Cell Reference API
Spreadsheet cell-reference maths for Excel, Google Sheets, LibreOffice and CSV tooling. Parse an A1 reference (AA10) into its column letter, 1-based column number, row and R1C1 form; build an A1 (and R1C1) reference from a row and a column given either as a letter or a number; and convert a column letter to its number and back (A→1, Z→26, AA→27, ZZ→702). Absolute markers ($A$1) are accepted. Perfect for code that generates spreadsheets, maps data to cells, builds formulas, or imports and exports ranges. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 4 endpoints. Distinct from CSV parsing and from generic number-base conversion.
api.oanor.com/cellref-api
