/**
 * State Serializers
 *
 * Implementations for serializing/deserializing AgentState.
 */
import type { AgentState, StateSerializer } from './types.js';
/**
 * JSON-based state serializer.
 * Handles standard JSON serialization with validation.
 */
export declare class JsonSerializer implements StateSerializer {
    readonly version = "1.0";
    /**
     * Serialize agent state to JSON string
     */
    serialize(state: AgentState): string;
    /**
     * Deserialize JSON string to agent state
     */
    deserialize(data: string): AgentState;
    /**
     * Validate state before serialization (public interface method).
     * This is called by checkpointers before saving to prevent corrupted checkpoints.
     * @throws StateError if state is invalid
     */
    validate(state: AgentState): void;
    /**
     * Validate that parsed data is a valid AgentState
     */
    private validateParsed;
    /**
     * Migrate from older versions (currently no-op for v1)
     */
    migrate(data: string, fromVersion: string): string;
}
/**
 * Compact JSON serializer (no pretty printing).
 * Useful for storage-constrained environments.
 */
export declare class CompactJsonSerializer implements StateSerializer {
    readonly version = "1.0";
    serialize(state: AgentState): string;
    deserialize(data: string): AgentState;
    /**
     * Validate state before serialization (public interface method).
     * This is called by checkpointers before saving to prevent corrupted checkpoints.
     * @throws StateError if state is invalid
     */
    validate(state: AgentState): void;
    private validateParsed;
}
/**
 * Default serializer instance
 */
export declare const defaultSerializer: JsonSerializer;