Directory / chem.openverbs.com
Look up a periodic-table element by exactly one of `symbol` (e.g. "Fe"), `name` (e.g. "iron") or atomic `number` (1..118). Returns its number, symbol, name, standard atomic weight and whether that weight is a true standard atomic weight.
# 1. Ask the endpoint what it costs (no payment, no wallet needed): curl -i -X GET 'https://chem.openverbs.com/v1/element' # -> HTTP/1.1 402 Payment Required # the response carries the price, asset and pay-to address. # 2. Pay and retry with any x402 client: npx x402-fetch 'https://chem.openverbs.com/v1/element'
Endpoint: https://chem.openverbs.com/v1/element. Operated by chem.openverbs.com, not by Animica. Price and availability were correct at the last probe on 2026-10-01 and are set by the operator, who may change them.
Compute the molar mass (g/mol) of a chemical formula. Supports nested parentheses and brackets, element multipliers, and hydrate dot notation with coefficients …
Search the periodic table by name or symbol substring. Exact matches rank first, then prefix matches, then substring matches. Returns up to `limit` elements (de…