@middy/ssm/index.d.ts

SSM (EC2 Systems Manager) parameters middleware for the middy framework

// Copyright 2017 - 2026 will Farrell, Luciano Mammino, and Middy contributors.
// SPDX-License-Identifier: MIT
import type { SSMClient, SSMClientConfig } from "@aws-sdk/client-ssm";
import type middy from "@middy/core";
import type { Options as MiddyOptions } from "@middy/util";
import type { Context as LambdaContext } from "aws-lambda";

export type ParamType<T> = string & { __returnType?: T };
export declare function ssmParam<T>(path: string): ParamType<T>;

export interface SSMOptions<AwsSSMClient = SSMClient>
	extends Omit<MiddyOptions<AwsSSMClient, SSMClientConfig>, "fetchData"> {
	fetchData?: { [key: string]: string | ParamType<unknown> };
	awsRequestLimit?: number;
}

export type Context<TOptions extends SSMOptions | undefined> =
	TOptions extends { setToContext: true }
		? TOptions extends { fetchData: infer TFetchData }
			? LambdaContext & {
					[Key in keyof TFetchData]: TFetchData[Key] extends ParamType<infer T>
						? T
						: unknown;
				}
			: never
		: LambdaContext;

export type Internal<TOptions extends SSMOptions | undefined> =
	TOptions extends SSMOptions
		? TOptions extends { fetchData: infer TFetchData }
			? {
					[Key in keyof TFetchData]: TFetchData[Key] extends ParamType<infer T>
						? T
						: unknown;
				}
			: {}
		: {};

declare function ssm<TOptions extends SSMOptions>(
	options?: TOptions,
): middy.MiddlewareObj<
	unknown,
	unknown,
	Error,
	Context<TOptions>,
	Internal<TOptions>
>;

export declare function ssmValidateOptions(
	options?: Record<string, unknown>,
): void;

export default ssm;