrics’ AI analytics, you gain an informational edge in markets that move faster than ever.

📈 Popular ETF Stocks in 2025

Here’s a list of top-performing ETF stocks across traditional and crypto sectors:

🧠 Final Thoughts

ETF stocks are a powerful investment tool in 2025, offering instant diversification, low fees, and easy access to traditional and crypto markets. Whether you're looking to build a retirement portfolio or ride the next Bitcoin rally, ETF stocks make it easier than ever to invest with confidence.

And with platforms like Token Metrics, you don’t need to guess your way through ETF trading. Use AI-driven insights, price predictions, and real-time data to get ahead of the curve—no matter what markets you trade.

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