Does https://<domain>/.well-known/apple-app-site-association exist? Requests the path and returns the HTTP status, content type, size and the first 300 characters when it is text. Presence of .well-known/apple-app-site-association tells you about the site's tooling and policies. $0.01 per check.

ERC-20 token metadata on Base, read live from the contract: name, symbol, decimals and total supply. Pass ?token=0x… (the token contract address). One eth_call set, no third-party API, no cache.

Live Chainlink price feed on Base, read from the oracle contract at request time: price, round id, last update and feed address. Pairs: ETH-USD, BTC-USD, SOL-USD, LINK-USD, CBETH-USD, AERO-USD, USDC-USD, EUR-USD. Pass ?pair=ETH-USD (default ETH-USD). No third-party API, no cache.

Status of a transaction on Base, read live: success or failure, block number, gas used, effective gas price, from, to. Pass ?hash=0x… (66 hex chars). Useful to confirm a payment or a call landed. No third-party API, no cache.

Encode and decode text: base64, hex and URL-encoding, both directions. POST JSON {"text": "…", "op": "base64"} where op is base64|base64d|hex|hexd|url|urld. Pure computation, nothing stored, no cache.

Encode and decode text: base64, hex and URL-encoding, both directions. POST JSON {"text": "…", "op": "base64"} where op is base64|base64d|hex|hexd|url|urld. Pure computation, nothing stored, no cache.

Hash text: keccak-256 (Ethereum) and SHA-256, plus byte length. POST JSON {"text": "…"} up to 20,000 characters. Pure computation, nothing stored, no cache.

Convert an amount of a crypto asset to USD using the live Chainlink price on Base. Pass ?from=ETH&amount=1.5 (assets: ETH, BTC, SOL, LINK, CBETH, AERO, EUR). Returns the rate used, the feed and its age. Oracle value, not a tradable quote. No cache.

ENS/basename name tools (pure computation): the namehash and labelhashes of a name, and its normalized form. POST JSON {"name": "alice.base.eth"}. Useful to build resolver calls yourself. Nothing stored, no cache.

A Base block read live from the chain: timestamp, transaction count, base fee, gas used and limit, miner. Pass ?n=<number> or omit for the latest block. No third-party API, no cache.

Convert an amount of a crypto asset to USD using the live Chainlink price on Base. Pass ?from=ETH&amount=1.5 (assets: ETH, BTC, SOL, LINK, CBETH, AERO, EUR). Returns the rate used, the feed and its age. Oracle value, not a tradable quote. No cache.

ERC-20 token metadata on Base, read live from the contract: name, symbol, decimals and total supply. Pass ?token=0x… (the token contract address). One eth_call set, no third-party API, no cache.

Status of a transaction on Base, read live: success or failure, block number, gas used, effective gas price, from, to. Pass ?hash=0x… (66 hex chars). Useful to confirm a payment or a call landed. No third-party API, no cache.

Hash text: keccak-256 (Ethereum) and SHA-256, plus byte length. POST JSON {"text": "…"} up to 20,000 characters. Pure computation, nothing stored, no cache.

ENS/basename name tools (pure computation): the namehash and labelhashes of a name, and its normalized form. POST JSON {"name": "alice.base.eth"}. Useful to build resolver calls yourself. Nothing stored, no cache.

A Base block read live from the chain: timestamp, transaction count, base fee, gas used and limit, miner. Pass ?n=<number> or omit for the latest block. No third-party API, no cache.

Solana SPL token profile and risk signals: supply, decimals, mint and freeze authorities (can the issuer mint more or freeze accounts?) and Token-2022 extensions.

Aave v3 position health for a wallet on five chains: collateral, debt, borrowing power, LTV, liquidation threshold and health factor with a risk label.

Uniswap v3 pool state on Base for a token pair: pool address per fee tier, spot price, tick, active liquidity and token reserves.

NFT lookup (ERC-721 / ERC-1155): collection name, owner, token URI and metadata (name, description, image, attributes).