Automated EPUB structural preflight

Automated screen for one base64-encoded EPUB, maximum 4 MiB. It checks ZIP structure, the EPUB mimetype and container, package manifest resource references, spine references, and basic title/identifier/navigation metadata.

Price: $0.05 USDC per call on Base via x402.

Send a POST request to /audit with JSON containing an epub_base64 string. An unpaid request should return HTTP 402 payment details; use an x402-compatible client to pay and retry.

Example

curl -X POST 'https://YOUR-DEPLOYED-HOST/audit' \
  -H 'Content-Type: application/json' \
  -d '{"epub_base64":"BASE64_ENCODED_EPUB"}'

Limits and caveats

Maximum EPUB input: 4 MiB; maximum 400 ZIP entries; each inspected expanded entry is limited to 2 MiB.
This is an automated structural screen, not EPUBCheck, complete EPUB conformance validation, accessibility or WCAG certification, assistive-technology testing, or a retailer acceptance guarantee.
Automated checks can miss problems. Submit only content you are authorized to process; do not send confidential or unpublished manuscripts unless you accept the risks of sending them to a hosted service.

Independent service; not affiliated with EPUB or any retailer.