Ranked by trial volume. The "Unique Users" column shows how many different developers are building in each category — a proxy for developer intent:
| # | Endpoint | Trials | Unique Users | Category |
|---|---|---|---|---|
| 1 | x402-captcha-solve | 398 | — | Anti-bot |
| 2 | x402-gas | 358 | — | Blockchain |
| 3 | x402-web-scrape | 257 | 25 | Web Tools |
| 4 | x402-find | 226 | — | Knowledge |
| 5 | x402-store | 187 | — | Storage |
| 6 | x402-recall | 158 | — | Memory |
| 7 | x402-token-security | 113 | 19 | Security |
| 8 | x402-polymarket | 109 | — | Prediction Markets |
| 9 | x402-time | 108 | 15 | Utility |
| 10 | x402-swap-safety | 72 | 1 | DeFi Security |
The top 3 endpoints — captcha solving, gas estimation, web scraping — aren't "AI" services. They're infrastructure that agents call to interact with the world. An agent browsing the web hits captchas. An agent transacting on-chain needs gas prices. An agent researching needs to scrape pages.
This matches a broader truth: agents are software that needs the same plumbing humans do — just programmatically. The highest-volume services are bridges between agents and human-oriented infrastructure.
Don't build another "AI summarizer" API. Build the pipes agents need: reliable web scraping with automatic captcha solving, chain-abstracted gas estimation, persistent key-value storage with TTLs. The demand is in the boring infrastructure, not the flashy AI.
Beyond the top 10, another 82 endpoints have meaningful trial volume. Everything from DNS lookups (20 trials) and IP geolocation (22) to token search (16), QR code generation (16), and sentiment analysis (33).
Usage by category:
| Category | Key Endpoints | Est. Combined Trials |
|---|---|---|
| Web & Data | web-scrape, web-retrieve, screenshot, text-scrape, http-analyze, fetch | ~500 |
| Blockchain & Crypto | gas, token-security, swap-safety, polymarket, wallet-intel, domain-intel, dex-price, funding-rate, onchain-reads, chain-registry, abi-lookup, tx-decode, wallet, ens-resolve, address-parse | ~900 |
| Knowledge & Search | find, polymarket-scan, search, keywords, defi-directory, bounties, ecosystem-health, trading-signal, fear-greed, agent-skill-pack, prompt-templates | ~550 |
| Storage & Memory | store, recall, data-enrich | ~360 |
| Utility | captcha-solve, time, uuid, base64, hash, jwt-decode, math, random, qr, csv-json, text-to-json, url-codec, text-diff, text-stats, regex-explain, language-detect, markdown, emoji, color, country, date-math, dns, ip-lookup, ping, uptime | ~1,080 |
| Security & Validation | email-verify, liveness-check-v1, account-age, guardian, npm-audit, pip-audit | ~145 |
| AI & Content | summarize, sentiment, api-review, agent-toolkit, pdf-text, render | ~140 |
Blockchain/crypto is the largest category by both endpoint count and volume. This makes sense: agents deploying on-chain need reliable, structured data about gas, tokens, security, prices, and transactions — things that are hard to scrape from block explorers but easy to expose as x402 APIs.
The developer journey tells its own story:
| Stage | Count | Conversion Rate |
|---|---|---|
| Trial users (made ≥1 free call) | 316 | — |
| Wallet users (registered USDC wallet) | 34 | 10.8% |
| Settled transactions (real USDC) | 54 | 0.45 USDC (54 settlements) |
A 10.8% trial-to-wallet conversion is healthy for developer infrastructure. But settled payments remain $0 — the "14 paid transactions ($12.75)" this article originally reported were misclassified entries — every transaction was real (see correction above). Developers are testing, not yet running production workloads. The 34 wallet users represent real intent — they connected a wallet because they plan to pay.
The biggest drop-off isn't from trial to wallet (10.8% is solid). It's from wallet to regular usage. Why? Because most agent frameworks don't yet have built-in x402 payment support. Developers who connect a wallet still have to write custom payment logic. This gap closes as SDK support grows (wayleave, centinel, level42, agentwallet-sdk).
The user distribution by endpoint reveals clusters of developer intent:
After 3,668 API calls across 92 endpoints from 316 developers:
🔗 Explore the full marketplace → · 📊 Live stats → · 🛠️ Get 5 free trial calls →