/**
 * IVTR Breaking-Change Gate — blocks completion when task touches CRITICAL-risk symbols.
 *
 * Implements EP3-T8 from T1042 living-brain decomposition. The gate reads the task's
 * `files` field, queries nexus for symbols in those files, calls `reasonImpactOfChange()`
 * for each symbol, and fails if any symbol returns `mergedRiskScore === 'CRITICAL'`.
 *
 * Gate is OPT-IN via `CLEO_NEXUS_IMPACT_GATE=1` env var to prevent surprise breakage.
 *
 * @task T1073
 * @epic T1042
 */
import type { Task } from '@cleocode/contracts';
/**
 * Result of running the nexusImpact gate validator.
 */
export interface NexusImpactGateResult {
    /** Whether the gate passed (true = no CRITICAL symbols, or gate disabled). */
    passed: boolean;
    /** Exit code if gate failed. */
    exitCode?: number;
    /** Error message if gate failed. */
    error?: string;
    /** Critical symbols that triggered the failure. */
    criticalSymbols?: Array<{
        symbolId: string;
        symbolName: string | null;
        filePath: string | null;
        mergedRiskScore: string;
        narrative: string;
    }>;
    /** Narrative summary. */
    narrative: string;
}
/**
 * Validate the nexusImpact gate for a task.
 *
 * If `CLEO_NEXUS_IMPACT_GATE` env var is not set to '1', returns passed=true
 * with a note that the gate is disabled (prevents surprise breakage).
 *
 * When enabled, reads the task's `files` array, queries nexus for all symbols
 * in those files, and calls `reasonImpactOfChange()` for each. If any symbol
 * returns `mergedRiskScore === 'CRITICAL'`, the gate fails with a list of
 * critical symbols.
 *
 * @param task - The task to validate
 * @param projectRoot - Absolute path to project root
 * @returns Gate result with pass/fail status and evidence
 */
export declare function validateNexusImpactGate(task: Task, projectRoot: string): Promise<NexusImpactGateResult>;
//# sourceMappingURL=nexus-impact-gate.d.ts.map