/**
 * centroid-router.ts — opt-in nearest-centroid agent router (ADR-527).
 *
 * Each agent label has one unit-length centroid: the mean MiniLM embedding of
 * its labelled example prompts (the ADR-391 corpus dev split, built by
 * `benchmarks/router/build-centroids.mjs`). A task goes to the label whose
 * centroid is most cosine-similar. When the top two scores are closer than
 * `margin`, the caller keeps the current router's pick instead.
 *
 * The artifact records the embedding model and dimension it was built with.
 * A query embedded any other way (for example MiniLM degraded to the hash
 * embedder) is never scored against it: `classify` returns `unavailable`.
 *
 * Gate: `CLAUDE_FLOW_ROUTER_CENTROID=1`. Off by default; the current router
 * is unchanged unless the flag is set.
 *
 * @module centroid-router
 */
export declare const CENTROID_ROUTER_ENV = "CLAUDE_FLOW_ROUTER_CENTROID";
export declare const CENTROID_MARGIN_ENV = "CLAUDE_FLOW_ROUTER_CENTROID_MARGIN";
export declare const CENTROID_ARTIFACT_ENV = "CLAUDE_FLOW_ROUTER_CENTROID_PATH";
export declare const CENTROID_SCHEMA = "ruflo.agent-centroids/1";
/** Label meaning "no agent fits"; the router abstains instead of picking one. */
export declare const ABSTAIN_LABEL = "none";
export interface CentroidArtifact {
    schema: typeof CENTROID_SCHEMA;
    /** Embedder kind the centroids live in. Only 'minilm' is built today. */
    embedder: 'minilm';
    /** Embedding model id reported by the local embedder when the artifact was built. */
    model: string;
    dim: number;
    /** Default top-two margin below which the caller falls back. */
    margin: number;
    /** sha256 of the corpus file the centroids were built from. */
    corpusSha256: string;
    split: string;
    labels: string[];
    /** Examples per label, aligned with `labels`. */
    support: number[];
    /** Unit-length centroids, aligned with `labels`. */
    centroids: number[][];
}
export type CentroidDecision = {
    status: 'decided';
    label: string;
    score: number;
    runnerUp: string;
    runnerUpScore: number;
    margin: number;
} | {
    status: 'fallback';
    label: string;
    score: number;
    runnerUp: string;
    runnerUpScore: number;
    margin: number;
    reason: string;
} | {
    status: 'unavailable';
    reason: string;
}
/** A learned route (AgentDB or a persisted SONA pattern) answered before the centroid router ran. */
 | {
    status: 'bypassed';
    reason: string;
};
export declare function centroidRouterEnabled(env?: NodeJS.ProcessEnv): boolean;
/** Margin from the env when it is a finite number in [0, 1], else the artifact default. */
export declare function resolveMargin(artifact: Pick<CentroidArtifact, 'margin'>, env?: NodeJS.ProcessEnv): number;
/** Throws with a specific message when the artifact is malformed. */
export declare function validateArtifact(a: unknown): CentroidArtifact;
/** Load (and cache) the artifact. Returns the error instead of throwing. */
export declare function loadCentroidArtifact(env?: NodeJS.ProcessEnv): {
    artifact: CentroidArtifact | null;
    error: string | null;
    path: string;
};
/**
 * Score one query embedding.
 * @param query   the query vector (any length; normalised here)
 * @param queryEmbedder the embedder that actually produced `query`
 * @param queryModel    the model id that produced it, when known
 */
export declare function classify(artifact: CentroidArtifact, query: ArrayLike<number>, queryEmbedder: string, queryModel: string | undefined, margin: number): CentroidDecision;
/** Test hook. */
export declare function __resetCentroidRouterForTests(): void;
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