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Really Simple Licensing (RSL)

Really Simple Licensing (RSL) is an open XML standard that lets publishers declare machine-readable usage, licensing, and compensation terms for AI crawlers and agents.
Updated August 1, 2026
AI

Definition

Really Simple Licensing (RSL) is an open, XML-based standard for expressing machine-readable licensing terms for digital assets. It was introduced in September 2025 and reached version 1.0 in December 2025, stewarded by the nonprofit RSL Collective, whose founders include RSS co-creator Eckart Walther. RSL deliberately builds on two familiar foundations: the RSS syndication format and the Robots Exclusion Protocol behind robots.txt.

Where robots.txt can only say allow or disallow, RSL describes terms. A publisher can declare that content is free for search indexing but licensed for AI training, or attach a payment model—free, attribution, subscription, pay-per-crawl, pay-per-inference, or a good-faith contribution. Pay-per-inference is the notable addition, billing when a model uses content to produce an answer rather than only when it fetches the page.

The standard ships with supporting protocols. The Crawler Authorization Protocol (CAP) uses an HTTP Authorization: License header so a server can verify permission and return 401 or 402 when it is missing. The Open License Protocol (OLP), an OAuth 2.0 extension, lets crawlers discover and acquire license tokens automatically. An encrypted media standard covers nonpublic assets such as books, video, and datasets. RSL documents are discovered through robots.txt, HTTP headers, RSS feeds, or HTML link elements.

RSL is a declaration layer, not an enforcement layer—much like robots.txt, it depends on good-faith compliance plus separate technical gates such as pay per crawl or Web Bot Auth. Early adopters included Reddit, Yahoo, Quora, and Medium, followed by publishers such as BuzzFeed, USA Today, and Vox Media. For GEO teams it is the most precise tool available for separating "index and cite me" from "train on me," which matters because those two decisions have opposite effects on AI search visibility.

Examples of Really Simple Licensing (RSL)

  • A publisher adds an RSL license file at the site root and references it from robots.txt, declaring free access for search indexing but pay-per-inference terms for AI answer generation.
  • A crawler without a valid license token requests a protected article and receives HTTP 401 Unauthorized rather than the content.
  • A media group uses RSL's pay-per-inference option so it is compensated whenever its reporting contributes to a generated answer, not just when a bot fetches the page.
  • A GEO team audits its RSL terms after noticing that a blanket AI restriction also suppressed the brand from AI Overviews and ChatGPT citations.

Terms related to Really Simple Licensing (RSL)

Publisher Licensing

Publisher licensing governs how AI companies access, train on, retrieve, display, or cite professional content.

AI

TDM Rights Reservation

TDM rights reservation is the use of legal and technical notices to reserve rights around text and data mining by AI systems.

AI

Pay Per Crawl

Pay per crawl is an arrangement where a site charges AI crawlers for each request using HTTP 402 Payment Required, instead of serving content for free or blocking it outright.

SEO

Content Signals

Content Signals is a robots.txt extension that lets publishers state how crawled content may be used—for search, AI input, or AI training—rather than only whether it may be fetched.

SEO

Web Bot Auth

Web Bot Auth is an IETF-track protocol that lets AI crawlers and agents cryptographically sign HTTP requests so sites can verify bot identity instead of trusting user-agent strings.

AI

Robots.txt

Root directory file instructing search engine and AI crawlers which pages to crawl or avoid—now critical for managing GPTBot, PerplexityBot, and ClaudeBot.

SEO

AI Web Crawlers

Bots deployed by AI companies to fetch web content for training and retrieval—comprising 95%+ of tracked crawler traffic, led by GPTBot and PerplexityBot.

AI

AI Training Data

The text, images, code, and multimedia content used to train large language models like current GPT models, Claude, and Gemini for AI applications.

AI

LLMs.txt

LLMs.txt is a proposed specification for controlling how AI crawlers and language models access website content, functioning as a robots.txt equivalent specifically designed for LLM interactions.

GEO

AI Regulation

AI Regulation encompasses the global framework of laws, guidelines, and standards governing the development, deployment, and use of artificial intelligence, including the landmark EU AI Act.

AI

Frequently Asked Questions about Really Simple Licensing (RSL)

Learn about AI visibility monitoring and how Promptwatch helps your brand succeed in AI search.

Robots.txt expresses binary crawl permissions: allow or disallow a path. RSL expresses licensing terms—what a crawler may do with the content, under which conditions, and at what price. RSL is designed to complement robots.txt, and RSL documents are commonly discovered through a reference in the robots.txt file.

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