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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 provides powerful crypto analytics, signals, and AI-driven tools to help you make smarter trading and investment decisions. Start exploring Token Metrics ratings and APIs today for data-driven success.

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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
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Recent Posts

Research

Regime Switching Explained: Why Smart Crypto Indices Move to Stablecoins

Token Metrics Team
6

The best trade in crypto isn't always a trade—sometimes it's knowing when to step aside. While traditional indices force you to ride every crash from peak to bottom, regime-switching indices take a smarter approach: participate when conditions warrant, preserve capital when they don't. This systematic method of moving between crypto exposure and stablecoins has become the defining feature of next-generation index products, with Token Metrics leading the implementation through data-driven market signals.

What Is Regime Switching?

Regime switching is a systematic investment approach that classifies market conditions into distinct states—typically "bullish" and "bearish"—then adjusts portfolio positioning accordingly. Unlike static indices that maintain constant exposure regardless of conditions, regime-switching strategies dynamically allocate between risk assets and defensive positions based on quantifiable signals.

In practice for crypto indices:

This isn't emotional market timing or gut-feel trading. It's rules-based risk management following consistent, transparent criteria. The decision to switch regimes comes from systematic signals, not fear or greed.

The Traditional Index Problem

Standard crypto indices like market-cap weighted baskets operate on a simple premise: buy the universe, hold forever, rebalance periodically. This works well in prolonged bull markets but fails catastrophically during extended bear cycles.

Real performance data illustrates the problem:

Net result: Investors who bought January 2021 and held through December 2022 saw minimal net gains despite experiencing a massive bull run. The issue isn't the bull market capture—traditional indices do fine when prices rise. The problem is forced participation during catastrophic drawdowns that destroy years of gains in months. A 75% drawdown requires a 300% gain just to break even.

Research across historical crypto cycles shows that systematic regime-switching approaches have historically reduced maximum drawdowns by 40-60% while capturing 70-85% of bull market upside—a compelling risk-adjusted return profile that buy-and-hold cannot match.

Why Stablecoins, Not Cash?

Regime-switching crypto indices face a unique constraint: they operate on-chain and must maintain 24/7 liquidity for instant redeployment. This makes stablecoins the optimal defensive asset for several critical reasons:

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The Signal Behind the Switch

The most critical component of regime-switching isn't the mechanism—it's the signal that triggers the switch. Token Metrics has built its reputation as a leading crypto analytics platform by developing sophisticated, data-driven market intelligence relied upon by over 50,000 traders and investors daily.

Token Metrics' Market Regime Detection employs a proprietary multi-factor model analyzing:

This synthesis results in a probabilistic assessment: whether the environment is bullish enough to risk capital or bearish enough to prioritize preservation.

Transparency is maintained by displaying current regime signals in real-time via visual market gauges, while proprietary model parameters and thresholds remain confidential to prevent strategic front-running.

Real Performance: When Regime Switching Matters Most

Regime-switching strategies excel during major bear markets that erode traditional portfolios:

Starting with $100,000 in November 2021, buy-and-hold would result in approximately $89,000 after recovering from -73%. The regime approach, with smaller drawdowns and better upside capture, could have grown the portfolio to around $152,000, emphasizing how avoiding large losses compounds benefits over time.

Implementation: How TM Global 100 Executes Switches

The TM Global 100 index automates regime switching with simplicity and transparency:

User Experience

Behind the Scenes

When signals turn bearish, the index:

Reversal when signals turn bullish follows the same systematic process.

The Cost of Switching

Every regime transition incurs costs:

Token Metrics estimates costs at approximately 0.8-1.5% per full switch, which becomes cost-effective when signals reliably avoid large drawdowns. Frequent whipsaws are mitigated by the model's stability factors, and projected costs are shown upfront for transparency.

Decision Framework: Is Regime Switching Right for You?

Consider regime switching if you:

Alternatively, if you have long-term horizons, believe markets are fully efficient, or prefer a buy-and-hold strategy, it might not suit you. Both approaches have their merits, but regime switching offers a balanced risk-adjusted profile for volatile crypto markets.

Where Research Meets Execution

Token Metrics has established itself as a leading crypto analytics platform by providing:

However, research alone isn't enough. The TM Global 100 index closes the gap between signal generation and automated execution—applying sophisticated regime logic seamlessly, enabling users to act on data-driven insights instantly with transparency and confidence.

Conclusion: Discipline Over Emotion

Regime switching removes emotional decision-making—often the hardest part of crypto investing. It systematically guides investors to participate during bull runs, protect capital during downturns, and avoid knee-jerk reactions to market volatility. This disciplined approach helps to sustain long-term growth while minimizing the pain of large drawdowns, demonstrating the evolution of systematic crypto investment strategies.

Click here to get early access to Token Metrics indices.

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.

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