diff --git a/packages/builder/src/components/common/CodeEditor/CodeEditor.svelte b/packages/builder/src/components/common/CodeEditor/CodeEditor.svelte
index fbf74d1e9b..0f4bc64e2a 100644
--- a/packages/builder/src/components/common/CodeEditor/CodeEditor.svelte
+++ b/packages/builder/src/components/common/CodeEditor/CodeEditor.svelte
@@ -49,6 +49,7 @@
   import type { EditorMode } from "@budibase/types"
   import type { BindingCompletion, CodeValidator } from "@/types"
   import { validateHbsTemplate } from "./validator/hbs"
+  import { validateJsTemplate } from "./validator/js"
 
   export let label: string | undefined = undefined
   export let completions: BindingCompletion[] = []
@@ -356,6 +357,9 @@
     if (mode === EditorModes.Handlebars) {
       const diagnostics = validateHbsTemplate(value, validations)
       editor.dispatch(setDiagnostics(editor.state, diagnostics))
+    } else if (mode === EditorModes.JS) {
+      const diagnostics = validateJsTemplate(value, validations)
+      editor.dispatch(setDiagnostics(editor.state, diagnostics))
     }
   }
 
diff --git a/packages/builder/src/components/common/CodeEditor/validator/js.ts b/packages/builder/src/components/common/CodeEditor/validator/js.ts
new file mode 100644
index 0000000000..20fb5abd07
--- /dev/null
+++ b/packages/builder/src/components/common/CodeEditor/validator/js.ts
@@ -0,0 +1,101 @@
+import { Parser } from "acorn"
+import * as walk from "acorn-walk"
+
+import type { Diagnostic } from "@codemirror/lint"
+import { CodeValidator } from "@/types"
+
+export function validateJsTemplate(
+  code: string,
+  validations: CodeValidator
+): Diagnostic[] {
+  const diagnostics: Diagnostic[] = []
+
+  try {
+    const ast = Parser.parse(code, {
+      ecmaVersion: "latest",
+      locations: true,
+      allowReturnOutsideFunction: true,
+    })
+
+    const lineOffsets: number[] = []
+    let offset = 0
+    for (const line of code.split("\n")) {
+      lineOffsets.push(offset)
+      offset += line.length + 1 // +1 for newline character
+    }
+
+    let hasReturnStatement = false
+    walk.ancestor(ast, {
+      ReturnStatement(node, _state, ancestors) {
+        if (
+          // it returns a value
+          node.argument &&
+          // and it is top level
+          ancestors.length === 2 &&
+          ancestors[0].type === "Program" &&
+          ancestors[1].type === "ReturnStatement"
+        ) {
+          hasReturnStatement = true
+        }
+      },
+      CallExpression(node) {
+        const callee: any = node.callee
+        if (
+          node.type === "CallExpression" &&
+          callee.object?.name === "helpers" &&
+          node.loc
+        ) {
+          const functionName = callee.property.name
+          const from =
+            lineOffsets[node.loc.start.line - 1] + node.loc.start.column
+          const to = lineOffsets[node.loc.end.line - 1] + node.loc.end.column
+
+          if (!(functionName in validations)) {
+            diagnostics.push({
+              from,
+              to,
+              severity: "warning",
+              message: `"${functionName}" function does not exist.`,
+            })
+            return
+          }
+
+          const { arguments: expectedArguments } = validations[functionName]
+          if (
+            expectedArguments &&
+            node.arguments.length !== expectedArguments.length
+          ) {
+            diagnostics.push({
+              from,
+              to,
+              severity: "error",
+              message: `Function "${functionName}" expects ${
+                expectedArguments.length
+              } parameters (${expectedArguments.join(", ")}), but got ${
+                node.arguments.length
+              }.`,
+            })
+          }
+        }
+      },
+    })
+
+    if (!hasReturnStatement) {
+      diagnostics.push({
+        from: 0,
+        to: code.length,
+        severity: "error",
+        message: "Your code must return a value.",
+      })
+    }
+  } catch (e: any) {
+    diagnostics.push({
+      from: 0,
+      to: code.length,
+      severity: "error",
+      message: `Syntax error: ${e.message}`,
+    })
+  }
+
+  return diagnostics
+}
diff --git a/packages/builder/src/components/common/CodeEditor/validator/tests/js.spec.ts b/packages/builder/src/components/common/CodeEditor/validator/tests/js.spec.ts
new file mode 100644
index 0000000000..cd9fe4684c
--- /dev/null
+++ b/packages/builder/src/components/common/CodeEditor/validator/tests/js.spec.ts
@@ -0,0 +1,156 @@
+import { validateJsTemplate } from "../js"
+import { CodeValidator } from "@/types"
+
+describe("js validator", () => {
+  it("validates valid code", () => {
+    const text = "return 7"
+    const validators = {}
+
+    const result = validateJsTemplate(text, validators)
+    expect(result).toEqual([])
+  })
+
+  it("does not validate runtime errors", () => {
+    const text = "return a"
+    const validators = {}
+
+    const result = validateJsTemplate(text, validators)
+    expect(result).toEqual([])
+  })
+
+  it("validates multiline code", () => {
+    const text = "const foo='bar'\nreturn 123"
+    const validators = {}
+
+    const result = validateJsTemplate(text, validators)
+    expect(result).toEqual([])
+  })
+
+  it("allows return not being on the last line", () => {
+    const text = "const foo='bar'\nreturn 123\nconsole.log(foo)"
+    const validators = {}
+
+    const result = validateJsTemplate(text, validators)
+    expect(result).toEqual([])
+  })
+
+  it("throws on missing return", () => {
+    const text = "const foo='bar'\nbar='foo'"
+    const validators = {}
+
+    const result = validateJsTemplate(text, validators)
+    expect(result).toEqual([
+      {
+        from: 0,
+        message: "Your code must return a value.",
+        severity: "error",
+        to: 25,
+      },
+    ])
+  })
+
+  it("checks that returns are at top level", () => {
+    const text = `
+    function call(){
+      return 1
+    }`
+    const validators = {}
+
+    const result = validateJsTemplate(text, validators)
+    expect(result).toEqual([
+      {
+        from: 0,
+        message: "Your code must return a value.",
+        severity: "error",
+        to: text.length,
+      },
+    ])
+  })
+
+  describe("helpers", () => {
+    const validators: CodeValidator = {
+      helperFunction: {
+        arguments: ["a", "b", "c"],
+      },
+    }
+
+    it("validates helpers with valid params", () => {
+      const text = "return helpers.helperFunction(1, 99, 'a')"
+
+      const result = validateJsTemplate(text, validators)
+      expect(result).toEqual([])
+    })
+
+    it("throws on too few params", () => {
+      const text = "return helpers.helperFunction(100)"
+
+      const result = validateJsTemplate(text, validators)
+      expect(result).toEqual([
+        {
+          from: 7,
+          message: `Function "helperFunction" expects 3 parameters (a, b, c), but got 1.`,
+          severity: "error",
+          to: 34,
+        },
+      ])
+    })
+
+    it("throws on too many params", () => {
+      const text = "return helpers.helperFunction( 1, 99, 'a', 100)"
+
+      const result = validateJsTemplate(text, validators)
+      expect(result).toEqual([
+        {
+          from: 7,
+          message: `Function "helperFunction" expects 3 parameters (a, b, c), but got 4.`,
+          severity: "error",
+          to: 47,
+        },
+      ])
+    })
+
+    it("validates helpers on inner functions", () => {
+      const text = `function call(){
+                      return helpers.helperFunction(1, 99)
+                    }
+                    return call()`
+
+      const result = validateJsTemplate(text, validators)
+      expect(result).toEqual([
+        {
+          from: 46,
+          message: `Function "helperFunction" expects 3 parameters (a, b, c), but got 2.`,
+          severity: "error",
+          to: 75,
+        },
+      ])
+    })
+
+    it("validates multiple helpers", () => {
+      const text =
+        "return helpers.helperFunction(1, 99, 'a') + helpers.helperFunction(1) + helpers.another(1) + helpers.another()"
+      const validators: CodeValidator = {
+        helperFunction: {
+          arguments: ["a", "b", "c"],
+        },
+        another: { arguments: [] },
+      }
+
+      const result = validateJsTemplate(text, validators)
+      expect(result).toEqual([
+        {
+          from: 44,
+          message: `Function "helperFunction" expects 3 parameters (a, b, c), but got 1.`,
+          severity: "error",
+          to: 69,
+        },
+        {
+          from: 72,
+          message: `Function "another" expects 0 parameters (), but got 1.`,
+          severity: "error",
+          to: 90,
+        },
+      ])
+    })
+  })
+})
diff --git a/packages/builder/src/components/common/bindings/BindingPanel.svelte b/packages/builder/src/components/common/bindings/BindingPanel.svelte
index 2c35acdf2d..9ebbc91309 100644
--- a/packages/builder/src/components/common/bindings/BindingPanel.svelte
+++ b/packages/builder/src/components/common/bindings/BindingPanel.svelte
@@ -377,6 +377,7 @@
               value={jsValue ? decodeJSBinding(jsValue) : jsValue}
               on:change={onChangeJSValue}
               {completions}
+              {validations}
               mode={EditorModes.JS}
               bind:getCaretPosition
               bind:insertAtPos