the402 x402 endpoint directory

Interest calculator, compound interest, simple interest, loan payment, mortgage calculator, annuity, APR APY, future v

SSL/TLS certificate inspection: issuer, subject, valid_from, valid_to, days_remaining, SAN list, fingerprint, signatur

Look up scholarly metadata for any DOI via CrossRef. Returns title, authors, journal, publication date, abstract, cita

Look up arXiv preprint metadata. Returns title, authors, abstract, publish/update dates, categories, PDF URL, DOI, com

Support and resistance levels for any crypto from live OKX candles - classic floor-trader pivots (P, R1-R3, S1-S3) plu

List the ERC20 tokens an address holds on Base with symbol, decimals and formatted balance for each nonzero position.

Translate text between languages via MyMemory (free, 50+ languages). Returns translated text and match quality. Use ?q

Get Hyperliquid vault summaries sorted by APR

Answers 402 via GET. Speaks the v2 dialect over the PAYMENT-REQUIRED header, charges $0.008 on base.

Query Polymarket markets with filtering, sorting, and pagination

Query Kalshi markets with filtering, sorting, and pagination

Search markets across Polymarket, Kalshi, Limitless, Opinion, and Predict.Fun in a single call

List Polymarket events with filtering and sorting

List Polymarket markets with cursor-based keyset pagination (same filters as /polymarket/markets)

List Predict.Fun markets with filtering and sorting

Get the global leaderboard of smart wallets

Query historical Polymarket trade data with flexible filtering

Fear & Greed index history.

Fetch all user positions with filtering and pagination

Token price history.

Get OHLCV candlestick data for a Binance trading pair

Compare performance across trading style cohorts

CEX ticker price for a trading pair.

List UMA oracle questions filtered by state (proposed, disputed, resolved, …)

List Polymarket events with cursor-based keyset pagination

List crypto up/down prediction markets

List Limitless markets with filtering and sorting

List Opinion markets with filtering and sorting

Raw SQL query against 80+ ClickHouse tables (sub-second).

Batch wallet label lookup (CEX, Whale, Bridge, MEV…).

Aggregated wallet profile across chains.

Aggregated project profile (token + DeFi + social).

Web search across crypto sources.

Yield pool ranking (lending, LP, staking).

Fetch historical orderbook snapshots for a Predict.Fun market

Fetch historical orderbook snapshots for an Opinion market

Fetch historical orderbook snapshots for a Limitless market

Fetch historical orderbook snapshots for a Kalshi market

Bulk identity lookup for up to 200 wallet addresses (POST body: {addresses: [..]})

Batch retrieve wallet profiles for multiple addresses

Fetch trading activity (merges, splits, redeems) for a user

Get current or historical price for a specific token

Discover markets where high-performing wallets are active

Get raw book ticker data at microsecond granularity

Get current or historical price for a specific token

Exchange order book depth.

Perpetual contract snapshot.

Top token holders with balances.

Wallet transaction history.

Token rankings (market cap, volume, change).