The encyclopedia · R&D & Science · Technical decision · 2000
Fielding's REST constraint made the web's own uniform verbs the API standard
REST derived a uniform-interface, stateless, cacheable style from the Web that later became the default API design.
W3C
the move
Thousands of systems wanted to expose themselves over the internet, but each built a bespoke RPC protocol, so no client could talk to two of them. The obstacle was not brains or bandwidth; it was an interface specialized to each service.
Fielding's dissertation showed the minimum was a uniform interface: identify resources with a URI, manipulate them through representations, keep messages self-descriptive, and use hypermedia as the engine of state, layered on the existing constraints of client-server, statelessness and cache.
Because REST reused HTTP's generic verbs rather than inventing new ones, a client that could fetch a page could also call an API. That is why REST became the default for web APIs, displacing the RPC and CORBA style.
why it works
- The uniform interface means one generic client and library set works against every REST API, collapsing the cost of integration.
- Because REST constrains rather than defines, and is built on HTTP, it needed no new protocol or stack to be deployed.
- Statelessness plus caching let middleware scale requests without the server knowing who a caller is between calls.
- Hypermedia as the engine of state lets a client discover affordances instead of hard-coding each endpoint.
what transfers
A standard derived from the thing that already runs everywhere inherits its reach; sometimes the biggest design decision is the constraint you refuse to add.
what came after
Fielding's dissertation was published in 2000 and REST became the dominant style for public and internal web APIs, replacing SOAP-style RPC. It later acquired conventions (OpenAPI, and the CRUD-over-HTTP reading that often underuses hypermedia), and some argue its strictest hypermedia form was rarely implemented, but the uniform-interface idea won.
references
- Representational State Transfer (REST), Fielding Dissertation Chapter 5
- Representational state transfer
spotted an error? The archive wants to know.