diff --git a/bin/configs/typescript-consolidated-composed-schemas.yaml b/bin/configs/typescript-consolidated-composed-schemas.yaml
new file mode 100644
index 000000000000..0da510f5bfc6
--- /dev/null
+++ b/bin/configs/typescript-consolidated-composed-schemas.yaml
@@ -0,0 +1,6 @@
+generatorName: typescript
+outputDir: samples/openapi3/client/petstore/typescript/builds/composed-schemas
+inputSpec: modules/openapi-generator/src/test/resources/3_0/composed-schemas.yaml
+templateDir: modules/openapi-generator/src/main/resources/typescript
+additionalProperties:
+  npmName: ts-petstore-client
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptClientCodegen.java
index 821d190f5eb4..926a4eb41bbd 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptClientCodegen.java
@@ -156,6 +156,7 @@ public TypeScriptClientCodegen() {
         typeMapping.put("ByteArray", "string");
         typeMapping.put("UUID", "string");
         typeMapping.put("Error", "Error");
+        typeMapping.put("AnyType", "any");
 
 
         cliOptions.add(new CliOption(NPM_NAME, "The name under which you want to publish generated npm package." +
@@ -893,6 +894,13 @@ public String toOneOfName(List<String> names, ComposedSchema composedSchema) {
         return String.join(" | ", types);
     }
 
+    @Override
+    public String toAllOfName(List<String> names, ComposedSchema composedSchema) {
+        List<String> types = getTypesFromSchemas(composedSchema.getAllOf());
+
+        return String.join(" & ", types);
+    }
+
     /**
      * Extracts the list of type names from a list of schemas.
      * Excludes `AnyType` if there are other valid types extracted.
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/.gitignore b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/.gitignore
new file mode 100644
index 000000000000..1521c8b7652b
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/.gitignore
@@ -0,0 +1 @@
+dist
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/.openapi-generator-ignore b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/.openapi-generator-ignore
new file mode 100644
index 000000000000..7484ee590a38
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/.openapi-generator-ignore
@@ -0,0 +1,23 @@
+# OpenAPI Generator Ignore
+# Generated by openapi-generator https://github.com/openapitools/openapi-generator
+
+# Use this file to prevent files from being overwritten by the generator.
+# The patterns follow closely to .gitignore or .dockerignore.
+
+# As an example, the C# client generator defines ApiClient.cs.
+# You can make changes and tell OpenAPI Generator to ignore just this file by uncommenting the following line:
+#ApiClient.cs
+
+# You can match any string of characters against a directory, file or extension with a single asterisk (*):
+#foo/*/qux
+# The above matches foo/bar/qux and foo/baz/qux, but not foo/bar/baz/qux
+
+# You can recursively match patterns against a directory, file or extension with a double asterisk (**):
+#foo/**/qux
+# This matches foo/bar/qux, foo/baz/qux, and foo/bar/baz/qux
+
+# You can also negate patterns with an exclamation (!).
+# For example, you can ignore all files in a docs folder with the file extension .md:
+#docs/*.md
+# Then explicitly reverse the ignore rule for a single file:
+#!docs/README.md
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/.openapi-generator/FILES b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/.openapi-generator/FILES
new file mode 100644
index 000000000000..3647b2a71bd5
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/.openapi-generator/FILES
@@ -0,0 +1,29 @@
+.gitignore
+README.md
+apis/DefaultApi.ts
+apis/baseapi.ts
+apis/exception.ts
+auth/auth.ts
+configuration.ts
+git_push.sh
+http/http.ts
+http/isomorphic-fetch.ts
+index.ts
+middleware.ts
+models/Cat.ts
+models/CatAllOf.ts
+models/Dog.ts
+models/DogAllOf.ts
+models/InlineObject.ts
+models/ObjectSerializer.ts
+models/PetByAge.ts
+models/PetByType.ts
+models/all.ts
+package.json
+rxjsStub.ts
+servers.ts
+tsconfig.json
+types/ObjectParamAPI.ts
+types/ObservableAPI.ts
+types/PromiseAPI.ts
+util.ts
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/.openapi-generator/VERSION b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/.openapi-generator/VERSION
new file mode 100644
index 000000000000..862529f8cacd
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/.openapi-generator/VERSION
@@ -0,0 +1 @@
+5.2.1-SNAPSHOT
\ No newline at end of file
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/README.md b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/README.md
new file mode 100644
index 000000000000..80b1ac5cc98b
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/README.md
@@ -0,0 +1,30 @@
+## ts-petstore-client@1.0.0
+
+This generator creates TypeScript/JavaScript client that utilizes fetch-api. 
+
+### Building
+
+To build and compile the typescript sources to javascript use:
+```
+npm install
+npm run build
+```
+
+### Publishing
+
+First build the package then run ```npm publish```
+
+### Consuming
+
+navigate to the folder of your consuming project and run one of the following commands.
+
+_published:_
+
+```
+npm install ts-petstore-client@1.0.0 --save
+```
+
+_unPublished (not recommended):_
+
+```
+npm install PATH_TO_GENERATED_PACKAGE --save
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/apis/DefaultApi.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/apis/DefaultApi.ts
new file mode 100644
index 000000000000..b2fe591913cf
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/apis/DefaultApi.ts
@@ -0,0 +1,213 @@
+// TODO: better import syntax?
+import { BaseAPIRequestFactory, RequiredError } from './baseapi';
+import {Configuration} from '../configuration';
+import { RequestContext, HttpMethod, ResponseContext, HttpFile} from '../http/http';
+import {ObjectSerializer} from '../models/ObjectSerializer';
+import {ApiException} from './exception';
+import {isCodeInRange} from '../util';
+
+import { Cat } from '../models/Cat';
+import { Dog } from '../models/Dog';
+import { InlineObject } from '../models/InlineObject';
+import { PetByAge } from '../models/PetByAge';
+import { PetByType } from '../models/PetByType';
+
+/**
+ * no description
+ */
+export class DefaultApiRequestFactory extends BaseAPIRequestFactory {
+
+    /**
+     * @param inlineObject 
+     */
+    public async filePost(inlineObject?: InlineObject, _options?: Configuration): Promise<RequestContext> {
+        let _config = _options || this.configuration;
+
+
+        // Path Params
+        const localVarPath = '/file';
+
+        // Make Request Context
+        const requestContext = _config.baseServer.makeRequestContext(localVarPath, HttpMethod.POST);
+        requestContext.setHeaderParam("Accept", "application/json, */*;q=0.8")
+
+        // Query Params
+
+        // Header Params
+
+        // Form Params
+
+
+        // Body Params
+        const contentType = ObjectSerializer.getPreferredMediaType([
+            "application/json"
+        ]);
+        requestContext.setHeaderParam("Content-Type", contentType);
+        const serializedBody = ObjectSerializer.stringify(
+            ObjectSerializer.serialize(inlineObject, "InlineObject", ""),
+            contentType
+        );
+        requestContext.setBody(serializedBody);
+
+        // Apply auth methods
+
+        return requestContext;
+    }
+
+    /**
+     * @param petByAgePetByType 
+     */
+    public async petsFilteredPatch(petByAgePetByType?: PetByAge | PetByType, _options?: Configuration): Promise<RequestContext> {
+        let _config = _options || this.configuration;
+
+
+        // Path Params
+        const localVarPath = '/pets-filtered';
+
+        // Make Request Context
+        const requestContext = _config.baseServer.makeRequestContext(localVarPath, HttpMethod.PATCH);
+        requestContext.setHeaderParam("Accept", "application/json, */*;q=0.8")
+
+        // Query Params
+
+        // Header Params
+
+        // Form Params
+
+
+        // Body Params
+        const contentType = ObjectSerializer.getPreferredMediaType([
+            "application/json"
+        ]);
+        requestContext.setHeaderParam("Content-Type", contentType);
+        const serializedBody = ObjectSerializer.stringify(
+            ObjectSerializer.serialize(petByAgePetByType, "PetByAge | PetByType", ""),
+            contentType
+        );
+        requestContext.setBody(serializedBody);
+
+        // Apply auth methods
+
+        return requestContext;
+    }
+
+    /**
+     * @param catDog 
+     */
+    public async petsPatch(catDog?: Cat | Dog, _options?: Configuration): Promise<RequestContext> {
+        let _config = _options || this.configuration;
+
+
+        // Path Params
+        const localVarPath = '/pets';
+
+        // Make Request Context
+        const requestContext = _config.baseServer.makeRequestContext(localVarPath, HttpMethod.PATCH);
+        requestContext.setHeaderParam("Accept", "application/json, */*;q=0.8")
+
+        // Query Params
+
+        // Header Params
+
+        // Form Params
+
+
+        // Body Params
+        const contentType = ObjectSerializer.getPreferredMediaType([
+            "application/json"
+        ]);
+        requestContext.setHeaderParam("Content-Type", contentType);
+        const serializedBody = ObjectSerializer.stringify(
+            ObjectSerializer.serialize(catDog, "Cat | Dog", ""),
+            contentType
+        );
+        requestContext.setBody(serializedBody);
+
+        // Apply auth methods
+
+        return requestContext;
+    }
+
+}
+
+export class DefaultApiResponseProcessor {
+
+    /**
+     * Unwraps the actual response sent by the server from the response context and deserializes the response content
+     * to the expected objects
+     *
+     * @params response Response returned by the server for a request to filePost
+     * @throws ApiException if the response code was not in [200, 299]
+     */
+     public async filePost(response: ResponseContext): Promise<void > {
+        const contentType = ObjectSerializer.normalizeMediaType(response.headers["content-type"]);
+        if (isCodeInRange("200", response.httpStatusCode)) {
+            return;
+        }
+
+        // Work around for missing responses in specification, e.g. for petstore.yaml
+        if (response.httpStatusCode >= 200 && response.httpStatusCode <= 299) {
+            const body: void = ObjectSerializer.deserialize(
+                ObjectSerializer.parse(await response.body.text(), contentType),
+                "void", ""
+            ) as void;
+            return body;
+        }
+
+        let body = response.body || "";
+        throw new ApiException<string>(response.httpStatusCode, "Unknown API Status Code!\nBody: \"" + body + "\"");
+    }
+
+    /**
+     * Unwraps the actual response sent by the server from the response context and deserializes the response content
+     * to the expected objects
+     *
+     * @params response Response returned by the server for a request to petsFilteredPatch
+     * @throws ApiException if the response code was not in [200, 299]
+     */
+     public async petsFilteredPatch(response: ResponseContext): Promise<void > {
+        const contentType = ObjectSerializer.normalizeMediaType(response.headers["content-type"]);
+        if (isCodeInRange("200", response.httpStatusCode)) {
+            return;
+        }
+
+        // Work around for missing responses in specification, e.g. for petstore.yaml
+        if (response.httpStatusCode >= 200 && response.httpStatusCode <= 299) {
+            const body: void = ObjectSerializer.deserialize(
+                ObjectSerializer.parse(await response.body.text(), contentType),
+                "void", ""
+            ) as void;
+            return body;
+        }
+
+        let body = response.body || "";
+        throw new ApiException<string>(response.httpStatusCode, "Unknown API Status Code!\nBody: \"" + body + "\"");
+    }
+
+    /**
+     * Unwraps the actual response sent by the server from the response context and deserializes the response content
+     * to the expected objects
+     *
+     * @params response Response returned by the server for a request to petsPatch
+     * @throws ApiException if the response code was not in [200, 299]
+     */
+     public async petsPatch(response: ResponseContext): Promise<void > {
+        const contentType = ObjectSerializer.normalizeMediaType(response.headers["content-type"]);
+        if (isCodeInRange("200", response.httpStatusCode)) {
+            return;
+        }
+
+        // Work around for missing responses in specification, e.g. for petstore.yaml
+        if (response.httpStatusCode >= 200 && response.httpStatusCode <= 299) {
+            const body: void = ObjectSerializer.deserialize(
+                ObjectSerializer.parse(await response.body.text(), contentType),
+                "void", ""
+            ) as void;
+            return body;
+        }
+
+        let body = response.body || "";
+        throw new ApiException<string>(response.httpStatusCode, "Unknown API Status Code!\nBody: \"" + body + "\"");
+    }
+
+}
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/apis/baseapi.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/apis/baseapi.ts
new file mode 100644
index 000000000000..fe7ee3d15118
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/apis/baseapi.ts
@@ -0,0 +1,37 @@
+import { Configuration } from '../configuration'
+
+/**
+ *
+ * @export
+ */
+export const COLLECTION_FORMATS = {
+    csv: ",",
+    ssv: " ",
+    tsv: "\t",
+    pipes: "|",
+};
+
+
+/**
+ * 
+ * @export
+ * @class BaseAPI
+ */
+export class BaseAPIRequestFactory {
+
+    constructor(protected configuration: Configuration) {
+    }
+};
+
+/**
+ * 
+ * @export
+ * @class RequiredError
+ * @extends {Error}
+ */
+export class RequiredError extends Error {
+    name: "RequiredError" = "RequiredError";
+    constructor(public field: string, msg?: string) {
+        super(msg);
+    }
+}
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/apis/exception.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/apis/exception.ts
new file mode 100644
index 000000000000..fb8d314eb41d
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/apis/exception.ts
@@ -0,0 +1,14 @@
+/**
+ * Represents an error caused by an api call i.e. it has attributes for a HTTP status code 
+ * and the returned body object.
+ *
+ * Example
+ * API returns a ErrorMessageObject whenever HTTP status code is not in [200, 299]
+ * => ApiException(404, someErrorMessageObject)
+ *
+ */
+export class ApiException<T> extends Error {
+    public constructor(public code: number, public body: T) {
+        super("HTTP-Code: " + code + "\nMessage: " + JSON.stringify(body))  
+    }
+}
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/auth/auth.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/auth/auth.ts
new file mode 100644
index 000000000000..fa859aaa0981
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/auth/auth.ts
@@ -0,0 +1,49 @@
+// typings for btoa are incorrect
+import { RequestContext } from "../http/http";
+
+/**
+ * Interface authentication schemes.
+ */
+export interface SecurityAuthentication {
+    /*
+     * @return returns the name of the security authentication as specified in OAI
+     */
+    getName(): string;
+
+    /**
+     * Applies the authentication scheme to the request context
+     *
+     * @params context the request context which should use this authentication scheme
+     */
+    applySecurityAuthentication(context: RequestContext): void | Promise<void>;
+}
+
+export interface TokenProvider {
+  getToken(): Promise<string> | string;
+}
+
+
+export type AuthMethods = {
+}
+
+export type ApiKeyConfiguration = string;
+export type HttpBasicConfiguration = { "username": string, "password": string };
+export type HttpBearerConfiguration = { tokenProvider: TokenProvider };
+export type OAuth2Configuration = { accessToken: string };
+
+export type AuthMethodsConfiguration = {
+}
+
+/**
+ * Creates the authentication methods from a swagger description.
+ *
+ */
+export function configureAuthMethods(config: AuthMethodsConfiguration | undefined): AuthMethods {
+    let authMethods: AuthMethods = {}
+
+    if (!config) {
+        return authMethods;
+    }
+
+    return authMethods;
+}
\ No newline at end of file
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/configuration.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/configuration.ts
new file mode 100644
index 000000000000..b78d85972a4a
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/configuration.ts
@@ -0,0 +1,66 @@
+import { HttpLibrary } from "./http/http";
+import { Middleware, PromiseMiddleware, PromiseMiddlewareWrapper } from "./middleware";
+import { IsomorphicFetchHttpLibrary as DefaultHttpLibrary } from "./http/isomorphic-fetch";
+import { BaseServerConfiguration, server1 } from "./servers";
+import { configureAuthMethods, AuthMethods, AuthMethodsConfiguration } from "./auth/auth";
+
+export interface Configuration {
+    readonly baseServer: BaseServerConfiguration;
+    readonly httpApi: HttpLibrary;
+    readonly middleware: Middleware[];
+    readonly authMethods: AuthMethods;
+}
+
+
+/**
+ * Interface with which a configuration object can be configured.
+ */
+export interface ConfigurationParameters {
+    /**
+     * Default server to use
+     */
+    baseServer?: BaseServerConfiguration;
+    /**
+     * HTTP library to use e.g. IsomorphicFetch
+     */
+    httpApi?: HttpLibrary;
+    /**
+     * The middlewares which will be applied to requests and responses
+     */
+    middleware?: Middleware[];
+    /**
+     * Configures all middlewares using the promise api instead of observables (which Middleware uses)
+     */
+    promiseMiddleware?: PromiseMiddleware[];
+    /**
+     * Configuration for the available authentication methods
+     */
+    authMethods?: AuthMethodsConfiguration
+}
+
+/**
+ * Configuration factory function
+ *
+ * If a property is not included in conf, a default is used:
+ *    - baseServer: server1
+ *    - httpApi: IsomorphicFetchHttpLibrary
+ *    - middleware: []
+ *    - promiseMiddleware: []
+ *    - authMethods: {}
+ *
+ * @param conf partial configuration
+ */
+export function createConfiguration(conf: ConfigurationParameters = {}): Configuration {
+    const configuration: Configuration = {
+        baseServer: conf.baseServer !== undefined ? conf.baseServer : server1,
+        httpApi: conf.httpApi || new DefaultHttpLibrary(),
+        middleware: conf.middleware || [],
+        authMethods: configureAuthMethods(conf.authMethods)
+    };
+    if (conf.promiseMiddleware) {
+        conf.promiseMiddleware.forEach(
+            m => configuration.middleware.push(new PromiseMiddlewareWrapper(m))
+        );
+    }
+    return configuration;
+}
\ No newline at end of file
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/git_push.sh b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/git_push.sh
new file mode 100644
index 000000000000..8442b80bb445
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/git_push.sh
@@ -0,0 +1,52 @@
+#!/bin/sh
+# ref: https://help.github.com/articles/adding-an-existing-project-to-github-using-the-command-line/
+#
+# Usage example: /bin/sh ./git_push.sh wing328 openapi-pestore-perl "minor update"
+
+git_user_id=$1
+git_repo_id=$2
+release_note=$3
+
+if [ "$git_user_id" = "" ]; then
+    git_user_id="GIT_USER_ID"
+    echo "[INFO] No command line input provided. Set \$git_user_id to $git_user_id"
+fi
+
+if [ "$git_repo_id" = "" ]; then
+    git_repo_id="GIT_REPO_ID"
+    echo "[INFO] No command line input provided. Set \$git_repo_id to $git_repo_id"
+fi
+
+if [ "$release_note" = "" ]; then
+    release_note="Minor update"
+    echo "[INFO] No command line input provided. Set \$release_note to $release_note"
+fi
+
+# Initialize the local directory as a Git repository
+git init
+
+# Adds the files in the local repository and stages them for commit.
+git add .
+
+# Commits the tracked changes and prepares them to be pushed to a remote repository. 
+git commit -m "$release_note"
+
+# Sets the new remote
+git_remote=`git remote`
+if [ "$git_remote" = "" ]; then # git remote not defined
+
+    if [ "$GIT_TOKEN" = "" ]; then
+        echo "[INFO] \$GIT_TOKEN (environment variable) is not set. Using the git credential in your environment."
+        git remote add origin https://github.com/${git_user_id}/${git_repo_id}.git
+    else
+        git remote add origin https://${git_user_id}:${GIT_TOKEN}@github.com/${git_user_id}/${git_repo_id}.git
+    fi
+
+fi
+
+git pull origin master
+
+# Pushes (Forces) the changes in the local repository up to the remote repository
+echo "Git pushing to https://github.com/${git_user_id}/${git_repo_id}.git"
+git push origin master 2>&1 | grep -v 'To https'
+
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/http/http.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/http/http.ts
new file mode 100644
index 000000000000..8b8219e910ff
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/http/http.ts
@@ -0,0 +1,220 @@
+// typings of url-parse are incorrect...
+// @ts-ignore 
+import * as URLParse from "url-parse";
+import { Observable, from } from '../rxjsStub';
+
+export * from './isomorphic-fetch';
+
+/**
+ * Represents an HTTP method.
+ */
+export enum HttpMethod {
+    GET = "GET",
+    HEAD = "HEAD",
+    POST = "POST",
+    PUT = "PUT",
+    DELETE = "DELETE",
+    CONNECT = "CONNECT",
+    OPTIONS = "OPTIONS",
+    TRACE = "TRACE",
+    PATCH = "PATCH"
+}
+
+/**
+ * Represents an HTTP file which will be transferred from or to a server.
+ */
+export type HttpFile = Blob & { readonly name: string };
+
+
+export class HttpException extends Error {
+    public constructor(msg: string) {
+        super(msg);
+    }
+}
+
+/**
+ * Represents the body of an outgoing HTTP request.
+ */
+export type RequestBody = undefined | string | FormData;
+
+/**
+ * Represents an HTTP request context
+ */
+export class RequestContext {
+    private headers: { [key: string]: string } = {};
+    private body: RequestBody = undefined;
+    private url: URLParse;
+
+    /**
+     * Creates the request context using a http method and request resource url
+     *
+     * @param url url of the requested resource
+     * @param httpMethod http method
+     */
+    public constructor(url: string, private httpMethod: HttpMethod) {
+        this.url = new URLParse(url, true);
+    }
+
+    /*
+     * Returns the url set in the constructor including the query string
+     *
+     */
+    public getUrl(): string {
+        return this.url.toString();
+    }
+
+    /**
+     * Replaces the url set in the constructor with this url.
+     *
+     */
+    public setUrl(url: string) {
+        this.url = new URLParse(url, true);
+    }
+
+    /**
+     * Sets the body of the http request either as a string or FormData
+     *
+     * Note that setting a body on a HTTP GET, HEAD, DELETE, CONNECT or TRACE
+     * request is discouraged.
+     * https://httpwg.org/http-core/draft-ietf-httpbis-semantics-latest.html#rfc.section.7.3.1
+     *
+     * @param body the body of the request
+     */
+    public setBody(body: RequestBody) {
+        this.body = body;
+    }
+
+    public getHttpMethod(): HttpMethod {
+        return this.httpMethod;
+    }
+
+    public getHeaders(): { [key: string]: string } {
+        return this.headers;
+    }
+
+    public getBody(): RequestBody {
+        return this.body;
+    }
+
+    public setQueryParam(name: string, value: string) {
+        let queryObj = this.url.query;
+        queryObj[name] = value;
+        this.url.set("query", queryObj);
+    }
+
+    /**
+     * Sets a cookie with the name and value. NO check  for duplicate cookies is performed
+     *
+     */
+    public addCookie(name: string, value: string): void {
+        if (!this.headers["Cookie"]) {
+            this.headers["Cookie"] = "";
+        }
+        this.headers["Cookie"] += name + "=" + value + "; ";
+    }
+
+    public setHeaderParam(key: string, value: string): void  { 
+        this.headers[key] = value;
+    }
+}
+
+export interface ResponseBody {
+    text(): Promise<string>;
+    binary(): Promise<Blob>;
+}
+
+/**
+ * Helper class to generate a `ResponseBody` from binary data
+ */
+export class SelfDecodingBody implements ResponseBody {
+    constructor(private dataSource: Promise<Blob>) {}
+
+    binary(): Promise<Blob> {
+        return this.dataSource;
+    }
+
+    async text(): Promise<string> {
+        const data: Blob = await this.dataSource;
+        // @ts-ignore
+        if (data.text) {
+            // @ts-ignore
+            return data.text();
+        }
+
+        return new Promise<string>((resolve, reject) => {
+            const reader = new FileReader();
+            reader.addEventListener("load", () => resolve(reader.result as string));
+            reader.addEventListener("error", () => reject(reader.error));
+            reader.readAsText(data);
+        });
+    }
+}
+
+export class ResponseContext {
+    public constructor(
+        public httpStatusCode: number,
+        public headers: { [key: string]: string },
+        public body: ResponseBody
+    ) {}
+
+    /**
+     * Parse header value in the form `value; param1="value1"`
+     *
+     * E.g. for Content-Type or Content-Disposition
+     * Parameter names are converted to lower case
+     * The first parameter is returned with the key `""`
+     */
+    public getParsedHeader(headerName: string): { [parameter: string]: string } {
+        const result: { [parameter: string]: string } = {};
+        if (!this.headers[headerName]) {
+            return result;
+        }
+
+        const parameters = this.headers[headerName].split(";");
+        for (const parameter of parameters) {
+            let [key, value] = parameter.split("=", 2);
+            key = key.toLowerCase().trim();
+            if (value === undefined) {
+                result[""] = key;
+            } else {
+                value = value.trim();
+                if (value.startsWith('"') && value.endsWith('"')) {
+                    value = value.substring(1, value.length - 1);
+                }
+                result[key] = value;
+            }
+        }
+        return result;
+    }
+
+    public async getBodyAsFile(): Promise<HttpFile> {
+        const data = await this.body.binary();
+        const fileName = this.getParsedHeader("content-disposition")["filename"] || "";
+        const contentType = this.headers["content-type"] || "";
+        try {
+            return new File([data], fileName, { type: contentType });
+        } catch (error) {
+            /** Fallback for when the File constructor is not available */
+            return Object.assign(data, {
+                name: fileName,
+                type: contentType
+            });
+        }
+    }
+}
+
+export interface HttpLibrary {
+    send(request: RequestContext): Observable<ResponseContext>;
+}
+
+export interface PromiseHttpLibrary {
+    send(request: RequestContext): Promise<ResponseContext>;
+}
+
+export function wrapHttpLibrary(promiseHttpLibrary: PromiseHttpLibrary): HttpLibrary {
+  return {
+    send(request: RequestContext): Observable<ResponseContext> {
+      return from(promiseHttpLibrary.send(request));
+    }
+  }
+}
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/http/isomorphic-fetch.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/http/isomorphic-fetch.ts
new file mode 100644
index 000000000000..3af85f3d902c
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/http/isomorphic-fetch.ts
@@ -0,0 +1,32 @@
+import {HttpLibrary, RequestContext, ResponseContext} from './http';
+import { from, Observable } from '../rxjsStub';
+import "whatwg-fetch";
+
+export class IsomorphicFetchHttpLibrary implements HttpLibrary {
+
+    public send(request: RequestContext): Observable<ResponseContext> {
+        let method = request.getHttpMethod().toString();
+        let body = request.getBody();
+
+        const resultPromise = fetch(request.getUrl(), {
+            method: method,
+            body: body as any,
+            headers: request.getHeaders(),
+            credentials: "same-origin"
+        }).then((resp: any) => {
+            const headers: { [name: string]: string } = {};
+            resp.headers.forEach((value: string, name: string) => {
+              headers[name] = value;
+            });
+
+            const body = {
+              text: () => resp.text(),
+              binary: () => resp.blob()
+            };
+            return new ResponseContext(resp.status, headers, body);
+        });
+
+        return from<Promise<ResponseContext>>(resultPromise);
+
+    }
+}
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/index.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/index.ts
new file mode 100644
index 000000000000..127f89d99723
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/index.ts
@@ -0,0 +1,11 @@
+export * from "./http/http";
+export * from "./auth/auth";
+export * from "./models/all";
+export { createConfiguration } from "./configuration"
+export { Configuration } from "./configuration"
+export * from "./apis/exception";
+export * from "./servers";
+
+export { PromiseMiddleware as Middleware } from './middleware';
+export { PromiseDefaultApi as DefaultApi } from './types/PromiseAPI';
+
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/middleware.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/middleware.ts
new file mode 100644
index 000000000000..e90071381890
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/middleware.ts
@@ -0,0 +1,66 @@
+import {RequestContext, ResponseContext} from './http/http';
+import { Observable, from } from './rxjsStub';
+
+/**
+ * Defines the contract for a middleware intercepting requests before
+ * they are sent (but after the RequestContext was created)
+ * and before the ResponseContext is unwrapped.
+ *
+ */
+export interface Middleware {
+    /**
+     * Modifies the request before the request is sent.
+     *
+     * @param context RequestContext of a request which is about to be sent to the server
+     * @returns an observable of the updated request context
+     *
+     */
+    pre(context: RequestContext): Observable<RequestContext>;
+    /**
+     * Modifies the returned response before it is deserialized.
+     *
+     * @param context ResponseContext of a sent request
+     * @returns an observable of the modified response context
+     */
+    post(context: ResponseContext): Observable<ResponseContext>;
+}
+
+export class PromiseMiddlewareWrapper implements Middleware {
+
+    public constructor(private middleware: PromiseMiddleware) {
+
+    }
+
+    pre(context: RequestContext): Observable<RequestContext> {
+        return from(this.middleware.pre(context));
+    }
+    
+    post(context: ResponseContext): Observable<ResponseContext> {
+        return from(this.middleware.post(context));
+    }
+
+}
+
+/**
+ * Defines the contract for a middleware intercepting requests before
+ * they are sent (but after the RequestContext was created)
+ * and before the ResponseContext is unwrapped.
+ *
+ */
+export interface PromiseMiddleware {
+    /**
+     * Modifies the request before the request is sent.
+     *
+     * @param context RequestContext of a request which is about to be sent to the server
+     * @returns an observable of the updated request context
+     *
+     */
+    pre(context: RequestContext): Promise<RequestContext>;
+        /**
+     * Modifies the returned response before it is deserialized.
+     *
+     * @param context ResponseContext of a sent request
+     * @returns an observable of the modified response context
+     */
+    post(context: ResponseContext): Promise<ResponseContext>;
+}
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/Cat.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/Cat.ts
new file mode 100644
index 000000000000..eb878d1537e4
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/Cat.ts
@@ -0,0 +1,43 @@
+/**
+ * Example
+ * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+ *
+ * OpenAPI spec version: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+import { CatAllOf } from './CatAllOf';
+import { HttpFile } from '../http/http';
+
+export class Cat {
+    'hunts'?: boolean;
+    'age'?: number;
+
+    static readonly discriminator: string | undefined = undefined;
+
+    static readonly attributeTypeMap: Array<{name: string, baseName: string, type: string, format: string}> = [
+        {
+            "name": "hunts",
+            "baseName": "hunts",
+            "type": "boolean",
+            "format": ""
+        },
+        {
+            "name": "age",
+            "baseName": "age",
+            "type": "number",
+            "format": ""
+        }    ];
+
+    static getAttributeTypeMap() {
+        return Cat.attributeTypeMap;
+    }
+    
+    public constructor() {
+    }
+}
+
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/CatAllOf.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/CatAllOf.ts
new file mode 100644
index 000000000000..f492b8a9474d
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/CatAllOf.ts
@@ -0,0 +1,42 @@
+/**
+ * Example
+ * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+ *
+ * OpenAPI spec version: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+import { HttpFile } from '../http/http';
+
+export class CatAllOf {
+    'hunts'?: boolean;
+    'age'?: number;
+
+    static readonly discriminator: string | undefined = undefined;
+
+    static readonly attributeTypeMap: Array<{name: string, baseName: string, type: string, format: string}> = [
+        {
+            "name": "hunts",
+            "baseName": "hunts",
+            "type": "boolean",
+            "format": ""
+        },
+        {
+            "name": "age",
+            "baseName": "age",
+            "type": "number",
+            "format": ""
+        }    ];
+
+    static getAttributeTypeMap() {
+        return CatAllOf.attributeTypeMap;
+    }
+    
+    public constructor() {
+    }
+}
+
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/Dog.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/Dog.ts
new file mode 100644
index 000000000000..456b63bd0388
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/Dog.ts
@@ -0,0 +1,46 @@
+/**
+ * Example
+ * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+ *
+ * OpenAPI spec version: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+import { DogAllOf } from './DogAllOf';
+import { HttpFile } from '../http/http';
+
+export class Dog {
+    'bark'?: boolean;
+    'breed'?: DogBreedEnum;
+
+    static readonly discriminator: string | undefined = undefined;
+
+    static readonly attributeTypeMap: Array<{name: string, baseName: string, type: string, format: string}> = [
+        {
+            "name": "bark",
+            "baseName": "bark",
+            "type": "boolean",
+            "format": ""
+        },
+        {
+            "name": "breed",
+            "baseName": "breed",
+            "type": "DogBreedEnum",
+            "format": ""
+        }    ];
+
+    static getAttributeTypeMap() {
+        return Dog.attributeTypeMap;
+    }
+    
+    public constructor() {
+    }
+}
+
+
+export type DogBreedEnum = "Dingo" | "Husky" | "Retriever" | "Shepherd" ;
+
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/DogAllOf.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/DogAllOf.ts
new file mode 100644
index 000000000000..75fb0ac2faea
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/DogAllOf.ts
@@ -0,0 +1,45 @@
+/**
+ * Example
+ * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+ *
+ * OpenAPI spec version: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+import { HttpFile } from '../http/http';
+
+export class DogAllOf {
+    'bark'?: boolean;
+    'breed'?: DogAllOfBreedEnum;
+
+    static readonly discriminator: string | undefined = undefined;
+
+    static readonly attributeTypeMap: Array<{name: string, baseName: string, type: string, format: string}> = [
+        {
+            "name": "bark",
+            "baseName": "bark",
+            "type": "boolean",
+            "format": ""
+        },
+        {
+            "name": "breed",
+            "baseName": "breed",
+            "type": "DogAllOfBreedEnum",
+            "format": ""
+        }    ];
+
+    static getAttributeTypeMap() {
+        return DogAllOf.attributeTypeMap;
+    }
+    
+    public constructor() {
+    }
+}
+
+
+export type DogAllOfBreedEnum = "Dingo" | "Husky" | "Retriever" | "Shepherd" ;
+
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/InlineObject.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/InlineObject.ts
new file mode 100644
index 000000000000..d6ffd66e6929
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/InlineObject.ts
@@ -0,0 +1,35 @@
+/**
+ * Example
+ * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+ *
+ * OpenAPI spec version: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+import { HttpFile } from '../http/http';
+
+export class InlineObject {
+    'file'?: any;
+
+    static readonly discriminator: string | undefined = undefined;
+
+    static readonly attributeTypeMap: Array<{name: string, baseName: string, type: string, format: string}> = [
+        {
+            "name": "file",
+            "baseName": "file",
+            "type": "any",
+            "format": ""
+        }    ];
+
+    static getAttributeTypeMap() {
+        return InlineObject.attributeTypeMap;
+    }
+    
+    public constructor() {
+    }
+}
+
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/ObjectSerializer.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/ObjectSerializer.ts
new file mode 100644
index 000000000000..70178da770e5
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/ObjectSerializer.ts
@@ -0,0 +1,238 @@
+export * from './Cat';
+export * from './CatAllOf';
+export * from './Dog';
+export * from './DogAllOf';
+export * from './InlineObject';
+export * from './PetByAge';
+export * from './PetByType';
+
+import { Cat } from './Cat';
+import { CatAllOf } from './CatAllOf';
+import { Dog , DogBreedEnum   } from './Dog';
+import { DogAllOf , DogAllOfBreedEnum   } from './DogAllOf';
+import { InlineObject } from './InlineObject';
+import { PetByAge } from './PetByAge';
+import { PetByType, PetByTypePetTypeEnum    } from './PetByType';
+
+/* tslint:disable:no-unused-variable */
+let primitives = [
+                    "string",
+                    "boolean",
+                    "double",
+                    "integer",
+                    "long",
+                    "float",
+                    "number",
+                    "any"
+                 ];
+
+const supportedMediaTypes: { [mediaType: string]: number } = {
+  "application/json": Infinity,
+  "application/octet-stream": 0
+}
+
+                 
+let enumsMap: Set<string> = new Set<string>([
+    "DogBreedEnum",
+    "DogAllOfBreedEnum",
+    "PetByTypePetTypeEnum",
+]);
+
+let typeMap: {[index: string]: any} = {
+    "Cat": Cat,
+    "CatAllOf": CatAllOf,
+    "Dog": Dog,
+    "DogAllOf": DogAllOf,
+    "InlineObject": InlineObject,
+    "PetByAge": PetByAge,
+    "PetByType": PetByType,
+}
+
+export class ObjectSerializer {
+    public static findCorrectType(data: any, expectedType: string) {
+        if (data == undefined) {
+            return expectedType;
+        } else if (primitives.indexOf(expectedType.toLowerCase()) !== -1) {
+            return expectedType;
+        } else if (expectedType === "Date") {
+            return expectedType;
+        } else {
+            if (enumsMap.has(expectedType)) {
+                return expectedType;
+            }
+
+            if (!typeMap[expectedType]) {
+                return expectedType; // w/e we don't know the type
+            }
+
+            // Check the discriminator
+            let discriminatorProperty = typeMap[expectedType].discriminator;
+            if (discriminatorProperty == null) {
+                return expectedType; // the type does not have a discriminator. use it.
+            } else {
+                if (data[discriminatorProperty]) {
+                    var discriminatorType = data[discriminatorProperty];
+                    if(typeMap[discriminatorType]){
+                        return discriminatorType; // use the type given in the discriminator
+                    } else {
+                        return expectedType; // discriminator did not map to a type
+                    }
+                } else {
+                    return expectedType; // discriminator was not present (or an empty string)
+                }
+            }
+        }
+    }
+
+    public static serialize(data: any, type: string, format: string) {
+        if (data == undefined) {
+            return data;
+        } else if (primitives.indexOf(type.toLowerCase()) !== -1) {
+            return data;
+        } else if (type.lastIndexOf("Array<", 0) === 0) { // string.startsWith pre es6
+            let subType: string = type.replace("Array<", ""); // Array<Type> => Type>
+            subType = subType.substring(0, subType.length - 1); // Type> => Type
+            let transformedData: any[] = [];
+            for (let index in data) {
+                let date = data[index];
+                transformedData.push(ObjectSerializer.serialize(date, subType, format));
+            }
+            return transformedData;
+        } else if (type === "Date") {
+            if (format == "date") {
+                let month = data.getMonth()+1
+                month = month < 10 ? "0" + month.toString() : month.toString()
+                let day = data.getDate();
+                day = day < 10 ? "0" + day.toString() : day.toString();
+
+                return data.getFullYear() + "-" + month + "-" + day;
+            } else {
+                return data.toISOString();
+            }
+        } else {
+            if (enumsMap.has(type)) {
+                return data;
+            }
+            if (!typeMap[type]) { // in case we dont know the type
+                return data;
+            }
+            
+            // Get the actual type of this object
+            type = this.findCorrectType(data, type);
+
+            // get the map for the correct type.
+            let attributeTypes = typeMap[type].getAttributeTypeMap();
+            let instance: {[index: string]: any} = {};
+            for (let index in attributeTypes) {
+                let attributeType = attributeTypes[index];
+                instance[attributeType.baseName] = ObjectSerializer.serialize(data[attributeType.name], attributeType.type, attributeType.format);
+            }
+            return instance;
+        }
+    }
+
+    public static deserialize(data: any, type: string, format: string) {
+        // polymorphism may change the actual type.
+        type = ObjectSerializer.findCorrectType(data, type);
+        if (data == undefined) {
+            return data;
+        } else if (primitives.indexOf(type.toLowerCase()) !== -1) {
+            return data;
+        } else if (type.lastIndexOf("Array<", 0) === 0) { // string.startsWith pre es6
+            let subType: string = type.replace("Array<", ""); // Array<Type> => Type>
+            subType = subType.substring(0, subType.length - 1); // Type> => Type
+            let transformedData: any[] = [];
+            for (let index in data) {
+                let date = data[index];
+                transformedData.push(ObjectSerializer.deserialize(date, subType, format));
+            }
+            return transformedData;
+        } else if (type === "Date") {
+            return new Date(data);
+        } else {
+            if (enumsMap.has(type)) {// is Enum
+                return data;
+            }
+
+            if (!typeMap[type]) { // dont know the type
+                return data;
+            }
+            let instance = new typeMap[type]();
+            let attributeTypes = typeMap[type].getAttributeTypeMap();
+            for (let index in attributeTypes) {
+                let attributeType = attributeTypes[index];
+                instance[attributeType.name] = ObjectSerializer.deserialize(data[attributeType.baseName], attributeType.type, attributeType.format);
+            }
+            return instance;
+        }
+    }
+
+
+    /**
+     * Normalize media type
+     *
+     * We currently do not handle any media types attributes, i.e. anything
+     * after a semicolon. All content is assumed to be UTF-8 compatible.
+     */
+    public static normalizeMediaType(mediaType: string | undefined): string | undefined {
+        if (mediaType === undefined) {
+            return undefined;
+        }
+        return mediaType.split(";")[0].trim().toLowerCase();
+    }
+
+    /**
+     * From a list of possible media types, choose the one we can handle best.
+     *
+     * The order of the given media types does not have any impact on the choice
+     * made.
+     */
+    public static getPreferredMediaType(mediaTypes: Array<string>): string {
+        /** According to OAS 3 we should default to json */
+        if (!mediaTypes) {
+            return "application/json";
+        }
+
+        const normalMediaTypes = mediaTypes.map(this.normalizeMediaType);
+        let selectedMediaType: string | undefined = undefined;
+        let selectedRank: number = -Infinity;
+        for (const mediaType of normalMediaTypes) {
+            if (supportedMediaTypes[mediaType!] > selectedRank) {
+                selectedMediaType = mediaType;
+                selectedRank = supportedMediaTypes[mediaType!];
+            }
+        }
+
+        if (selectedMediaType === undefined) {
+            throw new Error("None of the given media types are supported: " + mediaTypes.join(", "));
+        }
+
+        return selectedMediaType!;
+    }
+
+    /**
+     * Convert data to a string according the given media type
+     */
+    public static stringify(data: any, mediaType: string): string {
+        if (mediaType === "application/json") {
+            return JSON.stringify(data);
+        }
+
+        throw new Error("The mediaType " + mediaType + " is not supported by ObjectSerializer.stringify.");
+    }
+
+    /**
+     * Parse data from a string according to the given media type
+     */
+    public static parse(rawData: string, mediaType: string | undefined) {
+        if (mediaType === undefined) {
+            throw new Error("Cannot parse content. No Content-Type defined.");
+        }
+
+        if (mediaType === "application/json") {
+            return JSON.parse(rawData);
+        }
+
+        throw new Error("The mediaType " + mediaType + " is not supported by ObjectSerializer.parse.");
+    }
+}
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/PetByAge.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/PetByAge.ts
new file mode 100644
index 000000000000..bbd8a86a2666
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/PetByAge.ts
@@ -0,0 +1,42 @@
+/**
+ * Example
+ * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+ *
+ * OpenAPI spec version: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+import { HttpFile } from '../http/http';
+
+export class PetByAge {
+    'age': number;
+    'nickname'?: string;
+
+    static readonly discriminator: string | undefined = undefined;
+
+    static readonly attributeTypeMap: Array<{name: string, baseName: string, type: string, format: string}> = [
+        {
+            "name": "age",
+            "baseName": "age",
+            "type": "number",
+            "format": ""
+        },
+        {
+            "name": "nickname",
+            "baseName": "nickname",
+            "type": "string",
+            "format": ""
+        }    ];
+
+    static getAttributeTypeMap() {
+        return PetByAge.attributeTypeMap;
+    }
+    
+    public constructor() {
+    }
+}
+
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/PetByType.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/PetByType.ts
new file mode 100644
index 000000000000..2c8713e565af
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/PetByType.ts
@@ -0,0 +1,45 @@
+/**
+ * Example
+ * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+ *
+ * OpenAPI spec version: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+import { HttpFile } from '../http/http';
+
+export class PetByType {
+    'petType': PetByTypePetTypeEnum;
+    'hunts'?: boolean;
+
+    static readonly discriminator: string | undefined = undefined;
+
+    static readonly attributeTypeMap: Array<{name: string, baseName: string, type: string, format: string}> = [
+        {
+            "name": "petType",
+            "baseName": "pet_type",
+            "type": "PetByTypePetTypeEnum",
+            "format": ""
+        },
+        {
+            "name": "hunts",
+            "baseName": "hunts",
+            "type": "boolean",
+            "format": ""
+        }    ];
+
+    static getAttributeTypeMap() {
+        return PetByType.attributeTypeMap;
+    }
+    
+    public constructor() {
+    }
+}
+
+
+export type PetByTypePetTypeEnum = "Cat" | "Dog" ;
+
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/all.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/all.ts
new file mode 100644
index 000000000000..851c461ecf68
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/models/all.ts
@@ -0,0 +1,7 @@
+export * from './Cat'
+export * from './CatAllOf'
+export * from './Dog'
+export * from './DogAllOf'
+export * from './InlineObject'
+export * from './PetByAge'
+export * from './PetByType'
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/package.json b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/package.json
new file mode 100644
index 000000000000..1605e85eb131
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/package.json
@@ -0,0 +1,27 @@
+{
+  "name": "ts-petstore-client",
+  "version": "1.0.0",
+  "description": "OpenAPI client for ts-petstore-client",
+  "author": "OpenAPI-Generator Contributors",
+  "keywords": [
+    "fetch",
+    "typescript",
+    "openapi-client",
+    "openapi-generator"
+  ],
+  "license": "Unlicense",
+  "main": "./dist/index.js",
+  "typings": "./dist/index.d.ts",
+  "scripts": {
+    "build": "tsc",
+    "prepare": "npm run build"
+  },
+  "dependencies": {
+    "whatwg-fetch": "^3.0.0",
+    "es6-promise": "^4.2.4",
+    "url-parse": "^1.4.3"
+  },
+  "devDependencies": {
+    "typescript": "^3.9.3"
+  }
+}
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/rxjsStub.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/rxjsStub.ts
new file mode 100644
index 000000000000..4c73715a2486
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/rxjsStub.ts
@@ -0,0 +1,27 @@
+export class Observable<T> {
+  constructor(private promise: Promise<T>) {}
+
+  toPromise() {
+    return this.promise;
+  }
+
+  pipe<S>(callback: (value: T) => S | Promise<S>): Observable<S> {
+    return new Observable(this.promise.then(callback));
+  }
+}
+
+export function from<T>(promise: Promise<any>) {
+  return new Observable(promise);
+}
+
+export function of<T>(value: T) {
+  return new Observable<T>(Promise.resolve(value));
+}
+
+export function mergeMap<T, S>(callback: (value: T) => Observable<S>) {
+  return (value: T) => callback(value).toPromise();
+}
+
+export function map(callback: any) {
+  return callback;
+}
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/servers.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/servers.ts
new file mode 100644
index 000000000000..f1bd953bf872
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/servers.ts
@@ -0,0 +1,53 @@
+import { RequestContext, HttpMethod } from "./http/http";
+
+export interface BaseServerConfiguration {
+    makeRequestContext(endpoint: string, httpMethod: HttpMethod): RequestContext;
+}
+
+/**
+ *
+ * Represents the configuration of a server including its
+ * url template and variable configuration based on the url.
+ *
+ */
+export class ServerConfiguration<T extends { [key: string]: string }> implements BaseServerConfiguration {
+    public constructor(private url: string, private variableConfiguration: T) {}
+
+    /**
+     * Sets the value of the variables of this server.
+     *
+     * @param variableConfiguration a partial variable configuration for the variables contained in the url
+     */
+    public setVariables(variableConfiguration: Partial<T>) {
+        Object.assign(this.variableConfiguration, variableConfiguration);
+    }
+
+    public getConfiguration(): T {
+        return this.variableConfiguration
+    }
+
+    private getUrl() {
+        let replacedUrl = this.url;
+        for (const key in this.variableConfiguration) {
+            var re = new RegExp("{" + key + "}","g");
+            replacedUrl = replacedUrl.replace(re, this.variableConfiguration[key]);
+        }
+        return replacedUrl
+    }
+
+    /**
+     * Creates a new request context for this server using the url with variables
+     * replaced with their respective values and the endpoint of the request appended.
+     *
+     * @param endpoint the endpoint to be queried on the server
+     * @param httpMethod httpMethod to be used
+     *
+     */
+    public makeRequestContext(endpoint: string, httpMethod: HttpMethod): RequestContext {
+        return new RequestContext(this.getUrl() + endpoint, httpMethod);
+    }
+}
+
+export const server1 = new ServerConfiguration<{  }>("http://api.example.xyz/v1", {  })
+
+export const servers = [server1];
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/tsconfig.json b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/tsconfig.json
new file mode 100644
index 000000000000..ce51978eb866
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/tsconfig.json
@@ -0,0 +1,29 @@
+{
+  "compilerOptions": {
+    "strict": true,
+    /* Basic Options */
+    "target": "es5",
+    "module": "commonjs",
+    "moduleResolution": "node",
+    "declaration": true,
+ 
+    /* Additional Checks */
+     "noUnusedLocals": false,                /* Report errors on unused locals. */ // TODO: reenable (unused imports!)
+     "noUnusedParameters": false,            /* Report errors on unused parameters. */ // TODO: set to true again
+     "noImplicitReturns": true,             /* Report error when not all code paths in function return a value. */
+     "noFallthroughCasesInSwitch": true,    /* Report errors for fallthrough cases in switch statement. */
+
+    "removeComments": true,
+    "sourceMap": true,
+    "outDir": "./dist",
+    "noLib": false,
+    "lib": [ "es6", "dom" ],
+  },
+  "exclude": [
+    "dist",
+    "node_modules"
+  ],
+  "filesGlob": [
+    "./**/*.ts",
+  ]
+}
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/types/ObjectParamAPI.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/types/ObjectParamAPI.ts
new file mode 100644
index 000000000000..d94a613229e6
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/types/ObjectParamAPI.ts
@@ -0,0 +1,71 @@
+import { ResponseContext, RequestContext, HttpFile } from '../http/http';
+import * as models from '../models/all';
+import { Configuration} from '../configuration'
+
+import { Cat } from '../models/Cat';
+import { CatAllOf } from '../models/CatAllOf';
+import { Dog } from '../models/Dog';
+import { DogAllOf } from '../models/DogAllOf';
+import { InlineObject } from '../models/InlineObject';
+import { PetByAge } from '../models/PetByAge';
+import { PetByType } from '../models/PetByType';
+
+import { ObservableDefaultApi } from "./ObservableAPI";
+import { DefaultApiRequestFactory, DefaultApiResponseProcessor} from "../apis/DefaultApi";
+
+export interface DefaultApiFilePostRequest {
+    /**
+     * 
+     * @type InlineObject
+     * @memberof DefaultApifilePost
+     */
+    inlineObject?: InlineObject
+}
+
+export interface DefaultApiPetsFilteredPatchRequest {
+    /**
+     * 
+     * @type PetByAge | PetByType
+     * @memberof DefaultApipetsFilteredPatch
+     */
+    petByAgePetByType?: PetByAge | PetByType
+}
+
+export interface DefaultApiPetsPatchRequest {
+    /**
+     * 
+     * @type Cat | Dog
+     * @memberof DefaultApipetsPatch
+     */
+    catDog?: Cat | Dog
+}
+
+export class ObjectDefaultApi {
+    private api: ObservableDefaultApi
+
+    public constructor(configuration: Configuration, requestFactory?: DefaultApiRequestFactory, responseProcessor?: DefaultApiResponseProcessor) {
+        this.api = new ObservableDefaultApi(configuration, requestFactory, responseProcessor);
+    }
+
+    /**
+     * @param param the request object
+     */
+    public filePost(param: DefaultApiFilePostRequest, options?: Configuration): Promise<void> {
+        return this.api.filePost(param.inlineObject,  options).toPromise();
+    }
+
+    /**
+     * @param param the request object
+     */
+    public petsFilteredPatch(param: DefaultApiPetsFilteredPatchRequest, options?: Configuration): Promise<void> {
+        return this.api.petsFilteredPatch(param.petByAgePetByType,  options).toPromise();
+    }
+
+    /**
+     * @param param the request object
+     */
+    public petsPatch(param: DefaultApiPetsPatchRequest, options?: Configuration): Promise<void> {
+        return this.api.petsPatch(param.catDog,  options).toPromise();
+    }
+
+}
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/types/ObservableAPI.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/types/ObservableAPI.ts
new file mode 100644
index 000000000000..f9dd96c51981
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/types/ObservableAPI.ts
@@ -0,0 +1,96 @@
+import { ResponseContext, RequestContext, HttpFile } from '../http/http';
+import * as models from '../models/all';
+import { Configuration} from '../configuration'
+import { Observable, of, from } from '../rxjsStub';
+import {mergeMap, map} from  '../rxjsStub';
+import { Cat } from '../models/Cat';
+import { CatAllOf } from '../models/CatAllOf';
+import { Dog } from '../models/Dog';
+import { DogAllOf } from '../models/DogAllOf';
+import { InlineObject } from '../models/InlineObject';
+import { PetByAge } from '../models/PetByAge';
+import { PetByType } from '../models/PetByType';
+
+import { DefaultApiRequestFactory, DefaultApiResponseProcessor} from "../apis/DefaultApi";
+export class ObservableDefaultApi {
+    private requestFactory: DefaultApiRequestFactory;
+    private responseProcessor: DefaultApiResponseProcessor;
+    private configuration: Configuration;
+
+    public constructor(
+        configuration: Configuration,
+        requestFactory?: DefaultApiRequestFactory,
+        responseProcessor?: DefaultApiResponseProcessor
+    ) {
+        this.configuration = configuration;
+        this.requestFactory = requestFactory || new DefaultApiRequestFactory(configuration);
+        this.responseProcessor = responseProcessor || new DefaultApiResponseProcessor();
+    }
+
+    /**
+     * @param inlineObject 
+     */
+    public filePost(inlineObject?: InlineObject, _options?: Configuration): Observable<void> {
+        const requestContextPromise = this.requestFactory.filePost(inlineObject, _options);
+
+        // build promise chain
+        let middlewarePreObservable = from<RequestContext>(requestContextPromise);
+        for (let middleware of this.configuration.middleware) {
+            middlewarePreObservable = middlewarePreObservable.pipe(mergeMap((ctx: RequestContext) => middleware.pre(ctx)));
+        }
+
+        return middlewarePreObservable.pipe(mergeMap((ctx: RequestContext) => this.configuration.httpApi.send(ctx))).
+            pipe(mergeMap((response: ResponseContext) => {
+                let middlewarePostObservable = of(response);
+                for (let middleware of this.configuration.middleware) {
+                    middlewarePostObservable = middlewarePostObservable.pipe(mergeMap((rsp: ResponseContext) => middleware.post(rsp)));
+                }
+                return middlewarePostObservable.pipe(map((rsp: ResponseContext) => this.responseProcessor.filePost(rsp)));
+            }));
+    }
+ 
+    /**
+     * @param petByAgePetByType 
+     */
+    public petsFilteredPatch(petByAgePetByType?: PetByAge | PetByType, _options?: Configuration): Observable<void> {
+        const requestContextPromise = this.requestFactory.petsFilteredPatch(petByAgePetByType, _options);
+
+        // build promise chain
+        let middlewarePreObservable = from<RequestContext>(requestContextPromise);
+        for (let middleware of this.configuration.middleware) {
+            middlewarePreObservable = middlewarePreObservable.pipe(mergeMap((ctx: RequestContext) => middleware.pre(ctx)));
+        }
+
+        return middlewarePreObservable.pipe(mergeMap((ctx: RequestContext) => this.configuration.httpApi.send(ctx))).
+            pipe(mergeMap((response: ResponseContext) => {
+                let middlewarePostObservable = of(response);
+                for (let middleware of this.configuration.middleware) {
+                    middlewarePostObservable = middlewarePostObservable.pipe(mergeMap((rsp: ResponseContext) => middleware.post(rsp)));
+                }
+                return middlewarePostObservable.pipe(map((rsp: ResponseContext) => this.responseProcessor.petsFilteredPatch(rsp)));
+            }));
+    }
+ 
+    /**
+     * @param catDog 
+     */
+    public petsPatch(catDog?: Cat | Dog, _options?: Configuration): Observable<void> {
+        const requestContextPromise = this.requestFactory.petsPatch(catDog, _options);
+
+        // build promise chain
+        let middlewarePreObservable = from<RequestContext>(requestContextPromise);
+        for (let middleware of this.configuration.middleware) {
+            middlewarePreObservable = middlewarePreObservable.pipe(mergeMap((ctx: RequestContext) => middleware.pre(ctx)));
+        }
+
+        return middlewarePreObservable.pipe(mergeMap((ctx: RequestContext) => this.configuration.httpApi.send(ctx))).
+            pipe(mergeMap((response: ResponseContext) => {
+                let middlewarePostObservable = of(response);
+                for (let middleware of this.configuration.middleware) {
+                    middlewarePostObservable = middlewarePostObservable.pipe(mergeMap((rsp: ResponseContext) => middleware.post(rsp)));
+                }
+                return middlewarePostObservable.pipe(map((rsp: ResponseContext) => this.responseProcessor.petsPatch(rsp)));
+            }));
+    }
+ 
+}
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/types/PromiseAPI.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/types/PromiseAPI.ts
new file mode 100644
index 000000000000..4939db8127b3
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/types/PromiseAPI.ts
@@ -0,0 +1,54 @@
+import { ResponseContext, RequestContext, HttpFile } from '../http/http';
+import * as models from '../models/all';
+import { Configuration} from '../configuration'
+
+import { Cat } from '../models/Cat';
+import { CatAllOf } from '../models/CatAllOf';
+import { Dog } from '../models/Dog';
+import { DogAllOf } from '../models/DogAllOf';
+import { InlineObject } from '../models/InlineObject';
+import { PetByAge } from '../models/PetByAge';
+import { PetByType } from '../models/PetByType';
+import { ObservableDefaultApi } from './ObservableAPI';
+
+import { DefaultApiRequestFactory, DefaultApiResponseProcessor} from "../apis/DefaultApi";
+export class PromiseDefaultApi {
+    private api: ObservableDefaultApi
+
+    public constructor(
+        configuration: Configuration,
+        requestFactory?: DefaultApiRequestFactory,
+        responseProcessor?: DefaultApiResponseProcessor
+    ) {
+        this.api = new ObservableDefaultApi(configuration, requestFactory, responseProcessor);
+    }
+
+    /**
+     * @param inlineObject 
+     */
+    public filePost(inlineObject?: InlineObject, _options?: Configuration): Promise<void> {
+        const result = this.api.filePost(inlineObject, _options);
+        return result.toPromise();
+    }
+
+    /**
+     * @param petByAgePetByType 
+     */
+    public petsFilteredPatch(petByAgePetByType?: PetByAge | PetByType, _options?: Configuration): Promise<void> {
+        const result = this.api.petsFilteredPatch(petByAgePetByType, _options);
+        return result.toPromise();
+    }
+
+    /**
+     * @param catDog 
+     */
+    public petsPatch(catDog?: Cat | Dog, _options?: Configuration): Promise<void> {
+        const result = this.api.petsPatch(catDog, _options);
+        return result.toPromise();
+    }
+
+
+}
+
+
+
diff --git a/samples/openapi3/client/petstore/typescript/builds/composed-schemas/util.ts b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/util.ts
new file mode 100644
index 000000000000..07317f5828bc
--- /dev/null
+++ b/samples/openapi3/client/petstore/typescript/builds/composed-schemas/util.ts
@@ -0,0 +1,28 @@
+/**
+ * Returns if a specific http code is in a given code range
+ * where the code range is defined as a combination of digits 
+ * and "X" (the letter X) with a length of 3
+ *
+ * @param codeRange string with length 3 consisting of digits and "X" (the letter X)
+ * @param code the http status code to be checked against the code range
+ */
+export function isCodeInRange(codeRange: string, code: number): boolean {
+    // This is how the default value is encoded in OAG
+    if (codeRange === "0") {
+        return true;
+    }
+    if (codeRange == code.toString()) {
+        return true;
+    } else {
+        const codeString = code.toString();
+        if (codeString.length != codeRange.length) {
+            return false;
+        }
+        for (let i = 0; i < codeString.length; i++) {
+            if (codeRange.charAt(i) != "X" && codeRange.charAt(i) != codeString.charAt(i)) {
+                return false;
+            }
+        }
+        return true;
+    }
+}