@langchain/langgraph/dist/graph/zod/meta.d.ts

LangGraph

import { InteropZodObject, InteropZodType, InteropZodObjectShape } from "@langchain/core/utils/types";
import { BaseChannel } from "../../channels/base.js";
export declare const META_EXTRAS_DESCRIPTION_PREFIX = "lg:";
export type ReducedZodChannel<T extends InteropZodType, TReducerSchema extends InteropZodType> = T & {
    lg_reducer_schema: TReducerSchema;
};
export type InteropZodToStateDefinition<T extends InteropZodObject, TShape = InteropZodObjectShape<T>> = {
    [key in keyof TShape]: TShape[key] extends ReducedZodChannel<infer Schema, infer ReducerSchema> ? Schema extends InteropZodType<infer V> ? ReducerSchema extends InteropZodType<infer U> ? BaseChannel<V, U> : never : never : TShape[key] extends InteropZodType<infer V, infer U> ? BaseChannel<V, U> : never;
};
export interface SchemaMeta<TValue = any, TUpdate = TValue> {
    jsonSchemaExtra?: {
        langgraph_nodes?: string[];
        langgraph_type?: "prompt" | "messages";
        [key: string]: unknown;
    };
    reducer?: {
        schema?: InteropZodType<TUpdate>;
        fn: (a: TValue, b: TUpdate) => TValue;
    };
    default?: () => TValue;
    [key: string]: unknown;
}
/**
 * A registry for storing and managing metadata associated with schemas.
 * This class provides methods to get, extend, remove, and check metadata for a given schema.
 */
export declare class SchemaMetaRegistry {
    /**
     * Internal map storing schema metadata.
     * @internal
     */
    _map: WeakMap<InteropZodType, SchemaMeta<any, any>>;
    /**
     * Cache for extended schfemas.
     * @internal
     */
    _extensionCache: Map<string, WeakMap<InteropZodType, InteropZodType>>;
    /**
     * Retrieves the metadata associated with a given schema.
     * @template TValue The value type of the schema.
     * @template TUpdate The update type of the schema (defaults to TValue).
     * @param schema The schema to retrieve metadata for.
     * @returns The associated SchemaMeta, or undefined if not present.
     */
    get<TValue, TUpdate = TValue>(schema: InteropZodType<TValue>): SchemaMeta<TValue, TUpdate> | undefined;
    /**
     * Extends or sets the metadata for a given schema.
     * @template TValue The value type of the schema.
     * @template TUpdate The update type of the schema (defaults to TValue).
     * @param schema The schema to extend metadata for.
     * @param predicate A function that receives the existing metadata (or undefined) and returns the new metadata.
     */
    extend<TValue, TUpdate>(schema: InteropZodType<TValue>, predicate: (meta: SchemaMeta<TValue, TUpdate> | undefined) => SchemaMeta<TValue, TUpdate>): void;
    /**
     * Removes the metadata associated with a given schema.
     * @param schema The schema to remove metadata for.
     * @returns The SchemaMetaRegistry instance (for chaining).
     */
    remove(schema: InteropZodType): this;
    /**
     * Checks if metadata exists for a given schema.
     * @param schema The schema to check.
     * @returns True if metadata exists, false otherwise.
     */
    has(schema: InteropZodType): boolean;
    /**
     * Returns a mapping of channel instances for each property in the schema
     * using the associated metadata in the registry.
     *
     * This is used to create the `channels` object that's passed to the `Graph` constructor.
     *
     * @template T The shape of the schema.
     * @param schema The schema to extract channels from.
     * @returns A mapping from property names to channel instances.
     */
    getChannelsForSchema<T extends InteropZodObject>(schema: T): InteropZodToStateDefinition<T>;
    /**
     * Returns a modified schema that introspectively looks at all keys of the provided
     * object schema, and applies the augmentations based on meta provided with those keys
     * in the registry and the selectors provided in the `effects` parameter.
     *
     * This assumes that the passed in schema is the "root" schema object for a graph where
     * the keys of the schema are the channels of the graph. Because we need to represent
     * the input of a graph in a couple of different ways, the `effects` parameter allows
     * us to apply those augmentations based on pre determined conditions.
     *
     * @param schema The root schema object to extend.
     * @param effects The effects that are being applied.
     * @returns The extended schema.
     */
    getExtendedChannelSchemas<T extends InteropZodObject>(schema: T, effects: {
        /**
         * Augments the shape by using the reducer's schema if it exists
         */
        withReducerSchema?: boolean;
        /**
         * Applies the stringified jsonSchemaExtra as a description to the schema.
         */
        withJsonSchemaExtrasAsDescription?: boolean;
        /**
         * Applies the `.partial()` modifier to the schema.
         */
        asPartial?: boolean;
    }): InteropZodObject;
}
export declare const schemaMetaRegistry: SchemaMetaRegistry;
export declare function withLangGraph<TValue, TUpdate, TSchema extends InteropZodType<TValue>>(schema: TSchema, meta: SchemaMeta<TValue, TUpdate> & {
    reducer?: undefined;
}): TSchema;
export declare function withLangGraph<TValue, TUpdate, TSchema extends InteropZodType<TValue>>(schema: TSchema, meta: SchemaMeta<TValue, TUpdate>): ReducedZodChannel<TSchema, InteropZodType<TUpdate>>;