A pure-Rust mock runtime that derives HTTP, WebSocket, and gRPC behaviour from OpenAPI, AsyncAPI, and Protobuf documents, so clients under test can exercise a real contract without a real server.
Operation: A (method, path template) pair declared by an OpenAPI document, together with its parameters, request body, and declared responses. The unit behaviour attaches to. Avoid: Endpoint, route, handler, action
Route: The result of matching an incoming method and path against the router, naming the matched Operation and the values bound to its path parameters. Avoid: Match, lookup, endpoint
Channel:
A named AsyncAPI stream. spec-mock validates what arrives against the channel's
publish schema and replies using its subscribe schema. That is the specification's
view of the application, and it is the reverse of the client's — read these two field
names from the application's side, never the caller's.
Avoid: Topic, subject, stream
Scenario file: The sidecar document declaring scenarios and their stores, resolved alongside the OpenAPI document. Avoid: Behaviour file, config, overlay, companion
Scenario: A named flow through a mock's behaviour, comprising a starting state, a set of states, and the transitions between them. The unit of statefulness: a client opts into one by name and remains inside it for the life of a scenario instance. Avoid: Flow, test case, test scenario, session Note: "Scenario" also appears in this repository's specifications to mean a test case. Those are unrelated; see this file for the product sense.
Scenario instance: One concurrent, isolated run of a scenario, holding its own current state and its own store. A mock serves a single default instance until a client supplies a session. Avoid: Run, execution, world
Session: The client-supplied key naming a scenario instance. Requests carrying no session resolve to the mock's one default instance. Avoid: Instance (the session names an instance; it is not the instance)
State: A named position within a scenario. Exactly one state is current per scenario instance at any moment, and it determines which declared response an operation returns. Avoid: Status, phase, mode, step
Transition: The move from one state to another, triggered by a matched operation. A state reached with no transition declared for the next operation is terminal for that operation. Avoid: Edge, event, action, flow
Store: The retained invented resources belonging to one scenario instance, keyed by identifier. Operations write to it and are answered from it. Avoid: Database, cache, repository, state
Resource: An invented record held in a store, keyed by an identifier drawn from the request path. Every resource is schema-valid because it is generated from the schema its operation declares. Avoid: Entity, object, record, item
Validation issue: One structured failure, locating the offending value in the instance and the violated rule in the schema. HTTP, WebSocket, and gRPC all report failures in this one shape, without translation. Avoid: Error, violation, problem
Problem details: The RFC 7807 envelope carrying zero or more validation issues. Avoid: Error response, error body
Seed: The integer making generated data reproducible for a given request sequence. Determinism is a property of a sequence, not of a single request. Avoid: Salt, random seed
Mock mode: Whether the runtime invents responses or forwards to an upstream and validates what comes back. Avoid: Mode (ambiguous with state)