Urlanguage

Urlanguage is a theoretical formal language intended to express structured information about web resources directly within a URL. Proponents describe it as a tiny grammar that encodes resource type, actions, parameters, and constraints in a machine-readable way to guide retrieval, navigation, and interpretation by software.

The term appears in discussions on web architecture and semantic web, rather than as a widely adopted standard. It is used as a conceptual tool to reason about how much meaning can be embedded in URL strings without breaking interoperability. There is no single universal specification; different proposals show different syntaxes and vocabularies.

Core features include a formal grammar for tokens such as resource, action, value, and constraint; a canonical encoding method using URL-safe characters; and a defined semantics mapping to operations on a resource or query. The design often emphasizes readability by humans and parsability by machines, with emphasis on determinism and unambiguous interpretation.

Example: a URL following Urlanguage principles might encode a request to fetch a book record: https://example.org/api/urldata/book?action=retrieve&id=123&lang=en. Semantics would specify that this URL triggers a retrieval operation for the book with identifier 123 in English.

Applications include improving programmatic routing, enabling richer link metadata, and supporting automated agents. Critics argue that embedding semantics in URLs can increase complexity, reduce portability across systems, and lead to inconsistencies with existing URI standards.

See also: URI, URL, REST, semantic URL, linked data, semantic web.