/**
 * Transport health tracking
 *
 * Chromium and Firefox surface `ERR_BLOCKED_BY_CLIENT` (or the equivalent
 * "NetworkError when attempting to fetch") to the JS layer as a generic
 * `TypeError: Failed to fetch` — there is no programmatic way to tell a
 * cancelled-by-extension request apart from an offline or DNS failure.
 *
 * What we can do is notice the pattern. Once a handful of consecutive
 * top-level transport failures happen in a row we treat the transport as
 * "likely blocked" for the rest of the page session and:
 *
 *   1. Stop scheduling new requests (no more retries, no new session
 *      recording POSTs). The browser will keep logging
 *      `ERR_BLOCKED_BY_CLIENT` for any request the SDK *does* fire, so
 *      we minimise that noise by firing fewer of them.
 *   2. Log a single explanatory warning that points integrators at the
 *      reverse-proxy escape hatch so they aren't left guessing.
 *
 * A subsequent successful response resets the counter — transient
 * connectivity glitches don't latch the SDK into "blocked" mode.
 *
 * The state is *page-session scoped*. We deliberately do not persist it
 * to storage: ad-blocker filter lists change, the user might disable a
 * blocker for our domain, and we don't want a single bad page load to
 * cripple every future visit.
 */
/**
 * Record a top-level transport failure (network error / blocked / aborted).
 *
 * `scope` is the SDK module reporting the failure (e.g. `"replay"`,
 * `"capture"`); it's used purely for the warning log message.
 */
export declare function markTransportFailure(scope: string): void;
/**
 * Record a successful response. Resets the failure counter; a future run
 * of failures must accumulate from zero before flipping the flag again.
 *
 * Does NOT clear the `blocked` flag: once the SDK has decided to back
 * off in a session it stays backed off for the lifetime of that page.
 * Without this rule a single intermittent success between failures would
 * silently re-enable the retry storm we are trying to suppress.
 */
export declare function markTransportSuccess(): void;
/**
 * Once the SDK believes the transport is blocked, this returns `true`
 * for the rest of the page session. Callers should skip scheduling work
 * that would otherwise spam `ERR_BLOCKED_BY_CLIENT` into the console.
 */
export declare function isTransportLikelyBlocked(): boolean;
/**
 * Test-only reset. Not exported from the package barrel — only
 * `__tests__` should use it.
 */
export declare function __resetTransportHealthForTests(): void;