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Research

Top Free APIs Every Developer Should Know in 2024

Discover the best free-to-use APIs for crypto, AI, and data apps. See which trusted APIs developers rely on for robust features, reliability, and easy integration.
Token Metrics Team
5
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APIs are the silent workhorses powering today’s most innovative software. Whether you’re a crypto enthusiast automating portfolio analysis, or a web developer looking to enrich your app with real-time data, the right free API can supercharge your project—and your productivity. But with thousands out there, which free APIs truly stand out for reliability, ease of use, and breadth of features?

Why Free APIs Matter for Developers and Innovators

APIs—Application Programming Interfaces—allow applications to seamlessly interact, share insights, and build on each other's strengths. The best free-to-use APIs democratize access to powerful datasets, functionalities, and market signals. For crypto, AI, fintech, or simply creative digital projects, high-quality APIs can:

  • Accelerate product development with ready-made data and processing tools
  • Enable experiments in new tech areas without initial investment
  • Foster community-driven innovation thanks to open documentation and easy onboarding

However, not all free APIs are created equal. Some offer limited usage tiers, outdated data, or spotty reliability. That’s why informed selection is crucial, especially for mission-critical apps.

Top Free APIs for Cryptocurrency and Blockchain Projects

The crypto landscape thrives on transparency and timely data. For enthusiasts building bots, dashboards, or research tools, these free APIs consistently earn praise:

  • CoinGecko API: Delivers comprehensive token prices, volumes, and market data. Free tier includes generous rate limits and supports thousands of assets.
  • CoinMarketCap Public API: Offers price feeds and historical data for cryptocurrencies, ideal for analysts and monitoring tools.
  • Etherscan API: The go-to source for Ethereum blockchain explorers, enabling developers to fetch address balances, smart contract source, and token transactions for free.
  • Glassnode API (Free Tier): On-chain metrics and indicators, including supply activity and network health, are freely accessible for non-commercial use.

These APIs are often foundational building blocks for portfolio trackers, on-chain analytics, and even education platforms. Crucially, they’re maintained, well-documented, and support broad application ranges without requiring payment—or personal information—at the entry level.

Best Free APIs Across Data, AI, and Web Development

If your project stretches beyond crypto, the open web is full of powerful (yet freely accessible) APIs for various domains:

  1. OpenWeatherMap API: Real-time and forecast weather data for any global location. Great for travel, logistics, and even DeFi insurance products.
  2. NewsAPI: Aggregates global headlines and breaking news. Many developers use it for sentiment dashboards, trend-following, or daily newsletters.
  3. OpenAI API (trial/limited free tier): Enables natural language understanding, chatbots, and text processing. Developers can access some GPT models for experimentation on a free plan.
  4. RapidAPI Hub: A directory hosting hundreds of free-to-use APIs in every possible category—from sports to sentiment analysis. RapidAPI offers unified onboarding and monitoring.
  5. Public-APIs (GitHub Community List): An open-source, crowd-curated list of categorized free APIs, kept up to date for AI, datasets, image processing, and more.

These tools let you build everything from machine learning prototypes to hobbyist weather notifiers. Carefully review usage limits and (where relevant) data privacy arrangements as you scale your innovation.

How to Choose and Integrate Free APIs Securely

Not every free API is equally reliable or secure. Situations to consider include:

  • Data Accuracy and Uptime: Ensure the provider offers a clear SLA or uptime history, especially for finance or real-time apps.
  • Privacy: Favor APIs that don’t require sensitive personal data unless absolutely necessary.
  • API Limits and Scaling: Free tiers are often rate-limited. Consider future upgrades and monitor usage to avoid service interruptions.
  • Documentation and Community: Well-documented APIs, ideally with samples and open forums, accelerate integration and reduce confusion.

When integrating, secure your keys in environment variables, use HTTPS endpoints, and avoid exposing credentials in public sources. Always plan for error handling and fail-safes.

The Growing Role of Free APIs in AI and Analytics

The explosion of AI-generated insights and predictive analytics owes much to accessible APIs. With free endpoints for data labeling, model inference, and sentiment tracking, even small development teams can launch powerful, AI-enhanced products. Projects like Hugging Face’s free models hub or the OpenAI playground democratize once-complex capabilities, unlocking new digital frontiers for research and public good.

For crypto analysis, AI-backed APIs—like those from Token Metrics—combine quantitative techniques and machine learning to highlight actionable trends and on-chain activity. As free API ecosystems expand, expect an even richer toolbox for developers at every skill level.

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 an API and why are they essential in crypto or AI?

APIs let different software systems communicate and share data or services. In crypto, APIs deliver live price data, transaction histories, and on-chain analytics. In AI, APIs allow access to model inference, data labeling, and natural language processing, lowering barriers for developers and researchers.

Are free APIs truly reliable for production use?

Many free APIs maintain high uptime and data accuracy, especially those from reputable organizations. However, they may have stricter rate limits, fewer support options, or evolving terms. For mission-critical operations, always implement redundancy and review official service level commitments.

Which are the best free APIs for cryptocurrency analysis?

Popular options include CoinGecko, CoinMarketCap, and Etherscan for price and blockchain data. For AI-driven insights, platforms like Token Metrics provide actionable intelligence with robust free tiers.

How do I keep my API keys and data secure?

Never hardcode keys in public repos or client-side code. Use secure storage (environment variables or vaults), enforce HTTPS, rotate keys regularly, and monitor API access logs to identify anomalies.

What should I check before integrating any free API?

Review documentation, data freshness, rate limits, provider reputation, privacy compliance, and supported SDKs. Test endpoints in your dev environment and plan for graceful error handling to ensure resilience.

Disclaimer

This article is for informational purposes only and does not constitute financial, investment, or legal advice. Always perform due diligence when evaluating APIs, tools, or digital assets. No endorsement is implied. Third-party API providers may change terms at any time; verify details before production use.

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About Token Metrics
Token Metrics: AI-powered crypto research and ratings platform. We help investors make smarter decisions with unbiased Token Metrics Ratings, on-chain analytics, and editor-curated “Top 10” guides. Our platform distills thousands of data points into clear scores, trends, and alerts you can act on.
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analysts, data scientists, and crypto engineers
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analysts, data scientists, and crypto engineers
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analysts, data scientists, and crypto engineers
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Token Metrics Team
Token Metrics Team

Recent Posts

Research

Why Manual Crypto Portfolio Management Is Costing You Money (And Time)

Token Metrics Team
6

You're tracking 50+ tokens across three exchanges, updating your rebalancing spreadsheet every weekend, and second-guessing every exit decision at 2 AM. Sound familiar? Manual crypto portfolio management isn't just exhausting—it's expensive. Between missed rebalances, execution drag, and behavioral mistakes during volatility, DIY portfolio management quietly erodes returns before you see any market gains.

The data tells the story: investors who manually manage diversified crypto portfolios typically underperform comparable automated strategies by 12-18% annually, with 60% of that gap coming from operational inefficiency rather than market timing. If you're spending 10+ hours weekly maintaining positions, those hours have a cost—and it's higher than you think.

The Hidden Costs Destroying Your Returns

Time Drain: The 500-Hour Tax

Managing a diversified crypto portfolio demands constant vigilance. For investors holding 20+ positions, the weekly time investment breaks down to approximately:

  • Market monitoring: 5-8 hours tracking prices, news, and on-chain metrics
  • Rebalancing calculations: 2-3 hours determining optimal weights and required trades
  • Order execution: 3-5 hours placing trades across multiple platforms
  • Record keeping: 1-2 hours logging transactions for tax reporting
  • Research updates: 3-5 hours staying current on project developments

That's 14-23 hours weekly, or 728-1,196 hours annually. At a conservative $50/hour opportunity cost, you're spending $36,400-$59,800 in time value maintaining your portfolio. Even if you value your time at minimum wage, that's still $10,000+ in annual "sweat equity" that automated solutions eliminate.

Execution Drag: Death by a Thousand Trades

Small trades erode portfolios through accumulated friction. Every manual rebalance across a 50-token portfolio requires dozens of individual transactions, each incurring:

  • Trading fees: 0.1-0.5% per trade (average 0.25%)
  • Bid-ask spreads: 0.2-0.8% depending on liquidity
  • Slippage: 0.3-1.2% on smaller cap tokens
  • Gas fees: $2-50 per transaction depending on network congestion

For a $100,000 portfolio rebalanced monthly with 40 trades per rebalance, the costs add up:

  • Average cost per trade: ~$100
  • Monthly execution drag: $4,000
  • Annual execution drag: $48,000 (48% of portfolio value)

The smaller your individual trades, the worse the ratio becomes. A $500 rebalancing trade on a low-liquidity altcoin might pay $25 in fees—a 5% instant loss before any price movement.

Automated indices solve this. TM Global 100, Token Metrics' rules-based index, consolidates 100 individual positions into a single transaction at purchase, with weekly rebalances executed through optimized smart contract batching. Users typically save 3-7% annually in execution costs alone compared to manual approaches.

Behavioral Mistakes: Your Worst Enemy Is in the Mirror

Market psychology research shows that manual portfolio managers tend to make predictable, costly mistakes:

  • Panic selling during drawdowns: When Bitcoin drops 25% in a week, can you stick to your exit rules? Many override their plans during high volatility, often selling near local bottoms.
  • FOMO buying at peaks: Tokens up 300% in a week attract chase behavior, with managers entering after the movement is mostly over.
  • Rebalancing procrastination: Putting off rebalancing leads to drift, holding too much of past winners and missing new opportunities.

Token Metrics' systematic approach removes emotion from the equation. The TM Global 100 Index follows a transparent ruleset: hold the top 100 tokens by market cap during bullish phases, shift to stablecoins during bearish cycles, and rebalance weekly—eliminating emotional override and procrastination.

Missed Rebalances: Drifting Out of Position

Market cap rankings shift constantly. A token ranked #73 on Monday might hit #95 by Friday, or surge to #58. Without systematic rebalancing, your portfolio becomes a collection of recent winners or dumpers.

In Q3 2024, Solana ecosystem tokens surged while Ethereum DeFi tokens consolidated. Manual managers who missed weekly rebalances held too much ETH and insufficient SOL exposure. The result: 15-20% underperformance compared to systematically rebalanced portfolios. Data from Token Metrics shows that weekly rebalancing outperforms monthly or quarterly approaches by 8-12% annually.

Tax Reporting Nightmares

Every trade creates a taxable event. Manual managers executing over 200 trades yearly face:

  • Hours spent compiling transaction logs
  • Reconciliation across multiple exchanges
  • Cost-basis tracking for numerous lots
  • High professional accounting fees ($500-2,000+)

Automated solutions like Token Metrics provide transparent transaction logs for each rebalance, simplifying tax reporting and reducing accounting costs.

The Token Metrics Advantage: Research Meets Execution

Token Metrics has established itself as a leading crypto analytics platform, supporting over 50,000 users with AI-powered token ratings, market regime detection, portfolio optimization tools, and trading signals. But analysis alone isn't enough—implementation is crucial.

TM Global 100 Index bridges this gap. It turns research into actionable, tradeable products by automating rebalancing based on Token Metrics' signals and methodology. One click replaces hours of manual work, following a validated systematic approach.

Automation Without Compromise

The best automation is transparent. TM Global 100 offers:

  • Rules-Based Discipline: Bull markets—hold top 100 tokens; bear markets—move to stablecoins
  • Weekly rebalancing every Monday
  • Full methodology disclosure
  • One-Click execution via embedded self-custodial wallet
  • Real-time market insights and holdings visualization
  • Transaction logs with fees and timestamps

This streamlined process allows users to rapidly execute disciplined rebalancing, saving countless hours and increasing operational efficiency while maintaining asset control.

Decision Framework: When to Automate

Automation suits investors who:

  • Hold 15+ tokens and find rebalancing burdensome
  • Miss optimal rebalancing windows due to time constraints
  • Have experienced emotional trading decisions during volatility
  • Spend over 5 hours a week on portfolio management
  • Want broad exposure without manual tracking

Manual management may be suitable for those with fewer positions, active trading infrastructure, or tactical strategies. For most diversified portfolios, automation enhances efficiency and reduces operational errors.

The Compound Effect of Efficiency

Small inefficiencies compound over time. Over five years, a $50,000 portfolio managed manually with a 12% annual return minus 4-2-1% losses yields roughly a 5% net return, ending at about $63,814. A systematic approach with optimizer integration, zero behavioral errors, and regular rebalancing can attain a 13% net return, reaching approximately $92,246—an increase of over $28,000, not counting time saved.

Conclusion: Time Back, Returns Up

Manual crypto portfolio management made sense when portfolios were small and concentrated. Today’s diversified sets require operational discipline to prevent erosion of returns due to execution drag, missed rebalances, and emotional mistakes. Token Metrics built TM Global 100 to turn research into automated, transparent execution, reclaim your time, and boost portfolio discipline—without sacrificing control.

Research

Moonshots API: Discover Breakout Tokens Before the Crowd

Token Metrics Team
5

The biggest gains in crypto rarely come from the majors. They come from Moonshots—fast-moving tokens with breakout potential. The Moonshots API surfaces these candidates programmatically so you can rank, alert, and act inside your product. In this guide, you’ll call /v2/moonshots, display a high-signal list with TM Grade and Bullish tags, and wire it into bots, dashboards, or screeners in minutes. Start by grabbing your key at Get API Key, then Run Hello-TM and Clone a Template to ship fast.

What You’ll Build in 2 Minutes

Why This Matters

Discovery that converts. Users want more than price tickers, they want a curated, explainable list of high-potential tokens. The Moonshots API encapsulates multiple signals into a short list designed for exploration, alerts, and watchlists you can monetize.

Built for builders. The endpoint returns a consistent schema with grade, signal, and context so you can immediately sort, badge, and trigger workflows. With predictable latency and clear filters, you can scale to dashboards, mobile apps, and headless bots without reinventing the discovery pipeline.

Where to Find The Moonshots API

The cURL request for the Moonshots endpoint is displayed in the top right of the API Reference. Grab it and start tapping into the potential!

How It Works (Under the Hood)

The Moonshots endpoint aggregates a set of evidence—often combining TM Grade, signal state, and momentum/volume context—into a shortlist of breakout candidates. Each row includes a symbol, grade, signal, and timestamp, plus optional reason tags for transparency.

For UX, a common pattern is: headline list → token detail where you render TM Grade (quality), Trading Signals (timing), Support/Resistance (risk placement), Quantmetrics (risk-adjusted performance), and Price Prediction scenarios. This enables users to understand why a token was flagged and how to act with risk controls.

Polling vs webhooks. Dashboards typically poll with short-TTL caching. Alerting flows use scheduled jobs or webhooks to smooth traffic and avoid duplicates. Always make notifications idempotent.

Production Checklist

Use Cases & Patterns

Next Steps

FAQs

1) What does the Moonshots API return?

A list of breakout candidates with fields such as symbol, tm_grade, signal (often Bullish/Bearish), optional reason tags, and updated_at. Use it to drive discover tabs, alerts, and watchlists.

2) How fresh is the list? What about latency/SLOs?

The endpoint targets predictable latency and timely updates for dashboards and alerts. Use short-TTL caching and queued jobs/webhooks to avoid bursty polling.

3) How do I use Moonshots in a trading workflow?

Common stack: Moonshots for discovery, Trading Signals for timing, Support/Resistance for SL/TP, Quantmetrics for sizing, and Price Prediction for scenario context. Always backtest and paper-trade first.

4) I saw results like “+241%” and a “7.5% average return.” Are these guaranteed?

No. Any historical results are illustrative and not guarantees of future performance. Markets are risky; use risk management and testing.

5) Can I filter the Moonshots list?

Yes—pass parameters like min_grade, signal, and limit (as supported) to tailor to your audience and keep pages fast.

6) Do you provide SDKs or examples?

REST works with JavaScript and Python snippets above. Docs include quickstarts, Postman collections, and templates—start with Run Hello-TM.

7) Pricing, limits, and enterprise SLAs?

Begin free and scale up. See API plans for rate limits and enterprise options.

Research

Support and Resistance API: Auto-Calculate Smart Levels for Better Trades

Token Metrics Team
4

Most traders still draw lines by hand in TradingView. The support and resistance API from Token Metrics auto-calculates clean support and resistance levels from one request, so your dashboard, bot, or alerts can react instantly. In minutes, you’ll call /v2/resistance-support, render actionable levels for any token, and wire them into stops, targets, or notifications. Start by grabbing your key on Get API Key, then Run Hello-TM and Clone a Template to ship a production-ready feature fast.

What You’ll Build in 2 Minutes

A minimal script that fetches Support/Resistance via /v2/resistance-support for a symbol (e.g., BTC, SOL).

  • A one-liner curl to smoke-test your key.
  • A UI pattern to display nearest support, nearest resistance, level strength, and last updated time.

Next Endpoints to add

  • /v2/trading-signals (entries/exits)
  • /v2/hourly-trading-signals (intraday updates)
  • /v2/tm-grade (single-score context)
  • /v2/quantmetrics (risk/return framing)

Why This Matters

Precision beats guesswork. Hand-drawn lines are subjective and slow. The support and resistance API standardizes levels across assets and timeframes, enabling deterministic stops and take-profits your users (and bots) can trust.

Production-ready by design. A simple REST shape, predictable latency, and clear semantics let you add levels to token pages, automate SL/TP alerts, and build rule-based execution with minimal glue code.

Where to Find

Need the Support and Resistance data? The cURL request for it is in the top right of the API Reference for quick access.

👉 Keep momentum: Get API Key • Run Hello-TM • Clone a Template

How It Works (Under the Hood)

The Support/Resistance endpoint analyzes recent price structure to produce discrete levels above and below current price, along with strength indicators you can use for priority and styling. Query /v2/resistance-support?symbol=<ASSET>&timeframe=<HORIZON> to receive arrays of level objects and timestamps.

Polling vs webhooks. For dashboards, short-TTL caching and batched fetches keep pages snappy. For bots and alerts, use queued jobs or webhooks (where applicable) to avoid noisy, bursty polling—especially around market opens and major events.

Production Checklist

  • Rate limits: Respect plan caps; add client-side throttling.
  • Retries/backoff: Exponential backoff with jitter for 429/5xx; log failures.
  • Idempotency: Make alerting and order logic idempotent to prevent duplicates.
  • Caching: Memory/Redis/KV with short TTLs; pre-warm top symbols.
  • Batching: Fetch multiple assets per cycle; parallelize within rate limits.
  • Threshold logic: Add %-of-price buffers (e.g., alert at 0.3–0.5% from level).
  • Error catalog: Map common 4xx/5xx to actionable user guidance; keep request IDs.
  • Observability: Track p95/p99; measure alert precision (touch vs approach).
  • Security: Store API keys in a secrets manager; rotate regularly.

Use Cases & Patterns

  • Bot Builder (Headless): Use nearest support for stop placement and nearest resistance for profit targets. Combine with /v2/trading-signals for entries/exits and size via Quantmetrics (volatility, drawdown).
  • Dashboard Builder (Product): Add a Levels widget to token pages; badge strength (e.g., High/Med/Low) and show last touch time. Color the price region (below support, between levels, above resistance) for instant context.
  • Screener Maker (Lightweight Tools): “Close to level” sort: highlight tokens within X% of a strong level. Toggle alerts for approach vs breakout events.
  • Risk Management: Create policy rules like “no new long if price is within 0.2% of strong resistance.” Export daily level snapshots for audit/compliance.

Next Steps

  • Get API Key — generate a key and start free.
  • Run Hello-TM — verify your first successful call.
  • Clone a Template — deploy a levels panel or alerts bot today.
  • Watch the demo: Compare plans: Scale confidently with API plans.

FAQs

1) What does the Support & Resistance API return?

A JSON payload with arrays of support and resistance levels for a symbol (and optional timeframe), each with a price and strength indicator, plus an update timestamp.

2) How timely are the levels? What are the latency/SLOs?

The endpoint targets predictable latency suitable for dashboards and alerts. Use short-TTL caching for UIs, and queued jobs or webhooks for alerting to smooth traffic.

3) How do I trigger alerts or trades from levels?

Common patterns: alert when price is within X% of a level, touches a level, or breaks beyond with confirmation. Always make downstream actions idempotent and respect rate limits.

4) Can I combine levels with other endpoints?

Yes—pair with /v2/trading-signals for timing, /v2/tm-grade for quality context, and /v2/quantmetrics for risk sizing. This yields a complete decide-plan-execute loop.

5) Which timeframe should I use?

Intraday bots prefer shorter horizons; swing/position dashboards use daily or higher-timeframe levels. Offer a timeframe toggle and cache results per setting.

6) Do you provide SDKs or examples?

Use the REST snippets above (JS/Python). The docs include quickstarts, Postman collections, and templates—start with Run Hello-TM.

7) Pricing, limits, and enterprise SLAs?

Begin free and scale as you grow. See API plans for rate limits and enterprise SLA options.

Disclaimer

This content is for educational purposes only and does not constitute financial advice. Always conduct your own research before making any trading decisions.

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