Class RequestEngine

Build a fully-qualified URL from a path and optional query parameters.

GET a path with query params and parse the JSON reply into T. Every MaStR endpoint answers with a JSON document, so an empty body or a 204 is a MastrParseError, never a silent null.

Perform a GET with Accept negotiation and transient-error retries. Redirects are NOT followed — the canonical host answers directly, so a 3xx (e.g. a bad base URL bouncing to a portal page) surfaces as an error.

The engine enforces the transport contract itself, so it holds for a custom transport too: timeoutMs (an AbortSignal deadline), maxResponseBytes (checked on the body it gets back), any byte-array body, Headers/Map/any-case headers. Whatever a transport throws becomes a MastrNetworkError, and so does a malformed response; a reset connection (isTransientNetworkError) is retried like a 503.

text without the base URL's credentials: server text (an error body that echoes the request URL, the Authorization header or the decoded user:password) and transport text (fetch's "Failed to fetch ") can carry them. The client runs it on the Errors envelopes it turns into errors.