x402 Directory

Onchain

Paid onchain APIs an AI agent can call with x402.

516 endpoints

Onesource · Chain Network Info

Onesource · api.onesource.io

EVM network info - chain ID, block height, gas price, chain head age, and chain characteristics in one batched RPC call (eth_chainId + eth_blockNumber + eth_gasPrice + latest block header)

$0.001 Base 100% up 448 paid calls

Onesource · Chain Estimate GAS

Onesource · api.onesource.io

Estimate the gas a transaction will consume via eth_estimateGas before signing it

$0.004 Base 100% up 442 paid calls

Onesource · Chain Erc1155 Balance

Onesource · api.onesource.io

ERC1155 token balance via balanceOf (eth_call) - how many copies of a token_id a wallet holds

$0.003 Base 100% up 441 paid calls

Onesource · Chain Events

Onesource · api.onesource.io

Query Ethereum contract event logs via eth_getLogs - filter by contract, topic, and block range

$0.005 Base 100% up 433 paid calls

Onesource · Chain Code

Onesource · api.onesource.io

Check if an Ethereum address is a contract via eth_getCode - returns deployed bytecode

$0.003 Base 100% up 422 paid calls

Onesource · Chain Call

Onesource · api.onesource.io

Simulate a read-only Ethereum contract call via eth_call - no transaction sent

$0.005 Base 100% up 416 paid calls

Onesource · Chain Allowance

Onesource · api.onesource.io

ERC20 allowance via allowance (eth_call) - how much a spender is approved to move from an owner's wallet

$0.003 Base 100% up 415 paid calls

Nansen · TGM Holders

Nansen · api.nansen.ai

Get "Token God Mode" (TGM) holders data

$0.05 Base 100% up 269 paid calls

svm402-service · Discover

svm402-service · svm402.com

Discover newly active Solana tokens ranked by genuine organic activity, filtered to exclude wash trading. Optionally filter by minimum organic score and holder count. Call this to find tokens worth researching further with /analyze or /safety. — $0.02 USDC

$0.02 Solana 249 paid calls

Kronos Crypto Data & Forecasts · Price BTC

Kronos Crypto Data & Forecasts · kronossignals.com

Multi-source volume-weighted median (VWM) spot price for 16 crypto assets (BTC/ETH/SOL/BNB/XRP/DOGE/ADA/AVAX/LINK/DOT/LTC/TRX/BCH/ATOM/NEAR/APT). Aggregates Binance, Coinbase, Kraken, and OKX in parallel (2 s timeout per source). Includes 1% outlier rejection, cross-exchange spread %, confidence grading (high/medium/low), and per-source USD volume weights. Kaiko-style reference pricing — $0.02/call.

$0.02 Base 100% up 244 paid calls

Suverse · Solana Quote

Suverse · proxy.suverse.io

Bidirectional SPL token swap aggregator on Solana mainnet via Jupiter v6 routing across 30+ DEXs (Raydium, Orca, Meteora, Phoenix). USDC to BONK WIF POPCAT JUP RAY ORCA SOL MEW BOME or any SPL, and reverse to USDC. Two-step quote/execute x402 flow. 1% fee. AI agent swap. memecoin DEX.

$0.001 Solana 100% up 241 paid calls

Onesource · Chain Storage

Onesource · api.onesource.io

Read a raw storage slot from any Ethereum contract via eth_getStorageAt

$0.005 Base 100% up 232 paid calls

Onesource · Chain Pending

Onesource · api.onesource.io

Pending block - transactions not yet mined, via eth_getBlockByNumber("pending")

$0.01 Base 100% up 230 paid calls

Twin3 · Human

Twin3 · human.twin3.ai

Human verification for AI agents — proof of humanity, sybil resistance, and 'is this wallet a real person' answers in one paid call. Returns two ZK-style outputs about any EVM wallet: (1) total humanity score 0-255 (15 = baseline reCAPTCHA, 45 = + Google OAuth, 70 = + Apple ID, 105 = + 2FA, 255 = full stack), with optional `min_score=N` for a yes/no `passes` verdict; (2) per-method verification check via `check=telegram,apple,g2fa,...` — buyer must NAME the methods to ask about, we never enumerate the full set. Backed by 141,871 Twin Matrix Soulbound Tokens on BNB Chain plus the canonical humanity registry off-chain. The underlying verification list never leaves Twin3 — only verdicts.

$0.001 Base 216 paid calls

Crypto Spot Price · Crypto

Crypto Spot Price · x402.shizu.me

Current spot price for crypto trading pairs. Input: pair — a single pair (BTC-USD) or up to 10 comma-separated pairs (BTC-USD,ETH-USD,SOL-USD) returned in ONE call for the same price — poll a whole portfolio per tick. Returns amount and currency per pair. Real-time from Coinbase.

$0.007 Base 100% up 216 paid calls

Otto AI · Token Price

Otto AI · x402.ottoai.services

Live DEX token price in USD by ticker symbol or contract address across Base, Ethereum, Solana, Polygon, BSC, Arbitrum, Optimism and Avalanche (bare 0x tries Base then all chains, else network:address). Symbols resolve to the canonical top-market-cap asset — squat-proof. Flat JSON: price, 24h change, volume, market cap, FDV, liquidity — echoes the matched deployment. Token price, crypto price, DEX price. $0.001 per call.

$0.001 Base 100% up 205 paid calls

Kronos Crypto Data & Forecasts · Forecast BTC

Kronos Crypto Data & Forecasts · kronossignals.com

Real-time and ML-forecasted Bitcoin (BTC) price. Kronos deep-learning model: up-probability, expected close, price range, p10-p90 quantiles, forward volatility across 1h/4h/24h horizons. Crypto price prediction / price forecast API for AI agents and trading bots. Pay-per-call via x402 on Base USDC. Live track record at /api/stats: ~54% directional hit, ~70% in-range over 15k+ scored forecasts — measured on served predictions, not a backtest.

$0.05 Base 100% up 187 paid calls

Blockscout · Tokens Holders

Blockscout · api.blockscout.com

Access to api/v2/tokens/:address_hash/holders. List addresses holding a specific token sorted by balance

$0.002 Base 179 paid calls

Otto AI · Base Season

Otto AI · x402.ottoai.services

Base social intelligence: a Base sentiment read + quality-screened Base tokens (CoinGecko-listed, market-cap/age/liquidity gated) catching attention, each labelled with the basis it stands on (`rankedBy`: measured trusted-KOL signal, or the on-chain screen plus engagement), with KOL quotes inside a published window (`evidenceWindowDays`). Served from a cached snapshot while fresh (≤1h) and regenerated on demand when a read finds it stale.

$0.002 Base 100% up 175 paid calls

Otto AI · Base Ecosystem News

Otto AI · x402.ottoai.services

Base-chain ecosystem news for Base-native agents, not the general crypto firehose. Up to 12 Base-scoped headlines from the last 48h, each with its own permalink and publication timestamp, screened against the general /crypto-news feed; `screen` states what was dropped. The AI topic read is optional and is withheld, never padded with macro, when there is no Base coverage. Refreshed hourly from cache; a read past the freshness window pulls inline.

$0.001 Base 100% up 165 paid calls

Suverse · Base Quote

Suverse · proxy.suverse.io

Bidirectional ERC20 token swap aggregator on Base mainnet via LiFi routing across 20+ DEXs (Uniswap V3, Aerodrome, BaseSwap, SushiSwap). USDC to WETH AERO DEGEN BRETT TOSHI cbETH cbBTC or any ERC20, and reverse to USDC. Two-step quote/execute x402 flow. 1% fee. AI agent swap. L2 DEX.

$0.001 Base 100% up 153 paid calls