/**
 * invoke — the SigV4 auth strategy: Streamable HTTP, carried by the AWS SDK's
 * `InvokeAgentRuntime`.
 *
 * The MCP client speaks HTTP — a POST, a few headers, a JSON body — and the SDK
 * operation carries exactly that, field for field. This file is the mapping and
 * nothing else. Every name in it is the SDK's own (`InvokeAgentRuntimeRequest`
 * / `InvokeAgentRuntimeResponse` in `@aws-sdk/client-bedrock-agentcore`), read
 * off an installed package rather than recalled:
 *
 *   request                                       InvokeAgentRuntimeRequest
 *   ─────────────────────────────────────────────  ────────────────────────
 *   body                                          payload (bytes)
 *   content-type                                  contentType
 *   accept                                        accept
 *   mcp-session-id                                mcpSessionId
 *   mcp-protocol-version                          mcpProtocolVersion
 *   x-amzn-bedrock-agentcore-runtime-session-id   runtimeSessionId
 *   (the runtime, from options)                   agentRuntimeArn, qualifier, accountId
 *
 *   InvokeAgentRuntimeResponse                    response
 *   ─────────────────────────────────────────────  ────────────────────────
 *   statusCode                                    status
 *   contentType                                   content-type
 *   mcpSessionId                                  mcp-session-id
 *   mcpProtocolVersion                            mcp-protocol-version
 *   runtimeSessionId                              x-amzn-bedrock-agentcore-runtime-session-id
 *   response (a stream)                           body
 *
 * The signature is the SDK's: `send` signs every attempt with the client's own
 * credentials, so no credential passes through this file.
 *
 * ── The SDK's own retry is OFF ───────────────────────────────────────────────
 * The client built here has `maxAttempts: 1`. The SDK's standard policy would
 * re-send a `tools/call` after a 5xx or a dropped connection — a call that may
 * already have run, in the same pinned session — which a retry here must never
 * do on its own. Every retry goes through the transport's single loop instead,
 * which repeats only what the replay rule permits (`mcp/replay.ts`): the
 * refusals its retry policy recognises — the session-busy reply and a 429, each
 * assumed, not proven, to have run nothing — and a dropped connection only when
 * the app declared that for the tool. A `client` you pass keeps ITS policy:
 * build it with `maxAttempts: 1` for the same guarantee.
 *
 * ── A service exception is an ANSWER ─────────────────────────────────────────
 * When the service answers with a non-2xx status, the SDK throws instead of
 * returning — `RetryableConflictException` (409), `ThrottlingException` (429),
 * or a hosted server's own 404 as `Unknown`. Each is handed on as the `Response`
 * an HTTPS caller would have read: its status, its error type in
 * `x-amzn-errortype`, `retry-after` when the service sent one, and as the body
 * the server's own JSON-RPC error when it sent one (the SDK spreads a body it
 * cannot model onto the exception) — never the exception's message, which can
 * quote the signed request. What the MCP client may read of it is decided
 * once, by `safeAnswer.ts`. So the transport's retry decision sees the 409,
 * `mcpClient`'s 429 retry sees the 429, and the MCP client reports the
 * status. A failure with no status — the
 * network, an abort — never reached the service as an answer, and is thrown as
 * it is.
 *
 * ── What the operation cannot carry ──────────────────────────────────────────
 * Any method but POST. A GET (the optional server-message stream) and a DELETE
 * are answered HERE with 405, which the MCP Streamable HTTP spec defines as "not
 * offered" for both, so the MCP client carries on. And any header the operation
 * does not model — it has no field to put one in. A `'reuse'` connection's
 * DELETE never reaches this far: the session strategy turns it into a stop
 * (`STOP_RUNTIME_SESSION`), sent as `StopRuntimeSessionCommand`.
 *
 * ── The send gate runs after signing ─────────────────────────────────────────
 * A request the MCP client pool sent carries its send gate (`mcp/requestGuard.ts`).
 * Signing is asynchronous work inside the AWS SDK's `send`, so the gate is a
 * step on each COMMAND's own middleware stack, after the request is signed and
 * before the request handler sends it — never on the client's stack, so an AWS
 * client the app passed is not changed. A command with no stack (a double) has
 * the gate asked just before `send`, as every command also does.
 *
 * Pattern: Adapter (fetch ↔ command). Role: outer ring, lazy AWS peer dep.
 */
import type { ThrottleFetch } from '../../../mcp/throttleRetry.js';
/** A command-based SDK client — `send` is the only member this strategy uses. */
export interface AgentCoreRuntimeSdkClient {
    send(command: unknown, options?: {
        abortSignal?: AbortSignal;
    }): Promise<unknown>;
}
/** The slice of `@aws-sdk/client-bedrock-agentcore` this strategy touches. */
export interface BedrockAgentCoreRuntimeSdkModule {
    readonly BedrockAgentCoreClient?: new (config: {
        region?: string;
        maxAttempts?: number;
    }) => AgentCoreRuntimeSdkClient;
    readonly InvokeAgentRuntimeCommand?: new (input: unknown) => unknown;
    /** Needed under `session: 'reuse'`, where ending a client stops its runtime session. */
    readonly StopRuntimeSessionCommand?: new (input: unknown) => unknown;
}
/**
 * @internal The `init` key a `'reuse'` connection's stop rides under: the
 * runtime session id to stop (`transport.ts` · `stopSession`). A symbol, so no
 * request the MCP client makes can ever claim it.
 */
export declare const STOP_RUNTIME_SESSION: unique symbol;
/** Which runtime every request goes to, as the operation names it. */
export interface InvokeTarget {
    readonly agentRuntimeArn: string;
    readonly qualifier?: string;
    readonly accountId?: string;
}
/** What the strategy is built from: a region, and optionally what was injected. */
export interface InvokeSdkOptions {
    readonly region: string;
    /**
     * A client the caller built — its credentials, region and retry settings win,
     * so build it with `maxAttempts: 1` (see the module note).
     */
    readonly client?: AgentCoreRuntimeSdkClient;
    /** The SDK module the caller imported; otherwise the peer dep is loaded. */
    readonly sdk?: BedrockAgentCoreRuntimeSdkModule;
}
/**
 * The client and the command constructor this strategy sends with.
 *
 * Loaded when the transport is BUILT, not at the first call, so a missing peer
 * dependency is refused where the transport is declared rather than mid-run.
 *
 * @throws when the SDK cannot be loaded, or when it lacks what is needed.
 */
export declare function invokeSdk(options: InvokeSdkOptions): {
    readonly client: AgentCoreRuntimeSdkClient;
    readonly InvokeAgentRuntimeCommand: new (input: unknown) => unknown;
    readonly StopRuntimeSessionCommand?: new (input: unknown) => unknown;
};
/**
 * A `fetch` that sends each request as one `InvokeAgentRuntimeCommand`.
 *
 * The URL the MCP client passes is ignored on purpose: it names the endpoint for
 * reports and errors, while the invocation goes to `target` — the SDK resolves
 * the endpoint itself, from the client's region.
 */
export declare function invokeFetch(target: InvokeTarget, client: AgentCoreRuntimeSdkClient, InvokeAgentRuntimeCommand: new (input: unknown) => unknown, StopRuntimeSessionCommand?: new (input: unknown) => unknown): ThrottleFetch;