# Generate SDKs for REST APIs in API Gateway To call your REST API in a platform- or language-specific way, you must generate the platform- or language-specific SDK of the API. You generate your SDK after you create, test, and deploy your API to a stage. Currently, API Gateway supports generating an SDK for an API in Java, JavaScript, Java for Android, Objective-C or Swift for iOS, and Ruby. This section explains how to generate an SDK of an API Gateway API. It also demonstrates how to use the generated SDK in a Java app, a Java for Android app, Objective-C and Swift for iOS apps, and a JavaScript app. To facilitate the discussion, we use this API Gateway [API](simple-calc-lambda-api.md), which exposes this [Simple Calculator](simple-calc-nodejs-lambda-function.md) Lambda function. Before proceeding, create or import the API and deploy it at least once in API Gateway. For instructions, see [Deploy REST APIs in API Gateway](how-to-deploy-api.md). **Topics** + [ # Simple calculator Lambda function ](simple-calc-nodejs-lambda-function.md) + [ # Simple calculator API in API Gateway ](simple-calc-lambda-api.md) + [ # Simple calculator API OpenAPI definition ](simple-calc-lambda-api-swagger-definition.md) + [ # Generate the Java SDK of an API in API Gateway ](generate-java-sdk-of-an-api.md) + [ # Generate the Android SDK of an API in API Gateway ](generate-android-sdk-of-an-api.md) + [ # Generate the iOS SDK of an API in API Gateway ](generate-ios-sdk-of-an-api.md) + [ # Generate the JavaScript SDK of a REST API in API Gateway ](generate-javascript-sdk-of-an-api.md) + [ # Generate the Ruby SDK of an API in API Gateway ](generate-ruby-sdk-of-an-api.md) + [ # Generate SDKs for an API using AWS CLI commands in API Gateway ](how-to-generate-sdk-cli.md) # Simple calculator Lambda function As an illustration, we will use a Node.js Lambda function that performs the binary operations of addition, subtraction, multiplication and division. **Topics** + [ ## Simple calculator Lambda function input format ](#simple-calc-lambda-function-input-format) + [ ## Simple calculator Lambda function output format ](#simple-calc-lambda-function-output-format) + [ ## Simple calculator Lambda function implementation ](#simple-calc-lambda-function-implementation) ## Simple calculator Lambda function input format This function takes an input of the following format: ``` { "a": "Number", "b": "Number", "op": "string"} ``` where `op` can be any of `(+, -, *, /, add, sub, mul, div)`. ## Simple calculator Lambda function output format When an operation succeeds, it returns the result of the following format: ``` { "a": "Number", "b": "Number", "op": "string", "c": "Number"} ``` where `c` holds the result of the calculation. ## Simple calculator Lambda function implementation The implementation of the Lambda function is as follows: ``` export const handler = async function (event, context) { console.log("Received event:", JSON.stringify(event)); if ( event.a === undefined || event.b === undefined || event.op === undefined ) { return "400 Invalid Input"; } const res = {}; res.a = Number(event.a); res.b = Number(event.b); res.op = event.op; if (isNaN(event.a) || isNaN(event.b)) { return "400 Invalid Operand"; } switch (event.op) { case "+": case "add": res.c = res.a + res.b; break; case "-": case "sub": res.c = res.a - res.b; break; case "*": case "mul": res.c = res.a * res.b; break; case "/": case "div": if (res.b == 0) { return "400 Divide by Zero"; } else { res.c = res.a / res.b; } break; default: return "400 Invalid Operator"; } return res; }; ``` # Simple calculator API in API Gateway Our simple calculator API exposes three methods (GET, POST, GET) to invoke the [Simple calculator Lambda function](simple-calc-nodejs-lambda-function.md). A graphical representation of this API is shown as follows: ![\[Simple calculator API for generated SDK\]](http://docs.aws.amazon.com/apigateway/latest/developerguide/images/simple-calc-api-console-hierarchy-new-console.png) These three methods show different ways to supply the input for the backend Lambda function to perform the same operation: + The `GET /?a=...&b=...&op=...` method uses the query parameters to specify the input. + The `POST /` method uses a JSON payload of `{"a":"Number", "b":"Number", "op":"string"}` to specify the input. + The `GET /{a}/{b}/{op}` method uses the path parameters to specify the input. If not defined, API Gateway generates the corresponding SDK method name by combining the HTTP method and path parts. The root path part (`/`) is referred to as `Api Root`. For example, the default Java SDK method name for the API method of `GET /?a=...&b=...&op=...` is `getABOp`, the default SDK method name for `POST /` is `postApiRoot`, and the default SDK method name for `GET /{a}/{b}/{op}` is `getABOp`. Individual SDKs may customize the convention. Consult the documentation in the generated SDK source for SDK specific method names. You can, and should, override the default SDK method names by specifying the [operationName](https://docs.aws.amazon.com/apigateway/latest/api/API_Method.html#operationName) property on each API method. You can do so when [creating the API method](https://docs.aws.amazon.com/apigateway/latest/api/API_PutMethod.html) or [updating the API method](https://docs.aws.amazon.com/apigateway/latest/api/API_UpdateMethod.html) using the API Gateway REST API. In the API Swagger definition, you can set the `operationId` to achieve the same result. Before showing how to call these methods using an SDK generated by API Gateway for this API, let's recall briefly how to set them up. For detailed instructions, see [Develop REST APIs in API Gateway](rest-api-develop.md). If you're new to API Gateway, see [Choose an AWS Lambda integration tutorial](getting-started-with-lambda-integration.md) first. ## Create models for input and output To specify strongly typed input in the SDK, we create an `Input` model for the API. To describe the response body data type, we create an `Output` model and a `Result` model. **To create models for the input, output, and result** 1. In the main navigation pane, choose **Models**. 1. Choose **Create model**. 1. For **Name**, enter **input**. 1. For **Content type**, enter **application/json**. If no matching content type is found, request validation is not performed. To use the same model regardless of the content type, enter **\$1default**. 1. For **Model schema**, enter the following model: ``` { "$schema" : "$schema": "http://json-schema.org/draft-04/schema#", "type":"object", "properties":{ "a":{"type":"number"}, "b":{"type":"number"}, "op":{"type":"string"} }, "title":"Input" } ``` 1. Choose **Create model**. 1. Repeat the following steps to create an `Output` model and a `Result` model. For the `Output` model, enter the following for the **Model schema**: ``` { "$schema": "http://json-schema.org/draft-04/schema#", "type": "object", "properties": { "c": {"type":"number"} }, "title": "Output" } ``` For the `Result` model, enter the following for the **Model schema**. Replace the API ID `abc123` with your API ID. ``` { "$schema": "http://json-schema.org/draft-04/schema#", "type":"object", "properties":{ "input":{ "$ref":"https://apigateway.amazonaws.com/restapis/abc123/models/Input" }, "output":{ "$ref":"https://apigateway.amazonaws.com/restapis/abc123/models/Output" } }, "title":"Result" } ``` ## Set up GET / method query parameters For the `GET /?a=..&b=..&op=..` method, the query parameters are declared in **Method Request**: **To set up GET / URL query string parameters** 1. In the **Method request** section for the `GET` method on the root (`/`) resource, choose **Edit**. 1. Choose **URL query string parameters** and do the following: 1. Choose **Add query string**. 1. For **Name**, enter **a**. 1. Keep **Required** and **Caching** turned off. 1. Keep **Caching** turned off. Repeat the same steps and create a query string named **b** and a query string named **op**. 1. Choose **Save**. ## Set up data model for the payload as input to the backend For the `POST /` method, we create the `Input` model and add it to the method request to define the shape of input data. **To set up the data model for the payload as input to the backend** 1. In the **Method request** section, for the `POST` method on the root (`/`) resource choose **Edit**. 1. Choose **Request body**. 1. Choose **Add model**. 1. For **Content type**, enter **application/json**. 1. For **Model**, select **Input**. 1. Choose **Save**. With this model, your API customers can call the SDK to specify the input by instantiating an `Input` object. Without this model, your customers would be required to create dictionary object to represent the JSON input to the Lambda function. ## Set up data model for the result output from the backend For all three methods, we create the `Result` model and add it to the method's `Method Response` to define the shape of output returned by the Lambda function. **To set up the data model for the result output from the backend** 1. Select the **/\$1a\$1/\$1b\$1/\$1op\$1** resource, and then choose the **GET** method. 1. On the **Method response** tab, under **Response 200**, choose **Edit**. 1. Under **Response body**, choose **Add model**. 1. For **Content type**, enter **application/json**. 1. For **Model**, select **Result**. 1. Choose **Save**. With this model, your API customers can parse a successful output by reading properties of a `Result` object. Without this model, customers would be required to create dictionary object to represent the JSON output. # Simple calculator API OpenAPI definition The following is the OpenAPI definition of the simple calculator API. You can import it into your account. However, you need to reset the resource-based permissions on the [Lambda function](simple-calc-nodejs-lambda-function.md) after the import. To do so, re-select the Lambda function that you created in your account from the **Integration Request** in the API Gateway console. This will cause the API Gateway console to reset the required permissions. Alternatively, you can use AWS Command Line Interface for Lambda command of [add-permission](https://docs.aws.amazon.com/cli/latest/reference/lambda/add-permission.html). ------ #### [ OpenAPI 2.0 ] ``` { "swagger": "2.0", "info": { "version": "2016-09-29T20:27:30Z", "title": "SimpleCalc" }, "host": "t6dve4zn25.execute-api.us-west-2.amazonaws.com", "basePath": "/demo", "schemes": [ "https" ], "paths": { "/": { "get": { "consumes": [ "application/json" ], "produces": [ "application/json" ], "parameters": [ { "name": "op", "in": "query", "required": false, "type": "string" }, { "name": "a", "in": "query", "required": false, "type": "string" }, { "name": "b", "in": "query", "required": false, "type": "string" } ], "responses": { "200": { "description": "200 response", "schema": { "$ref": "#/definitions/Result" } } }, "x-amazon-apigateway-integration": { "requestTemplates": { "application/json": "#set($inputRoot = $input.path('$'))\n{\n \"a\" : $input.params('a'),\n \"b\" : $input.params('b'),\n \"op\" : \"$input.params('op')\"\n}" }, "uri": "arn:aws:apigateway:us-west-2:lambda:path/2015-03-31/functions/arn:aws:lambda:us-west-2:123456789012:function:Calc/invocations", "passthroughBehavior": "when_no_templates", "httpMethod": "POST", "responses": { "default": { "statusCode": "200", "responseTemplates": { "application/json": "#set($inputRoot = $input.path('$'))\n{\n \"input\" : {\n \"a\" : $inputRoot.a,\n \"b\" : $inputRoot.b,\n \"op\" : \"$inputRoot.op\"\n },\n \"output\" : {\n \"c\" : $inputRoot.c\n }\n}" } } }, "type": "aws" } }, "post": { "consumes": [ "application/json" ], "produces": [ "application/json" ], "parameters": [ { "in": "body", "name": "Input", "required": true, "schema": { "$ref": "#/definitions/Input" } } ], "responses": { "200": { "description": "200 response", "schema": { "$ref": "#/definitions/Result" } } }, "x-amazon-apigateway-integration": { "uri": "arn:aws:apigateway:us-west-2:lambda:path/2015-03-31/functions/arn:aws:lambda:us-west-2:123456789012:function:Calc/invocations", "passthroughBehavior": "when_no_match", "httpMethod": "POST", "responses": { "default": { "statusCode": "200", "responseTemplates": { "application/json": "#set($inputRoot = $input.path('$'))\n{\n \"input\" : {\n \"a\" : $inputRoot.a,\n \"b\" : $inputRoot.b,\n \"op\" : \"$inputRoot.op\"\n },\n \"output\" : {\n \"c\" : $inputRoot.c\n }\n}" } } }, "type": "aws" } } }, "/{a}": { "x-amazon-apigateway-any-method": { "consumes": [ "application/json" ], "produces": [ "application/json" ], "parameters": [ { "name": "a", "in": "path", "required": true, "type": "string" } ], "responses": { "404": { "description": "404 response" } }, "x-amazon-apigateway-integration": { "requestTemplates": { "application/json": "{\"statusCode\": 200}" }, "passthroughBehavior": "when_no_match", "responses": { "default": { "statusCode": "404", "responseTemplates": { "application/json": "{ \"Message\" : \"Can't $context.httpMethod $context.resourcePath\" }" } } }, "type": "mock" } } }, "/{a}/{b}": { "x-amazon-apigateway-any-method": { "consumes": [ "application/json" ], "produces": [ "application/json" ], "parameters": [ { "name": "a", "in": "path", "required": true, "type": "string" }, { "name": "b", "in": "path", "required": true, "type": "string" } ], "responses": { "404": { "description": "404 response" } }, "x-amazon-apigateway-integration": { "requestTemplates": { "application/json": "{\"statusCode\": 200}" }, "passthroughBehavior": "when_no_match", "responses": { "default": { "statusCode": "404", "responseTemplates": { "application/json": "{ \"Message\" : \"Can't $context.httpMethod $context.resourcePath\" }" } } }, "type": "mock" } } }, "/{a}/{b}/{op}": { "get": { "consumes": [ "application/json" ], "produces": [ "application/json" ], "parameters": [ { "name": "a", "in": "path", "required": true, "type": "string" }, { "name": "b", "in": "path", "required": true, "type": "string" }, { "name": "op", "in": "path", "required": true, "type": "string" } ], "responses": { "200": { "description": "200 response", "schema": { "$ref": "#/definitions/Result" } } }, "x-amazon-apigateway-integration": { "requestTemplates": { "application/json": "#set($inputRoot = $input.path('$'))\n{\n \"a\" : $input.params('a'),\n \"b\" : $input.params('b'),\n \"op\" : \"$input.params('op')\"\n}" }, "uri": "arn:aws:apigateway:us-west-2:lambda:path/2015-03-31/functions/arn:aws:lambda:us-west-2:123456789012:function:Calc/invocations", "passthroughBehavior": "when_no_templates", "httpMethod": "POST", "responses": { "default": { "statusCode": "200", "responseTemplates": { "application/json": "#set($inputRoot = $input.path('$'))\n{\n \"input\" : {\n \"a\" : $inputRoot.a,\n \"b\" : $inputRoot.b,\n \"op\" : \"$inputRoot.op\"\n },\n \"output\" : {\n \"c\" : $inputRoot.c\n }\n}" } } }, "type": "aws" } } } }, "definitions": { "Input": { "type": "object", "properties": { "a": { "type": "number" }, "b": { "type": "number" }, "op": { "type": "string" } }, "title": "Input" }, "Output": { "type": "object", "properties": { "c": { "type": "number" } }, "title": "Output" }, "Result": { "type": "object", "properties": { "input": { "$ref": "#/definitions/Input" }, "output": { "$ref": "#/definitions/Output" } }, "title": "Result" } } } ``` ------ #### [ OpenAPI 3.0 ] ``` { "openapi" : "3.0.1", "info" : { "title" : "SimpleCalc", "version" : "2016-09-29T20:27:30Z" }, "servers" : [ { "url" : "https://t6dve4zn25.execute-api.us-west-2.amazonaws.com/{basePath}", "variables" : { "basePath" : { "default" : "demo" } } } ], "paths" : { "/{a}/{b}" : { "x-amazon-apigateway-any-method" : { "parameters" : [ { "name" : "a", "in" : "path", "required" : true, "schema" : { "type" : "string" } }, { "name" : "b", "in" : "path", "required" : true, "schema" : { "type" : "string" } } ], "responses" : { "404" : { "description" : "404 response", "content" : { } } }, "x-amazon-apigateway-integration" : { "type" : "mock", "responses" : { "default" : { "statusCode" : "404", "responseTemplates" : { "application/json" : "{ \"Message\" : \"Can't $context.httpMethod $context.resourcePath\" }" } } }, "requestTemplates" : { "application/json" : "{\"statusCode\": 200}" }, "passthroughBehavior" : "when_no_match" } } }, "/{a}/{b}/{op}" : { "get" : { "parameters" : [ { "name" : "a", "in" : "path", "required" : true, "schema" : { "type" : "string" } }, { "name" : "b", "in" : "path", "required" : true, "schema" : { "type" : "string" } }, { "name" : "op", "in" : "path", "required" : true, "schema" : { "type" : "string" } } ], "responses" : { "200" : { "description" : "200 response", "content" : { "application/json" : { "schema" : { "$ref" : "#/components/schemas/Result" } } } } }, "x-amazon-apigateway-integration" : { "type" : "aws", "httpMethod" : "POST", "uri" : "arn:aws:apigateway:us-west-2:lambda:path/2015-03-31/functions/arn:aws:lambda:us-west-2:111122223333:function:Calc/invocations", "responses" : { "default" : { "statusCode" : "200", "responseTemplates" : { "application/json" : "#set($inputRoot = $input.path('$'))\n{\n \"input\" : {\n \"a\" : $inputRoot.a,\n \"b\" : $inputRoot.b,\n \"op\" : \"$inputRoot.op\"\n },\n \"output\" : {\n \"c\" : $inputRoot.c\n }\n}" } } }, "requestTemplates" : { "application/json" : "#set($inputRoot = $input.path('$'))\n{\n \"a\" : $input.params('a'),\n \"b\" : $input.params('b'),\n \"op\" : \"$input.params('op')\"\n}" }, "passthroughBehavior" : "when_no_templates" } } }, "/" : { "get" : { "parameters" : [ { "name" : "op", "in" : "query", "schema" : { "type" : "string" } }, { "name" : "a", "in" : "query", "schema" : { "type" : "string" } }, { "name" : "b", "in" : "query", "schema" : { "type" : "string" } } ], "responses" : { "200" : { "description" : "200 response", "content" : { "application/json" : { "schema" : { "$ref" : "#/components/schemas/Result" } } } } }, "x-amazon-apigateway-integration" : { "type" : "aws", "httpMethod" : "POST", "uri" : "arn:aws:apigateway:us-west-2:lambda:path/2015-03-31/functions/arn:aws:lambda:us-west-2:111122223333:function:Calc/invocations", "responses" : { "default" : { "statusCode" : "200", "responseTemplates" : { "application/json" : "#set($inputRoot = $input.path('$'))\n{\n \"input\" : {\n \"a\" : $inputRoot.a,\n \"b\" : $inputRoot.b,\n \"op\" : \"$inputRoot.op\"\n },\n \"output\" : {\n \"c\" : $inputRoot.c\n }\n}" } } }, "requestTemplates" : { "application/json" : "#set($inputRoot = $input.path('$'))\n{\n \"a\" : $input.params('a'),\n \"b\" : $input.params('b'),\n \"op\" : \"$input.params('op')\"\n}" }, "passthroughBehavior" : "when_no_templates" } }, "post" : { "requestBody" : { "content" : { "application/json" : { "schema" : { "$ref" : "#/components/schemas/Input" } } }, "required" : true }, "responses" : { "200" : { "description" : "200 response", "content" : { "application/json" : { "schema" : { "$ref" : "#/components/schemas/Result" } } } } }, "x-amazon-apigateway-integration" : { "type" : "aws", "httpMethod" : "POST", "uri" : "arn:aws:apigateway:us-west-2:lambda:path/2015-03-31/functions/arn:aws:lambda:us-west-2:111122223333:function:Calc/invocations", "responses" : { "default" : { "statusCode" : "200", "responseTemplates" : { "application/json" : "#set($inputRoot = $input.path('$'))\n{\n \"input\" : {\n \"a\" : $inputRoot.a,\n \"b\" : $inputRoot.b,\n \"op\" : \"$inputRoot.op\"\n },\n \"output\" : {\n \"c\" : $inputRoot.c\n }\n}" } } }, "passthroughBehavior" : "when_no_match" } } }, "/{a}" : { "x-amazon-apigateway-any-method" : { "parameters" : [ { "name" : "a", "in" : "path", "required" : true, "schema" : { "type" : "string" } } ], "responses" : { "404" : { "description" : "404 response", "content" : { } } }, "x-amazon-apigateway-integration" : { "type" : "mock", "responses" : { "default" : { "statusCode" : "404", "responseTemplates" : { "application/json" : "{ \"Message\" : \"Can't $context.httpMethod $context.resourcePath\" }" } } }, "requestTemplates" : { "application/json" : "{\"statusCode\": 200}" }, "passthroughBehavior" : "when_no_match" } } } }, "components" : { "schemas" : { "Input" : { "title" : "Input", "type" : "object", "properties" : { "a" : { "type" : "number" }, "b" : { "type" : "number" }, "op" : { "type" : "string" } } }, "Output" : { "title" : "Output", "type" : "object", "properties" : { "c" : { "type" : "number" } } }, "Result" : { "title" : "Result", "type" : "object", "properties" : { "input" : { "$ref" : "#/components/schemas/Input" }, "output" : { "$ref" : "#/components/schemas/Output" } } } } } } ``` ------ # Generate the Java SDK of an API in API Gateway The following procedure shows how to generate the Java SDK of an API in API Gateway. **To generate the Java SDK of an API in API Gateway** 1. Sign in to the API Gateway console at [https://console.aws.amazon.com/apigateway](https://console.aws.amazon.com/apigateway). 1. Choose a REST API. 1. Choose **Stages**. 1. In the **Stages** pane, select the name of the stage. 1. Open the **Stage actions** menu, and then choose **Generate SDK**. 1. For **Platform**, choose the **Java** platform and do the following: 1. For **Service Name**, specify the name of your SDK. For example, **SimpleCalcSdk**. This becomes the name of your SDK client class. The name corresponds to the `` tag under `` in the pom.xml file, which is in the SDK's project folder. Do not include hyphens. 1. For **Java Package Name**, specify a package name for your SDK. For example, **examples.aws.apig.simpleCalc.sdk**. This package name is used as the namespace of your SDK library. Do not include hyphens. 1. For **Java Build System**, enter **maven** or **gradle** to specify the build system. 1. For **Java Group Id**, enter a group identifier for your SDK project. For example, enter **my-apig-api-examples**. This identifier corresponds to the `` tag under `` in the `pom.xml` file, which is in the SDK's project folder. 1. For **Java Artifact Id**, enter an artifact identifier for your SDK project. For example, enter **simple-calc-sdk**. This identifier corresponds to the `` tag under `` in the `pom.xml` file, which is in the SDK's project folder. 1. For **Java Artifact Version**, enter a version identifier string. For example, **1.0.0**. This version identifier corresponds to the `` tag under `` in the `pom.xml` file, which is in the SDK's project folder. 1. For **Source Code License Text**, enter the license text of your source code, if any. 1. Choose **Generate SDK**, and then follow the on-screen directions to download the SDK generated by API Gateway. Follow the instructions in [Use a Java SDK generated by API Gateway for a REST API](how-to-call-apigateway-generated-java-sdk.md) to use the generated SDK. Every time you update an API, you must redeploy the API and regenerate the SDK to have the updates included. # Generate the Android SDK of an API in API Gateway The following procedure shows how to generate the Android SDK of an API in API Gateway. **To generate the Android SDK of an API in API Gateway** 1. Sign in to the API Gateway console at [https://console.aws.amazon.com/apigateway](https://console.aws.amazon.com/apigateway). 1. Choose a REST API. 1. Choose **Stages**. 1. In the **Stages** pane, select the name of the stage. 1. Open the **Stage actions** menu, and then choose **Generate SDK**. 1. For **Platform**, choose the Android platform and do the following: 1. For **Group ID**, enter the unique identifier for the corresponding project. This is used in the `pom.xml` file (for example, **com.mycompany**). 1. For **Invoker package**, enter the namespace for the generated client classes (for example, **com.mycompany.clientsdk**). 1. For **Artifact ID**, enter the name of the compiled .jar file without the version. This is used in the `pom.xml` file (for example, **aws-apigateway-api-sdk**). 1. For **Artifact version**, enter the artifact version number for the generated client. This is used in the `pom.xml` file and should follow a *major*.*minor*.*patch* pattern (for example, **1.0.0**). 1. Choose **Generate SDK**, and then follow the on-screen directions to download the SDK generated by API Gateway. Follow the instructions in [Use an Android SDK generated by API Gateway for a REST API](how-to-generate-sdk-android.md) to use the generated SDK. Every time you update an API, you must redeploy the API and regenerate the SDK to have the updates included. # Generate the iOS SDK of an API in API Gateway The following procedure shows how to generate the iOS SDK of an API in API Gateway. **To generate the iOS SDK of an API in API Gateway** 1. Sign in to the API Gateway console at [https://console.aws.amazon.com/apigateway](https://console.aws.amazon.com/apigateway). 1. Choose a REST API. 1. Choose **Stages**. 1. In the **Stages** pane, select the name of the stage. 1. Open the **Stage actions** menu, and then choose **Generate SDK**. 1. For **Platform**, choose the **iOS (Objective-C) or iOS (Swift)** platform and do the following: 1. Type a unique prefix in the **Prefix** box. The effect of prefix is as follows: if you assign, for example, **SIMPLE\$1CALC** as the prefix for the SDK of the [SimpleCalc](simple-calc-lambda-api.md) API with `input`, `output`, and `result` models, the generated SDK will contain the `SIMPLE_CALCSimpleCalcClient` class that encapsulates the API, including the method requests/responses. In addition, the generated SDK will contain the `SIMPLE_CALCinput`, `SIMPLE_CALCoutput`, and `SIMPLE_CALCresult` classes to represent the input, output, and results, respectively, to represent the request input and response output. For more information, see [Use iOS SDK generated by API Gateway for a REST API in Objective-C or Swift](how-to-generate-sdk-ios.md). 1. Choose **Generate SDK**, and then follow the on-screen directions to download the SDK generated by API Gateway. Follow the instructions in [Use iOS SDK generated by API Gateway for a REST API in Objective-C or Swift](how-to-generate-sdk-ios.md) to use the generated SDK. Every time you update an API, you must redeploy the API and regenerate the SDK to have the updates included. # Generate the JavaScript SDK of a REST API in API Gateway The following procedure shows how to generate the JaveScript SDK of an API in API Gateway. **To generate the JavaScript SDK of an API in API Gateway** 1. Sign in to the API Gateway console at [https://console.aws.amazon.com/apigateway](https://console.aws.amazon.com/apigateway). 1. Choose a REST API. 1. Choose **Stages**. 1. In the **Stages** pane, select the name of the stage. 1. Open the **Stage actions** menu, and then choose **Generate SDK**. 1. For **Platform**, choose the **JavaScript** platform. 1. Choose **Generate SDK**, and then follow the on-screen directions to download the SDK generated by API Gateway. Follow the instructions in [Use a JavaScript SDK generated by API Gateway for a REST API](how-to-generate-sdk-javascript.md) to use the generated SDK. Every time you update an API, you must redeploy the API and regenerate the SDK to have the updates included. # Generate the Ruby SDK of an API in API Gateway The following procedure shows how to generate the Ruby SDK of an API in API Gateway. **To generate the Ruby SDK of an API in API Gateway** 1. Sign in to the API Gateway console at [https://console.aws.amazon.com/apigateway](https://console.aws.amazon.com/apigateway). 1. Choose a REST API. 1. Choose **Stages**. 1. In the **Stages** pane, select the name of the stage. 1. Open the **Stage actions** menu, and then choose **Generate SDK**. 1. For **Platform**, choose the **Ruby** platform and do the following: 1. For **Service Name**, specify the name of your SDK. For example, **SimpleCalc**. This is used to generate the Ruby Gem namespace of your API. The name must be all letters, (`a-zA-Z`), without any other special characters or numbers. 1. For **Ruby Gem Name**, specify the name of the Ruby Gem to contain the generated SDK source code for your API. By default, it is the lower-cased service name plus the `-sdk` suffix—for example, **simplecalc-sdk**. 1. For **Ruby Gem Version**, specify a version number for the generated Ruby Gem. By default, it is set to `1.0.0`. 1. Choose **Generate SDK**, and then follow the on-screen directions to download the SDK generated by API Gateway. Follow the instructions in [Use a Ruby SDK generated by API Gateway for a REST API](how-to-call-sdk-ruby.md) to use the generated SDK. Every time you update an API, you must redeploy the API and regenerate the SDK to have the updates included. # Generate SDKs for an API using AWS CLI commands in API Gateway You can use AWS CLI to generate and download an SDK of an API for a supported platform by calling the [get-sdk](https://docs.aws.amazon.com/cli/latest/reference/apigateway/get-sdk.html) command. We demonstrate this for some of the supported platforms in the following. **Topics** + [ ## Generate and download the Java for Android SDK using the AWS CLI ](#how-to-generate-sdk-cli-android) + [ ## Generate and download the JavaScript SDK using the AWS CLI ](#how-to-generate-sdk-cli-js) + [ ## Generate and download the Ruby SDK using the AWS CLI ](#how-to-generate-sdk-cli-ruby) ## Generate and download the Java for Android SDK using the AWS CLI To generate and download a Java for Android SDK generated by API Gateway of an API (`udpuvvzbkc`) at a given stage (`test`), call the command as follows: ``` aws apigateway get-sdk \ --rest-api-id udpuvvzbkc \ --stage-name test \ --sdk-type android \ --parameters groupId='com.mycompany',\ invokerPackage='com.mycompany.myApiSdk',\ artifactId='myApiSdk',\ artifactVersion='0.0.1' \ ~/apps/myApi/myApi-android-sdk.zip ``` The last input of `~/apps/myApi/myApi-android-sdk.zip` is the path to the downloaded SDK file named `myApi-android-sdk.zip`. ## Generate and download the JavaScript SDK using the AWS CLI To generate and download a JavaScript SDK generated by API Gateway of an API (`udpuvvzbkc`) at a given stage (`test`), call the command as follows: ``` aws apigateway get-sdk \ --rest-api-id udpuvvzbkc \ --stage-name test \ --sdk-type javascript \ ~/apps/myApi/myApi-js-sdk.zip ``` The last input of `~/apps/myApi/myApi-js-sdk.zip` is the path to the downloaded SDK file named `myApi-js-sdk.zip`. ## Generate and download the Ruby SDK using the AWS CLI To generate and download a Ruby SDK of an API (`udpuvvzbkc`) at a given stage (`test`), call the command as follows: ``` aws apigateway get-sdk \ --rest-api-id udpuvvzbkc \ --stage-name test \ --sdk-type ruby \ --parameters service.name=myApiRubySdk,ruby.gem-name=myApi,ruby.gem-version=0.01 \ ~/apps/myApi/myApi-ruby-sdk.zip ``` The last input of `~/apps/myApi/myApi-ruby-sdk.zip` is the path to the downloaded SDK file named `myApi-ruby-sdk.zip`. Next, we show how to use the generated SDK to call the underlying API. For more information, see [Invoke REST APIs in API Gateway](how-to-call-api.md).