Glossary
Every term the courses use, defined in one line and then in a paragraph. Written to be read out of order.
Showing 6 of 6 matching “Contract”
An agreed set of messages two systems exchange.
The contract between two pieces of software: which requests are valid, and what shape the answers take. Both sides can be rewritten freely as long as the contract holds, which is what makes independent teams possible.
The agreed shape of messages between systems.
What each side promises the other about requests and responses. Exists whether or not anyone wrote it down. Shared types turn a broken contract into a build error instead of a production incident.
See also API, Breaking change
A recorded, ordered change to your data’s shape.
A versioned schema change applied identically in every environment. Needed because code can be rolled back in seconds and data cannot. Safe changes expand first, then contract days later.
Calling a named function on another machine.
An API style where you invoke an action directly rather than modelling resources. With shared types, a contract break becomes a build error, which is why it suits an app talking to its own backend.
See also Server function, REST, API
A function you call from the client that runs on the server.
Written like a normal function, but the build replaces the body with a network call in the client bundle and the real implementation only ever exists on the server. You get a typed contract for free and the server code never ships to the browser.
See also RPC, Validation, Secret
Running old and new API shapes side by side.
Offering /v1 and /v2 so existing callers keep working while new ones use the new shape. The same expand-then-contract idea as a safe schema migration, applied to an API.
See also Breaking change, Deprecation