diff --git a/src/lib/schemaToForm.ts b/src/lib/schemaToForm.ts
index 7023d624..98a16714 100644
--- a/src/lib/schemaToForm.ts
+++ b/src/lib/schemaToForm.ts
@@ -15,6 +15,7 @@ export interface FormFieldConfig {
   maxFiles?: number
   placeholder?: string
   hidden?: boolean  // x-hidden fields are optional and hidden by default
+  schemaType?: string  // Original schema type (e.g. 'integer' vs 'number')
 }
 
 export function validateFormValues(fields: FormFieldConfig[], values: Record<string, unknown>): Record<string, string> {
@@ -256,6 +257,7 @@ function propertyToField(
       return {
         ...baseField,
         type: prop['x-ui-component'] === 'slider' ? 'slider' : 'number',
+        schemaType: prop.type,
         min: prop.minimum,
         max: prop.maximum,
         step: prop.step,
diff --git a/src/pages/SmartPlaygroundPage.tsx b/src/pages/SmartPlaygroundPage.tsx
index 575fe06c..e6630bad 100644
--- a/src/pages/SmartPlaygroundPage.tsx
+++ b/src/pages/SmartPlaygroundPage.tsx
@@ -359,15 +359,19 @@ export function SmartPlaygroundPage() {
       ? family.mapValues({ ...formValues }, resolvedVariantId)
       : formValues
     const variantFieldNames = getVariantFieldNames(resolvedModel)
+    const integerFields = new Set(visibleFields.filter(f => f.schemaType === 'integer').map(f => f.name))
     const cleanedValues: Record<string, unknown> = {}
     for (const [key, value] of Object.entries(mappedValues)) {
       if (!variantFieldNames.has(key)) continue
       if (value === undefined || value === null || value === '') continue
       if (Array.isArray(value) && value.length === 0) continue
-      cleanedValues[key] = value
+      // Ensure integer fields are sent as integers (API rejects non-integer values)
+      cleanedValues[key] = integerFields.has(key) && typeof value === 'number'
+        ? Math.round(value)
+        : value
     }
     return cleanedValues
-  }, [resolvedModel, formValues, family, resolvedVariantId])
+  }, [resolvedModel, formValues, family, resolvedVariantId, visibleFields])
 
   // Run prediction (single or batch)
   const handleRun = useCallback(async () => {
diff --git a/src/stores/playgroundStore.ts b/src/stores/playgroundStore.ts
index 1ab4aa09..a6a8ea98 100644
--- a/src/stores/playgroundStore.ts
+++ b/src/stores/playgroundStore.ts
@@ -384,9 +384,13 @@ export const usePlaygroundStore = create<PlaygroundState>((set, get) => ({
     try {
       // Clean up form values - remove empty strings and undefined
       const cleanedInput: Record<string, unknown> = {}
+      const integerFields = new Set(formFields.filter(f => f.schemaType === 'integer').map(f => f.name))
       for (const [key, value] of Object.entries(formValues)) {
         if (value !== '' && value !== undefined && value !== null) {
-          cleanedInput[key] = value
+          // Ensure integer fields are sent as integers (API rejects non-integer values)
+          cleanedInput[key] = integerFields.has(key) && typeof value === 'number'
+            ? Math.round(value)
+            : value
         }
       }
       const normalizedInput = normalizePayloadArrays(cleanedInput, formFields)
@@ -455,9 +459,12 @@ export const usePlaygroundStore = create<PlaygroundState>((set, get) => ({
 
     // Clean input values
     const cleanedBase: Record<string, unknown> = {}
+    const integerFields = new Set(formFields.filter(f => f.schemaType === 'integer').map(f => f.name))
     for (const [key, value] of Object.entries(formValues)) {
       if (value !== '' && value !== undefined && value !== null) {
-        cleanedBase[key] = value
+        cleanedBase[key] = integerFields.has(key) && typeof value === 'number'
+          ? Math.round(value)
+          : value
       }
     }