/**
 * Estimate how a model request's context is composed (system / history / tools).
 * Metadata-only: no prompt text is stored — only role counts and token estimates.
 *
 * Used for reliability ops and regression harnesses. Does not truncate context.
 */
import type { ChatMessage, ToolDefinition } from "../types.js";
export interface ContextBreakdown {
    /** Rough total estimated tokens for messages (+ tools if provided). */
    readonly estimatedTotalTokens: number;
    readonly systemTokens: number;
    readonly userTokens: number;
    readonly assistantTokens: number;
    readonly toolResultTokens: number;
    readonly toolSchemaTokens: number;
    readonly messageCount: number;
    readonly systemMessageCount: number;
    readonly userMessageCount: number;
    readonly assistantMessageCount: number;
    readonly toolMessageCount: number;
    /** High-level system subsections when detected by prefix. */
    readonly systemParts: {
        readonly constitutionTokens: number;
        readonly planTokens: number;
        readonly scopeTokens: number;
        readonly sessionStateTokens: number;
        readonly compactionMemoryTokens: number;
        readonly otherSystemTokens: number;
    };
    readonly toolDefinitionCount: number;
}
/**
 * Build a metadata-only breakdown of an assembled completion request.
 */
export declare function buildContextBreakdown(messages: readonly ChatMessage[], tools?: readonly ToolDefinition[] | undefined): ContextBreakdown;
/** Flatten for audit/diagnostic logs (numeric keys only — no content). */
export declare function contextBreakdownAuditPayload(breakdown: ContextBreakdown): Record<string, number>;
export declare function describeDominantContextBlock(messages: readonly ChatMessage[], tools?: readonly ToolDefinition[] | undefined): string;
export declare function toolSchemaHash(tools: readonly ToolDefinition[] | undefined): string;