/**
 * Pipeline step: Deliver results to a callback URL.
 *
 * After the pipeline completes and the report is published, this step
 * derives the report's events, filters by the caller's `events` selection,
 * builds a signed webhook envelope, and POSTs it to the caller's callback
 * URL. Used for API-triggered evaluations where the caller wants push-based
 * result delivery.
 *
 * This step is always optional — callback failure never blocks the pipeline.
 * The result is already in the Content Lake (system of record).
 *
 * @see packages/eval/src/pipeline/callback-delivery.ts
 * @see docs/design-docs/api-service-gateway.md
 */
import { type AppContext, type PipelineState, type PipelineStep, type StepResult, type ValidationIssue } from "../../_vendor/ailf-core/index.d.ts";
import { type CallbackConfig } from "../../pipeline/callback-delivery.js";
export declare class CallbackStep implements PipelineStep {
    private readonly callback;
    private readonly jobId?;
    readonly name = "callback-delivery";
    readonly optional = true;
    constructor(callback: CallbackConfig, jobId?: string | undefined);
    check(): ValidationIssue[];
    execute(ctx: AppContext, state: PipelineState): Promise<StepResult>;
}
