import type { MCPRequestIdFormat } from "./types.js";
/**
 * Per-transport allocator for outgoing JSON-RPC request ids.
 *
 * JSON-RPC 2.0 permits String and Number ids equally, but the wider MCP
 * ecosystem (reference SDKs included) issues incrementing integers, so servers
 * are best tested against numbers — Apple's `xcrun mcpbridge` even logs
 * `mcpbridge.DecodeError Code=1` and never answers a string id. Integers are
 * therefore the default. `"string"` opts a server back into collision-resistant
 * snowflake ids.
 *
 * The counter is per instance and never reset, so ids stay unique for the life
 * of the transport even though a reconnect rejects and clears every pending
 * request.
 */
export declare class RequestIdAllocator {
    #private;
    next(format: MCPRequestIdFormat | undefined): string | number;
}