/**
 * Invoke one tool on one upstream MCP server (DES-MCP-TOOLS-001 §6 step 6).
 *
 * - One connection per call: connect, `tools/call`, close. The upstream is reached exactly as the
 *   registry's probe reaches it (`transportFor`: the SDK's safe env for stdio plus the ONE variable
 *   the secret is injected into, or the one auth header for http), so the secret is resolved and
 *   injected here and nowhere else.
 * - Bounded: connect and call share one deadline; a hung upstream is closed and the call fails
 *   with the error class `timeout`.
 * - Every failure is classified ({@link classifyUpstreamError}) so the broker can decide whether a
 *   retry is allowed (step 7: transport errors, 429 and 5xx only) and what the call record says.
 *
 * A `rest` upstream is not an MCP server: its tools are single HTTP requests (`rest.ts`).
 *
 * The result is returned RAW: the broker scrubs it (D-2) before anything else sees it.
 */
import type { McpRestMapping } from '../core/types.js';
import { type McpUpstreamConfig } from './probe.js';
import { UpstreamCallError } from './upstream-error.js';
/** The default per-call deadline (connect + call). */
export declare const MCP_CALL_TIMEOUT_MS = 30000;
export { UpstreamCallError, type UpstreamErrorClass } from './upstream-error.js';
/** A `tools/call` result as the upstream sent it (`content`, `structuredContent?`, `isError?`, ...). */
export type UpstreamToolResult = Record<string, unknown>;
export type Invoker = (config: McpUpstreamConfig, secret: string | null, tool: string, args: Record<string, unknown>, timeoutMs: number, 
/** A `rest` tool's request mapping (slice S5a); `null` for an MCP server's tool. */
rest?: McpRestMapping | null) => Promise<UpstreamToolResult>;
/**
 * Classify a failure: transport errors (the connection could not be made or closed under the
 * call), HTTP 429 and 5xx are retryable; a timeout, any other HTTP status and a JSON-RPC error the
 * server answered are not.
 */
export declare function classifyUpstreamError(err: unknown): UpstreamCallError;
/** The real invoker. */
export declare const invokeMcpTool: Invoker;
//# sourceMappingURL=invoke.d.ts.map