diff --git a/apps/webapp/app/components/code/JSONEditor.tsx b/apps/webapp/app/components/code/JSONEditor.tsx
index 0313120b14..db85a9cd9f 100644
--- a/apps/webapp/app/components/code/JSONEditor.tsx
+++ b/apps/webapp/app/components/code/JSONEditor.tsx
@@ -1,5 +1,5 @@
-import { json as jsonLang } from "@codemirror/lang-json";
-import type { ViewUpdate } from "@codemirror/view";
+import { json as jsonLang, jsonParseLinter } from "@codemirror/lang-json";
+import type { EditorView, ViewUpdate } from "@codemirror/view";
 import { CheckIcon, ClipboardIcon, TrashIcon } from "@heroicons/react/20/solid";
 import type { ReactCodeMirrorProps, UseCodeMirror } from "@uiw/react-codemirror";
 import { useCodeMirror } from "@uiw/react-codemirror";
@@ -8,6 +8,7 @@ import { cn } from "~/utils/cn";
 import { Button } from "../primitives/Buttons";
 import { getEditorSetup } from "./codeMirrorSetup";
 import { darkTheme } from "./codeMirrorTheme";
+import { linter, lintGutter, type Diagnostic } from "@codemirror/lint";
 
 export interface JSONEditorProps extends Omit<ReactCodeMirrorProps, "onBlur"> {
   defaultValue?: string;
@@ -18,18 +19,35 @@ export interface JSONEditorProps extends Omit<ReactCodeMirrorProps, "onBlur"> {
   onBlur?: (code: string) => void;
   showCopyButton?: boolean;
   showClearButton?: boolean;
+  linterEnabled?: boolean;
+  allowEmpty?: boolean;
 }
 
 const languages = {
   json: jsonLang,
 };
 
+function emptyAwareJsonLinter() {
+  return (view: EditorView): Diagnostic[] => {
+    const content = view.state.doc.toString().trim();
+
+    // return no errors if content is empty
+    if (!content) {
+      return [];
+    }
+
+    return jsonParseLinter()(view);
+  };
+}
+
 type JSONEditorDefaultProps = Partial<JSONEditorProps>;
 
 const defaultProps: JSONEditorDefaultProps = {
   language: "json",
   readOnly: true,
   basicSetup: false,
+  linterEnabled: true,
+  allowEmpty: true,
 };
 
 export function JSONEditor(opts: JSONEditorProps) {
@@ -44,6 +62,8 @@ export function JSONEditor(opts: JSONEditorProps) {
     autoFocus,
     showCopyButton = true,
     showClearButton = true,
+    linterEnabled,
+    allowEmpty,
   } = {
     ...defaultProps,
     ...opts,
@@ -56,6 +76,19 @@ export function JSONEditor(opts: JSONEditorProps) {
 
   extensions.push(languageExtension());
 
+  if (linterEnabled) {
+    extensions.push(lintGutter());
+
+    switch (language) {
+      case "json": {
+        extensions.push(allowEmpty ? linter(emptyAwareJsonLinter()) : linter(jsonParseLinter()));
+        break;
+      }
+      default:
+        language satisfies never;
+    }
+  }
+
   const editor = useRef<HTMLDivElement>(null);
   const settings: Omit<UseCodeMirror, "onBlur"> = {
     ...opts,
diff --git a/apps/webapp/app/components/code/codeMirrorSetup.ts b/apps/webapp/app/components/code/codeMirrorSetup.ts
index 89988c3d9b..811a6ebc29 100644
--- a/apps/webapp/app/components/code/codeMirrorSetup.ts
+++ b/apps/webapp/app/components/code/codeMirrorSetup.ts
@@ -1,8 +1,7 @@
 import { closeBrackets } from "@codemirror/autocomplete";
 import { indentWithTab } from "@codemirror/commands";
-import { jsonParseLinter } from "@codemirror/lang-json";
 import { bracketMatching } from "@codemirror/language";
-import { lintGutter, lintKeymap, linter } from "@codemirror/lint";
+import { lintKeymap } from "@codemirror/lint";
 import { highlightSelectionMatches } from "@codemirror/search";
 import { Prec, type Extension } from "@codemirror/state";
 import {
@@ -21,8 +20,6 @@ export function getEditorSetup(showLineNumbers = true, showHighlights = true): A
     dropCursor(),
     bracketMatching(),
     closeBrackets(),
-    lintGutter(),
-    linter(jsonParseLinter()),
     Prec.highest(
       keymap.of([
         {
diff --git a/apps/webapp/app/components/code/codeMirrorTheme.ts b/apps/webapp/app/components/code/codeMirrorTheme.ts
index 74d074b3cd..2516705134 100644
--- a/apps/webapp/app/components/code/codeMirrorTheme.ts
+++ b/apps/webapp/app/components/code/codeMirrorTheme.ts
@@ -39,6 +39,32 @@ export function darkTheme(): Extension {
         fontSize: "14px",
       },
 
+      ".cm-tooltip.cm-tooltip-lint": {
+        backgroundColor: tooltipBackground,
+      },
+
+      ".cm-diagnostic": {
+        padding: "4px 8px",
+        color: ivory,
+        fontFamily: "Geist Mono Variable",
+        fontSize: "12px",
+      },
+
+      ".cm-diagnostic-error": {
+        borderLeft: "2px solid #e11d48",
+      },
+
+      ".cm-lint-marker-error": {
+        content: "none",
+        backgroundColor: "#e11d48",
+        height: "100%",
+        width: "2px",
+      },
+
+      ".cm-lintPoint:after": {
+        borderBottom: "4px solid #e11d48",
+      },
+
       ".cm-cursor, .cm-dropCursor": { borderLeftColor: cursor },
       "&.cm-focused .cm-selectionBackground, .cm-selectionBackground, .cm-content ::selection": {
         backgroundColor: selection,
@@ -82,6 +108,7 @@ export function darkTheme(): Extension {
 
       ".cm-tooltip": {
         border: "none",
+        marginTop: "6px",
         backgroundColor: tooltipBackground,
       },
       ".cm-tooltip .cm-tooltip-arrow:before": {
diff --git a/apps/webapp/app/routes/_app.orgs.$organizationSlug.projects.$projectParam.env.$envParam.test.tasks.$taskParam/route.tsx b/apps/webapp/app/routes/_app.orgs.$organizationSlug.projects.$projectParam.env.$envParam.test.tasks.$taskParam/route.tsx
index 6205336d75..abdfcda4c3 100644
--- a/apps/webapp/app/routes/_app.orgs.$organizationSlug.projects.$projectParam.env.$envParam.test.tasks.$taskParam/route.tsx
+++ b/apps/webapp/app/routes/_app.orgs.$organizationSlug.projects.$projectParam.env.$envParam.test.tasks.$taskParam/route.tsx
@@ -291,7 +291,6 @@ function StandardTaskForm({ task, runs }: { task: TestTask["task"]; runs: Standa
                 }}
                 height="100%"
                 autoFocus={!tab || tab === "payload"}
-                placeholder="{ }"
                 className={cn("h-full overflow-auto", tab === "metadata" && "hidden")}
               />
               <JSONEditor
diff --git a/apps/webapp/app/v3/testTask.ts b/apps/webapp/app/v3/testTask.ts
index 289d519524..764f6b09f7 100644
--- a/apps/webapp/app/v3/testTask.ts
+++ b/apps/webapp/app/v3/testTask.ts
@@ -4,46 +4,42 @@ export const TestTaskData = z
   .discriminatedUnion("triggerSource", [
     z.object({
       triggerSource: z.literal("STANDARD"),
-      payload: z.string().transform((payload, ctx) => {
-        try {
-          const data = JSON.parse(payload);
-          return data as any;
-        } catch (e) {
-          console.log("parsing error", e);
+      payload: z
+        .string()
+        .optional()
+        .transform((val, ctx) => {
+          if (!val) {
+            return {};
+          }
 
-          if (e instanceof Error) {
-            ctx.addIssue({
-              code: z.ZodIssueCode.custom,
-              message: e.message,
-            });
-          } else {
+          try {
+            return JSON.parse(val);
+          } catch {
             ctx.addIssue({
               code: z.ZodIssueCode.custom,
-              message: "This is invalid JSON",
+              message: "Payload must be a valid JSON string",
             });
+            return z.NEVER;
+          }
+        }),
+      metadata: z
+        .string()
+        .optional()
+        .transform((val, ctx) => {
+          if (!val) {
+            return {};
           }
-        }
-      }),
-      metadata: z.string().transform((metadata, ctx) => {
-        try {
-          const data = JSON.parse(metadata);
-          return data as any;
-        } catch (e) {
-          console.log("parsing error", e);
 
-          if (e instanceof Error) {
-            ctx.addIssue({
-              code: z.ZodIssueCode.custom,
-              message: e.message,
-            });
-          } else {
+          try {
+            return JSON.parse(val);
+          } catch {
             ctx.addIssue({
               code: z.ZodIssueCode.custom,
-              message: "This is invalid JSON",
+              message: "Metadata must be a valid JSON string",
             });
+            return z.NEVER;
           }
-        }
-      }),
+        }),
     }),
     z.object({
       triggerSource: z.literal("SCHEDULED"),