Concepts

The concepts below are the words every page uses, each defined in one sentence and grouped by the part of an API it belongs to.

Concept	Part	Definition
Product	Platform	What a Startup sells; an API Product is one whose Definition declares operations.
Definition	Platform	The one record every Interface of an API is generated from, so no two Interfaces can disagree.
Operation	Contract	One callable Verb on a Noun, named by its operationId, with its path, parameters, return schema, example, price and run.
Interface	Contract	One way to reach the same Definition, served on the API host itself: the API, MCP, SDK, Docs and App among them.
Machine register	Contract	A file an agent reads instead of a page: OpenAPI 3.1, llms.txt, a Markdown twin, agents.json or the pricing document.
Wrapped Source	Contract	An outside source an API Product wraps, declared as one descriptor: its operations, Offer, meters, limits, tenancy and error map.
Namespace	Address	The unit of isolation an API serves from; a Customer keeps its calls in the namespace of the Startup that uses the API.
Host	Address	The home Domain of the Startup an API belongs to: every Interface of the API answers there, and every link stays there.
Key	Caller	The credential a Customer presents on a call; the platform checks it on every call and never stores it.
Entitlement	Caller	What a Key may call: the operations an accepted Offer grants, checked on every call through every Interface.
Test twin	Caller	The separate namespace a test or dev Key calls into; its books never post and it never touches live records.
Price	Terms	The posted rate of one call that returns a result: the same number in its cost header and on its usage Event.
Meter	Terms	Counts each priced call once, by the token of its usage Event, so a retried request counts once.
Limit	Terms	A cap checked and reserved before a call runs; when the check cannot run, the call does not run.
Batch	Execution	One request that runs 1 to 100 calls as one Action, each item answering exactly what the API answers alone.
Action	Execution	The record a call is accepted as before it runs, so its Limits are reserved and its end is kept.
Problem	Evidence	The error document a failed call answers: the RFC 9457 fields plus a stable machine code.
Call record	Evidence	The kept record of one call: what was called, by which Key, through which Interface, what it answered and cost.
Provenance	Evidence	Who asserted a fact and how, on four axes; an ingested record that cannot be stamped is rejected, never defaulted.
Dashboard	Evidence	The page every keyed API serves at `/dashboard`: one Key and its calls, in HTML, Markdown and JSON.