/**
 * Workflow, agent, and tool version tuple utilities.
 *
 * Captures a `(workflowVersion, agentVersion, toolVersions[])` tuple on every
 * event-log entry and provides diff utilities to detect mismatches between
 * stored tuples and currently-registered definitions when resuming workflows.
 *
 * @module core/workflow-version-tuple
 */
/** Version tuple captured at workflow start and on every event-log entry. */
export type WorkflowVersionTuple = {
    workflowVersion: string;
    agentVersion?: string;
    /** Sorted `"${name}@${version}"` strings, one per tool. */
    toolVersions?: string[];
};
/** A single tool-level version change surfaced by {@link diffWorkflowVersionTuples}. */
export type WorkflowToolVersionChange = {
    tool: string;
    change: 'added';
    to: string;
} | {
    tool: string;
    change: 'removed';
    from: string;
} | {
    tool: string;
    change: 'changed';
    from: string;
    to: string;
};
/** Structured field-level diff between two {@link WorkflowVersionTuple}s. */
export type WorkflowVersionDiff = {
    workflowVersion?: [string, string];
    agentVersion?: [string, string];
    toolVersions?: WorkflowToolVersionChange[];
};
/**
 * Collect sorted `"${name}@${version}"` version strings from a tool array.
 *
 * Each element exposes a `name` plus an optional `version`. Missing versions
 * default to `"0.0.0"`. The returned array is sorted alphabetically so
 * comparisons are order-independent.
 */
export declare function collectToolVersions(tools: Array<{
    name: string;
    version?: string | undefined;
}>): string[];
/**
 * Compare two {@link WorkflowVersionTuple}s and return structured field-level diffs.
 *
 * Only fields that actually differ are included in the output. An empty
 * object means the tuples are identical.
 */
export declare function diffWorkflowVersionTuples(stored: WorkflowVersionTuple, registered: WorkflowVersionTuple): WorkflowVersionDiff;
/**
 * Format a human-readable summary of a {@link WorkflowVersionDiff} for error messages.
 *
 * Returns an empty string when the diff has no changes.
 */
export declare function formatWorkflowVersionDiff(diff: WorkflowVersionDiff): string;