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Our x402 Integration Is Live: Pay-Per-Call Access to Token Metrics—No API Key Required

Use your crypto wallet to call Token Metrics endpoints on demand. Pay per call with USDC or get a 10% discount with TMAI. No monthly subscriptions, no API keys, just headers and code.
Token Metrics Team
7 min read
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Developers are already shipping with x402 at scale: 450,000+ weekly transactions, 700+ projects. This momentum is why our Token Metrics x402 integration matters for agents and apps that need real crypto intelligence on demand. You can now pay per API call using HTTP 402 and the x-coinbase-402 header, no API key required.

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Summary: Pay per API call to Token Metrics with x402 on Base using USDC or TMAI, set x-coinbase-402: true, and get instant access to trading signals, grades, and AI reports.

Check out the x402 ecosystem on Coingecko.

  

What You Get

Token Metrics now supports x402, the HTTP-native payment protocol from Coinbase. Users can call any public endpoint by paying per request with a wallet, eliminating API key management and upfront subscriptions. This makes Token Metrics data instantly accessible to AI agents, researchers, and developers who want on-demand crypto intelligence.

x402 enables truly flexible access where you pay only for what you use, with transparent per-call pricing in USDC or TMAI. The integration is live now across all Token Metrics public endpoints, from trading signals to AI reports. Here's everything you need to start calling Token Metrics with x402 today.

Quick Start

Get started with x402 + Token Metrics in three steps.

  1. Create a wallet client: Follow the x402 Quickstart for Buyers to set up a wallet client (Node.js with viem or Python with eth-account). Link: https://docs.cdp.coinbase.com/x402/docs/quickstart-buyers
  2. Set required headers: Add x-coinbase-402: true to any Token Metrics request. Optionally set x-payment-token: tmai for a 10% discount (defaults to usdc). Do not send x-api-key when using x402.
  3. Call any endpoint: Make a request to https://api.tokenmetrics.com/v2/[endpoint] with your wallet client. Payment happens automatically via x402 settlement.

That is it. Your wallet pays per call, and you get instant access to Token Metrics data with no subscription overhead.

Required Headers

  

Endpoint Pricing

Transparent per-call pricing across all Token Metrics public endpoints. Pay in USDC or get 10% off with TMAI.

  

  

  

  

All prices are per single call. Paying with TMAI automatically applies a 10% discount.

Try It on x402 Composer

If you want to see x402 + Token Metrics in action without writing code, head to x402 Composer. Composer is x402scan's playground for AI agents that pay per tool call. You can open a Token Metrics agent, chat with it, and watch real tool calls and USDC/TMAI settlements stream into the live Feed.

Composer surfaces active agents using Token Metrics endpoints like trading signals, price predictions, and AI reports. It is a great way to explore what is possible before you build your own integration. Link: https://x402scan.com/composer

Why x402 Changes the Game

Traditional API access requires upfront subscriptions, fixed rate limits, and key management overhead. x402 flips that model by letting you pay per call with a crypto wallet, with no API keys or monthly commitments. This is especially powerful for AI agents, which need flexible, on-demand access to external data without human intervention.

For Token Metrics, x402 unlocks agentic commerce where agents can autonomously pull crypto intelligence, pay only for what they use, and compose our endpoints with other x402-enabled tools like Heurist Mesh, Tavily, and Firecrawl. It is HTTP-native payments meeting real-world agent workflows.

What is x402?

x402 is an open-source HTTP-native payment protocol developed by Coinbase. It uses the HTTP 402 status code (Payment Required) to enable pay-per-request access to APIs and services. When you make a request with the x-coinbase-402 header, the server returns a payment challenge, your wallet signs and submits payment, and the server fulfills the request once settlement is verified.

The protocol runs on Base and Solana, with USDC and TMAI as the primary payment tokens. x402 is designed for composability, agents can chain multiple paid calls across different providers in a single workflow, paying each service directly without intermediaries. Learn more at the x402 Quickstart for Buyers: https://docs.cdp.coinbase.com/x402/docs/quickstart-buyers

FAQs

Do I need an API key to use x402 with Token Metrics?

No. When you set x-coinbase-402: true, your wallet signature replaces API key authentication. Do not send x-api-key in your requests.

Can I use x402 with a free trial or test wallet?

Yes, but you will need testnet USDC or TMAI on Base Sepolia (testnet) for development. Production calls require mainnet tokens.

How do I see my payment history?

Check x402scan for transaction logs and tool call history. Your wallet will also show outgoing USDC/TMAI transactions. Visit https://www.x402scan.com.

What happens if my wallet balance is too low?

The x402 client will return a payment failure before making the API call. Top up your wallet and retry.

Can I use x402 in production apps?

Yes. x402 is live on Base mainnet. Set appropriate spend limits and handle payment errors gracefully in your code.

Next Steps

Disclosure

Educational and informational purposes only. x402 involves crypto payments on public blockchains. Understand the risks, manage your wallet security, and test thoroughly before production use. Token Metrics does not provide financial advice.

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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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Token Metrics Team
Token Metrics Team

Recent Posts

Research

Mastering Paginated API Responses: Efficiently Listing All Transactions

Token Metrics Team
5

Managing large volumes of blockchain transaction data is a common challenge for developers building crypto dashboards, on-chain analytics tools, or AI applications. Most APIs limit responses to prevent server overload, making pagination the default when listing all transactions. But how can you reliably and efficiently gather complete transaction histories? Let’s dive into proven strategies for handling paginated API responses.

Understanding Pagination in Transaction APIs

APIs often implement pagination to break up large datasets—such as transaction histories—into manageable portions. When requesting transaction data, instead of receiving thousands of records in one call (which could strain bandwidth or lead to timeouts), the API returns a subset (a "page") and instructions for fetching subsequent pages.

  • Limit/Offset Pagination: Requests specify a limit (number of items) and an offset (start position).
  • Cursor-Based Pagination: Uses tokens or "cursors" (often IDs or timestamps) as references to the next page, which is more efficient for real-time data.
  • Keyset Pagination: Similar to cursor-based; leverages unique keys, usually better for large, ordered datasets.

Each method affects performance, reliability, and implementation details. Understanding which your API uses is the first step to robust transaction retrieval.

Choosing the Right Pagination Strategy

Every API is unique—some allow only cursor-based access, while others support limit/offset or even page numbering. Choosing the right approach hinges on your project’s requirements and the API provider’s documentation. For crypto transaction logs or on-chain data:

  • Cursor-based pagination is preferred—It is resilient to data changes (such as new transactions added between requests), reducing the risk of skipping or duplicating data.
  • Limit/offset is practical for static datasets but can be less reliable for live transaction streams.
  • Hybrid approaches—Some APIs provide hybrid mechanisms to optimize performance and consistency.

For example, the Token Metrics API leverages pagination to ensure large data requests (such as all transactions for a wallet) remain consistent and performant.

Best Practices for Handling Paginated API Responses

To list all transactions efficiently, adhere to these best practices:

  1. Read Documentation Thoroughly: Know how the API signals the next page—via URL, a token, or parameters.
  2. Implement Robust Iteration: Build loops that collect results from each page and continue until no more data remains. Always respect API rate limits and error codes.
  3. De-Duplicate Transactions: Especially important with cursor or keyset strategies, as overlapping results can occur due to data changes during retrieval.
  4. Handle API Rate Limits and Errors: Pause or back-off if rate-limited, and implement retry logic for transient errors.
  5. Use Asynchronous Fetching Carefully: For performance, asynchronous requests are powerful—but be wary of race conditions, ordering, and incomplete data.

Below is a generic pseudocode example for cursor-based pagination:

results = []
cursor = None
while True:
    response = api.get_transactions(cursor=cursor)
    results.extend(response['transactions'])
    if not response['next_cursor']:
        break
    cursor = response['next_cursor']

This approach ensures completeness and flexibility, even for large or frequently-updated transaction lists.

Scaling Crypto Data Retrieval for AI, Analysis, and Automation

For large portfolios, trading bots, or AI agents analyzing multi-chain transactions, efficiently handling paginated API responses is critical. Considerations include:

  • Parallelizing Requests: If the API supports it—and rate limits allow—fetching different address histories or block ranges in parallel speeds up data loading.
  • Stream Processing: Analyze transactions as they arrive, rather than storing millions of rows in memory.
  • Data Freshness: Transaction data changes rapidly; leveraging APIs with webhooks or real-time "tailing" (where you fetch new data as it arrives) can improve reliability.
  • Integration with AI Tools: Automate anomaly detection, value tracking, or reporting by feeding retrieved transactions into analytics platforms. Advanced solutions like Token Metrics can supercharge analysis with AI-driven insights from unified APIs.

Security Considerations and Data Integrity

When fetching transaction data, always practice security hygiene:

  • Secure API Keys: Protect your API credentials. Never expose them in public code repositories.
  • Validate All Data: Even reputable APIs may deliver malformed data or unexpected results. Safeguard against bugs with schema checks and error handling.
  • Respect Privacy and Compliance: If handling user data, ensure storage and processing are secure and privacy-respectful.

Systematically checking for data consistency between pages helps ensure you don’t miss or double-count transactions—a key concern for compliance and reporting analytics.

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 pagination in APIs and why is it used?

Pagination is the process of breaking up a large dataset returned by an API into smaller segments, called pages. This practice prevents bandwidth issues and server overload, improving response times and reliability when dealing with extensive data sets such as blockchain transactions.

Which pagination method is best for crypto transaction APIs?

Cursor-based pagination is typically best for live or evolving datasets like blockchain transactions, as it’s less prone to data inconsistency and works well with rapid updates. However, always follow your chosen API’s recommendations for optimal performance.

How do you ensure no transactions are missed or duplicated?

Always implement data de-duplication by tracking unique transaction IDs. Carefully handle cursors or offsets, and consider double-checking against expected transaction counts or hashes for reliability.

Can I fetch all transactions from multiple addresses at once?

This depends on the API's capabilities. Some APIs allow multi-address querying, while others require paginated requests per address. When retrieving multiple lists in parallel, monitor rate limits and system memory usage.

How can AI and analytics platforms benefit from proper pagination handling?

Efficient handling of paginated responses ensures complete, timely transaction histories—empowering AI-driven analytics tools to perform advanced analysis, detect patterns, and automate compliance tasks without missing critical data.

Disclaimer

This blog post is for informational and educational purposes only. Nothing herein constitutes investment advice or an offer to buy or sell any asset. Please consult relevant documentation and a qualified professional before building production systems.

Research

Mastering API Rate Limits: Reliable Crypto Data Integration

Token Metrics Team
6

APIs are the backbone of most crypto applications, delivering vital real-time market prices, on-chain analytics, and network signals. Yet, while integrating a crypto data endpoint is powerful, developers quickly discover a common pain point: API rate limits. Mishandling these constraints can cause data gaps, failed requests, or even temporary bans—potentially compromising user experience or the accuracy of your analytics. Understanding how to manage API rate limits effectively ensures stable, scalable access to critical blockchain information.

Understanding API Rate Limits and Why They Exist

API rate limits are enforced restrictions on how many requests a client can send to an endpoint within a defined period—such as 60 requests per minute or 1,000 per day. Crypto data providers implement these limits to maintain their infrastructure stability, prevent abuse, and ensure fair resource allocation for all clients. The most common rate-limiting strategies include:

  • Fixed Window Limiting: A set number of requests per calendar window, resetting at defined intervals.
  • Sliding Window Limiting: Counts requests within a moving window, allowing more flexibility and better smoothing of spikes.
  • Token Buckets and Leaky Buckets: Algorithm-based approaches to queue, throttle, and allow bursting of requests within defined thresholds.

Unintentional breaches—like a runaway script or a poorly timed batch request—will result in HTTP 429 errors (“Too Many Requests”), potentially leading to temporary blocks. Therefore, proactively understanding rate limits is crucial for both robust integrations and courteous API consumption.

Detecting and Interpreting Rate Limit Errors in Crypto APIs

When your app or research tool interacts with a crypto data API, receiving a rate-limit error is an opportunity to optimize, not a dead end. Most reputable API providers, including those specializing in crypto, supplement response headers with usage limits and reset timers. Key signals to watch for:

  • Status Code 429: This HTTP response explicitly signals that you’ve exceeded the allowed request quota.
  • Response Headers: Look for headers like X-RateLimit-Limit, X-RateLimit-Remaining, and X-RateLimit-Reset. These values tell you your total quota, remaining requests, and when you can send requests again.
  • Error Messages: Many APIs provide contextual messages to guide backoff or retry behavior—pay close attention to any documentation or sample payloads.

Building logic into your client to surface or log these errors is essential. This helps in troubleshooting, performance monitoring, and future-proofing your systems as API usage scales.

Strategies to Handle API Rate Limits Effectively

Efficient handling of API rate limits is key for building dependable crypto apps, trading dashboards, and automated research agents. Here are recommended strategies:

  1. Implement Exponential Backoff and Retry Logic: Instead of retrying immediately on failure, wait progressively longer spans when facing 429 errors. This reduces the likelihood of repeated rejections and aligns with reputable rate-limiting frameworks.
  2. Utilize API Response Headers: Programmatically monitor quota headers; pause or throttle requests once the remaining count approaches zero.
  3. Batch and Cache Data: Where possible, batch queries and cache common results. For instance, if you repeatedly request current BTC prices or ERC-20 token details, store and periodically refresh the data instead of fetching each time.
  4. Distribute Requests: If integrating multiple endpoints or accounts, round-robin or stagger calls to mitigate bursts that could breach per-user or per-IP limits.
  5. Plan for Rate-Limit Spikes: Design your system to degrade gracefully when access is temporarily halted—queue requests, retry after the X-RateLimit-Reset time, or show cached info with a ‘refresh’ indicator.

These techniques not only ensure consistent access but also demonstrate good API citizenship, which can be crucial if you later negotiate higher access tiers or custom SLAs with a provider.

Choosing the Right Crypto Data API Provider and Access Plan

Providers vary widely in their rate limit policies—public/free APIs typically impose strict quotas, while premium plans offer greater flexibility. When selecting an API for your crypto project, assess:

  • Request Quotas: Are the given free or paid rate limits sufficient based on your projected usage and scaling plans?
  • Available Endpoints: Can you consolidate data (e.g., batch price endpoints) to reduce total requests?
  • Historical vs. Real-Time Data: Does your use case require tick-by-tick data, or will periodic snapshots suffice?
  • Support for Webhooks or Streaming: Some providers offer webhooks or WebSocket feeds, greatly reducing the need for frequent polling and manual rate limit management.
  • Transparency and Documentation: Comprehensive docs and explicit communication on limits, error codes, and upgrade paths make long-term integration smoother.

Regulatory and operational needs can also influence choice—some institutional settings require SLAs or security controls only available on enterprise tiers.

Unlocking Reliability with AI and Automation

The rise of AI agents and automated research scripts has made dynamic API rate-limit management even more critical. Advanced systems can:

  • Dynamically Adjust Polling Rates: Use monitoring or predictive AI to modulate fetching frequency based on quota and data volatility.
  • Contextual Decision-Making: Pause or prioritize high-value queries when usage nears the quota, supporting mission-critical research without service interruptions.
  • Error Pattern Analysis: Leverage logs to identify patterns in rate limit hits, optimizing workflows without manual intervention.

Solutions like Token Metrics combine robust crypto APIs with AI-driven research—offering developers programmable access and insights while simplifying best-practice integration and rate management.

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

FAQs About Handling API Rate Limits with Crypto Data Endpoints

What happens if I ignore API rate limits?

If you consistently exceed rate limits, you'll likely receive 429 errors, experience dropped requests, and risk a temporary or permanent ban. Responsible handling is essential for reliable data access.

Can I bypass rate limits by using multiple accounts?

Attempting to circumvent limits by creating many accounts or cycling IPs is discouraged and may violate API terms of use. It's better to work with providers for a proper upgrade or optimization strategy.

What libraries or tools help with rate limit handling?

Popular HTTP libraries like Axios (JavaScript), requests (Python), and HTTPX have built-in or community-supported retry/backoff plugins. Check your API ecosystem for recommended middlewares or SDKs supporting rate-limiting logic.

How does rate limiting differ between major crypto API providers?

Each provider implements unique quotas: some limit based on IP, API key, or endpoint type, and some support higher throughput via premium plans or batch querying. Always review documentation for specifics.

Should I contact support if I need higher API limits?

Yes. Many crypto API services offer tailored plans or enterprise integrations with higher quotas. Proactively communicating your use case helps unlock better terms and ensures ongoing support.

Disclaimer

This content is for educational and informational purposes only. It does not constitute investment advice, recommendation, or an offer to buy or sell any financial instrument. Use all APIs and tools in accordance with their terms and applicable regulations.

Research

How to Retrieve Bitcoin’s Current Price Using Public Crypto APIs

Token Metrics Team
6

Whether you're building a crypto dashboard, conducting blockchain research, or creating an automated trading bot, access to real-time Bitcoin pricing is essential. But how do developers and data analysts retrieve the current price of Bitcoin from a public crypto API—and what are the key considerations when choosing an API for this purpose?

Why Crypto APIs Are Core to Bitcoin Price Data

Crypto APIs—or Application Programming Interfaces—are structured gateways that let apps, bots, or websites communicate seamlessly with live crypto data sources. Instead of manually visiting exchanges or aggregators, an API call instantly delivers Bitcoin's current price in a standardized, machine-readable format. This capability underpins everything from price tickers to advanced algorithmic and AI-driven research tools.

Several types of organizations offer public crypto APIs, including:

Public APIs generally support unauthenticated (no login) endpoints for basic pricing, though many now require an API key for higher request rates and advanced data. Whether you’re a beginner or building a sophisticated AI agent, choosing the right crypto API—and querying it appropriately—is the foundational step.

Step-by-Step: Retrieving Bitcoin’s Price from a Public API

The most straightforward way to retrieve Bitcoin's current price is to query a reputable crypto API from your application or terminal. Here’s a typical workflow:

For more advanced needs, consider APIs offering historical pricing, volume data, or exchange-specific quotes, and always respect each provider’s usage policy.

Practical Examples: Using Python and JavaScript to Fetch Bitcoin’s Price

Let’s look at how you might programmatically retrieve Bitcoin price data using Python and JavaScript. These examples use the free CoinGecko public endpoint, but principles are similar for other providers (including Token Metrics). Remember: Always insert your API key if required and consult the provider's documentation for up-to-date endpoints.

For APIs requiring an API key, you typically add it via a header or as part of the URL (e.g., ?apikey=YOUR_API_KEY). Always treat keys securely and avoid sharing them in public code repositories.

How to Choose the Right Public Crypto API for Bitcoin Price Retrieval

Not all crypto APIs are equal: coverage, latency, historical data availability, and advanced analytics vary widely. Here are key factors to evaluate:

For enterprise or analytics-focused use cases, APIs like Token Metrics add value through comprehensive data sets, trading signals, and AI-powered insights, enabling deeper quantitative or on-chain research workflows.

Leveraging AI and Real-Time Crypto Analytics for Bitcoin Price Data

Modern crypto research isn’t just about fetching a price—it’s about contextualizing that price within broader trends. AI and machine learning models, including those powering platforms like Token Metrics, ingest live price feeds, on-chain metrics, social sentiment, and more to provide actionable analytics and deeper market understanding.

For developers and researchers, integrating public crypto price APIs is often the first step in powering:

Choosing an API that delivers not only price, but also analytical data, can accelerate both research and application development.

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

FAQs: Retrieving Bitcoin’s Current Price from Public APIs

What is a public crypto API?

A public crypto API is an interface provided by exchanges or data aggregators that allows users to access cryptocurrency data—such as price, volume, and other metrics—without requiring private access or fees. Some APIs may still require free registration for an API key.

Is public API Bitcoin price data real-time or delayed?

This depends on the provider. Leading APIs typically offer real-time or near real-time data (updated every second), but some aggregate or free APIs may introduce short delays. Always check the documentation for specifics on data freshness.

Are there rate limits for public crypto APIs?

Yes. Almost all public APIs have rate limits—typically restricting the number of requests per minute or per day. These are put in place to prevent abuse and ensure fair access for all users. Higher limits may be available with paid plans or API keys.

Can I use public Bitcoin price APIs for commercial projects?

This depends on the API’s terms of service. While many offer free public endpoints, commercial usage may be subject to tighter limits or require a paid plan. Always review the provider’s terms, especially for high-frequency or enterprise use.

How secure is it to use public crypto APIs?

Public APIs themselves are generally secure when accessed over HTTPS. However, always protect your API keys, follow provider best practices, and avoid exposing sensitive credentials in public code repositories or front-end codebases.

Disclaimer

This article is for informational purposes only. It does not constitute financial advice, recommendations, or endorsements. Always conduct independent research and comply with all applicable laws and API usage terms before integrating third-party data sources.

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