import type { IrreversibleMigration, MigrationContext } from '../migration-types';
export interface BackfillSnapshotRow {
    runId: string;
    messageGroupId: string | null;
    runIds: string[] | null;
    tree: string | null;
    createdAt: Date;
}
export interface BackfillMessageRow {
    id: string;
    role: string;
    content: string;
    createdAt: Date;
}
export interface SynthesizedRow {
    runId: string;
    type: string;
    payload: string;
    createdAt: Date;
}
export declare function extractMessageText(content: string): string;
export declare function synthesizeThreadEvents(input: {
    snapshots: BackfillSnapshotRow[];
    assistantMessages: BackfillMessageRow[];
    existingRunIds: ReadonlySet<string>;
}): SynthesizedRow[];
export declare class BackfillInstanceAiEventLog1784000000051 implements IrreversibleMigration {
    up({ escape, runQuery }: MigrationContext): Promise<void>;
}