# RSL: Machine-Readable Content Licensing for AI

> RSL (Really Simple Licensing) attaches five machine-readable AI license models: free, attribution, subscription, pay-per-crawl, pay-per-inference.

## RSL licenses content to AI machine-readably

RSL (Really Simple Licensing) is a machine-readable content-licensing standard that lets a publisher attach explicit terms to content for AI use, so the license travels with the content as parseable data rather than prose in a ToS page. An RSL license is publisher-controlled and referenced from `robots.txt`, which lets it be enforced at the edge (e.g. by Cloudflare reading the declared terms). RSL is a Layer-6 protocol; its launch date, exact model set/names, and adopters must be verified against the primary `rslstandard.org` spec at build.

## RSL spans five license models from free to pay-per-inference

- **Free** — use with no fee and no required credit.
- **Attribution** — use it, but credit and link the source.
- **Subscription** — flat-fee access for a licensee.
- **Pay-per-crawl** — charge per fetch.
- **Pay-per-inference** — charge each time the content is used to generate an answer.

The `rslstandard.org` spec is the authority for the names and definitions; confirm at build.

## Pay-per-inference prices the use, not just the fetch

**Pay-per-crawl** prices the *fetch* — the publisher is paid on retrieval. **Pay-per-inference** prices the *use in an answer* — the publisher is paid each time the content informs a generated response, aligning payment with the value an AI extracts. Because RSL is machine-readable and edge-enforceable, either model can be declared and collected without the publisher running its own billing stack.

Related: [RSL Layer-6 spec](/protocols/licensing/rsl) · [RSL in the Lexicon](/glossary/rsl) · [pay-per-crawl explained](/access-economics/pay-per-crawl) · [licensing layer](/protocols/licensing) · [AI access economics](/access-economics) · [audit your site](/services)