diff --git a/.eslintignore b/.eslintignore
index 4e982747..25d162b6 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -1,5 +1,6 @@
 # unconventional js
 /blueprints/*/files/
+**/*.d.ts
 
 # compiled output
 /dist/
diff --git a/.eslintrc.cjs b/.eslintrc.cjs
index 136bbaba..3003166b 100644
--- a/.eslintrc.cjs
+++ b/.eslintrc.cjs
@@ -12,6 +12,7 @@ module.exports = {
       parserOptions: {
         ecmaVersion: 'latest',
         sourceType: 'module',
+        requireConfigFile: false,
         babelOptions: {
           root: __dirname,
         },
diff --git a/package.json b/package.json
index aa90abe0..fe34b028 100644
--- a/package.json
+++ b/package.json
@@ -12,6 +12,10 @@
       "types": "./src/index.d.ts",
       "default": "./src/index.js"
     },
+    "./*": {
+      "types": "./src/*.d.ts",
+      "default": "./src/*.js"
+    },
     "./addon-main.js": "./addon-main.cjs"
   },
   "files": [
@@ -26,6 +30,7 @@
     "start": "rollup --config --watch"
   },
   "dependencies": {
+    "@ember/test-waiters": "^3.1.0",
     "@embroider/addon-shim": "^1.8.7"
   },
   "devDependencies": {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 3fa984e4..154827cc 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -8,6 +8,9 @@ importers:
 
   .:
     dependencies:
+      '@ember/test-waiters':
+        specifier: ^3.1.0
+        version: 3.1.0
       '@embroider/addon-shim':
         specifier: ^1.8.7
         version: 1.9.0
diff --git a/src/errors.d.ts b/src/errors.d.ts
new file mode 100644
index 00000000..fd05e214
--- /dev/null
+++ b/src/errors.d.ts
@@ -0,0 +1,44 @@
+/**
+ * Checks if the given response represents an unauthorized request error
+ */
+export function isUnauthorizedResponse(response: Response): boolean;
+
+/**
+ * Checks if the given response represents a forbidden request error
+ */
+export function isForbiddenResponse(response: Response): boolean;
+
+/**
+ * Checks if the given response represents an invalid request error
+ */
+export function isInvalidResponse(response: Response): boolean;
+
+/**
+ * Checks if the given response represents a bad request error
+ */
+export function isBadRequestResponse(response: Response): boolean;
+
+/**
+ * Checks if the given response represents a "not found" error
+ */
+export function isNotFoundResponse(response: Response): boolean;
+
+/**
+ * Checks if the given response represents a "gone" error
+ */
+export function isGoneResponse(response: Response): boolean;
+
+/**
+ * Checks if the given error is an "abort" error
+ */
+export function isAbortError(error: DOMException): boolean;
+
+/**
+ * Checks if the given response represents a conflict error
+ */
+export function isConflictResponse(response: Response): boolean;
+
+/**
+ * Checks if the given response represents a server error
+ */
+export function isServerErrorResponse(response: Response): boolean;
diff --git a/src/errors.js b/src/errors.js
new file mode 100644
index 00000000..cb85c7e8
--- /dev/null
+++ b/src/errors.js
@@ -0,0 +1,35 @@
+export function isUnauthorizedResponse(response) {
+  return response.status === 401;
+}
+
+export function isForbiddenResponse(response) {
+  return response.status === 403;
+}
+
+export function isInvalidResponse(response) {
+  return response.status === 422;
+}
+
+export function isBadRequestResponse(response) {
+  return response.status === 400;
+}
+
+export function isNotFoundResponse(response) {
+  return response.status === 404;
+}
+
+export function isGoneResponse(response) {
+  return response.status === 410;
+}
+
+export function isAbortError(error) {
+  return error.name == 'AbortError';
+}
+
+export function isConflictResponse(response) {
+  return response.status === 409;
+}
+
+export function isServerErrorResponse(response) {
+  return response.status >= 500 && response.status < 600;
+}
diff --git a/src/utils/serialize-query-params.d.ts b/src/utils/serialize-query-params.d.ts
new file mode 100644
index 00000000..687282e4
--- /dev/null
+++ b/src/utils/serialize-query-params.d.ts
@@ -0,0 +1,9 @@
+/**
+ * Helper function that turns the data/body of a request into a query param string.
+ * This is directly copied from jQuery.param.
+ */
+export function serializeQueryParams(
+  queryParamsObject: object | string,
+): string;
+
+export default serializeQueryParams;
diff --git a/src/utils/serialize-query-params.js b/src/utils/serialize-query-params.js
new file mode 100644
index 00000000..bf046221
--- /dev/null
+++ b/src/utils/serialize-query-params.js
@@ -0,0 +1,67 @@
+const RBRACKET = /\[\]$/;
+
+function isPlainObject(obj) {
+  return Object.prototype.toString.call(obj) === '[object Object]';
+}
+
+/**
+ * Helper function that turns the data/body of a request into a query param string.
+ * This is directly copied from jQuery.param.
+ */
+export function serializeQueryParams(queryParamsObject) {
+  var s = [];
+
+  function buildParams(prefix, obj) {
+    var i, len, key;
+
+    if (prefix) {
+      if (Array.isArray(obj)) {
+        for (i = 0, len = obj.length; i < len; i++) {
+          if (RBRACKET.test(prefix)) {
+            add(s, prefix, obj[i]);
+          } else {
+            buildParams(
+              prefix + '[' + (typeof obj[i] === 'object' ? i : '') + ']',
+              obj[i],
+            );
+          }
+        }
+      } else if (isPlainObject(obj)) {
+        for (key in obj) {
+          buildParams(prefix + '[' + key + ']', obj[key]);
+        }
+      } else {
+        add(s, prefix, obj);
+      }
+    } else if (Array.isArray(obj)) {
+      for (i = 0, len = obj.length; i < len; i++) {
+        add(s, obj[i].name, obj[i].value);
+      }
+    } else {
+      for (key in obj) {
+        buildParams(key, obj[key]);
+      }
+    }
+    return s;
+  }
+
+  return buildParams('', queryParamsObject).join('&').replace(/%20/g, '+');
+}
+
+/**
+ * Part of the `serializeQueryParams` helper function.
+ */
+function add(s, k, v) {
+  // Strip out keys with undefined value and replace null values with
+  // empty strings (mimics jQuery.ajax)
+  if (v === undefined) {
+    return;
+  } else if (v === null) {
+    v = '';
+  }
+
+  v = typeof v === 'function' ? v() : v;
+  s[s.length] = `${encodeURIComponent(k)}=${encodeURIComponent(v)}`;
+}
+
+export default serializeQueryParams;