diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0af6043..530f8b9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # deverything
 
+## 0.43.0
+
+### Minor Changes
+
+- add 3rd party helpers (no deps)
+
 ## 0.42.2
 
 ### Patch Changes
diff --git a/package.json b/package.json
index 4f4c523..6ccfa4e 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "deverything",
-  "version": "0.42.2",
+  "version": "0.43.0",
   "description": "Everything you need for Dev",
   "main": "./dist/index.js",
   "module": "./dist/index.mjs",
diff --git a/src/helpers/cyclicalItem.test.ts b/src/helpers/cyclicalItem.test.ts
new file mode 100644
index 0000000..c4d77d2
--- /dev/null
+++ b/src/helpers/cyclicalItem.test.ts
@@ -0,0 +1,21 @@
+import { describe, expect, test } from "@jest/globals";
+import { cyclicalItem } from "./cyclicalItem";
+
+describe("cyclicalItem", () => {
+  test("works", async () => {
+    expect(cyclicalItem([], 0)).toBe(undefined);
+    expect(cyclicalItem([], 1)).toBe(undefined);
+  });
+
+  test("works", async () => {
+    expect(cyclicalItem([1], 0)).toBe(1);
+    expect(cyclicalItem([1], 1)).toBe(1);
+  });
+
+  test("works", async () => {
+    expect(cyclicalItem([1, 2, 3], 0)).toBe(1);
+    expect(cyclicalItem([1, 2, 3], 2)).toBe(3);
+    expect(cyclicalItem([1, 2, 3], 3)).toBe(1);
+    expect(cyclicalItem([1, 2, 3], 30)).toBe(1);
+  });
+});
diff --git a/src/helpers/cyclicalItem.ts b/src/helpers/cyclicalItem.ts
new file mode 100644
index 0000000..3025d6f
--- /dev/null
+++ b/src/helpers/cyclicalItem.ts
@@ -0,0 +1,6 @@
+/**
+ * @returns element from array at index, if index is greater than array length, it will loop back to the start of the array
+ */
+export const cyclicalItem = <T>(array: T[], index: number): T => {
+  return array[index % array.length];
+};
diff --git a/src/helpers/firstKey.ts b/src/helpers/firstKey.ts
index fece476..7c97a5d 100644
--- a/src/helpers/firstKey.ts
+++ b/src/helpers/firstKey.ts
@@ -1,4 +1,5 @@
-import { PlainObject } from "../types";
+import { ObjectKey, PlainObject } from "../types";
 import { getKeys } from "./getKeys";
 
-export const firstKey = (arg: PlainObject): string => getKeys(arg)[0];
+export const firstKey = <T extends PlainObject>(arg: T): ObjectKey<T> =>
+  getKeys(arg)[0];
diff --git a/src/helpers/firstValue.ts b/src/helpers/firstValue.ts
index ffb673e..65cf650 100644
--- a/src/helpers/firstValue.ts
+++ b/src/helpers/firstValue.ts
@@ -1,3 +1,4 @@
-import { PlainObject } from "../types";
+import { ObjectValue, PlainObject } from "../types";
 
-export const firstValue = (arg: PlainObject): any => Object.values(arg)[0];
+export const firstValue = <T extends PlainObject>(arg: T): ObjectValue<T> =>
+  Object.values(arg)[0];
diff --git a/src/helpers/getKeys.test.ts b/src/helpers/getKeys.test.ts
index 3f62e56..ba9e081 100644
--- a/src/helpers/getKeys.test.ts
+++ b/src/helpers/getKeys.test.ts
@@ -2,16 +2,12 @@ import { describe, expect, test } from "@jest/globals";
 import { getKeys } from "./getKeys";
 
 describe("getKeys", () => {
-  test("{}", async () => {
+  test("constructors", async () => {
     expect(getKeys(new Date())).toStrictEqual([]);
-    expect(getKeys(Date)).toStrictEqual([]);
-    expect(getKeys(Function)).toStrictEqual([]);
-    expect(getKeys(new Function())).toStrictEqual([]);
     expect(getKeys(new Object())).toStrictEqual([]);
-    expect(getKeys(new Array())).toStrictEqual([]);
   });
 
-  test("keys", async () => {
+  test("objects", async () => {
     expect(getKeys({ a: 1, b: 2 })).toStrictEqual(["a", "b"]);
     expect(getKeys({ [Symbol.for("1")]: 1, b: 2 })).toStrictEqual([
       "b",
diff --git a/src/helpers/getKeys.ts b/src/helpers/getKeys.ts
index 9e43566..4965414 100644
--- a/src/helpers/getKeys.ts
+++ b/src/helpers/getKeys.ts
@@ -1,12 +1,14 @@
-export const getKeys = (arg: object) => {
-  return Object.keys(arg).concat(getEnumerableOwnPropertySymbols(arg));
+import { ObjectKeys, PlainObject } from "../types";
+
+export const getKeys = <T extends PlainObject>(obj: T): ObjectKeys<T> => {
+  return Object.keys(obj).concat(getEnumerableOwnPropertySymbols(obj));
 };
 
 // Object.keys does not return enumerable symbols
-export const getEnumerableOwnPropertySymbols = (arg: object): any[] => {
+export const getEnumerableOwnPropertySymbols = (obj: object): any[] => {
   return Object.getOwnPropertySymbols
-    ? Object.getOwnPropertySymbols(arg).filter(function (symbol) {
-        return Object.propertyIsEnumerable.call(arg, symbol);
+    ? Object.getOwnPropertySymbols(obj).filter(function (symbol) {
+        return Object.propertyIsEnumerable.call(obj, symbol);
       })
     : [];
 };
diff --git a/src/helpers/index.ts b/src/helpers/index.ts
index 9efcc06..7b9ca13 100644
--- a/src/helpers/index.ts
+++ b/src/helpers/index.ts
@@ -4,6 +4,7 @@ export * from "./arrayIntersection";
 export * from "./capitalize";
 export * from "./clamp";
 export * from "./cleanSpaces";
+export * from "./cyclicalItem";
 export * from "./dir";
 export * from "./enumKeys";
 export * from "./enumValues";
@@ -18,6 +19,7 @@ export * from "./keysLength";
 export * from "./last";
 export * from "./lastIndex";
 export * from "./merge";
+export * from "./mergeArrays";
 export * from "./moveToFirst";
 export * from "./moveToLast";
 export * from "./normalizeNumber";
diff --git a/src/helpers/mergeArrays.test.ts b/src/helpers/mergeArrays.test.ts
new file mode 100644
index 0000000..bc1d489
--- /dev/null
+++ b/src/helpers/mergeArrays.test.ts
@@ -0,0 +1,13 @@
+import { describe, expect, test } from "@jest/globals";
+import { mergeArrays } from "./mergeArrays";
+
+describe("mergeArrays", () => {
+  test("array", async () => {
+    expect(mergeArrays([], [])).toStrictEqual([]);
+    expect(mergeArrays([1, 2, 3], [1])).toStrictEqual([1, 2, 3]);
+    expect(mergeArrays([1, 2, 3, 3], [1, 3])).toStrictEqual([1, 2, 3, 3]);
+    expect(mergeArrays([1, 2, 3, 3], [1, 3, 4, 4])).toStrictEqual([
+      1, 2, 3, 3, 4, 4,
+    ]);
+  });
+});
diff --git a/src/helpers/mergeArrays.ts b/src/helpers/mergeArrays.ts
new file mode 100644
index 0000000..275cbe4
--- /dev/null
+++ b/src/helpers/mergeArrays.ts
@@ -0,0 +1,11 @@
+/**
+ * @description Merge two arrays, unique values, no options
+ * @example mergeArrays([1,2,3], [2,3,4]) => [1,2,3,4]
+ */
+export const mergeArrays = (arrayA: any[], arrayB: any[]) => {
+  return arrayA.concat(
+    arrayB.filter((item) => {
+      return !arrayA.includes(item); // TODO: use isSame for objects
+    })
+  );
+};
diff --git a/src/index.ts b/src/index.ts
index a79f0c5..742819e 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,7 +1,9 @@
 export * from "./checks";
+export * from "./formatters";
 export * from "./helpers";
 export * from "./math";
+export * from "./prisma";
 export * from "./random";
+export * from "./trpc";
 export * from "./types";
 export * from "./validators";
-export * from "./formatters";
diff --git a/src/math/index.ts b/src/math/index.ts
index c56f936..3ce5728 100644
--- a/src/math/index.ts
+++ b/src/math/index.ts
@@ -2,4 +2,5 @@ export * from "./average";
 export * from "./max";
 export * from "./min";
 export * from "./multiply";
+export * from "./percentageChange";
 export * from "./sum";
diff --git a/src/math/percentageChange.test.ts b/src/math/percentageChange.test.ts
new file mode 100644
index 0000000..8771ef5
--- /dev/null
+++ b/src/math/percentageChange.test.ts
@@ -0,0 +1,31 @@
+import { describe, expect, test } from "@jest/globals";
+import { percentageChange } from "./percentageChange";
+
+describe("percentageChange", () => {
+  test("simple", async () => {
+    expect(
+      percentageChange({
+        current: 10,
+        previous: 12,
+      })
+    ).toBe(-16.67);
+    expect(
+      percentageChange({
+        current: 0,
+        previous: 12,
+      })
+    ).toBe(0);
+    expect(
+      percentageChange({
+        current: 0,
+        previous: 0,
+      })
+    ).toBe(0);
+    expect(
+      percentageChange({
+        current: 99,
+        previous: 0,
+      })
+    ).toBe(0);
+  });
+});
diff --git a/src/math/percentageChange.ts b/src/math/percentageChange.ts
new file mode 100644
index 0000000..3b5dfd5
--- /dev/null
+++ b/src/math/percentageChange.ts
@@ -0,0 +1,16 @@
+import { isPositiveInt } from "../validators";
+
+export const percentageChange = ({
+  previous,
+  current,
+}: {
+  previous: number;
+  current: number;
+}): number => {
+  if (!isPositiveInt(previous) || !isPositiveInt(current)) return 0;
+  if (current === 0 && previous === 0) return 0;
+  if (current === 0 && previous !== 0) return -100;
+  if (current !== 0 && previous === 0) return 100;
+  const perChange = ((current - previous) * 100) / previous;
+  return parseFloat(perChange.toFixed(2));
+};
diff --git a/src/prisma/checkIsPrismaRefMissingError.ts b/src/prisma/checkIsPrismaRefMissingError.ts
new file mode 100644
index 0000000..9f2b4a8
--- /dev/null
+++ b/src/prisma/checkIsPrismaRefMissingError.ts
@@ -0,0 +1,18 @@
+/**
+ * Useful for no-op queries where you want to make sure the error is a unique constraint error.
+ * @example
+ * try {
+ *   await query();
+ * } catch (e) {
+ *   checkIsPrismaUniqueConstraintError(e);
+ *   // carry on with other stuff, it is a unique constraint error
+ * }
+ * @link https://www.prisma.io/docs/concepts/components/prisma-client/handling-exceptions-and-errors
+ * @link https://www.prisma.io/docs/reference/api-reference/error-reference#p2002
+ */
+export const checkIsPrismaRefMissingError = (error: Error) => {
+  if (!isPrismaRefMissingError(error)) throw error;
+};
+
+export const isPrismaRefMissingError = (error: Error & { code?: string }) =>
+  error.code === "P2025";
diff --git a/src/prisma/checkIsPrismaUniqueConstraintError.ts b/src/prisma/checkIsPrismaUniqueConstraintError.ts
new file mode 100644
index 0000000..3d46edb
--- /dev/null
+++ b/src/prisma/checkIsPrismaUniqueConstraintError.ts
@@ -0,0 +1,19 @@
+/**
+ * Useful for no-op queries where you want to make sure the error is a unique constraint error.
+ * @example
+ * try {
+ *   await query();
+ * } catch (e) {
+ *   checkIsPrismaUniqueConstraintError(e);
+ *   // carry on with other stuff, it is a unique constraint error
+ * }
+ * @link https://www.prisma.io/docs/concepts/components/prisma-client/handling-exceptions-and-errors
+ * @link https://www.prisma.io/docs/reference/api-reference/error-reference#p2002
+ */
+export const checkIsPrismaUniqueConstraintError = (error: Error) => {
+  if (!isPrismaUniqueConstraintError(error)) throw error;
+};
+
+export const isPrismaUniqueConstraintError = (
+  error: Error & { code?: string }
+) => error.code === "P2002";
diff --git a/src/prisma/index.ts b/src/prisma/index.ts
new file mode 100644
index 0000000..b3d8044
--- /dev/null
+++ b/src/prisma/index.ts
@@ -0,0 +1 @@
+export * from "./prismaDateRange";
diff --git a/src/prisma/prismaDateRange.ts b/src/prisma/prismaDateRange.ts
new file mode 100644
index 0000000..d0dece5
--- /dev/null
+++ b/src/prisma/prismaDateRange.ts
@@ -0,0 +1,16 @@
+import { parseDate } from "../helpers/parseDate";
+import { DateRange } from "../types/Date";
+
+export const prismaDateRange = ({ startDate, endDate }: DateRange) => {
+  const gte = parseDate(startDate);
+  const lt = parseDate(endDate);
+
+  if (!gte || !lt) {
+    throw new Error("prismaDateRange: Invalid date range");
+  }
+
+  return {
+    gte,
+    lt,
+  };
+};
diff --git a/src/trpc/formatTrpcInputQueryString.ts b/src/trpc/formatTrpcInputQueryString.ts
new file mode 100644
index 0000000..af88c48
--- /dev/null
+++ b/src/trpc/formatTrpcInputQueryString.ts
@@ -0,0 +1,7 @@
+import { PlainObject } from "../types";
+
+export const formatTrpcInputQueryString = (input: PlainObject) => {
+  return new URLSearchParams({
+    input: JSON.stringify(input),
+  });
+};
diff --git a/src/trpc/index.ts b/src/trpc/index.ts
new file mode 100644
index 0000000..01845f6
--- /dev/null
+++ b/src/trpc/index.ts
@@ -0,0 +1 @@
+export * from "./formatTrpcInputQueryString";