The BoltzPay SDK ships with a built-in directory of 25 verified paid API endpoints across two payment protocols (x402 and L402). All endpoints were confirmed live as of February 2026.
The directory is static and bundled with the SDK. Entries may become outdated as endpoints go online or offline. Use the discover command or sdk.discover() method to probe endpoints in real-time and get live pricing.
Directory entries
x402 (USDC on-chain)
Crypto Data
| Name | URL | Price | Description |
|---|
| Invy — Token Holdings | https://invy.bot/api | $0.05 | Token holdings lookup across Base, Ethereum, and Solana |
| x402-tools — Polymarket Trending | https://x402-tools.vercel.app/api/polymarket/trending | $0.01 | Trending prediction markets from Polymarket |
| Einstein AI — Top Tokens | https://emc2ai.io/x402/bitquery/top-tokens | $0.55 | Top tokens by market cap via Bitquery |
| Einstein AI — Whale Intel | https://emc2ai.io/x402/bitquery/whale-intel/raw | $0.85 | Whale wallet intelligence and tracking |
| Silverback — DeFi Top Protocols | https://silverback-x402.onrender.com/api/v1/top-protocols | $0.01 | Top DeFi protocols by TVL with multichain data |
| x402scan — Top Merchants | https://x402scan-j55w7ornb-merit-systems.vercel.app/api/data/merchants | $0.01 | Top x402 merchants by transaction volume |
| OttoAI — Token Security Audit | https://x402.ottoai.services/token-security | $0.01 | Token security scan — honeypot, rug pull, proxy detection |
| Zapper — Token Ranking | https://public.zapper.xyz/x402/token-ranking | $0.01 | Trending tokens ranked by swap activity and adoption velocity |
| Zapper — DeFi Balances | https://public.zapper.xyz/x402/defi-balances | $0.01 | DeFi positions (LP, lending, yield) for wallet addresses |
| Zapper — Transaction History | https://public.zapper.xyz/x402/transaction-history | $0.01 | Transaction history with interpretations for wallet addresses |
Utilities
| Name | URL | Price | Description |
|---|
| x402-tools — Concerts | https://x402-tools.vercel.app/api/concerts | $0.01 | Event and concert discovery |
| Auor — Public Holidays | https://api.auor.io/open-holidays/v1/public | $0.01 | Public holiday calendar by country and year |
| SocioLogic — Cryptographic RNG | https://rng.sociologic.ai/random/int | $0.01 | Cryptographically secure random integer |
| Grapevine — IPFS Gateway | https://gateway.grapevine.fyi/x402/cid/bafkreib7s7xuwc57wri43lyauwjeyfx3zqyc4ue34td5o7ab6wxp7sbqhm | $0.01 | IPFS content retrieval via x402 payment gateway |
Research
| Name | URL | Price | Description |
|---|
| PubMed Trends | https://pubmed.sekgen.xyz/api/v1/trends | $0.01 | Academic publication trends from PubMed |
| Hugen Scout — Intelligence Report | https://scout.hugen.tokyo/scout/report | $0.01 | Multi-source intelligence report from HN, GitHub, npm, PyPI |
| Name | URL | Price | Description |
|---|
| Creative-Tim — Shadcn Blocks | https://x402.creative-tim.com/shadcn-blocks/user-payment | $0.01 | View Shadcn UI component source code after payment |
Demo
| Name | URL | Price | Description |
|---|
| Nickel Joke (Testnet) | https://nickeljoke.vercel.app/api/joke | $0.005 (testnet) | Joke API on Base Sepolia testnet — useful for E2E testing |
| Hello World | https://hello-world-x402.vercel.app/hello | $0.01 | Returns “Hello World” after payment — simplest x402 sanity test |
| BoostPass Ping | https://boostpass.qrbase.xyz/api/x402/ping | $0.01 | Simple ping with payment confirmation and sender address |
| SkillfulAI — Demo Premium | https://api-dev.agents.skillfulai.io/api/x402/demo/mainnet/premium | $0.01 | Demo premium endpoint with payment verification details |
L402 (Bitcoin Lightning)
Crypto Data
| Name | URL | Price | Description |
|---|
| Satring — Analytics | https://satring.com/api/v1/analytics | 100 sats | Bitcoin and Lightning network analytics (90 services, categories, pricing) |
| Satring — Service Reputation | https://satring.com/api/v1/services/lightning-faucet-fortune/reputation | 100 sats | Detailed reputation report for L402 services (replace slug in URL) |
Categories
The directory organizes endpoints into 5 categories:
| Category | Description | x402 | L402 | Total |
|---|
crypto-data | Blockchain data, token analytics, DeFi, whale tracking | 10 | 2 | 12 |
utilities | Holidays, RNG, IPFS, events | 4 | 0 | 4 |
demo | Test and demo endpoints (often on testnet) | 4 | 0 | 4 |
research | Academic and intelligence reports | 2 | 0 | 2 |
dev-tools | UI components and developer resources | 1 | 0 | 1 |
Programmatic access
API_DIRECTORY
The full directory as a readonly array of ApiDirectoryEntry objects.
import { API_DIRECTORY } from '@boltzpay/sdk';
for (const entry of API_DIRECTORY) {
console.log(`${entry.name}: ${entry.url} (${entry.pricing})`);
}
ApiDirectoryEntry
interface ApiDirectoryEntry {
readonly name: string;
readonly url: string;
readonly protocol: string;
readonly category: string;
readonly description: string;
readonly pricing: string;
readonly chain?: string;
readonly status?: "live" | "testnet";
}
getDirectoryCategories()
Returns all distinct categories present in the directory.
import { getDirectoryCategories } from '@boltzpay/sdk';
const categories = getDirectoryCategories();
// ["crypto-data", "utilities", "demo", "research", "dev-tools"]
filterDirectory(category?)
Filter the directory by category. Returns the full directory if no category is provided.
import { filterDirectory } from '@boltzpay/sdk';
const cryptoApis = filterDirectory('crypto-data');
// Returns 12 entries in the crypto-data category
const all = filterDirectory();
// Returns all 25 entries
Live discovery
The static directory gives you a starting point, but endpoints can go offline. Use discover for real-time probing.
SDK
const entries = await sdk.discover({ category: 'crypto-data' });
for (const entry of entries) {
if (entry.live.status === 'live') {
console.log(`${entry.name}: ${entry.live.livePrice} (${entry.live.protocol})`);
}
}
Results are sorted by status: live first, then offline, error, and free.
CLI
# Discover all endpoints
boltzpay discover
# Filter by category
boltzpay discover -c crypto-data
# JSON output for scripting
boltzpay --json discover -c utilities
MCP
AI agents can call the boltzpay_discover tool:
Use boltzpay_discover with category "crypto-data" to find blockchain data APIs.
Probe timeout
Each endpoint probe has a 5-second timeout (DISCOVER_PROBE_TIMEOUT_MS = 5000). Endpoints that do not respond within 5 seconds are marked as offline with reason "Timeout".
You can pass an AbortSignal to cancel all probes early:
const controller = new AbortController();
setTimeout(() => controller.abort(), 10_000); // 10s total budget
const entries = await sdk.discover({
category: 'crypto-data',
signal: controller.signal,
});