import type { OutputStream } from './index.js';
export declare function isToolTraceEnabled(): boolean;
/** One-line summary of a single tool invocation's params — short enough to chain. */
declare function summarizeToolInput(name: string, input: any): string;
/** Compose the Slack line. Truncates from the tail when total exceeds MAX_LINE_LEN. */
declare function renderToolLine(toolName: string, summaries: string[], opts?: {
    prefix?: string | null;
}): string;
export interface ToolTraceOptions {
    /** Prefix prepended to the line; used by multi-agent threads (e.g. `*[writer]*`). */
    slotPrefix?: string | null;
}
export declare class ToolTrace {
    private stream;
    private region;
    private prefix;
    /** Name of the currently-open group (null if no open group). */
    private groupName;
    /** Accumulated summaries for the open group; rendered on every update. */
    private groupSummaries;
    constructor(stream: OutputStream, opts?: ToolTraceOptions);
    onToolUse(name: string, input: any): void;
    /** Seal the current group on the tool-trace side. The stream's mutable region
     *  is not touched here — the next `stream.emitText(text)` or
     *  `stream.openMutable(...)` will seal it naturally. */
    flush(): void;
}
/** Factory: returns a ToolTrace wired to the given OutputStream, or null if the feature is disabled or stream is missing. */
export declare function createToolTrace(stream: OutputStream | null | undefined, opts?: ToolTraceOptions): ToolTrace | null;
export declare const _test: {
    summarizeToolInput: typeof summarizeToolInput;
    renderToolLine: typeof renderToolLine;
};
export {};