#publishing

Bookbinding and print-production maths as an API, computed locally and deterministically — the spine-width and imposition numbers a book designer, printer or self-publisher needs to lay out a title. The spine endpoint computes the spine width from the page count and the paper's bulk: spine = page count ÷ pages-per-inch (the printer's paper spec, typically ~400–500 for book stock), or leaves × sheet caliper, plus the cover boards — so a 250-page book on 400-PPI stock has a 0.625-inch (15.9 mm) spine. The imposition endpoint works out the binding layout: for saddle-stitch it rounds the page count up to the next multiple of four (one folded sheet is four pages) and reports the blanks to pad and the sheets; for perfect-bound or section-sewn books it gathers the pages into signatures of 8, 16 or 32 and reports the signature count, the required page total and the blank pages. Everything is computed locally and deterministically, so it is instant and private. Ideal for self-publishing, print-on-demand, book-design, prepress and printing app developers, spine-and-cover and imposition tools, and graphic-design education. Pure local computation — no key, no third-party service, instant. Page count counts both sides; PPI is the paper spec. Live, nothing stored. 2 compute endpoints. For paper weight use a paper API and for DPI/resolution a resolution API.

api.oanor.com/bookbinding-api

ISBN validation and conversion as an API, computed locally and deterministically. The validate endpoint detects whether a code is an ISBN-10 or an ISBN-13, ignores hyphens and spaces, and verifies the check digit — ISBN-10 with the mod-11 scheme whose last character may be the letter X (for 10), and ISBN-13 with the weighted 1-3-1-3 mod-10 scheme — so 0-306-40615-2 and 978-0-306-40615-7 both validate while a wrong check digit is rejected. The checkdigit endpoint computes the trailing check digit for a 9-digit ISBN-10 stem or a 12-digit ISBN-13 stem (and recomputes it for a full code). The convert endpoint converts between the two forms: an ISBN-10 becomes an ISBN-13 by prefixing 978 and recomputing the check, and a 978-prefixed ISBN-13 converts back to ISBN-10 (979-prefixed codes have no ISBN-10 equivalent). Everything is computed locally and deterministically, so it is instant and private. Ideal for publishing, library, bookstore, catalogue, e-commerce and metadata app developers, ISBN-validation and barcode tools, and inventory systems. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is ISBN-specific validation and conversion; for generic Luhn/Verhoeff check digits use a check-digit API.

api.oanor.com/isbn-api

The TeX and LaTeX package ecosystem — CTAN, the Comprehensive TeX Archive Network — as an API. Look up any of CTAN's ~6,900 packages for its caption and description, latest version and date, license, authors (with resolved names), aliases, topics, home and repository links, and whether it ships with MiKTeX and TeX Live; search the whole registry by name and caption; and resolve any CTAN author id to a name. Covers the TeX/LaTeX world from PGF/TikZ, Beamer and KOMA-Script to amsmath, biblatex and listings. Live from the official CTAN JSON API. Ideal for LaTeX editors and tooling, package dashboards, academic-publishing pipelines and TeX ecosystem analytics. Open data from CTAN.

api.oanor.com/ctan-api