/**
 * System-Prompt slot subflow builder
 *
 * Pattern: Builder (returns a FlowChart mountable via addSubFlowChartNext).
 * Role:    Layer-3 context engineering; inside Layer-5 primitives
 *          (LLMCall, Agent). Ported from v1's buildSystemPromptSubflow
 *          to InjectionRecord + SlotComposition shape.
 * Emits:   None directly. Writes to conventional scope keys; ContextRecorder
 *          observes and emits context.* events.
 *
 * Minimal scope for Phase 3e: static prompt string OR a dynamic function
 * of the input. Full SystemPromptProvider / Skill / RAG integration
 * arrives in Phase 5.
 */
import type { FlowChart } from 'footprintjs';
/**
 * Function that produces the system prompt string given runtime scope
 * context. Receives the subflow's $getArgs() payload.
 */
export type SystemPromptFn = (args: {
    readonly userMessage?: string;
    readonly iteration?: number;
}) => string | Promise<string>;
export interface SystemPromptSlotConfig {
    /** Static string OR a function. Empty string → no injection, empty slot. */
    readonly prompt: string | SystemPromptFn;
    /** Budget cap (chars). Default: 4000. */
    readonly budgetCap?: number;
    /** Optional description — where this prompt originated (e.g. "agent.system()"). */
    readonly reason?: string;
}
/**
 * Build the System-Prompt slot subflow.
 *
 * Mount with:
 *   builder.addSubFlowChartNext(SUBFLOW_IDS.SYSTEM_PROMPT, buildSystemPromptSlot(cfg), 'System Prompt', {
 *     inputMapper: (parent) => ({ userMessage: parent.userMessage, iteration: parent.iteration }),
 *     outputMapper: (sf) => ({ systemPromptInjections: sf.systemPromptInjections }),
 *   })
 */
export declare function buildSystemPromptSlot(config: SystemPromptSlotConfig): FlowChart;