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How to Use x402 with Token Metrics: Composer Walkthrough + Copy-Paste Axios/HTTPX Clients

Learn x402 in two parts: first, use Token Metrics tools in Composer and watch paid API calls happen live. Then, build your own client with production-ready Axios and Python code that auto-handles payment flows.
Token Metrics Team
9 min read
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What You Will Learn — Two-Paragraph Opener

This tutorial shows you how to use x402 with Token Metrics in two ways. First, we will walk through x402 Composer, where you can run Token Metrics agents, ask questions, and see pay-per-request tool calls stream into a live Feed with zero code. Second, we will give you copy-paste Axios and HTTPX clients that handle the full x402 flow (402 challenge, wallet payment, automatic retry) so you can integrate Token Metrics into your own apps.

Whether you are exploring x402 for the first time or building production agent workflows, this guide has you covered. By the end, you will understand how x402 payments work under the hood and have working code you can ship today. Let's start with the no-code option in Composer.

Start using Token Metrics X402 integration here. https://www.x402scan.com/server/244415a1-d172-4867-ac30-6af563fd4d25 

Part 1: Try x402 + Token Metrics in Composer (No Code Required)

x402 Composer is a playground for AI agents that pay per tool call. You can test Token Metrics endpoints, see live payment settlements, and understand the x402 flow before writing any code.

What Is Composer?

Composer is x402scan's hosted environment for building and using AI agents that pay for external resources via x402. It provides a chat interface, an agent directory, and a real-time Feed showing every tool call and payment across the ecosystem. Token Metrics endpoints are available as tools that agents can call on demand.

Explore Composer: https://x402scan.com/composer

Step-by-Step Walkthrough

Follow these steps to run a Token Metrics query and watch the payment happen in real time.

  1. Open the Composer agents directory: Go to https://x402scan.com/composer/agents and browse available agents. Look for agents tagged with "Token Metrics" or "crypto analytics." Or check our our integration here. https://www.x402scan.com/server/244415a1-d172-4867-ac30-6af563fd4d25 
  2. Select an agent: Click into an agent that uses Token Metrics endpoints (for example, a trading signals agent or market intelligence agent). You will see the agent's description, configured tools, and recent activity.
  3. Click "Use Agent": This opens a chat interface where you can run prompts against the agent's configured tools.
  4. Run a query: Type a question that requires calling a Token Metrics endpoint, for example "Give me the latest TM Grade for Ethereum" or "What are the top 5 moonshot tokens right now?" and hit send.
  5. Watch the Feed: As the agent processes your request, it will call the relevant Token Metrics endpoint. Open the Composer Feed (https://x402scan.com/composer/feed) in a new tab to see the tool call appear in real time with payment details (USDC or TMAI amount, timestamp, status).

 

Composer agents directory: Composer Agents page: Each agent shows tool stack, messages, and recent activity.

 

Individual agent page: Agent detail page: View tools, description, and click "Use Agent" to start.

[INSERT SCREENSHOT: Chat interface]

Chat interface: Chat UI: Ask a question like "What are the top trading signals for BTC today?"

[INSERT SCREENSHOT: Composer Feed]

Composer Feed: Live Feed: Each tool call shows the endpoint, payment token, amount, and settlement status.

That is the x402 flow in action. The agent's wallet paid for the API call automatically, the server verified payment, and the data came back. No API keys, no monthly bills, just pay-per-use access.

Key Observations from Composer

  • Tool calls show the exact endpoint called (like /v2/tm-grade or /v2/moonshot-tokens)
  • Payments display in USDC or TMAI with the per-call cost
  • The Feed updates in real time, you can see other agents making calls across the ecosystem
  • You can trace each call back to the agent and message that triggered it
  • This is how agentic commerce works: agents autonomously pay for resources as needed

Part 2: Build Your Own x402 Client (Axios + HTTPX)

Now that you have seen x402 in action, let's build your own client that can call Token Metrics endpoints with automatic payment handling.

How x402 Works (Quick Refresher)

When you make a request with the x-coinbase-402 header, the Token Metrics API returns a 402 Payment Required response with payment instructions (recipient address, amount, chain). Your x402 client reads this challenge, signs a payment transaction with your wallet, submits it to the blockchain, and then retries the original request with proof of payment. The server verifies the settlement and returns the data. The x402-axios and x402 Python libraries handle this flow automatically.

Prerequisites

  • A wallet with a private key (use a testnet wallet for development on Base Sepolia, or a mainnet wallet for production on Base)
  • USDC or TMAI in your wallet (testnet USDC for testing, mainnet tokens for production)
  • Node.js 18+ and npm (for Axios example) or Python 3.9+ (for HTTPX example)
  • Basic familiarity with async/await patterns

Recommended Token Metrics Endpoints for x402

These endpoints are commonly used by agents and developers building on x402. All are pay-per-call with transparent pricing.

Full endpoint list and docs: https://developers.tokenmetrics.com 

Common Errors and How to Fix Them

Here are the most common issues developers encounter with x402 and their solutions.

Error: Payment Failed (402 Still Returned After Retry)

This usually means your wallet does not have enough USDC or TMAI to cover the call, or the payment transaction failed on-chain.

  • Check your wallet balance on Base (use a block explorer or your wallet app)
  • Make sure you are on the correct network (Base mainnet for production, Base Sepolia for testnet)
  • Verify your private key has permission to spend the token (no allowance issues for most x402 flows, but check if using a smart contract wallet)
  • Try a smaller request or switch to a cheaper endpoint to test

Error: Network Timeout

x402 requests take longer than standard API calls because they include a payment transaction. If you see timeouts, increase your client timeout.

  • Set timeout to at least 30 seconds (30000ms in Axios, 30.0 in HTTPX)
  • Check your RPC endpoint is responsive (viem/eth-account uses public RPCs by default, which can be slow)
  • Consider using a dedicated RPC provider (Alchemy, Infura, QuickNode) for faster settlement

Error: 429 Rate Limit Exceeded

Even with pay-per-call, Token Metrics enforces rate limits to prevent abuse. If you hit a 429, back off and retry.

  • Implement exponential backoff (wait 1s, 2s, 4s, etc. between retries)
  • Spread requests over time instead of bursting
  • For high-volume use cases, contact Token Metrics to discuss rate limit increases

Error: Invalid Header or Missing x-coinbase-402

If you forget the x-coinbase-402: true header, the server will treat your request as a standard API call and may return a 401 Unauthorized if no API key is present.

  • Always include x-coinbase-402: true in headers for x402 requests
  • Do not send x-api-key when using x402 (the header is mutually exclusive)
  • Double-check header spelling (it is x-coinbase-402, not x-402 or x-coinbase-payment)

Production Tips

  • Use environment variables for private keys, never hardcode them
  • Set reasonable max_payment limits to avoid overspending (especially with TMAI)
  • Log payment transactions for accounting and debugging
  • Monitor your wallet balance and set up alerts for low funds
  • Test thoroughly on Base Sepolia testnet before going to mainnet
  • Use TMAI for production to get the 10% discount on every call
  • Cache responses when possible to reduce redundant paid calls
  • Implement retry logic with exponential backoff for transient errors

Why This Matters for Agents

Traditional APIs force agents to carry API keys, which creates security risks and requires human intervention for key rotation and billing. With x402, agents can pay for themselves using wallet funds, making them truly autonomous. This unlocks agentic commerce where AI systems compose services on the fly, paying only for what they need without upfront subscriptions or complex auth flows.

For Token Metrics specifically, x402 means agents can pull real-time crypto intelligence (signals, grades, predictions, research) as part of their decision loops. They can chain our endpoints with other x402-enabled tools like Heurist Mesh (on-chain data), Tavily (web search), and Firecrawl (content extraction) to build sophisticated, multi-source analysis workflows. It is HTTP-native payments meeting real-world agent use cases.

FAQs

Can I use the same wallet for multiple agents?

Yes. Each agent (or client instance) can use the same wallet, but be aware of nonce management if making concurrent requests. The x402 libraries handle this automatically.

Do I need to approve token spending before using x402?

No. The x402 payment flow uses direct transfers, not approvals. Your wallet just needs sufficient balance.

Can I see my payment history?

Yes. Check x402scan (https://x402scan.com/composer/feed) for a live feed of all x402 transactions, or view your wallet's transaction history on a Base block explorer.

What if I want to use a different payment token?

Currently x402 with Token Metrics supports USDC and TMAI on Base. To request support for additional tokens, contact Token Metrics.

How do I switch from testnet to mainnet?

Change your viem chain from baseSepolia to base (in Node.js) or update your RPC URL (in Python). Make sure your wallet has mainnet USDC or TMAI.

Can I use x402 in browser-based apps?

Yes, but you will need a browser wallet extension (like MetaMask or Coinbase Wallet) and a frontend-compatible x402 library. The current x402-axios and x402-python libraries are designed for server-side or Node.js environments.

Next Steps

Disclosure

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

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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

What Is a Crypto Index? Why Weekly Rebalancing Matters (2025)

Token Metrics Team
4

Understanding how to efficiently manage exposure in the dynamic world of cryptocurrency can seem daunting. Crypto indices provide a structured approach, helping investors and traders maintain diversified exposure without constant oversight. This article explores what crypto indices are, how they work, and why their rebalancing strategies are crucial in 2025.

What Is a Crypto Index?

A crypto index is a rules-based basket of digital assets that tracks a specific set of cryptocurrencies, such as the top-100 by market capitalization. These indices are designed to reflect broad market trends while reducing the complexity of individual asset management. They typically rebalance periodically to maintain consistent exposure, adapting to market fluctuations over time.

How Crypto Indices Work

The core mechanism involves a few key processes:

Benefits of Using Crypto Indices

Crypto indices offer several advantages:

How to Get Early Access to a Crypto Index

Investors interested in accessing crypto indices can follow a straightforward process:

Decision Guide: Is This for You?

Crypto indices may suit different kinds of investors:

Understanding your trading style and risk appetite can help determine if a crypto index fits within your broader strategy.

Discover Crypto Gems with Token Metrics AI

Get Started For Free

FAQs

What is a crypto index?

A crypto index is a rules-based basket that tracks a defined set of assets (e.g., the top-100 by market cap), with a scheduled rebalance to keep exposure aligned. Token Metrics applies that idea and adds a regime switch to stablecoins.

How often does TM Global 100 rebalance?

Weekly. Constituents and weights update on schedule; if the market regime changes, the portfolio can switch between tokens and stablecoins outside that cadence.

What triggers the move to stablecoins?

A proprietary market signal. Bullish: hold the top-100 basket. Bearish: exit to stablecoins and wait for a re-entry signal.

Can I fund with USDC or fiat?

At launch, funding options including wallet-funding supported by the embedded smart wallet and supported chains; USDC payouts are available when selling. Details are available during the buy/sell process.

Is the wallet custodial?

No. The embedded wallet is self-custodial—you control your funds and keys.

How are fees shown?

Before confirming, you'll see estimated gas costs, platform fees, max slippage, and minimum expected value.

How do I join the waitlist?

Visit the Token Metrics indices hub, open TM Global 100, and tap “Join Waitlist.” We will notify you once trading opens.

Security, Risk & Transparency

Self-custody: Embedded smart wallet with user-controlled keys. Transparency: Clear rules, holdings Treemap, and transactions logs. Fees: Shown before confirmation. Limitations: Signals can be wrong, no performance guarantees. Availability may vary by region and device.

Disclaimer

Crypto is volatile and can lose value. Past performance does not predict future results. This article is for research and educational purposes only, not financial advice.

Research

Predictable Crypto: The Index That Moves to Stablecoins When It Should (2025)

Token Metrics Team
4

If you’ve ever wished for a crypto index that participates broadly in bull markets yet steps aside when risk turns south, this is it. Token Metrics Global 100 is a rules-based index that holds the top 100 crypto assets when our market signal is bullish—and moves fully to stablecoins when it isn’t. It rebalances weekly, shows transparent holdings and transaction logs, and can be purchased in one click with an embedded wallet. That’s disciplined exposure, minus the micromanagement. → Join the waitlist to be first to trade TM Global 100.

Why Indices Matters in October 2025

Two things define this cycle: speed and uncertainty. Narratives rotate in weeks, not months, and individual-coin risk can swamp portfolios. Indices let you own the market when conditions warrant, while a regime-switching approach aims to sidestep drawdowns by cutting risk to stablecoins. (A crypto index is a rules-based basket tracking a defined universe—here, a top-100 market-cap set—with scheduled rebalances.)

How the TM Global 100 Index Works

Regime switching: Bull: hold the top 100 by market cap. Bear: move fully to stablecoins, wait for a bullish re-entry signal.

Weekly rebalancing: Updates weights and constituents to reflect the current top-100 list.

Transparency: A Strategy modal explains rules; a Gauge shows the live market signal; Holdings appear in Treemap + Table; and every rebalance/transaction is logged.

What you’ll see on launch: Price tile • “100 tokens” • “rebalances weekly” • one-click Buy Index flow. → See the strategy and rules. (TM Global 100 strategy)

Benefits at a Glance (Why This Beats DIY)

Time back: No more tracking 100 tickers or manual reweights. The weekly job runs for you.

Discipline on drawdowns: The stablecoin switch enforces risk management when the signal turns.

Less execution drag: One embedded wallet checkout vs. dozens of small trades that add slippage and fees.

See everything: Gauge → Treemap → Transactions Log—know what you hold, and what changed.

Own the market when it’s worth it: Capture broad upside in bullish regimes with top-100 breadth.

Step-by-Step: How to Get Early Access (Waitlist)

Open the Token Metrics Indices hub.

Tap TM Global 100 and select Join Waitlist.

(Optional) Connect wallet to preview the one-click Buy flow and funding options.

On launch, you’ll receive an email and in-app prompt.

Click Buy Index → review fees/slippage/holdings → confirm. Most users finish in ~90 seconds.

Track your position under My Indices with real-time P&L and a full transactions history. → Join the waitlist to be first to trade TM Global 100.

Decision Guide: Is This Right for You?

  • Hands-Off Allocator: Want broad exposure without micromanaging? Consider TM Global 100 for rules-based coverage.
  • Active Trader: Prefer a disciplined core that exits to stables while you run satellite bets.
  • TM Member/Prospect: Already read our research? This turns it into an actionable, one-click index.
  • New to On-Chain: Embedded wallet + clear fees and logs lower the operational lift.
  • Skeptical of Black Boxes: Full strategy copy, holdings, and rebalance logs are visible—no mystery knobs.

FAQs

What is a “crypto index”?

A rules-based basket that tracks a defined universe (here: top-100 market cap), with scheduled rebalances and clear inclusion criteria.

How often does the index rebalance?

Weekly, with additional full-portfolio switches when the market regime changes.

What triggers the move to stablecoins?

A proprietary market signal. Bullish: hold top-100. Bearish: move fully to stablecoins until re-entry.

Can I fund with USDC or fiat?

You’ll use the embedded wallet and supported on-chain assets; USDC is supported for selling. Funding options surface based on chain/wallet at checkout.

Is the wallet custodial?

No. It’s an embedded, self-custodial smart wallet—you control funds.

How are fees shown?

At checkout, you’ll see estimated gas, platform fee, max slippage, and minimum expected value before confirming.

How do I join the waitlist?

Visit the Indices hub, open TM Global 100, and tap Join Waitlist; we’ll notify you at launch.

Security, Risk & Transparency

Self-custody: Embedded smart wallet; you hold keys.

Operational clarity: Strategy modal, Holdings treemap/table, and Transactions log.

Fee & slippage preview: All shown before you confirm.

Regime logic limits: Signals can be wrong; switching can incur spreads and gas.

Region notes: Chain and asset support may vary by user wallet and jurisdiction.

Crypto is volatile and can lose value. Past performance is not indicative of future results. This article is for research/education, not financial advice.

Conclusion

If you want broad upside when it’s worth it and stablecoins when it’s not—with weekly rebalances, transparent logs, and a 90-second buy flow—Token Metrics Global 100 was built for you. Join the waitlist now and be first to trade at launch.

Research

How Do People Research Tokens and Coins Before Buying? A Complete Guide

Talha Ahmad
5 min

The cryptocurrency market has evolved from a niche digital experiment into a multi-trillion-dollar asset class. With thousands of tokens and coins available across hundreds of exchanges, the question isn't whether you should research before buying—it's how to conduct that research effectively. Smart investors know that thorough due diligence is the difference between identifying the next promising project and falling victim to a costly mistake.

The Foundation: Understanding What You're Buying

Before diving into specific research methods, successful crypto investors start by understanding the fundamental difference between various digital assets. Bitcoin operates as digital gold and a store of value, while Ethereum functions as a programmable blockchain platform. Other tokens serve specific purposes within their ecosystems—governance rights, utility functions, or revenue-sharing mechanisms.

The first step in any research process involves reading the project's whitepaper. This technical document outlines the problem the project aims to solve, its proposed solution, tokenomics, and roadmap. While whitepapers can be dense, they reveal whether a project has substance or merely hype. Pay attention to whether the team clearly articulates a real-world problem and presents a viable solution.

Analyzing the Team and Development Activity

A cryptocurrency project is only as strong as the team behind it. Investors scrutinize founder backgrounds, checking their LinkedIn profiles, previous projects, and industry reputation. Have they built successful companies before? Do they have relevant technical expertise? Anonymous teams aren't automatically red flags, but they require extra scrutiny and compelling reasons for their anonymity.

Development activity serves as a crucial health indicator for any blockchain project. GitHub repositories reveal whether developers are actively working on the project or if it's effectively abandoned. Regular commits, open issues being addressed, and community contributions all signal a vibrant, evolving project. Conversely, repositories with no activity for months suggest a project that may be dying or was never serious to begin with.

Diving Into Tokenomics and Supply Mechanics

Understanding a token's economic model is essential for predicting its long-term value potential. Investors examine total supply, circulating supply, and emission schedules. Is the token inflationary or deflationary? How many tokens do the team and early investors hold, and when do those tokens unlock? Large unlock events can trigger significant price drops as insiders sell.

The token's utility within its ecosystem matters tremendously. Does holding the token provide governance rights, staking rewards, or access to platform features? Tokens without clear utility often struggle to maintain value over time. Smart researchers also investigate how value accrues to token holders—whether through buybacks, burning mechanisms, or revenue sharing.

Evaluating Market Metrics and Trading Data

Price action tells only part of the story, but market metrics provide valuable context. Trading volume indicates liquidity—can you buy or sell significant amounts without drastically moving the price? Market capitalization helps determine a token's relative size and potential growth runway. A small-cap project has more room to grow but carries higher risk.

On-chain metrics offer deeper insights into token health. Active addresses, transaction volume, and network usage reveal actual adoption versus speculation. High trading volume on exchanges with minimal on-chain activity might indicate wash trading or manipulation. Token distribution matters too—if a small number of wallets hold most of the supply, the token faces centralization risks and potential price manipulation.

Leveraging Advanced Analytics Platforms

Professional crypto investors increasingly rely on sophisticated analytics platforms that aggregate multiple data sources and provide actionable insights. Token Metrics has emerged as a leading crypto trading and analytics platform, offering comprehensive research tools that save investors countless hours of manual analysis.

Token Metrics combines artificial intelligence with expert analysis to provide ratings and predictions across thousands of cryptocurrencies. The platform evaluates projects across multiple dimensions—technology, team, market metrics, and risk factors—delivering clear scores that help investors quickly identify promising opportunities. Rather than manually tracking dozens of metrics across multiple websites, users access consolidated dashboards that present the information that matters most.

The platform's AI-driven approach analyzes historical patterns and current trends to generate price predictions and trading signals. For investors overwhelmed by the complexity of crypto research, Token Metrics serves as an invaluable decision-support system, translating raw data into understandable recommendations. The platform covers everything from established cryptocurrencies to emerging DeFi tokens and NFT projects, making it a one-stop solution for comprehensive market research.

Assessing Community and Social Sentiment

Cryptocurrency projects thrive or die based on their communities. Active, engaged communities signal genuine interest and adoption, while astroturfed communities relying on bots and paid shillers raise red flags. Investors monitor project Discord servers, Telegram channels, and Twitter activity to gauge community health.

Social sentiment analysis has become increasingly sophisticated, with tools tracking mentions, sentiment polarity, and influencer engagement across platforms. Sudden spikes in social volume might indicate organic excitement about a partnership or product launch—or orchestrated pump-and-dump schemes. Experienced researchers distinguish between authentic enthusiasm and manufactured hype.

Understanding Regulatory and Security Considerations

The regulatory landscape significantly impacts cryptocurrency projects. Researchers investigate whether projects have faced regulatory scrutiny, registered as securities, or implemented compliance measures. Geographic restrictions, potential legal challenges, and regulatory clarity all affect long-term viability.

Security audits from reputable firms like CertiK, Trail of Bits, or ConsenSys Diligence provide crucial assurance about smart contract safety. Unaudited contracts carry significant risk of exploits and bugs. Researchers also examine a project's history—has it been hacked before? How did the team respond to security incidents?

Reading Between the Lines: Red Flags and Warning Signs

Experienced investors develop instincts for spotting problematic projects. Guaranteed returns and promises of unrealistic gains are immediate red flags. Legitimate projects acknowledge risk and market volatility rather than making impossible promises. Copied whitepapers, stolen team photos, or vague technical descriptions suggest scams.

Pressure tactics like "limited time offers" or artificial scarcity designed to force quick decisions without research are classic manipulation techniques. Projects with more focus on marketing than product development, especially those heavily promoted by influencers being paid to shill, warrant extreme skepticism.

The Research Never Stops

Cryptocurrency research isn't a one-time activity but an ongoing process. Markets evolve rapidly, projects pivot, teams change, and new competitors emerge. Successful investors establish systems for monitoring their holdings and staying updated on developments. Setting up Google Alerts, following project social channels, and regularly reviewing analytics help maintain awareness of changing conditions.

Whether you're evaluating established cryptocurrencies or exploring emerging altcoins, thorough research remains your best defense against losses and your greatest tool for identifying opportunities. The time invested in understanding what you're buying pays dividends through better decision-making and improved portfolio performance in this dynamic, high-stakes market.

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