diff --git a/README.md b/README.md
index 6af029f36..6b3e0c19b 100644
--- a/README.md
+++ b/README.md
@@ -10,11 +10,15 @@
 
 🚀 Convert [OpenAPI 3.0][openapi3] and [2.0 (Swagger)][openapi2] schemas to TypeScript interfaces using Node.js.
 
-💅 The output is prettified with [Prettier][prettier] (and can be customized!).
+**Features**
 
-👉 Works for both local and remote resources (filesystem and HTTP).
+- Convert [Open API 3.x][openapi3] and [Swagger 2.x][openapi2] to TypeScript types
+- Load schemas either from local `.yaml` or `.json` files, or from a remote URL (simple authentication supported with the `--auth` flag)
+- Supports remote `$ref`s using [json-schema-ref-parser][json-schema-ref-parser]
+- Formats output using [Prettier][prettier]
+- Uses the latest TypeScript 4.0 syntax
 
-View examples:
+**Examples**
 
 - [Stripe, OpenAPI 2.0](./examples/stripe-openapi2.ts)
 - [Stripe, OpenAPI 3.0](./examples/stripe-openapi3.ts)
@@ -106,19 +110,24 @@ npm i --save-dev openapi-typescript
 ```
 
 ```js
-const { readFileSync } = require("fs");
+const fs = require("fs");
 const openapiTS = require("openapi-typescript").default;
 
-const input = JSON.parse(readFileSync("spec.json", "utf8")); // Input can be any JS object (OpenAPI format)
-const output = openapiTS(input); // Outputs TypeScript defs as a string (to be parsed, or written to a file)
+// option 1: load [object] as schema (JSON only)
+const schema = await fs.promises.readFile("spec.json", "utf8") // must be OpenAPI JSON
+const output = await openapiTS(JSON.parse(schema));
+
+// option 2: load [string] as local file (YAML or JSON; released in v3.3)
+const localPath = path.join(__dirname, 'spec.yaml'); // may be YAML or JSON format
+const output = await openapiTS(localPath);
+
+// option 3: load [string] as remote URL (YAML or JSON; released in v3.3)
+const output = await openapiTS('https://myurl.com/v1/openapi.yaml');
 ```
 
-The Node API is a bit more flexible: it will only take a JS object as input (OpenAPI format), and return a string of TS
-definitions. This lets you pull from any source (a Swagger server, local files, etc.), and similarly lets you parse,
-post-process, and save the output anywhere.
+The Node API may be useful if dealing with dynamically-created schemas, or you’re using within context of a larger application. Pass in either a JSON-friendly object to load a schema from memory, or a string to load a schema from a local file or remote URL (it will load the file quickly using built-in Node methods). Note that a YAML string isn’t supported in the Node.js API; either use the CLI or convert to JSON using [js-yaml][js-yaml] first.
 
-If your specs are in YAML, you’ll have to convert them to JS objects using a library such as [js-yaml][js-yaml]. If
-you’re batching large folders of specs, [glob][glob] may also come in handy.
+⚠️ As of `v3.3`, this is an async function.
 
 #### Custom Formatter
 
@@ -164,6 +173,7 @@ encouraged but not required.
 
 [glob]: https://www.npmjs.com/package/glob
 [js-yaml]: https://www.npmjs.com/package/js-yaml
+[json-schema-ref-parser]: https://github.com/APIDevTools/json-schema-ref-parser
 [namespace]: https://www.typescriptlang.org/docs/handbook/namespaces.html
 [npm-run-all]: https://www.npmjs.com/package/npm-run-all
 [openapi-format]: https://swagger.io/specification/#data-types
diff --git a/bin/cli.js b/bin/cli.js
index f3ed4c08a..33be91a70 100755
--- a/bin/cli.js
+++ b/bin/cli.js
@@ -6,7 +6,6 @@ const path = require("path");
 const meow = require("meow");
 const glob = require("tiny-glob");
 const { default: openapiTS } = require("../dist/cjs/index.js");
-const { loadSpec } = require("./loaders");
 
 const cli = meow(
   `Usage
@@ -70,25 +69,15 @@ function errorAndExit(errorMessage) {
 async function generateSchema(pathToSpec) {
   const output = cli.flags.output ? OUTPUT_FILE : OUTPUT_STDOUT; // FILE or STDOUT
 
-  // load spec
-  let spec = undefined;
-  try {
-    spec = await loadSpec(pathToSpec, {
-      auth: cli.flags.auth,
-      log: output !== OUTPUT_STDOUT,
-    });
-  } catch (err) {
-    errorAndExit(`❌ ${err}`);
-  }
-
   // generate schema
-  const result = openapiTS(spec, {
-    auth: cli.flags.auth,
+  const result = await openapiTS(pathToSpec, {
     additionalProperties: cli.flags.additionalProperties,
-    immutableTypes: cli.flags.immutableTypes,
+    auth: cli.flags.auth,
     defaultNonNullable: cli.flags.defaultNonNullable,
+    immutableTypes: cli.flags.immutableTypes,
     prettierConfig: cli.flags.prettierConfig,
     rawSchema: cli.flags.rawSchema,
+    silent: output === OUTPUT_STDOUT,
     version: cli.flags.version,
   });
 
@@ -108,13 +97,14 @@ async function generateSchema(pathToSpec) {
     console.log(green(`🚀 ${pathToSpec} -> ${bold(outputFile)} [${time}ms]`));
   } else {
     process.stdout.write(result);
+    // if stdout, (still) don’t log anything to console!
   }
 
   return result;
 }
 
 async function main() {
-  const output = cli.flags.output ? OUTPUT_FILE : OUTPUT_STDOUT; // FILE or STDOUT
+  let output = cli.flags.output ? OUTPUT_FILE : OUTPUT_STDOUT; // FILE or STDOUT
   const pathToSpec = cli.input[0];
 
   if (output === OUTPUT_FILE) {
@@ -148,7 +138,7 @@ async function main() {
     errorAndExit(`❌ Expected directory for --output if using glob patterns. Received "${cli.flags.output}".`);
   }
 
-  // generate schema(s)
+  // generate schema(s) in parallel
   await Promise.all(
     inputSpecPaths.map(async (specPath) => {
       if (cli.flags.output !== "." && output === OUTPUT_FILE) {
diff --git a/bin/loaders/index.js b/bin/loaders/index.js
deleted file mode 100644
index ef6a64308..000000000
--- a/bin/loaders/index.js
+++ /dev/null
@@ -1,69 +0,0 @@
-const mime = require("mime");
-const yaml = require("js-yaml");
-const { bold, yellow } = require("kleur");
-
-const loadFromFs = require("./loadFromFs");
-const loadFromHttp = require("./loadFromHttp");
-
-async function load(pathToSpec, { auth }) {
-  // option 1: remote URL
-  if (/^https?:\/\//.test(pathToSpec)) {
-    try {
-      return loadFromHttp(pathToSpec, { auth });
-    } catch (e) {
-      if (e.code === "ENOTFOUND") {
-        throw new Error(
-          `The URL ${pathToSpec} could not be reached. Ensure the URL is correct, that you're connected to the internet and that the URL is reachable via a browser.`
-        );
-      }
-      throw e;
-    }
-  }
-
-  // option 2: local file
-  return {
-    body: loadFromFs(pathToSpec),
-    contentType: mime.getType(pathToSpec),
-  };
-}
-
-async function loadSpec(pathToSpec, { auth, log = true }) {
-  if (log === true) {
-    console.log(yellow(`🔭 Loading spec from ${bold(pathToSpec)}…`)); // only log if not writing to stdout
-  }
-
-  const { body, contentType } = await load(pathToSpec, { auth });
-
-  switch (contentType) {
-    case "application/openapi+yaml":
-    case "text/yaml": {
-      try {
-        return yaml.load(body);
-      } catch (err) {
-        throw new Error(`YAML: ${err.toString()}`);
-      }
-    }
-    case "application/json":
-    case "application/json5":
-    case "application/openapi+json": {
-      try {
-        return JSON.parse(body);
-      } catch (err) {
-        throw new Error(`JSON: ${err.toString()}`);
-      }
-    }
-    default: {
-      try {
-        return JSON.parse(body); // unknown attempt 1: JSON
-      } catch (err1) {
-        try {
-          return yaml.load(body); // unknown attempt 2: YAML
-        } catch (err2) {
-          // give up: unknown type
-          throw new Error(`Unknown format${contentType ? `: "${contentType}"` : ""}. Only YAML or JSON supported.`);
-        }
-      }
-    }
-  }
-}
-exports.loadSpec = loadSpec;
diff --git a/bin/loaders/loadFromFs.js b/bin/loaders/loadFromFs.js
deleted file mode 100644
index 0ac58ef4b..000000000
--- a/bin/loaders/loadFromFs.js
+++ /dev/null
@@ -1,14 +0,0 @@
-const fs = require("fs");
-const path = require("path");
-
-function loadFromFs(pathToSpec) {
-  const pathname = path.resolve(process.cwd(), pathToSpec);
-  const pathExists = fs.existsSync(pathname);
-
-  if (!pathExists) {
-    throw new Error(`Cannot find spec under the following path: ${pathname}`);
-  }
-
-  return fs.readFileSync(pathname, "utf8");
-}
-module.exports = loadFromFs;
diff --git a/bin/loaders/loadFromHttp.js b/bin/loaders/loadFromHttp.js
deleted file mode 100644
index e0be1b3ca..000000000
--- a/bin/loaders/loadFromHttp.js
+++ /dev/null
@@ -1,57 +0,0 @@
-const http = require("http");
-const https = require("https");
-const { parse } = require("url");
-
-// config
-const MAX_REDIRECT_COUNT = 10;
-
-function fetch(url, opts, { redirectCount = 0 } = {}) {
-  return new Promise((resolve, reject) => {
-    const { protocol } = parse(url);
-
-    if (protocol !== "http:" && protocol !== "https:") {
-      throw new Error(`Unsupported protocol: "${protocol}". URL must start with "http://" or "https://".`);
-    }
-
-    const fetchMethod = protocol === "https:" ? https : http;
-    const req = fetchMethod.request(url, opts, (res) => {
-      let rawData = "";
-      res.setEncoding("utf8");
-      res.on("data", (chunk) => {
-        rawData += chunk;
-      });
-      res.on("end", () => {
-        // 2xx: OK
-        if (res.statusCode >= 200 && res.statusCode < 300) {
-          return resolve({
-            body: rawData,
-            contentType: res.headers["content-type"].split(";")[0].trim(),
-          });
-        }
-
-        // 3xx: follow redirect (if given)
-        if (res.statusCode >= 300 && res.headers.location) {
-          redirectCount += 1;
-          if (redirectCount >= MAX_REDIRECT_COUNT) {
-            reject(`Max redirects exceeded`);
-            return;
-          }
-          console.log(`🚥 Redirecting to ${res.headers.location}…`);
-          return fetch(res.headers.location, opts).then(resolve);
-        }
-
-        // everything else: throw
-        return reject(rawData || `${res.statusCode} ${res.statusMessage}`);
-      });
-    });
-    req.on("error", (err) => {
-      reject(err);
-    });
-    req.end();
-  });
-}
-
-function loadFromHttp(pathToSpec, { auth }) {
-  return fetch(pathToSpec, { method: "GET", auth });
-}
-module.exports = loadFromHttp;
diff --git a/package-lock.json b/package-lock.json
index 52bb8e37d..b94debb13 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -13,6 +13,7 @@
         "kleur": "^4.1.4",
         "meow": "^9.0.0",
         "mime": "^2.5.2",
+        "node-fetch": "^2.6.1",
         "prettier": "^2.3.0",
         "tiny-glob": "^0.2.9"
       },
@@ -20,12 +21,14 @@
         "openapi-typescript": "bin/cli.js"
       },
       "devDependencies": {
-        "@types/jest": "^26.0.14",
-        "@types/js-yaml": "^4.0.0",
-        "@typescript-eslint/eslint-plugin": "^4.26.0",
-        "@typescript-eslint/parser": "^4.26.0",
-        "codecov": "^3.8.1",
-        "eslint": "^7.26.0",
+        "@types/jest": "^26.0.23",
+        "@types/js-yaml": "^4.0.1",
+        "@types/mime": "^2.0.3",
+        "@types/node-fetch": "^2.5.10",
+        "@typescript-eslint/eslint-plugin": "^4.25.0",
+        "@typescript-eslint/parser": "^4.25.0",
+        "codecov": "^3.8.2",
+        "eslint": "^7.27.0",
         "eslint-config-prettier": "^8.3.0",
         "eslint-plugin-prettier": "^3.4.0",
         "jest": "^27.0.3",
@@ -1241,6 +1244,12 @@
       "integrity": "sha512-cxWFQVseBm6O9Gbw1IWb8r6OS4OhSt3hPZLkFApLjM8TEXROBuQGLAH2i2gZpcXdLBIrpXuTDhH7Vbm1iXmNGA==",
       "dev": true
     },
+    "node_modules/@types/mime": {
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/@types/mime/-/mime-2.0.3.tgz",
+      "integrity": "sha512-Jus9s4CDbqwocc5pOAnh8ShfrnMcPHuJYzVcSUU7lrh8Ni5HuIqX3oilL86p3dlTrk0LzHRCgA/GQ7uNCw6l2Q==",
+      "dev": true
+    },
     "node_modules/@types/minimist": {
       "version": "1.2.1",
       "resolved": "https://registry.npmjs.org/@types/minimist/-/minimist-1.2.1.tgz",
@@ -1252,6 +1261,16 @@
       "integrity": "sha512-z/5Yd59dCKI5kbxauAJgw6dLPzW+TNOItNE00PkpzNwUIEwdj/Lsqwq94H5DdYBX7C13aRA0CY32BK76+neEUA==",
       "dev": true
     },
+    "node_modules/@types/node-fetch": {
+      "version": "2.5.10",
+      "resolved": "https://registry.npmjs.org/@types/node-fetch/-/node-fetch-2.5.10.tgz",
+      "integrity": "sha512-IpkX0AasN44hgEad0gEF/V6EgR5n69VEqPEgnmoM8GsIGro3PowbWs4tR6IhxUTyPLpOn+fiGG6nrQhcmoCuIQ==",
+      "dev": true,
+      "dependencies": {
+        "@types/node": "*",
+        "form-data": "^3.0.0"
+      }
+    },
     "node_modules/@types/normalize-package-data": {
       "version": "2.4.0",
       "resolved": "https://registry.npmjs.org/@types/normalize-package-data/-/normalize-package-data-2.4.0.tgz",
@@ -2393,9 +2412,9 @@
       }
     },
     "node_modules/eslint": {
-      "version": "7.26.0",
-      "resolved": "https://registry.npmjs.org/eslint/-/eslint-7.26.0.tgz",
-      "integrity": "sha512-4R1ieRf52/izcZE7AlLy56uIHHDLT74Yzz2Iv2l6kDaYvEu9x+wMB5dZArVL8SYGXSYV2YAg70FcW5Y5nGGNIg==",
+      "version": "7.27.0",
+      "resolved": "https://registry.npmjs.org/eslint/-/eslint-7.27.0.tgz",
+      "integrity": "sha512-JZuR6La2ZF0UD384lcbnd0Cgg6QJjiCwhMD6eU4h/VGPcVGwawNNzKU41tgokGXnfjOOyI6QIffthhJTPzzuRA==",
       "dev": true,
       "dependencies": {
         "@babel/code-frame": "7.12.11",
@@ -2406,12 +2425,14 @@
         "debug": "^4.0.1",
         "doctrine": "^3.0.0",
         "enquirer": "^2.3.5",
+        "escape-string-regexp": "^4.0.0",
         "eslint-scope": "^5.1.1",
         "eslint-utils": "^2.1.0",
         "eslint-visitor-keys": "^2.0.0",
         "espree": "^7.3.1",
         "esquery": "^1.4.0",
         "esutils": "^2.0.2",
+        "fast-deep-equal": "^3.1.3",
         "file-entry-cache": "^6.0.1",
         "functional-red-black-tree": "^1.0.1",
         "glob-parent": "^5.0.0",
@@ -2423,7 +2444,7 @@
         "js-yaml": "^3.13.1",
         "json-stable-stringify-without-jsonify": "^1.0.1",
         "levn": "^0.4.1",
-        "lodash": "^4.17.21",
+        "lodash.merge": "^4.6.2",
         "minimatch": "^3.0.4",
         "natural-compare": "^1.4.0",
         "optionator": "^0.9.1",
@@ -2432,7 +2453,7 @@
         "semver": "^7.2.1",
         "strip-ansi": "^6.0.0",
         "strip-json-comments": "^3.1.0",
-        "table": "^6.0.4",
+        "table": "^6.0.9",
         "text-table": "^0.2.0",
         "v8-compile-cache": "^2.0.3"
       },
@@ -2531,6 +2552,18 @@
         "@babel/highlight": "^7.10.4"
       }
     },
+    "node_modules/eslint/node_modules/escape-string-regexp": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/escape-string-regexp/-/escape-string-regexp-4.0.0.tgz",
+      "integrity": "sha512-TtpcNJ3XAzx3Gq8sWRzJaVajRs0uVxA2YAkdb1jm2YkPz4G6egUFAyA3n5vtEIZefPk5Wa4UXbKuS5fKkJWdgA==",
+      "dev": true,
+      "engines": {
+        "node": ">=10"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/eslint/node_modules/globals": {
       "version": "13.6.0",
       "resolved": "https://registry.npmjs.org/globals/-/globals-13.6.0.tgz",
@@ -5115,6 +5148,24 @@
       "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==",
       "dev": true
     },
+    "node_modules/lodash.clonedeep": {
+      "version": "4.5.0",
+      "resolved": "https://registry.npmjs.org/lodash.clonedeep/-/lodash.clonedeep-4.5.0.tgz",
+      "integrity": "sha1-4j8/nE+Pvd6HJSnBBxhXoIblzO8=",
+      "dev": true
+    },
+    "node_modules/lodash.merge": {
+      "version": "4.6.2",
+      "resolved": "https://registry.npmjs.org/lodash.merge/-/lodash.merge-4.6.2.tgz",
+      "integrity": "sha512-0KpjqXRVvrYyCsX1swR/XTK0va6VQkQM6MNo7PqW77ByjAhoARA8EfrP1N4+KlKj8YS0ZUCtRT/YUuhyYDujIQ==",
+      "dev": true
+    },
+    "node_modules/lodash.truncate": {
+      "version": "4.4.2",
+      "resolved": "https://registry.npmjs.org/lodash.truncate/-/lodash.truncate-4.4.2.tgz",
+      "integrity": "sha1-WjUNoLERO4N+z//VgSy+WNbq4ZM=",
+      "dev": true
+    },
     "node_modules/lru-cache": {
       "version": "6.0.0",
       "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-6.0.0.tgz",
@@ -5327,7 +5378,6 @@
       "version": "2.6.1",
       "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-2.6.1.tgz",
       "integrity": "sha512-V4aYg89jEoVRxRb2fJdAg8FHvI7cEyYdVAh94HH0UIK8oJxUfkjlDQN9RbMx+bEjP7+ggMiFRprSti032Oipxw==",
-      "dev": true,
       "engines": {
         "node": "4.x || >=6.0.0"
       }
@@ -5987,6 +6037,23 @@
         "node": ">=8"
       }
     },
+    "node_modules/slice-ansi": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/slice-ansi/-/slice-ansi-4.0.0.tgz",
+      "integrity": "sha512-qMCMfhY040cVHT43K9BFygqYbUPFZKHOg7K73mtTWJRb8pyP3fzf4Ixd5SzdEJQ6MRUg/WBnOLxghZtKKurENQ==",
+      "dev": true,
+      "dependencies": {
+        "ansi-styles": "^4.0.0",
+        "astral-regex": "^2.0.0",
+        "is-fullwidth-code-point": "^3.0.0"
+      },
+      "engines": {
+        "node": ">=10"
+      },
+      "funding": {
+        "url": "https://github.com/chalk/slice-ansi?sponsor=1"
+      }
+    },
     "node_modules/source-map": {
       "version": "0.6.1",
       "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
@@ -6179,30 +6246,36 @@
       "dev": true
     },
     "node_modules/table": {
-      "version": "6.0.7",
-      "resolved": "https://registry.npmjs.org/table/-/table-6.0.7.tgz",
-      "integrity": "sha512-rxZevLGTUzWna/qBLObOe16kB2RTnnbhciwgPbMMlazz1yZGVEgnZK762xyVdVznhqxrfCeBMmMkgOOaPwjH7g==",
+      "version": "6.7.1",
+      "resolved": "https://registry.npmjs.org/table/-/table-6.7.1.tgz",
+      "integrity": "sha512-ZGum47Yi6KOOFDE8m223td53ath2enHcYLgOCjGr5ngu8bdIARQk6mN/wRMv4yMRcHnCSnHbCEha4sobQx5yWg==",
       "dev": true,
       "dependencies": {
-        "ajv": "^7.0.2",
-        "lodash": "^4.17.20",
+        "ajv": "^8.0.1",
+        "lodash.clonedeep": "^4.5.0",
+        "lodash.truncate": "^4.4.2",
         "slice-ansi": "^4.0.0",
-        "string-width": "^4.2.0"
+        "string-width": "^4.2.0",
+        "strip-ansi": "^6.0.0"
       },
       "engines": {
         "node": ">=10.0.0"
       }
     },
     "node_modules/table/node_modules/ajv": {
-      "version": "7.1.1",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-7.1.1.tgz",
-      "integrity": "sha512-ga/aqDYnUy/o7vbsRTFhhTsNeXiYb5JWDIcRIeZfwRNCefwjNTVYCGdGSUrEmiu3yDK3vFvNbgJxvrQW4JXrYQ==",
+      "version": "8.5.0",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-8.5.0.tgz",
+      "integrity": "sha512-Y2l399Tt1AguU3BPRP9Fn4eN+Or+StUGWCUpbnFyXSo8NZ9S4uj+AG2pjs5apK+ZMOwYOz1+a+VKvKH7CudXgQ==",
       "dev": true,
       "dependencies": {
         "fast-deep-equal": "^3.1.1",
         "json-schema-traverse": "^1.0.0",
         "require-from-string": "^2.0.2",
         "uri-js": "^4.2.2"
+      },
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/epoberezkin"
       }
     },
     "node_modules/table/node_modules/json-schema-traverse": {
@@ -6211,20 +6284,6 @@
       "integrity": "sha512-NM8/P9n3XjXhIZn1lLhkFaACTOURQXjWhV4BA/RnOv8xvgqtqpAX9IO4mRQxSx1Rlo4tqzeqb0sOlruaOy3dug==",
       "dev": true
     },
-    "node_modules/table/node_modules/slice-ansi": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/slice-ansi/-/slice-ansi-4.0.0.tgz",
-      "integrity": "sha512-qMCMfhY040cVHT43K9BFygqYbUPFZKHOg7K73mtTWJRb8pyP3fzf4Ixd5SzdEJQ6MRUg/WBnOLxghZtKKurENQ==",
-      "dev": true,
-      "dependencies": {
-        "ansi-styles": "^4.0.0",
-        "astral-regex": "^2.0.0",
-        "is-fullwidth-code-point": "^3.0.0"
-      },
-      "engines": {
-        "node": ">=10"
-      }
-    },
     "node_modules/teeny-request": {
       "version": "7.0.1",
       "resolved": "https://registry.npmjs.org/teeny-request/-/teeny-request-7.0.1.tgz",
@@ -7799,6 +7858,12 @@
       "integrity": "sha512-cxWFQVseBm6O9Gbw1IWb8r6OS4OhSt3hPZLkFApLjM8TEXROBuQGLAH2i2gZpcXdLBIrpXuTDhH7Vbm1iXmNGA==",
       "dev": true
     },
+    "@types/mime": {
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/@types/mime/-/mime-2.0.3.tgz",
+      "integrity": "sha512-Jus9s4CDbqwocc5pOAnh8ShfrnMcPHuJYzVcSUU7lrh8Ni5HuIqX3oilL86p3dlTrk0LzHRCgA/GQ7uNCw6l2Q==",
+      "dev": true
+    },
     "@types/minimist": {
       "version": "1.2.1",
       "resolved": "https://registry.npmjs.org/@types/minimist/-/minimist-1.2.1.tgz",
@@ -7810,6 +7875,16 @@
       "integrity": "sha512-z/5Yd59dCKI5kbxauAJgw6dLPzW+TNOItNE00PkpzNwUIEwdj/Lsqwq94H5DdYBX7C13aRA0CY32BK76+neEUA==",
       "dev": true
     },
+    "@types/node-fetch": {
+      "version": "2.5.10",
+      "resolved": "https://registry.npmjs.org/@types/node-fetch/-/node-fetch-2.5.10.tgz",
+      "integrity": "sha512-IpkX0AasN44hgEad0gEF/V6EgR5n69VEqPEgnmoM8GsIGro3PowbWs4tR6IhxUTyPLpOn+fiGG6nrQhcmoCuIQ==",
+      "dev": true,
+      "requires": {
+        "@types/node": "*",
+        "form-data": "^3.0.0"
+      }
+    },
     "@types/normalize-package-data": {
       "version": "2.4.0",
       "resolved": "https://registry.npmjs.org/@types/normalize-package-data/-/normalize-package-data-2.4.0.tgz",
@@ -8663,9 +8738,9 @@
       }
     },
     "eslint": {
-      "version": "7.26.0",
-      "resolved": "https://registry.npmjs.org/eslint/-/eslint-7.26.0.tgz",
-      "integrity": "sha512-4R1ieRf52/izcZE7AlLy56uIHHDLT74Yzz2Iv2l6kDaYvEu9x+wMB5dZArVL8SYGXSYV2YAg70FcW5Y5nGGNIg==",
+      "version": "7.27.0",
+      "resolved": "https://registry.npmjs.org/eslint/-/eslint-7.27.0.tgz",
+      "integrity": "sha512-JZuR6La2ZF0UD384lcbnd0Cgg6QJjiCwhMD6eU4h/VGPcVGwawNNzKU41tgokGXnfjOOyI6QIffthhJTPzzuRA==",
       "dev": true,
       "requires": {
         "@babel/code-frame": "7.12.11",
@@ -8676,12 +8751,14 @@
         "debug": "^4.0.1",
         "doctrine": "^3.0.0",
         "enquirer": "^2.3.5",
+        "escape-string-regexp": "^4.0.0",
         "eslint-scope": "^5.1.1",
         "eslint-utils": "^2.1.0",
         "eslint-visitor-keys": "^2.0.0",
         "espree": "^7.3.1",
         "esquery": "^1.4.0",
         "esutils": "^2.0.2",
+        "fast-deep-equal": "^3.1.3",
         "file-entry-cache": "^6.0.1",
         "functional-red-black-tree": "^1.0.1",
         "glob-parent": "^5.0.0",
@@ -8693,7 +8770,7 @@
         "js-yaml": "^3.13.1",
         "json-stable-stringify-without-jsonify": "^1.0.1",
         "levn": "^0.4.1",
-        "lodash": "^4.17.21",
+        "lodash.merge": "^4.6.2",
         "minimatch": "^3.0.4",
         "natural-compare": "^1.4.0",
         "optionator": "^0.9.1",
@@ -8702,7 +8779,7 @@
         "semver": "^7.2.1",
         "strip-ansi": "^6.0.0",
         "strip-json-comments": "^3.1.0",
-        "table": "^6.0.4",
+        "table": "^6.0.9",
         "text-table": "^0.2.0",
         "v8-compile-cache": "^2.0.3"
       },
@@ -8716,6 +8793,12 @@
             "@babel/highlight": "^7.10.4"
           }
         },
+        "escape-string-regexp": {
+          "version": "4.0.0",
+          "resolved": "https://registry.npmjs.org/escape-string-regexp/-/escape-string-regexp-4.0.0.tgz",
+          "integrity": "sha512-TtpcNJ3XAzx3Gq8sWRzJaVajRs0uVxA2YAkdb1jm2YkPz4G6egUFAyA3n5vtEIZefPk5Wa4UXbKuS5fKkJWdgA==",
+          "dev": true
+        },
         "globals": {
           "version": "13.6.0",
           "resolved": "https://registry.npmjs.org/globals/-/globals-13.6.0.tgz",
@@ -10821,6 +10904,24 @@
       "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==",
       "dev": true
     },
+    "lodash.clonedeep": {
+      "version": "4.5.0",
+      "resolved": "https://registry.npmjs.org/lodash.clonedeep/-/lodash.clonedeep-4.5.0.tgz",
+      "integrity": "sha1-4j8/nE+Pvd6HJSnBBxhXoIblzO8=",
+      "dev": true
+    },
+    "lodash.merge": {
+      "version": "4.6.2",
+      "resolved": "https://registry.npmjs.org/lodash.merge/-/lodash.merge-4.6.2.tgz",
+      "integrity": "sha512-0KpjqXRVvrYyCsX1swR/XTK0va6VQkQM6MNo7PqW77ByjAhoARA8EfrP1N4+KlKj8YS0ZUCtRT/YUuhyYDujIQ==",
+      "dev": true
+    },
+    "lodash.truncate": {
+      "version": "4.4.2",
+      "resolved": "https://registry.npmjs.org/lodash.truncate/-/lodash.truncate-4.4.2.tgz",
+      "integrity": "sha1-WjUNoLERO4N+z//VgSy+WNbq4ZM=",
+      "dev": true
+    },
     "lru-cache": {
       "version": "6.0.0",
       "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-6.0.0.tgz",
@@ -10985,8 +11086,7 @@
     "node-fetch": {
       "version": "2.6.1",
       "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-2.6.1.tgz",
-      "integrity": "sha512-V4aYg89jEoVRxRb2fJdAg8FHvI7cEyYdVAh94HH0UIK8oJxUfkjlDQN9RbMx+bEjP7+ggMiFRprSti032Oipxw==",
-      "dev": true
+      "integrity": "sha512-V4aYg89jEoVRxRb2fJdAg8FHvI7cEyYdVAh94HH0UIK8oJxUfkjlDQN9RbMx+bEjP7+ggMiFRprSti032Oipxw=="
     },
     "node-int64": {
       "version": "0.4.0",
@@ -11462,6 +11562,17 @@
       "integrity": "sha512-g9Q1haeby36OSStwb4ntCGGGaKsaVSjQ68fBxoQcutl5fS1vuY18H3wSt3jFyFtrkx+Kz0V1G85A4MyAdDMi2Q==",
       "dev": true
     },
+    "slice-ansi": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/slice-ansi/-/slice-ansi-4.0.0.tgz",
+      "integrity": "sha512-qMCMfhY040cVHT43K9BFygqYbUPFZKHOg7K73mtTWJRb8pyP3fzf4Ixd5SzdEJQ6MRUg/WBnOLxghZtKKurENQ==",
+      "dev": true,
+      "requires": {
+        "ansi-styles": "^4.0.0",
+        "astral-regex": "^2.0.0",
+        "is-fullwidth-code-point": "^3.0.0"
+      }
+    },
     "source-map": {
       "version": "0.6.1",
       "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
@@ -11618,21 +11729,23 @@
       "dev": true
     },
     "table": {
-      "version": "6.0.7",
-      "resolved": "https://registry.npmjs.org/table/-/table-6.0.7.tgz",
-      "integrity": "sha512-rxZevLGTUzWna/qBLObOe16kB2RTnnbhciwgPbMMlazz1yZGVEgnZK762xyVdVznhqxrfCeBMmMkgOOaPwjH7g==",
+      "version": "6.7.1",
+      "resolved": "https://registry.npmjs.org/table/-/table-6.7.1.tgz",
+      "integrity": "sha512-ZGum47Yi6KOOFDE8m223td53ath2enHcYLgOCjGr5ngu8bdIARQk6mN/wRMv4yMRcHnCSnHbCEha4sobQx5yWg==",
       "dev": true,
       "requires": {
-        "ajv": "^7.0.2",
-        "lodash": "^4.17.20",
+        "ajv": "^8.0.1",
+        "lodash.clonedeep": "^4.5.0",
+        "lodash.truncate": "^4.4.2",
         "slice-ansi": "^4.0.0",
-        "string-width": "^4.2.0"
+        "string-width": "^4.2.0",
+        "strip-ansi": "^6.0.0"
       },
       "dependencies": {
         "ajv": {
-          "version": "7.1.1",
-          "resolved": "https://registry.npmjs.org/ajv/-/ajv-7.1.1.tgz",
-          "integrity": "sha512-ga/aqDYnUy/o7vbsRTFhhTsNeXiYb5JWDIcRIeZfwRNCefwjNTVYCGdGSUrEmiu3yDK3vFvNbgJxvrQW4JXrYQ==",
+          "version": "8.5.0",
+          "resolved": "https://registry.npmjs.org/ajv/-/ajv-8.5.0.tgz",
+          "integrity": "sha512-Y2l399Tt1AguU3BPRP9Fn4eN+Or+StUGWCUpbnFyXSo8NZ9S4uj+AG2pjs5apK+ZMOwYOz1+a+VKvKH7CudXgQ==",
           "dev": true,
           "requires": {
             "fast-deep-equal": "^3.1.1",
@@ -11646,17 +11759,6 @@
           "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-1.0.0.tgz",
           "integrity": "sha512-NM8/P9n3XjXhIZn1lLhkFaACTOURQXjWhV4BA/RnOv8xvgqtqpAX9IO4mRQxSx1Rlo4tqzeqb0sOlruaOy3dug==",
           "dev": true
-        },
-        "slice-ansi": {
-          "version": "4.0.0",
-          "resolved": "https://registry.npmjs.org/slice-ansi/-/slice-ansi-4.0.0.tgz",
-          "integrity": "sha512-qMCMfhY040cVHT43K9BFygqYbUPFZKHOg7K73mtTWJRb8pyP3fzf4Ixd5SzdEJQ6MRUg/WBnOLxghZtKKurENQ==",
-          "dev": true,
-          "requires": {
-            "ansi-styles": "^4.0.0",
-            "astral-regex": "^2.0.0",
-            "is-fullwidth-code-point": "^3.0.0"
-          }
         }
       }
     },
diff --git a/package.json b/package.json
index bcd052bda..af70ceb83 100644
--- a/package.json
+++ b/package.json
@@ -49,7 +49,7 @@
     "prepare": "npm run build",
     "pregenerate": "npm run build",
     "test": "npm run build && jest --no-cache --test-timeout=10000",
-    "test:coverage": "npm run build && jest --no-cache --coverage && codecov",
+    "test:coverage": "npm run build && jest --no-cache --test-timeout=10000 --coverage && codecov",
     "typecheck": "tsc --noEmit",
     "version": "npm run build"
   },
@@ -59,16 +59,19 @@
     "kleur": "^4.1.4",
     "meow": "^9.0.0",
     "mime": "^2.5.2",
+    "node-fetch": "^2.6.1",
     "prettier": "^2.3.0",
     "tiny-glob": "^0.2.9"
   },
   "devDependencies": {
-    "@types/jest": "^26.0.14",
-    "@types/js-yaml": "^4.0.0",
-    "@typescript-eslint/eslint-plugin": "^4.26.0",
-    "@typescript-eslint/parser": "^4.26.0",
-    "codecov": "^3.8.1",
-    "eslint": "^7.26.0",
+    "@types/jest": "^26.0.23",
+    "@types/js-yaml": "^4.0.1",
+    "@types/mime": "^2.0.3",
+    "@types/node-fetch": "^2.5.10",
+    "@typescript-eslint/eslint-plugin": "^4.25.0",
+    "@typescript-eslint/parser": "^4.25.0",
+    "codecov": "^3.8.2",
+    "eslint": "^7.27.0",
     "eslint-config-prettier": "^8.3.0",
     "eslint-plugin-prettier": "^3.4.0",
     "jest": "^27.0.3",
diff --git a/src/index.ts b/src/index.ts
index c5bbb15c1..b3d83c7cf 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,6 +1,8 @@
 import path from "path";
+import { bold, yellow } from "kleur";
 import prettier from "prettier";
 import parserTypescript from "prettier/parser-typescript";
+import load, { resolveSchema } from "./load";
 import { swaggerVersion } from "./utils";
 import { transformAll } from "./transform/index";
 import { GlobalContext, OpenAPI2, OpenAPI3, SchemaObject, SwaggerToTSOptions } from "./types";
@@ -14,28 +16,70 @@ export const WARNING_MESSAGE = `/**
 
 `;
 
-export default function openapiTS(
-  schema: OpenAPI2 | OpenAPI3 | Record<string, SchemaObject>,
-  options: SwaggerToTSOptions = {}
-): string {
-  // 1. set up context
+export default async function openapiTS(
+  schema: string | OpenAPI2 | OpenAPI3 | Record<string, SchemaObject>,
+  options: SwaggerToTSOptions = {} as any
+): Promise<string> {
   const ctx: GlobalContext = {
     additionalProperties: options.additionalProperties || false,
     auth: options.auth,
     defaultNonNullable: options.defaultNonNullable || false,
-    formatter: typeof options.formatter === "function" ? options.formatter : undefined,
+    formatter: options && typeof options.formatter === "function" ? options.formatter : undefined,
     immutableTypes: options.immutableTypes || false,
     rawSchema: options.rawSchema || false,
-    version: options.version || swaggerVersion(schema as OpenAPI2 | OpenAPI3),
+    version: options.version || 3,
   } as any;
 
-  // 2. generate output
+  // note: we may be loading many large schemas into memory at once; take care to reuse references without cloning
+
+  // 1. load schema
+  let rootSchema: Record<string, any> = {};
+  let external: Record<string, Record<string, any>> = {};
+  if (typeof schema === "string") {
+    const schemaURL = resolveSchema(schema);
+    if (options.silent === false) console.log(yellow(`🔭 Loading spec from ${bold(schemaURL.href)}…`));
+    const schemas: Record<string, Record<string, any>> = {};
+    await load(schemaURL, {
+      ...ctx,
+      schemas,
+      rootURL: schemaURL, // as it crawls schemas recursively, it needs to know which is the root to resolve everything relative to
+    });
+    for (const k of Object.keys(schemas)) {
+      if (k === schemaURL.href) {
+        rootSchema = schemas[k];
+      } else {
+        external[k] = schemas[k];
+      }
+    }
+  } else {
+    rootSchema = schema;
+  }
+
+  // 2. generate raw output
   let output = WARNING_MESSAGE;
-  const rootTypes = transformAll(schema, { ...ctx });
+
+  // 2a. root schema
+  if (!options?.version && !ctx.rawSchema) ctx.version = swaggerVersion(rootSchema as any); // note: root version cascades down to all subschemas
+  const rootTypes = transformAll(rootSchema, { ...ctx });
   for (const k of Object.keys(rootTypes)) {
-    if (typeof rootTypes[k] !== "string") continue;
-    output += `export interface ${k} {\n  ${rootTypes[k]}\n}\n\n`;
+    if (typeof rootTypes[k] === "string") {
+      output += `export interface ${k} {\n  ${rootTypes[k]}\n}\n\n`;
+    }
+  }
+
+  // 2b. external schemas (subschemas)
+  output += `export interface external {\n`;
+  const externalKeys = Object.keys(external);
+  externalKeys.sort((a, b) => a.localeCompare(b, "en", { numeric: true })); // sort external keys because they may have resolved in a different order each time
+  for (const subschemaURL of externalKeys) {
+    output += `  "${subschemaURL}": {\n`;
+    const subschemaTypes = transformAll(external[subschemaURL], { ...ctx, namespace: subschemaURL });
+    for (const k of Object.keys(subschemaTypes)) {
+      output += `    "${k}": {\n      ${subschemaTypes[k]}\n    }\n`;
+    }
+    output += `  }\n`;
   }
+  output += `}\n\n`;
 
   // 3. Prettify
   let prettierOptions: prettier.Options = {
@@ -44,7 +88,7 @@ export default function openapiTS(
   };
   if (options && options.prettierConfig) {
     try {
-      const userOptions = prettier.resolveConfig.sync(path.resolve(process.cwd(), options.prettierConfig));
+      const userOptions = await prettier.resolveConfig(path.resolve(process.cwd(), options.prettierConfig));
       prettierOptions = {
         ...(userOptions || {}),
         ...prettierOptions,
diff --git a/src/load.ts b/src/load.ts
new file mode 100644
index 000000000..8db8f0a05
--- /dev/null
+++ b/src/load.ts
@@ -0,0 +1,170 @@
+import fs from "fs";
+import path from "path";
+import { URL } from "url";
+import fetch, { Headers } from "node-fetch";
+import mime from "mime";
+import yaml from "js-yaml";
+import { GlobalContext } from "./types";
+import { parseRef } from "./utils";
+
+type PartialSchema = Record<string, any>; // not a very accurate type, but this is easier to deal with before we know we’re dealing with a valid spec
+
+function parseSchema(schema: any, type: "YAML" | "JSON") {
+  if (type === "YAML") {
+    try {
+      return yaml.load(schema);
+    } catch (err) {
+      throw new Error(`YAML: ${err.toString()}`);
+    }
+  } else {
+    try {
+      return JSON.parse(schema);
+    } catch (err) {
+      throw new Error(`JSON: ${err.toString()}`);
+    }
+  }
+}
+
+function isFile(url: URL): boolean {
+  return url.protocol === "file:";
+}
+
+export function resolveSchema(url: string): URL {
+  // option 1: remote
+  if (url.startsWith("http://") || url.startsWith("https://")) {
+    return new URL(url);
+  }
+
+  // option 2: local
+  const localPath = path.isAbsolute(url) ? new URL("", `file://${url}`) : new URL(url, `file://${process.cwd()}/`); // if absolute path is provided use that; otherwise search cwd\
+  if (!fs.existsSync(localPath)) {
+    throw new Error(`Could not locate ${url}`);
+  } else if (fs.statSync(localPath).isDirectory()) {
+    throw new Error(`${localPath} is a directory not a file`);
+  }
+  return localPath;
+}
+
+interface LoadOptions extends GlobalContext {
+  rootURL: URL;
+  schemas: { [url: string]: PartialSchema };
+}
+
+// temporary cache for load()
+let urlCache = new Set<string>(); // URL cache (prevent URLs from being loaded over and over)
+
+/** Load a schema from local path or remote URL */
+export default async function load(schemaURL: URL, options: LoadOptions): Promise<{ [url: string]: PartialSchema }> {
+  if (urlCache.has(schemaURL.href)) return options.schemas; // exit early if this has already been scanned
+  urlCache.add(schemaURL.href); // add URL to cache
+
+  const schemas = options.schemas;
+
+  let contents = "";
+  let contentType = "";
+
+  if (isFile(schemaURL)) {
+    // load local
+    contents = await fs.promises.readFile(schemaURL, "utf8");
+    contentType = mime.getType(schemaURL.href) || "";
+  } else {
+    // load remote
+    const headers = new Headers();
+    if (options.auth) headers.set("Authorization", options.auth);
+    const res = await fetch(schemaURL.href, { method: "GET", headers });
+    contentType = res.headers.get("Content-Type") || "";
+    contents = await res.text();
+  }
+
+  const isYAML = contentType === "application/openapi+yaml" || contentType === "text/yaml";
+  const isJSON =
+    contentType === "application/json" ||
+    contentType === "application/json5" ||
+    contentType === "application/openapi+json";
+  if (isYAML) {
+    schemas[schemaURL.href] = parseSchema(contents, "YAML");
+  } else if (isJSON) {
+    schemas[schemaURL.href] = parseSchema(contents, "JSON");
+  } else {
+    // if contentType is unknown, guess
+    try {
+      schemas[schemaURL.href] = parseSchema(contents, "JSON");
+    } catch (err1) {
+      try {
+        schemas[schemaURL.href] = parseSchema(contents, "YAML");
+      } catch (err2) {
+        throw new Error(`Unknown format${contentType ? `: "${contentType}"` : ""}. Only YAML or JSON supported.`); // give up: unknown type
+      }
+    }
+  }
+
+  // scan $refs, but don’t transform (load everything in parallel)
+  const refPromises: Promise<any>[] = [];
+  schemas[schemaURL.href] = JSON.parse(JSON.stringify(schemas[schemaURL.href]), (k, v) => {
+    if (k !== "$ref" || typeof v !== "string") return v;
+
+    const { url: refURL } = parseRef(v);
+    if (refURL) {
+      // load $refs (only if new) and merge subschemas with top-level schema
+      const nextURL =
+        refURL.startsWith("http://") || refURL.startsWith("https://") ? new URL(refURL) : new URL(refURL, schemaURL);
+      refPromises.push(
+        load(nextURL, options).then((subschemas) => {
+          for (const subschemaURL of Object.keys(subschemas)) {
+            schemas[subschemaURL] = subschemas[subschemaURL];
+          }
+        })
+      );
+      return v.replace(refURL, nextURL.href); // resolve relative URLs to absolute URLs so the schema can be flattened
+    }
+    return v;
+  });
+  await Promise.all(refPromises);
+
+  // transform $refs once, at the root schema, after all have been scanned & downloaded (much easier to do here when we have the context)
+  if (schemaURL.href === options.rootURL.href) {
+    for (const subschemaURL of Object.keys(schemas)) {
+      // transform $refs in schema
+      schemas[subschemaURL] = JSON.parse(JSON.stringify(schemas[subschemaURL]), (k, v) => {
+        if (k !== "$ref" || typeof v !== "string") return v;
+        if (!v.includes("#")) return v; // already transformed; skip
+
+        const { url, parts } = parseRef(v);
+        // scenario 1: resolve all external URLs so long as they don’t point back to root schema
+        if (url && new URL(url).href !== options.rootURL.href) {
+          const relativeURL =
+            isFile(new URL(url)) && isFile(options.rootURL)
+              ? path.posix.relative(path.posix.dirname(options.rootURL.href), url)
+              : url;
+          return `external["${relativeURL}"]["${parts.join('"]["')}"]`; // export external ref
+        }
+        // scenario 2: treat all $refs in external schemas as external
+        if (!url && subschemaURL !== options.rootURL.href) {
+          const relativeURL =
+            isFile(new URL(subschemaURL)) && isFile(options.rootURL)
+              ? path.posix.relative(path.posix.dirname(options.rootURL.href), subschemaURL)
+              : subschemaURL;
+          return `external["${relativeURL}"]["${parts.join('"]["')}"]`; // export external ref
+        }
+
+        // scenario 3: transform all $refs pointing back to root schema
+        const [base, ...rest] = parts;
+        return `${base}["${rest.join('"]["')}"]`; // transform other $refs to the root schema (including external refs that point back to the root schema)
+      });
+
+      // use relative keys for external schemas (schemas generated on different machines should have the same namespace)
+      if (subschemaURL !== options.rootURL.href) {
+        const relativeURL =
+          isFile(new URL(subschemaURL)) && isFile(options.rootURL)
+            ? path.posix.relative(path.posix.dirname(options.rootURL.href), subschemaURL)
+            : subschemaURL;
+        if (relativeURL !== subschemaURL) {
+          schemas[relativeURL] = schemas[subschemaURL];
+          delete schemas[subschemaURL];
+        }
+      }
+    }
+  }
+
+  return schemas;
+}
diff --git a/src/transform/operation.ts b/src/transform/operation.ts
index bb8b10136..f72db95cb 100644
--- a/src/transform/operation.ts
+++ b/src/transform/operation.ts
@@ -1,5 +1,5 @@
 import { GlobalContext, OperationObject, ParameterObject, PathItemObject } from "../types";
-import { comment, isRef, transformRef, tsReadonly } from "../utils";
+import { comment, isRef, tsReadonly } from "../utils";
 import { transformParametersArray } from "./parameters";
 import { transformRequestBodyObj } from "./request";
 import { transformResponsesObj } from "./responses";
@@ -29,7 +29,7 @@ export function transformOperationObj(operation: OperationObject, options: Trans
 
   if (operation.requestBody) {
     if (isRef(operation.requestBody)) {
-      output += `  ${readonly}requestBody: ${transformRef(operation.requestBody.$ref)};\n`;
+      output += `  ${readonly}requestBody: ${operation.requestBody.$ref};\n`;
     } else {
       if (operation.requestBody.description) output += comment(operation.requestBody.description);
       output += `  ${readonly}requestBody: {\n  ${transformRequestBodyObj(operation.requestBody, ctx)}  }\n`;
diff --git a/src/transform/parameters.ts b/src/transform/parameters.ts
index 01a9a1348..57ee2ad9a 100644
--- a/src/transform/parameters.ts
+++ b/src/transform/parameters.ts
@@ -19,7 +19,7 @@ export function transformParametersArray(
   let mappedParams: Record<string, Record<string, ParameterObject>> = {};
   for (const paramObj of parameters as any[]) {
     if (paramObj.$ref && globalParameters) {
-      const paramName = paramObj.$ref.split("/").pop(); // take last segment
+      const paramName = paramObj.$ref.split('["').pop().replace(/"\]$/, ""); // take last segment
       if (globalParameters[paramName]) {
         const reference = globalParameters[paramName] as any;
         if (!mappedParams[reference.in]) mappedParams[reference.in] = {};
diff --git a/src/transform/paths.ts b/src/transform/paths.ts
index e40ab6a7e..1cc429e10 100644
--- a/src/transform/paths.ts
+++ b/src/transform/paths.ts
@@ -1,5 +1,5 @@
 import { GlobalContext, OperationObject, ParameterObject, PathItemObject } from "../types";
-import { comment, transformRef, tsReadonly } from "../utils";
+import { comment, tsReadonly } from "../utils";
 import { transformOperationObj } from "./operation";
 import { transformParametersArray } from "./parameters";
 
@@ -19,7 +19,7 @@ export function transformPathsObj(paths: Record<string, PathItemObject>, options
     if (pathItem.description) output += comment(pathItem.description); // add comment
 
     if (pathItem.$ref) {
-      output += `  ${readonly}"${url}": ${transformRef(pathItem.$ref)};\n`;
+      output += `  ${readonly}"${url}": ${pathItem.$ref};\n`;
       continue;
     }
 
@@ -33,7 +33,8 @@ export function transformPathsObj(paths: Record<string, PathItemObject>, options
       if (operation.operationId) {
         // if operation has operationId, abstract into top-level operations object
         operations[operation.operationId] = { operation, pathItem };
-        output += `    ${readonly}"${method}": operations["${operation.operationId}"];\n`;
+        const namespace = ctx.namespace ? `external["${ctx.namespace}"]["operations"]` : `operations`;
+        output += `    ${readonly}"${method}": ${namespace}["${operation.operationId}"];\n`;
       } else {
         // otherwise, inline operation
         output += `    ${readonly}"${method}": {\n      ${transformOperationObj(operation, {
diff --git a/src/transform/request.ts b/src/transform/request.ts
index 74eb15169..ead72cc98 100644
--- a/src/transform/request.ts
+++ b/src/transform/request.ts
@@ -5,8 +5,7 @@ import { transformSchemaObj } from "./schema";
 export function transformRequestBodies(requestBodies: Record<string, RequestBody>, ctx: GlobalContext) {
   let output = "";
 
-  for (const name of Object.keys(requestBodies)) {
-    const requestBody = requestBodies[name];
+  for (const [name, requestBody] of Object.entries(requestBodies)) {
     if (requestBody && requestBody.description) output += `  ${comment(requestBody.description)}`;
     output += `  "${name}": {\n    ${transformRequestBodyObj(requestBody, ctx)}\n  }\n`;
   }
@@ -21,8 +20,7 @@ export function transformRequestBodyObj(requestBody: RequestBody, ctx: GlobalCon
 
   if (requestBody.content && Object.keys(requestBody.content).length) {
     output += `  ${readonly}content: {\n`; // open content
-    for (const k of Object.keys(requestBody.content)) {
-      const v = requestBody.content[k];
+    for (const [k, v] of Object.entries(requestBody.content)) {
       output += `      ${readonly}"${k}": ${transformSchemaObj(v.schema, { ...ctx, required: new Set<string>() })};\n`;
     }
     output += `    }\n`; // close content
diff --git a/src/transform/responses.ts b/src/transform/responses.ts
index 90d231254..f0f1adf96 100644
--- a/src/transform/responses.ts
+++ b/src/transform/responses.ts
@@ -1,5 +1,5 @@
 import { GlobalContext } from "../types";
-import { comment, transformRef, tsReadonly } from "../utils";
+import { comment, tsReadonly } from "../utils";
 import { transformHeaderObjMap } from "./headers";
 import { transformSchemaObj } from "./schema";
 
@@ -16,7 +16,7 @@ export function transformResponsesObj(responsesObj: Record<string, any>, ctx: Gl
     if (response.description) output += comment(response.description);
 
     if (response.$ref) {
-      output += `  ${readonly}${statusCode}: ${transformRef(response.$ref)};\n`; // reference
+      output += `  ${readonly}${statusCode}: ${response.$ref};\n`; // reference
       continue;
     }
 
@@ -30,7 +30,7 @@ export function transformResponsesObj(responsesObj: Record<string, any>, ctx: Gl
     // headers
     if (response.headers && Object.keys(response.headers).length) {
       if (response.headers.$ref) {
-        output += `    ${readonly}headers: ${transformRef(response.headers.$ref)};\n`;
+        output += `    ${readonly}headers: ${response.headers.$ref};\n`;
       } else {
         output += `    ${readonly}headers: {\n      ${transformHeaderObjMap(response.headers, {
           ...ctx,
diff --git a/src/transform/schema.ts b/src/transform/schema.ts
index d7dfe2f7b..eb7d8d407 100644
--- a/src/transform/schema.ts
+++ b/src/transform/schema.ts
@@ -1,15 +1,5 @@
 import { GlobalContext } from "../types";
-import {
-  comment,
-  nodeType,
-  transformRef,
-  tsArrayOf,
-  tsIntersectionOf,
-  tsPartial,
-  tsReadonly,
-  tsTupleOf,
-  tsUnionOf,
-} from "../utils";
+import { comment, nodeType, tsArrayOf, tsIntersectionOf, tsPartial, tsReadonly, tsTupleOf, tsUnionOf } from "../utils";
 
 interface TransformSchemaObjOptions extends GlobalContext {
   required: Set<string>;
@@ -27,6 +17,7 @@ export function transformSchemaObjMap(obj: Record<string, any>, options: Transfo
 
   for (const k of Object.keys(obj)) {
     const v = obj[k];
+
     // 1. JSDoc comment (goes above property)
     if (v.description) output += comment(v.description);
 
@@ -75,7 +66,7 @@ export function transformSchemaObj(node: any, options: TransformSchemaObjOptions
     // transform core type
     switch (nodeType(node)) {
       case "ref": {
-        output += transformRef(node.$ref);
+        output += node.$ref; // these were transformed at load time when remote schemas were resolved; return as-is
         break;
       }
       case "string":
diff --git a/src/types.ts b/src/types.ts
index ce3a273ef..681d53eff 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,4 +1,4 @@
-import { URL } from "url";
+import type { URL } from "url";
 
 export interface OpenAPI2 {
   swagger: string; // required
@@ -130,6 +130,8 @@ export interface SwaggerToTSOptions {
   prettierConfig?: string;
   /** (optional) Parsing input document as raw schema rather than OpenAPI document */
   rawSchema?: boolean;
+  /** (optional) Should logging be suppressed? (necessary for STDOUT) */
+  silent?: boolean;
   /** (optional) OpenAPI version. Must be present if parsing raw schema */
   version?: number;
 }
diff --git a/src/utils.ts b/src/utils.ts
index 4d17f3f85..027633b9d 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -14,6 +14,18 @@ export function comment(text: string): string {
   */\n`;
 }
 
+export function parseRef(ref: string): { url?: string; parts: string[] } {
+  if (typeof ref !== "string" || !ref.includes("#")) return { parts: [] };
+  const [url, parts] = ref.split("#");
+  return {
+    url: url || undefined,
+    parts: parts
+      .split("/") // split by special character
+      .filter((p) => !!p) // remove empty parts
+      .map(decodeRef), // decode encoded chars
+  };
+}
+
 /** Is this a ReferenceObject? (note: this is just a TypeScript helper for nodeType() below) */
 export function isRef(obj: any): obj is ReferenceObject {
   return !!obj.$ref;
@@ -85,14 +97,14 @@ export function swaggerVersion(definition: OpenAPI2 | OpenAPI3): 2 | 3 {
   );
 }
 
-/** Convert $ref to TS ref */
-export function transformRef(ref: string, root = ""): string {
-  // TODO: load external file
-  const isExternalRef = !ref.startsWith("#"); // if # isn’t first character, we can assume this is a remote schema
-  if (isExternalRef) return "any";
+/** Decode $ref (https://swagger.io/docs/specification/using-ref/#escape) */
+export function decodeRef(ref: string): string {
+  return ref.replace(/\~0/g, "~").replace(/\~1/g, "/").replace(/"/g, '\\"');
+}
 
-  const parts = ref.replace(/^#\//, root).split("/");
-  return `${parts[0]}["${parts.slice(1).join('"]["')}"]`;
+/** Encode $ref (https://swagger.io/docs/specification/using-ref/#escape) */
+export function encodeRef(ref: string): string {
+  return ref.replace(/\~/g, "~0").replace(/\//g, "~1");
 }
 
 /** Convert T into T[]; */
@@ -125,9 +137,3 @@ export function tsUnionOf(types: Array<string | number | boolean>): string {
   if (types.length === 1) return `${types[0]}`; // don’t add parentheses around one thing
   return `(${types.join(") | (")})`;
 }
-
-/** Convert the components object and a 'components["parameters"]["param"]' string into the `param` object **/
-export function unrefComponent(components: any, ref: string): any {
-  const [type, object] = ref.match(/(?<=\[")([^"]+)/g) as string[];
-  return components[type][object];
-}
diff --git a/tests/bin/cli.test.ts b/tests/bin/cli.test.ts
index 1517e261e..61f633288 100644
--- a/tests/bin/cli.test.ts
+++ b/tests/bin/cli.test.ts
@@ -37,7 +37,7 @@ describe("cli", () => {
   });
 
   it("supports glob paths", async () => {
-    execSync(`../../bin/cli.js \"specs/*.yaml\" -o generated/`, { cwd: __dirname }); // Quotes are necessary because shells like zsh treats glob weirdly
+    execSync(`../../bin/cli.js "specs/*.yaml" -o generated/`, { cwd: __dirname }); // Quotes are necessary because shells like zsh treats glob weirdly
     const [generatedPetstore, expectedPetstore, generatedManifold, expectedManifold] = await Promise.all([
       fs.promises.readFile(path.join(__dirname, "generated", "specs", "petstore.ts"), "utf8"),
       fs.promises.readFile(path.join(__dirname, "expected", "petstore.ts"), "utf8"),
diff --git a/tests/bin/expected/manifold.ts b/tests/bin/expected/manifold.ts
index 821bda220..41eb3b0d0 100644
--- a/tests/bin/expected/manifold.ts
+++ b/tests/bin/expected/manifold.ts
@@ -1008,3 +1008,5 @@ export interface parameters {
 }
 
 export interface operations {}
+
+export interface external {}
diff --git a/tests/bin/expected/petstore.ts b/tests/bin/expected/petstore.ts
index 756d358ac..152806e25 100644
--- a/tests/bin/expected/petstore.ts
+++ b/tests/bin/expected/petstore.ts
@@ -463,3 +463,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/bin/expected/prettier-js.ts b/tests/bin/expected/prettier-js.ts
index a7f99b44e..3f89d5a70 100644
--- a/tests/bin/expected/prettier-js.ts
+++ b/tests/bin/expected/prettier-js.ts
@@ -463,3 +463,5 @@ export interface operations {
     }
   }
 }
+
+export interface external {}
diff --git a/tests/bin/expected/prettier-json.ts b/tests/bin/expected/prettier-json.ts
index a7f99b44e..3f89d5a70 100644
--- a/tests/bin/expected/prettier-json.ts
+++ b/tests/bin/expected/prettier-json.ts
@@ -463,3 +463,5 @@ export interface operations {
     }
   }
 }
+
+export interface external {}
diff --git a/tests/bin/expected/stdout.ts b/tests/bin/expected/stdout.ts
index 756d358ac..152806e25 100644
--- a/tests/bin/expected/stdout.ts
+++ b/tests/bin/expected/stdout.ts
@@ -463,3 +463,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/empty-definitions.test.ts b/tests/empty-definitions.test.ts
index 38907a810..b33a9478b 100644
--- a/tests/empty-definitions.test.ts
+++ b/tests/empty-definitions.test.ts
@@ -1,7 +1,7 @@
 import openapiTS from "../src/index";
 
 describe("allow empty definitions", () => {
-  it("allow empty definitions", () => {
+  it("allow empty definitions", async () => {
     const schema = {
       swagger: "2.0",
       paths: {
@@ -16,7 +16,7 @@ describe("allow empty definitions", () => {
                 description: "Pet object that needs to be added to the store",
                 required: true,
                 schema: {
-                  $ref: "#/definitions/Pet",
+                  $ref: 'definitions["Pet"]',
                 },
               },
             ],
@@ -30,11 +30,7 @@ describe("allow empty definitions", () => {
       },
     };
 
-    expect(
-      openapiTS(schema as any, {
-        version: 2,
-      })
-    ).toBe(`/**
+    expect(await openapiTS(schema as any, { version: 2 })).toBe(`/**
  * This file was auto-generated by openapi-typescript.
  * Do not make direct changes to the file.
  */
@@ -59,14 +55,11 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
 `);
 
-    expect(
-      openapiTS(schema as any, {
-        immutableTypes: true,
-        version: 2,
-      })
-    ).toBe(`/**
+    expect(await openapiTS(schema as any, { immutableTypes: true, version: 2 })).toBe(`/**
  * This file was auto-generated by openapi-typescript.
  * Do not make direct changes to the file.
  */
@@ -91,6 +84,8 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
 `);
   });
 });
diff --git a/tests/formatter.test.ts b/tests/formatter.test.ts
index f7882b427..41bfe7d01 100644
--- a/tests/formatter.test.ts
+++ b/tests/formatter.test.ts
@@ -1,7 +1,7 @@
 import { default as openapiTS } from "../src/index";
 
 describe("formatter", () => {
-  it("basic", () => {
+  it("basic", async () => {
     const schema = {
       openapi: "3.0.1",
       components: {
@@ -14,7 +14,7 @@ describe("formatter", () => {
       },
     };
     expect(
-      openapiTS(schema, {
+      await openapiTS(schema, {
         formatter(schemaObj) {
           if (schemaObj.format === "date-time") {
             return "Date";
@@ -37,10 +37,12 @@ export interface components {
 }
 
 export interface operations {}
+
+export interface external {}
 `);
   });
 
-  it("hasObject", () => {
+  it("hasObject", async () => {
     const schemaHasObject = {
       openapi: "3.0.1",
       components: {
@@ -64,7 +66,7 @@ export interface operations {}
     };
 
     expect(
-      openapiTS(schemaHasObject, {
+      await openapiTS(schemaHasObject, {
         formatter(schemaObj) {
           if (schemaObj.format === "date-time") {
             return "Date";
@@ -91,6 +93,8 @@ export interface components {
 }
 
 export interface operations {}
+
+export interface external {}
 `);
   });
 });
diff --git a/tests/operation.test.ts b/tests/operation.test.ts
index 21736931e..a161becdf 100644
--- a/tests/operation.test.ts
+++ b/tests/operation.test.ts
@@ -12,10 +12,10 @@ describe("requestBody", () => {
     requestBody: {
       content: {
         "application/json": {
-          schema: { $ref: "#/components/schemas/Pet" },
+          schema: { $ref: 'components["schemas"]["Pet"]' },
         },
         "application/xml": {
-          schema: { $ref: "#/components/schemas/Pet" },
+          schema: { $ref: 'components["schemas"]["Pet"]' },
         },
       },
     },
@@ -40,6 +40,7 @@ describe("requestBody", () => {
       transformOperationObj(basicSchema, {
         ...defaults,
         immutableTypes: true,
+        rawSchema: false,
         version: 3,
       }).trim()
     ).toBe(`readonly requestBody: {
@@ -51,7 +52,7 @@ describe("requestBody", () => {
   });
 
   const refSchema = {
-    requestBody: { $ref: "#/components/requestBodies/Request" },
+    requestBody: { $ref: 'components["requestBodies"]["Request"]' },
   };
 
   it("$ref", () => {
@@ -68,6 +69,7 @@ describe("requestBody", () => {
       transformOperationObj(refSchema, {
         ...defaults,
         immutableTypes: true,
+        rawSchema: false,
         version: 3,
       }).trim()
     ).toBe(`readonly requestBody: components["requestBodies"]["Request"];`);
diff --git a/tests/parameters.test.ts b/tests/parameters.test.ts
index 4d2c3f77e..3d96b7df8 100644
--- a/tests/parameters.test.ts
+++ b/tests/parameters.test.ts
@@ -49,6 +49,7 @@ describe("transformParametersArray()", () => {
         transformParametersArray(basicSchema as any, {
           ...defaults,
           immutableTypes: true,
+          rawSchema: false,
           version: 2,
         }).trim()
       ).toBe(
@@ -66,9 +67,9 @@ describe("transformParametersArray()", () => {
     });
 
     const refSchema = [
-      { $ref: "#/parameters/per_page" },
-      { $ref: "#/parameters/page" },
-      { $ref: "#/parameters/since" },
+      { $ref: 'parameters["per_page"]' },
+      { $ref: 'parameters["page"]' },
+      { $ref: 'parameters["since"]' },
     ];
 
     it("$ref", () => {
@@ -155,6 +156,7 @@ describe("transformParametersArray()", () => {
         transformParametersArray(basicSchema as any, {
           ...defaults,
           immutableTypes: true,
+          rawSchema: false,
           version: 3,
         }).trim()
       ).toBe(
@@ -169,9 +171,9 @@ describe("transformParametersArray()", () => {
     });
 
     const refSchema = [
-      { $ref: "#/components/parameters/per_page" },
-      { $ref: "#/components/parameters/page" },
-      { $ref: "#/components/parameters/since" },
+      { $ref: 'components["parameters"]["per_page"]' },
+      { $ref: 'components["parameters"]["page"]' },
+      { $ref: 'components["parameters"]["since"]' },
     ];
 
     it("$ref", () => {
@@ -212,7 +214,7 @@ describe("transformParametersArray()", () => {
     });
 
     it("nullable", () => {
-      const schema = [
+      const schema: any = [
         { in: "query", name: "nullableString", schema: { type: "string", nullable: true } },
         { in: "query", name: "nullableNum", schema: { type: "number", nullable: true } },
       ];
diff --git a/tests/paths.test.ts b/tests/paths.test.ts
index 288af88f2..f42c16579 100644
--- a/tests/paths.test.ts
+++ b/tests/paths.test.ts
@@ -48,7 +48,7 @@ describe("transformPathsObj", () => {
                 schema: {
                   type: "object",
                   properties: {
-                    results: { type: "array", items: { $ref: "#/components/schemas/SearchResult" } },
+                    results: { type: "array", items: { $ref: 'components["schemas"]["SearchResult"]' } },
                     total: { type: "integer" },
                   },
                   additionalProperties: false,
@@ -60,7 +60,7 @@ describe("transformPathsObj", () => {
           404: {
             content: {
               "application/json": {
-                schema: { $ref: "#/components/schemas/ErrorResponse" },
+                schema: { $ref: 'components["schemas"]["ErrorResponse"]' },
               },
             },
           },
@@ -276,7 +276,7 @@ describe("transformPathsObj", () => {
       },
       delete: {
         operationId: "testsDelete",
-        requestBody: { $ref: "#/components/schemas/Pet" },
+        requestBody: { $ref: 'components["schemas"]["Pet"]' },
       },
     },
   };
@@ -344,8 +344,11 @@ describe("transformPathsObj", () => {
           {
             "/some/path": {
               get: {
-                parameters: [{ $ref: "#/components/parameters/param1" }, { $ref: "#/components/parameters/param2" }],
-                responses: { 400: { $ref: "#/components/responses/400BadRequest" } },
+                parameters: [
+                  { $ref: 'components["parameters"]["param1"]' },
+                  { $ref: 'components["parameters"]["param2"]' },
+                ],
+                responses: { 400: { $ref: 'components["responses"]["400BadRequest"]' } },
               },
             },
           },
diff --git a/tests/raw-schema.test.ts b/tests/raw-schema.test.ts
index 0f4c19db8..e31d6a4b9 100644
--- a/tests/raw-schema.test.ts
+++ b/tests/raw-schema.test.ts
@@ -1,7 +1,7 @@
 import openapiTS from "../src/index";
 
 describe("rawSchema", () => {
-  it("v2", () => {
+  it("v2", async () => {
     const v2schema = {
       User: {
         type: "object",
@@ -13,12 +13,7 @@ describe("rawSchema", () => {
       },
     };
 
-    expect(
-      openapiTS(v2schema, {
-        rawSchema: true,
-        version: 2,
-      })
-    ).toBe(`/**
+    expect(await openapiTS(v2schema, { rawSchema: true, version: 2 })).toBe(`/**
  * This file was auto-generated by openapi-typescript.
  * Do not make direct changes to the file.
  */
@@ -30,10 +25,13 @@ export interface definitions {
     /** user email */
     email: string;
   };
-}\n`);
+}
+
+export interface external {}
+`);
   });
 
-  it("v3", () => {
+  it("v3", async () => {
     const v3schema = {
       User: {
         type: "object",
@@ -46,12 +44,7 @@ export interface definitions {
       },
     };
 
-    expect(
-      openapiTS(v3schema, {
-        rawSchema: true,
-        version: 3,
-      })
-    ).toBe(`/**
+    expect(await openapiTS(v3schema, { rawSchema: true, version: 3 })).toBe(`/**
  * This file was auto-generated by openapi-typescript.
  * Do not make direct changes to the file.
  */
@@ -63,6 +56,9 @@ export interface schemas {
     /** user email */
     email: string;
   };
-}\n`);
+}
+
+export interface external {}
+`);
   });
 });
diff --git a/tests/remote-schema/remote-schema.test.ts b/tests/remote-schema/remote-schema.test.ts
new file mode 100644
index 000000000..07ccf3a20
--- /dev/null
+++ b/tests/remote-schema/remote-schema.test.ts
@@ -0,0 +1,510 @@
+import path from "path";
+import openapiTS from "../../src/index";
+
+describe("remote $refs", () => {
+  it("resolves remote $refs", async () => {
+    const types = await openapiTS(path.join(__dirname, "spec", "spec.yml"));
+    expect(types).toEqual(`/**
+ * This file was auto-generated by openapi-typescript.
+ * Do not make direct changes to the file.
+ */
+
+export interface paths {}
+
+export interface components {
+  schemas: {
+    /** this is a duplicate of subschema/remote1.yml */
+    Circular: string;
+    Remote1: external["subschema/remote1.yml"]["components"]["schemas"]["Remote1"];
+    Pet: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Pet"];
+  };
+}
+
+export interface operations {}
+
+export interface external {
+  "https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml": {
+    paths: {
+      "/pet": {
+        put: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["updatePet"];
+        post: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["addPet"];
+      };
+      "/pet/findByStatus": {
+        /** Multiple status values can be provided with comma separated strings */
+        get: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["findPetsByStatus"];
+      };
+      "/pet/findByTags": {
+        /** Muliple tags can be provided with comma separated strings. Use         tag1, tag2, tag3 for testing. */
+        get: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["findPetsByTags"];
+      };
+      "/pet/{petId}": {
+        /** Returns a single pet */
+        get: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["getPetById"];
+        post: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["updatePetWithForm"];
+        delete: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["deletePet"];
+      };
+      "/pet/{petId}/uploadImage": {
+        post: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["uploadFile"];
+      };
+      "/store/inventory": {
+        /** Returns a map of status codes to quantities */
+        get: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["getInventory"];
+      };
+      "/store/order": {
+        post: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["placeOrder"];
+      };
+      "/store/order/{orderId}": {
+        /** For valid response try integer IDs with value >= 1 and <= 10.         Other values will generated exceptions */
+        get: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["getOrderById"];
+        /** For valid response try integer IDs with positive integer value.         Negative or non-integer values will generate API errors */
+        delete: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["deleteOrder"];
+      };
+      "/user": {
+        /** This can only be done by the logged in user. */
+        post: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["createUser"];
+      };
+      "/user/createWithArray": {
+        post: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["createUsersWithArrayInput"];
+      };
+      "/user/createWithList": {
+        post: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["createUsersWithListInput"];
+      };
+      "/user/login": {
+        get: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["loginUser"];
+      };
+      "/user/logout": {
+        get: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["logoutUser"];
+      };
+      "/user/{username}": {
+        get: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["getUserByName"];
+        /** This can only be done by the logged in user. */
+        put: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["updateUser"];
+        /** This can only be done by the logged in user. */
+        delete: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["operations"]["deleteUser"];
+      };
+    };
+    components: {
+      schemas: {
+        Order: {
+          id?: number;
+          petId?: number;
+          quantity?: number;
+          shipDate?: string;
+          /** Order Status */
+          status?: "placed" | "approved" | "delivered";
+          complete?: boolean;
+        };
+        Category: {
+          id?: number;
+          name?: string;
+        };
+        User: {
+          id?: number;
+          username?: string;
+          firstName?: string;
+          lastName?: string;
+          email?: string;
+          password?: string;
+          phone?: string;
+          /** User Status */
+          userStatus?: number;
+        };
+        Tag: {
+          id?: number;
+          name?: string;
+        };
+        Pet: {
+          id?: number;
+          category?: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Category"];
+          name: string;
+          photoUrls: string[];
+          tags?: external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Tag"][];
+          /** pet status in the store */
+          status?: "available" | "pending" | "sold";
+        };
+        ApiResponse: {
+          code?: number;
+          type?: string;
+          message?: string;
+        };
+      };
+    };
+    operations: {
+      updatePet: {
+        responses: {
+          /** Invalid ID supplied */
+          400: unknown;
+          /** Pet not found */
+          404: unknown;
+          /** Validation exception */
+          405: unknown;
+        };
+        /** Pet object that needs to be added to the store */
+        requestBody: {
+          content: {
+            "application/json": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Pet"];
+            "application/xml": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Pet"];
+          };
+        };
+      };
+      addPet: {
+        responses: {
+          /** Invalid input */
+          405: unknown;
+        };
+        /** Pet object that needs to be added to the store */
+        requestBody: {
+          content: {
+            "application/json": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Pet"];
+            "application/xml": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Pet"];
+          };
+        };
+      };
+      /** Multiple status values can be provided with comma separated strings */
+      findPetsByStatus: {
+        parameters: {
+          query: {
+            /** Status values that need to be considered for filter */
+            status: ("available" | "pending" | "sold")[];
+          };
+        };
+        responses: {
+          /** successful operation */
+          200: {
+            content: {
+              "application/xml": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Pet"][];
+              "application/json": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Pet"][];
+            };
+          };
+          /** Invalid status value */
+          400: unknown;
+        };
+      };
+      /** Muliple tags can be provided with comma separated strings. Use         tag1, tag2, tag3 for testing. */
+      findPetsByTags: {
+        parameters: {
+          query: {
+            /** Tags to filter by */
+            tags: string[];
+          };
+        };
+        responses: {
+          /** successful operation */
+          200: {
+            content: {
+              "application/xml": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Pet"][];
+              "application/json": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Pet"][];
+            };
+          };
+          /** Invalid tag value */
+          400: unknown;
+        };
+      };
+      /** Returns a single pet */
+      getPetById: {
+        parameters: {
+          path: {
+            /** ID of pet to return */
+            petId: number;
+          };
+        };
+        responses: {
+          /** successful operation */
+          200: {
+            content: {
+              "application/xml": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Pet"];
+              "application/json": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Pet"];
+            };
+          };
+          /** Invalid ID supplied */
+          400: unknown;
+          /** Pet not found */
+          404: unknown;
+        };
+      };
+      updatePetWithForm: {
+        parameters: {
+          path: {
+            /** ID of pet that needs to be updated */
+            petId: number;
+          };
+        };
+        responses: {
+          /** Invalid input */
+          405: unknown;
+        };
+        requestBody: {
+          content: {
+            "application/x-www-form-urlencoded": {
+              /** Updated name of the pet */
+              name?: string;
+              /** Updated status of the pet */
+              status?: string;
+            };
+          };
+        };
+      };
+      deletePet: {
+        parameters: {
+          header: {
+            api_key?: string;
+          };
+          path: {
+            /** Pet id to delete */
+            petId: number;
+          };
+        };
+        responses: {
+          /** Invalid ID supplied */
+          400: unknown;
+          /** Pet not found */
+          404: unknown;
+        };
+      };
+      uploadFile: {
+        parameters: {
+          path: {
+            /** ID of pet to update */
+            petId: number;
+          };
+        };
+        responses: {
+          /** successful operation */
+          200: {
+            content: {
+              "application/json": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["ApiResponse"];
+            };
+          };
+        };
+        requestBody: {
+          content: {
+            "multipart/form-data": {
+              /** Additional data to pass to server */
+              additionalMetadata?: string;
+              /** file to upload */
+              file?: string;
+            };
+          };
+        };
+      };
+      /** Returns a map of status codes to quantities */
+      getInventory: {
+        responses: {
+          /** successful operation */
+          200: {
+            content: {
+              "application/json": { [key: string]: number };
+            };
+          };
+        };
+      };
+      placeOrder: {
+        responses: {
+          /** successful operation */
+          200: {
+            content: {
+              "application/xml": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Order"];
+              "application/json": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Order"];
+            };
+          };
+          /** Invalid Order */
+          400: unknown;
+        };
+        /** order placed for purchasing the pet */
+        requestBody: {
+          content: {
+            "*/*": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Order"];
+          };
+        };
+      };
+      /** For valid response try integer IDs with value >= 1 and <= 10.         Other values will generated exceptions */
+      getOrderById: {
+        parameters: {
+          path: {
+            /** ID of pet that needs to be fetched */
+            orderId: number;
+          };
+        };
+        responses: {
+          /** successful operation */
+          200: {
+            content: {
+              "application/xml": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Order"];
+              "application/json": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["Order"];
+            };
+          };
+          /** Invalid ID supplied */
+          400: unknown;
+          /** Order not found */
+          404: unknown;
+        };
+      };
+      /** For valid response try integer IDs with positive integer value.         Negative or non-integer values will generate API errors */
+      deleteOrder: {
+        parameters: {
+          path: {
+            /** ID of the order that needs to be deleted */
+            orderId: number;
+          };
+        };
+        responses: {
+          /** Invalid ID supplied */
+          400: unknown;
+          /** Order not found */
+          404: unknown;
+        };
+      };
+      /** This can only be done by the logged in user. */
+      createUser: {
+        responses: {
+          /** successful operation */
+          default: unknown;
+        };
+        /** Created user object */
+        requestBody: {
+          content: {
+            "*/*": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["User"];
+          };
+        };
+      };
+      createUsersWithArrayInput: {
+        responses: {
+          /** successful operation */
+          default: unknown;
+        };
+        /** List of user object */
+        requestBody: {
+          content: {
+            "*/*": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["User"][];
+          };
+        };
+      };
+      createUsersWithListInput: {
+        responses: {
+          /** successful operation */
+          default: unknown;
+        };
+        /** List of user object */
+        requestBody: {
+          content: {
+            "*/*": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["User"][];
+          };
+        };
+      };
+      loginUser: {
+        parameters: {
+          query: {
+            /** The user name for login */
+            username: string;
+            /** The password for login in clear text */
+            password: string;
+          };
+        };
+        responses: {
+          /** successful operation */
+          200: {
+            headers: {
+              /** calls per hour allowed by the user */
+              "X-Rate-Limit"?: number;
+              /** date in UTC when token expires */
+              "X-Expires-After"?: string;
+            };
+            content: {
+              "application/xml": string;
+              "application/json": string;
+            };
+          };
+          /** Invalid username/password supplied */
+          400: unknown;
+        };
+      };
+      logoutUser: {
+        responses: {
+          /** successful operation */
+          default: unknown;
+        };
+      };
+      getUserByName: {
+        parameters: {
+          path: {
+            /** The name that needs to be fetched. Use user1 for testing. */
+            username: string;
+          };
+        };
+        responses: {
+          /** successful operation */
+          200: {
+            content: {
+              "application/xml": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["User"];
+              "application/json": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["User"];
+            };
+          };
+          /** Invalid username supplied */
+          400: unknown;
+          /** User not found */
+          404: unknown;
+        };
+      };
+      /** This can only be done by the logged in user. */
+      updateUser: {
+        parameters: {
+          path: {
+            /** name that need to be updated */
+            username: string;
+          };
+        };
+        responses: {
+          /** Invalid user supplied */
+          400: unknown;
+          /** User not found */
+          404: unknown;
+        };
+        /** Updated user object */
+        requestBody: {
+          content: {
+            "*/*": external["https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml"]["components"]["schemas"]["User"];
+          };
+        };
+      };
+      /** This can only be done by the logged in user. */
+      deleteUser: {
+        parameters: {
+          path: {
+            /** The name that needs to be deleted */
+            username: string;
+          };
+        };
+        responses: {
+          /** Invalid username supplied */
+          400: unknown;
+          /** User not found */
+          404: unknown;
+        };
+      };
+    };
+  };
+  "subschema/remote1.yml": {
+    paths: {};
+    components: {
+      schemas: {
+        /** this is a duplicate of spec.yml#components/schemas/Remote1 */
+        Remote1: string;
+        Remote2: external["subschema/remote2.yml"]["components"]["schemas"]["Remote2"];
+        Circular: components["schemas"]["Circular"];
+      };
+    };
+    operations: {};
+  };
+  "subschema/remote2.yml": {
+    paths: {};
+    components: {
+      schemas: {
+        Remote2: string;
+      };
+    };
+    operations: {};
+  };
+}
+`);
+  });
+});
diff --git a/tests/remote-schema/spec/spec.yml b/tests/remote-schema/spec/spec.yml
new file mode 100644
index 000000000..20b960c88
--- /dev/null
+++ b/tests/remote-schema/spec/spec.yml
@@ -0,0 +1,10 @@
+openapi: 3.1.0
+components:
+  schemas:
+    Circular:
+      description: this is a duplicate of subschema/remote1.yml
+      type: string
+    Remote1:
+      $ref: "./subschema/remote1.yml#components/schemas/Remote1"
+    Pet:
+      $ref: "https://raw.githubusercontent.com/drwpow/openapi-typescript/main/tests/v3/specs/petstore.yaml#components/schemas/Pet"
diff --git a/tests/remote-schema/spec/subschema/remote1.yml b/tests/remote-schema/spec/subschema/remote1.yml
new file mode 100644
index 000000000..af31b6087
--- /dev/null
+++ b/tests/remote-schema/spec/subschema/remote1.yml
@@ -0,0 +1,10 @@
+openapi: 3.1.0
+components:
+  schemas:
+    Remote1:
+      description: this is a duplicate of spec.yml#components/schemas/Remote1
+      type: string
+    Remote2:
+      $ref: "./remote2.yml#components/schemas/Remote2"
+    Circular:
+      $ref: "../spec.yml#components/schemas/Circular"
diff --git a/tests/remote-schema/spec/subschema/remote2.yml b/tests/remote-schema/spec/subschema/remote2.yml
new file mode 100644
index 000000000..2b7a00843
--- /dev/null
+++ b/tests/remote-schema/spec/subschema/remote2.yml
@@ -0,0 +1,5 @@
+openapi: 3.1.0
+components:
+  schemas:
+    Remote2:
+      type: string
diff --git a/tests/schema.test.ts b/tests/schema.test.ts
index b0a0c7506..80d7b9140 100644
--- a/tests/schema.test.ts
+++ b/tests/schema.test.ts
@@ -35,7 +35,7 @@ describe("SchemaObject", () => {
       type: "object",
       properties: {
         object: {
-          properties: { string: { type: "string" }, number: { $ref: "#/components/schemas/object_ref" } },
+          properties: { string: { type: "string" }, number: { $ref: 'components["schemas"]["object_ref"]' } },
           type: "object",
         },
       },
@@ -99,12 +99,12 @@ describe("SchemaObject", () => {
       );
 
       // $ref
-      expect(transform({ type: "array", items: { $ref: "#/components/schemas/ArrayItem" } }, { ...defaults })).toBe(
+      expect(transform({ type: "array", items: { $ref: 'components["schemas"]["ArrayItem"]' } }, { ...defaults })).toBe(
         `(components["schemas"]["ArrayItem"])[]`
       );
 
       // inferred
-      expect(transform({ items: { $ref: "#/components/schemas/ArrayItem" } }, { ...defaults })).toBe(
+      expect(transform({ items: { $ref: 'components["schemas"]["ArrayItem"]' } }, { ...defaults })).toBe(
         `(components["schemas"]["ArrayItem"])[]`
       );
 
@@ -134,10 +134,10 @@ describe("SchemaObject", () => {
       expect(transform({ type: "array", items: { enum: ["chocolate", "vanilla"] } }, opts)).toBe(
         `readonly (('chocolate') | ('vanilla'))[]`
       );
-      expect(transform({ type: "array", items: { $ref: "#/components/schemas/ArrayItem" } }, opts)).toBe(
+      expect(transform({ type: "array", items: { $ref: 'components["schemas"]["ArrayItem"]' } }, opts)).toBe(
         `readonly (components["schemas"]["ArrayItem"])[]`
       );
-      expect(transform({ items: { $ref: "#/components/schemas/ArrayItem" } }, opts)).toBe(
+      expect(transform({ items: { $ref: 'components["schemas"]["ArrayItem"]' } }, opts)).toBe(
         `readonly (components["schemas"]["ArrayItem"])[]`
       );
       expect(transform({ type: "array", items: { type: "string" }, nullable: true }, opts)).toBe(
@@ -205,15 +205,10 @@ describe("SchemaObject", () => {
     });
 
     it("$ref", () => {
-      expect(transform({ $ref: "#/components/parameters/ReferenceObject" }, { ...defaults })).toBe(
+      expect(transform({ $ref: 'components["parameters"]["ReferenceObject"]' }, { ...defaults })).toBe(
         `components["parameters"]["ReferenceObject"]`
       );
     });
-
-    // TODO: allow import later
-    it("$ref (external)", () => {
-      expect(transform({ $ref: "./external.yaml" }, { ...defaults })).toBe(`any`);
-    });
   });
 
   describe("advanced", () => {
@@ -230,7 +225,7 @@ describe("SchemaObject", () => {
       );
 
       // $ref
-      expect(transform({ additionalProperties: { $ref: "#/definitions/Message" } }, { ...defaults })).toBe(
+      expect(transform({ additionalProperties: { $ref: 'definitions["Message"]' } }, { ...defaults })).toBe(
         `{ [key: string]: definitions["Message"]; }`
       );
     });
@@ -240,7 +235,7 @@ describe("SchemaObject", () => {
         transform(
           {
             allOf: [
-              { $ref: "#/components/schemas/base" },
+              { $ref: 'components["schemas"]["base"]' },
               { properties: { string: { type: "string" } }, type: "object" },
             ],
             properties: { password: { type: "string" } },
@@ -256,9 +251,9 @@ describe("SchemaObject", () => {
         transform(
           {
             anyOf: [
-              { $ref: "#/components/schemas/StringType" },
-              { $ref: "#/components/schemas/NumberType" },
-              { $ref: "#/components/schemas/BooleanType" },
+              { $ref: 'components["schemas"]["StringType"]' },
+              { $ref: 'components["schemas"]["NumberType"]' },
+              { $ref: 'components["schemas"]["BooleanType"]' },
             ],
           },
           { ...defaults }
@@ -272,7 +267,7 @@ describe("SchemaObject", () => {
       // standard
       expect(
         transform(
-          { oneOf: [{ type: "string" }, { type: "number" }, { $ref: "#/components/schemas/one_of_ref" }] },
+          { oneOf: [{ type: "string" }, { type: "number" }, { $ref: 'components["schemas"]["one_of_ref"]' }] },
           { ...defaults }
         )
       ).toBe(`(string) | (number) | (components["schemas"]["one_of_ref"])`);
diff --git a/tests/v2/expected/http.ts b/tests/v2/expected/http.ts
index 821bda220..41eb3b0d0 100644
--- a/tests/v2/expected/http.ts
+++ b/tests/v2/expected/http.ts
@@ -1008,3 +1008,5 @@ export interface parameters {
 }
 
 export interface operations {}
+
+export interface external {}
diff --git a/tests/v2/expected/manifold.immutable.ts b/tests/v2/expected/manifold.immutable.ts
index d1861c25c..e212726af 100644
--- a/tests/v2/expected/manifold.immutable.ts
+++ b/tests/v2/expected/manifold.immutable.ts
@@ -1008,3 +1008,5 @@ export interface parameters {
 }
 
 export interface operations {}
+
+export interface external {}
diff --git a/tests/v2/expected/manifold.ts b/tests/v2/expected/manifold.ts
index 821bda220..41eb3b0d0 100644
--- a/tests/v2/expected/manifold.ts
+++ b/tests/v2/expected/manifold.ts
@@ -1008,3 +1008,5 @@ export interface parameters {
 }
 
 export interface operations {}
+
+export interface external {}
diff --git a/tests/v2/expected/null-in-enum.immutable.ts b/tests/v2/expected/null-in-enum.immutable.ts
index fa8369306..90e19f228 100644
--- a/tests/v2/expected/null-in-enum.immutable.ts
+++ b/tests/v2/expected/null-in-enum.immutable.ts
@@ -36,3 +36,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v2/expected/null-in-enum.ts b/tests/v2/expected/null-in-enum.ts
index c45e97102..c68291f5e 100644
--- a/tests/v2/expected/null-in-enum.ts
+++ b/tests/v2/expected/null-in-enum.ts
@@ -36,3 +36,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v2/expected/petstore.immutable.ts b/tests/v2/expected/petstore.immutable.ts
index 27b5d502c..e15f6a629 100644
--- a/tests/v2/expected/petstore.immutable.ts
+++ b/tests/v2/expected/petstore.immutable.ts
@@ -421,3 +421,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v2/expected/petstore.ts b/tests/v2/expected/petstore.ts
index 25907ad8a..da09e750f 100644
--- a/tests/v2/expected/petstore.ts
+++ b/tests/v2/expected/petstore.ts
@@ -421,3 +421,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v2/expected/stripe.immutable.ts b/tests/v2/expected/stripe.immutable.ts
index 90e6a68e1..e7795258f 100644
--- a/tests/v2/expected/stripe.immutable.ts
+++ b/tests/v2/expected/stripe.immutable.ts
@@ -27435,3 +27435,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v2/expected/stripe.ts b/tests/v2/expected/stripe.ts
index e7306c4be..7d1d87ce0 100644
--- a/tests/v2/expected/stripe.ts
+++ b/tests/v2/expected/stripe.ts
@@ -27402,3 +27402,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v3/expected/github.additional.ts b/tests/v3/expected/github.additional.ts
index db97aa21d..43fc5518c 100644
--- a/tests/v3/expected/github.additional.ts
+++ b/tests/v3/expected/github.additional.ts
@@ -31282,3 +31282,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v3/expected/github.immutable.ts b/tests/v3/expected/github.immutable.ts
index 5d18a1e34..27d3d2fa8 100644
--- a/tests/v3/expected/github.immutable.ts
+++ b/tests/v3/expected/github.immutable.ts
@@ -31221,3 +31221,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v3/expected/github.ts b/tests/v3/expected/github.ts
index 1e8e3892d..61798a50e 100644
--- a/tests/v3/expected/github.ts
+++ b/tests/v3/expected/github.ts
@@ -31216,3 +31216,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v3/expected/http.ts b/tests/v3/expected/http.ts
index d133f154c..fc73734c7 100644
--- a/tests/v3/expected/http.ts
+++ b/tests/v3/expected/http.ts
@@ -1145,3 +1145,5 @@ export interface components {
 }
 
 export interface operations {}
+
+export interface external {}
diff --git a/tests/v3/expected/manifold.additional.ts b/tests/v3/expected/manifold.additional.ts
index 135358b63..174ab51f3 100644
--- a/tests/v3/expected/manifold.additional.ts
+++ b/tests/v3/expected/manifold.additional.ts
@@ -1151,3 +1151,5 @@ export interface components {
 }
 
 export interface operations {}
+
+export interface external {}
diff --git a/tests/v3/expected/manifold.immutable.ts b/tests/v3/expected/manifold.immutable.ts
index f4a54add4..9a6af9045 100644
--- a/tests/v3/expected/manifold.immutable.ts
+++ b/tests/v3/expected/manifold.immutable.ts
@@ -1145,3 +1145,5 @@ export interface components {
 }
 
 export interface operations {}
+
+export interface external {}
diff --git a/tests/v3/expected/manifold.ts b/tests/v3/expected/manifold.ts
index d133f154c..fc73734c7 100644
--- a/tests/v3/expected/manifold.ts
+++ b/tests/v3/expected/manifold.ts
@@ -1145,3 +1145,5 @@ export interface components {
 }
 
 export interface operations {}
+
+export interface external {}
diff --git a/tests/v3/expected/null-in-enum.additional.ts b/tests/v3/expected/null-in-enum.additional.ts
index 1f18e072b..9d5f87fc5 100644
--- a/tests/v3/expected/null-in-enum.additional.ts
+++ b/tests/v3/expected/null-in-enum.additional.ts
@@ -36,3 +36,5 @@ export interface components {
 }
 
 export interface operations {}
+
+export interface external {}
diff --git a/tests/v3/expected/null-in-enum.immutable.ts b/tests/v3/expected/null-in-enum.immutable.ts
index cce6a886e..929c981d0 100644
--- a/tests/v3/expected/null-in-enum.immutable.ts
+++ b/tests/v3/expected/null-in-enum.immutable.ts
@@ -36,3 +36,5 @@ export interface components {
 }
 
 export interface operations {}
+
+export interface external {}
diff --git a/tests/v3/expected/null-in-enum.ts b/tests/v3/expected/null-in-enum.ts
index 5e162ed60..2ecf336bf 100644
--- a/tests/v3/expected/null-in-enum.ts
+++ b/tests/v3/expected/null-in-enum.ts
@@ -36,3 +36,5 @@ export interface components {
 }
 
 export interface operations {}
+
+export interface external {}
diff --git a/tests/v3/expected/petstore-openapitools.additional.ts b/tests/v3/expected/petstore-openapitools.additional.ts
index c4050a457..0c41353d5 100644
--- a/tests/v3/expected/petstore-openapitools.additional.ts
+++ b/tests/v3/expected/petstore-openapitools.additional.ts
@@ -476,3 +476,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v3/expected/petstore-openapitools.immutable.ts b/tests/v3/expected/petstore-openapitools.immutable.ts
index a3af49f30..9a7133970 100644
--- a/tests/v3/expected/petstore-openapitools.immutable.ts
+++ b/tests/v3/expected/petstore-openapitools.immutable.ts
@@ -476,3 +476,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v3/expected/petstore-openapitools.ts b/tests/v3/expected/petstore-openapitools.ts
index 26fc4794b..4c18dac6f 100644
--- a/tests/v3/expected/petstore-openapitools.ts
+++ b/tests/v3/expected/petstore-openapitools.ts
@@ -476,3 +476,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v3/expected/petstore.additional.ts b/tests/v3/expected/petstore.additional.ts
index 59460406a..c0635c287 100644
--- a/tests/v3/expected/petstore.additional.ts
+++ b/tests/v3/expected/petstore.additional.ts
@@ -463,3 +463,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v3/expected/petstore.immutable.ts b/tests/v3/expected/petstore.immutable.ts
index b4367c609..5e095a3fa 100644
--- a/tests/v3/expected/petstore.immutable.ts
+++ b/tests/v3/expected/petstore.immutable.ts
@@ -463,3 +463,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v3/expected/petstore.ts b/tests/v3/expected/petstore.ts
index 756d358ac..152806e25 100644
--- a/tests/v3/expected/petstore.ts
+++ b/tests/v3/expected/petstore.ts
@@ -463,3 +463,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v3/expected/stripe.additional.ts b/tests/v3/expected/stripe.additional.ts
index 68cf15715..78c565ea9 100644
--- a/tests/v3/expected/stripe.additional.ts
+++ b/tests/v3/expected/stripe.additional.ts
@@ -31339,3 +31339,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v3/expected/stripe.immutable.ts b/tests/v3/expected/stripe.immutable.ts
index 9ea5ab877..1d4653648 100644
--- a/tests/v3/expected/stripe.immutable.ts
+++ b/tests/v3/expected/stripe.immutable.ts
@@ -30969,3 +30969,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}
diff --git a/tests/v3/expected/stripe.ts b/tests/v3/expected/stripe.ts
index 8461aba6e..93186a7bd 100644
--- a/tests/v3/expected/stripe.ts
+++ b/tests/v3/expected/stripe.ts
@@ -30920,3 +30920,5 @@ export interface operations {
     };
   };
 }
+
+export interface external {}