/**
 * Exhaustiveness enforcement for the translation IR.
 *
 * A translation layer fails quietly: an unhandled content part or event variant
 * becomes a missing tool call, and the only symptom is the next hop rejecting a
 * request nobody can explain. `assertProxyIRExhaustive` makes that a compile
 * error instead. Passing a value whose type is not `never` does not type-check,
 * so a new IR variant breaks every `switch` that has not handled it.
 *
 * It throws at runtime as well, because the compile-time guarantee only holds for
 * values that really are typed. A wire payload narrowed from `unknown` can reach a
 * default branch at runtime, and failing loudly there beats translating a request
 * with a silently dropped element.
 */
import type { ProxyIRContentPart, ProxyIRResponseEvent, ProxyIRTerminalOutcome, ProxyIRUnmappableValue } from "../types/index.js";
/**
 * Refuse an unhandled IR variant.
 *
 * `context` names the switch that failed, since the value alone rarely says which
 * of several exhaustive switches over the same union let it through.
 */
export declare function assertProxyIRExhaustive(value: never, context: string): never;
/** Mark a wire value no codec could represent, preserving it for the caller. */
export declare function proxyIRUnmappable(sourceKind: string, reason: string, raw: unknown): ProxyIRUnmappableValue;
/** Narrow a collected codec result to the unmappable marker. */
export declare function isProxyIRUnmappable(value: unknown): value is ProxyIRUnmappableValue;
/**
 * Name a content part for a diagnostic.
 *
 * This lives in `src` rather than in the suite that asserts on it because
 * `tsconfig.json` excludes `test`: an exhaustive switch written only in a test
 * gives no compile-time guarantee at all. These describers are the shipped
 * consumers that pin every union, so adding an IR variant fails `tsc --noEmit`
 * here before it can reach a codec that silently drops it.
 *
 * Deliberately excludes the payload of text, thinking and tool arguments: a
 * describer's output reaches logs and span attributes, and prompt content does
 * not belong there.
 */
export declare function describeProxyIRPart(part: ProxyIRContentPart): string;
/** Name a stream event for a diagnostic, without its payload. */
export declare function describeProxyIRResponseEvent(event: ProxyIRResponseEvent): string;
/** Name a terminal outcome, keeping an unmodelled upstream stop reason visible. */
export declare function describeProxyIRTerminalOutcome(outcome: ProxyIRTerminalOutcome): string;