/**
 * API breaking-change detection over route reflection.
 *
 * `snapshotRoutes` turns an app (or reflected descriptors) into a plain-JSON snapshot - the
 * `standard` validators are dropped, so a snapshot survives `JSON.stringify` and can be committed
 * as a CI baseline. `diffRouteSnapshots` compares two snapshots and classifies every change by
 * wire compatibility, direction-aware:
 *
 *   request direction (body/query - what clients SEND):  a new required field, a removed field, or
 *     a narrowed type breaks existing callers; widening (new optional field, enum superset,
 *     required→optional) is compatible.
 *   response direction (response/sse/errors - what clients RECEIVE): a removed field, a field made
 *     optional, or a widened type breaks existing readers; narrowing (new field, optional→required,
 *     enum subset) is compatible.
 *
 * The classifier FAILS CLOSED: a schema change it cannot prove compatible is reported as breaking.
 * Schemas without JSON Schema metadata (validation-only Standard Schemas) cannot be compared and
 * yield `info` - never a silent pass presented as proof.
 */
import { type JsonSchema, type ReflectedSchemaField } from "./reflection.js";
/** One schema position in a snapshot: JSON Schema metadata only, no validator. */
export interface SchemaSnapshot {
    readonly jsonSchema?: JsonSchema;
    readonly fields?: readonly ReflectedSchemaField[];
}
export interface RouteSnapshotSchema {
    readonly headers?: SchemaSnapshot;
    readonly body?: SchemaSnapshot;
    readonly query?: SchemaSnapshot;
    readonly response?: SchemaSnapshot;
    readonly sse?: SchemaSnapshot;
    readonly errors?: Readonly<Record<string, SchemaSnapshot>>;
}
/** One route in a snapshot - plain JSON, safe to persist as a CI baseline. */
export interface RouteSnapshot {
    readonly method: string;
    readonly path: string;
    readonly schema?: RouteSnapshotSchema;
}
export type DiffSeverity = "breaking" | "compatible" | "info";
export interface RouteChange {
    readonly severity: DiffSeverity;
    readonly method: string;
    readonly path: string;
    /** Which part of the contract changed; "route" for add/remove of the whole route. */
    readonly section: "route" | "headers" | "body" | "query" | "response" | "sse" | "errors";
    /** The top-level field (or error status) the change is about, when field-granular. */
    readonly field?: string;
    readonly message: string;
}
export interface RoutesDiff {
    readonly changes: readonly RouteChange[];
    /** True when any change is `breaking` - the CI-gate signal. */
    readonly hasBreaking: boolean;
}
/**
 * Snapshot an app's routes (anything `reflectRoutes` accepts) as plain JSON. Validators are
 * dropped; only introspectable JSON Schema metadata is kept, so the result round-trips through
 * `JSON.stringify` unchanged.
 */
export declare function snapshotRoutes(source: unknown): readonly RouteSnapshot[];
/**
 * Diff two route snapshots (`snapshotRoutes` output, possibly restored from JSON). Every change is
 * classified breaking/compatible/info; `hasBreaking` is the CI-gate bit.
 */
export declare function diffRouteSnapshots(before: readonly RouteSnapshot[], after: readonly RouteSnapshot[]): RoutesDiff;
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