diff --git a/frontend/src/components/SchemaInput.vue b/frontend/src/components/SchemaInput.vue
new file mode 100644
index 0000000..e31d220
--- /dev/null
+++ b/frontend/src/components/SchemaInput.vue
@@ -0,0 +1,490 @@
+<script setup>
+import { ref, computed, watch } from 'vue'
+
+const props = defineProps({
+  /** JSON schema object describing the input structure */
+  schema: { type: Object, required: true },
+  /** Current value of the input (can be any type) */
+  modelValue: { type: [Object, Array, String, Number, Boolean, null], default: () => null }
+})
+
+const emit = defineEmits(['update:modelValue'])
+
+/**
+ * Convert value to matching schema type based on schema type
+ */
+function coerceValue(val, schemaType) {
+  if (schemaType === 'dynamic') return val ?? null
+
+  switch (schemaType) {
+    case 'object': return val ?? {}
+    case 'array': return Array.isArray(val) ? val : []
+    case 'string': return String(val ?? '')
+    case 'number': return typeof val === 'number' ? val : 0
+    case 'boolean': return typeof val === 'boolean' ? val : false
+    default: return val
+  }
+}
+
+/**
+ * Generate schema-specific default value
+ */
+function defaultValue(type) {
+  if (type === 'dynamic') return null
+  if (type === 'object') return {}
+  if (type === 'array') return []
+  if (type === 'string') return ''
+  if (type === 'number') return 0
+  if (type === 'boolean') return false
+  return null
+}
+
+const currentValue = computed({
+  get: () => props.modelValue,
+  set: (val) => {
+    if (props.schema.type === 'object') {
+      emit('update:modelValue', coerceValue(val, 'object'))
+    } else if (props.schema.type === 'array') {
+      emit('update:modelValue', coerceValue(val, 'array'))
+    } else {
+      emit('update:modelValue', val)
+    }
+  }
+})
+
+function setObjectProperty(key, value) {
+  const current = currentValue.value || {}
+  emit('update:modelValue', coerceValue({ ...current, [key]: value }, 'object'))
+}
+
+function setArrayElement(index, value) {
+  const current = currentValue.value || []
+  const newArr = [...current]
+  newArr[index] = value
+  emit('update:modelValue', coerceValue(newArr, 'array'))
+}
+
+function addObjectProperty() {
+  const current = currentValue.value || {}
+  let i = Object.keys(current).length
+  let newKey = `prop_${i}`
+  while (newKey in current) newKey = `prop_${++i}`
+  emit('update:modelValue', coerceValue({ ...current, [newKey]: defaultValue('string') }, 'object'))
+}
+
+function removeObjectProperty(key) {
+  // Copy first: never mutate the prop object in place.
+  const current = { ...(currentValue.value || {}) }
+  delete current[key]
+  emit('update:modelValue', coerceValue(current, 'object'))
+}
+
+/** Rename an object property key (fires on @change of the key input). */
+function renameObjectProperty(oldKey, newKey) {
+  newKey = newKey.trim()
+  if (!newKey || newKey === oldKey) return
+  const current = currentValue.value || {}
+  if (newKey in current) return // would silently overwrite another property
+  const out = {}
+  for (const [k, v] of Object.entries(current)) {
+    out[k === oldKey ? newKey : k] = v
+  }
+  emit('update:modelValue', coerceValue(out, 'object'))
+}
+
+function addArrayElement() {
+  const current = currentValue.value || []
+  const newItem = props.schema.items?.type === 'dynamic'
+    ? defaultValue('object')
+    : defaultValue(props.schema.items?.type || 'object')
+  const newArr = [...current, newItem]
+  emit('update:modelValue', coerceValue(newArr, 'array'))
+}
+
+function removeArrayElement(index) {
+  const current = currentValue.value || []
+  const newArr = [...current]
+  newArr.splice(index, 1)
+  emit('update:modelValue', coerceValue(newArr, 'array'))
+}
+
+function handleStringChange(val) {
+  // e.target.value is already a string; emit it verbatim so the displayed
+  // text and the stored value stay identical (no JSON quoting round-trip).
+  emit('update:modelValue', val)
+}
+
+function handleNumberChange(val) {
+  const num = parseFloat(val)
+  emit('update:modelValue', isNaN(num) ? 0 : num)
+}
+
+function handleBooleanChange(val) {
+  emit('update:modelValue', coerceValue(val, 'boolean'))
+}
+
+function handleDynamicChange(val) {
+  // val is the selected type name ('object' | 'array' | 'string' | 'number' |
+  // 'boolean' | 'null'); emit that type's default VALUE, not the type name.
+  // defaultValue('null') falls through to null, which is the intended result.
+  emit('update:modelValue', defaultValue(val))
+}
+
+function handleArrayTypeChange(index, type) {
+  const current = currentValue.value || []
+  const newArr = [...current]
+  newArr[index] = defaultValue(type)
+  emit('update:modelValue', coerceValue(newArr, 'array'))
+}
+
+function valueToDisplay() {
+  const val = currentValue.value
+  if (val === null || val === undefined) return ''
+  return JSON.stringify(val, null, 2)
+}
+
+function textareaHeight(value) {
+  const lines = String(value ?? '').split('\n').length
+  const height = Math.max(1.5, lines * 1.5)
+  return `${Math.min(height, 8)}rem`
+}
+
+/**
+ * Best-effort schema type for a runtime value.
+ * Plain `typeof` alone is not enough: typeof null === 'object' and
+ * typeof [] === 'object'.
+ */
+function inferSchemaType(value) {
+  if (value === null || value === undefined) return 'null'
+  if (Array.isArray(value)) return 'array'
+  const t = typeof value
+  if (t === 'string' || t === 'number' || t === 'boolean' || t === 'object') return t
+  return 'string'
+}
+
+/**
+ * Schema for a single object property. The declared schema
+ * (schema.properties[key]) wins; only keys without a declaration fall back
+ * to inferring the type from the current value.
+ */
+function propertySchema(key, value) {
+  const declared = props.schema.properties?.[key]
+  if (declared && declared.type) {
+    const t = Array.isArray(declared.type) ? declared.type.find(x => x !== 'null') : declared.type
+    if (t === 'integer') return { type: 'number' }
+    if (t) return { ...declared, type: t }
+  }
+  return { type: inferSchemaType(value) }
+}
+
+// Fallback editor state: raw JSON text in a local ref so half-typed JSON is
+// not clobbered by re-renders. Emitted back through JSON.parse once valid.
+const fallbackText = ref('')
+watch(
+  () => props.modelValue,
+  () => { fallbackText.value = valueToDisplay() },
+  { immediate: true }
+)
+
+function handleFallbackChange(val) {
+  fallbackText.value = val
+  if (val.trim() === '') {
+    emit('update:modelValue', null)
+    return
+  }
+  try {
+    emit('update:modelValue', JSON.parse(val))
+  } catch (e) {
+    // Not valid JSON yet: keep the typed text; emit as soon as it parses.
+  }
+}
+</script>
+
+<template>
+  <!-- Object type: nested properties -->
+  <div v-if="props.schema.type === 'object'" class="schema-input">
+    <div class="object-container">
+      <div v-for="(prop, key) in (currentValue || {})" :key="key" class="object-row">
+        <input
+          type="text"
+          :value="key"
+          @change="(e) => renameObjectProperty(key, e.target.value)"
+          class="property-key"
+        />
+        <span class="colon">:</span>
+        <SchemaInput
+          v-if="prop !== undefined"
+          :schema="propertySchema(key, prop)"
+          :model-value="prop"
+          @update:model-value="(v) => setObjectProperty(key, v)"
+          class="property-value"
+        />
+        <button class="btn-remove" @click="removeObjectProperty(key)" title="Remove property">×</button>
+      </div>
+      <button class="btn-add" @click="addObjectProperty">+ Add Property</button>
+    </div>
+  </div>
+
+  <!-- Array type: list of items -->
+  <div v-else-if="props.schema.type === 'array'" class="schema-input">
+    <div class="array-container">
+      <div v-if="(currentValue || []).length === 0" class="empty-array">Array is empty</div>
+      <div v-for="(item, idx) in (currentValue || [])" :key="idx" class="array-row">
+        <span class="array-index">{{ idx }}:</span>
+        <SchemaInput
+          v-if="!props.schema.items || props.schema.items.type !== 'dynamic'"
+          :schema="props.schema.items || { type: inferSchemaType(item) }"
+          :model-value="item"
+          @update:model-value="(v) => setArrayElement(idx, v)"
+          class="array-value"
+        />
+        <div v-else class="dynamic-item">
+          <select
+            :value="inferSchemaType(item)"
+            @change="(e) => handleArrayTypeChange(idx, e.target.value)"
+            class="item-type-select"
+          >
+            <option value="object">Object</option>
+            <option value="array">Array</option>
+            <option value="string">String</option>
+            <option value="number">Number</option>
+            <option value="boolean">Boolean</option>
+            <option value="null">Empty</option>
+          </select>
+          <SchemaInput
+            v-if="item !== null && item !== undefined"
+            :schema="{ type: inferSchemaType(item) }"
+            :model-value="item"
+            @update:model-value="(v) => setArrayElement(idx, v)"
+          />
+        </div>
+        <button class="btn-remove" @click="removeArrayElement(idx)" title="Remove item">×</button>
+      </div>
+      <button class="btn-add" @click="addArrayElement">+ Add Item</button>
+    </div>
+  </div>
+
+  <!-- String type: textarea with auto-height -->
+  <div v-else-if="props.schema.type === 'string'" class="schema-input">
+    <textarea
+      :value="currentValue ?? ''"
+      @input="(e) => handleStringChange(e.target.value)"
+      class="string-input"
+      :style="{ height: textareaHeight(currentValue) }"
+      spellcheck="false"
+    />
+  </div>
+
+  <!-- Number type: number input -->
+  <div v-else-if="props.schema.type === 'number'" class="schema-input">
+    <input
+      type="number"
+      :value="currentValue ?? ''"
+      @input="(e) => handleNumberChange(e.target.value)"
+      class="number-input"
+    />
+  </div>
+
+  <!-- Boolean type: checkbox -->
+  <div v-else-if="props.schema.type === 'boolean'" class="schema-input">
+    <label class="checkbox-label">
+      <input
+        type="checkbox"
+        :checked="currentValue ?? false"
+        @change="(e) => handleBooleanChange(e.target.checked)"
+      />
+      <span>{{ currentValue !== false ? 'Checked' : 'Unchecked' }}</span>
+    </label>
+  </div>
+
+  <!-- Dynamic type: allows any value including empty -->
+  <div v-else-if="props.schema.type === 'dynamic'" class="schema-input">
+    <div class="dynamic-container">
+      <div class="dynamic-selector">
+        <label>Dynamic Value:</label>
+        <select
+          :value="currentValue === null || currentValue === undefined ? 'null' : inferSchemaType(currentValue)"
+          @change="(e) => handleDynamicChange(e.target.value)"
+          class="dynamic-select"
+        >
+          <option value="object">Object {}</option>
+          <option value="array">Array []</option>
+          <option value="string">String ""</option>
+          <option value="number">Number 0</option>
+          <option value="boolean">Boolean false</option>
+          <option value="null">Empty (null)</option>
+        </select>
+      </div>
+      <SchemaInput
+        v-if="currentValue !== null && currentValue !== undefined"
+        :schema="{ type: inferSchemaType(currentValue) }"
+        :model-value="currentValue"
+        @update:model-value="emit('update:modelValue', $event)"
+      />
+    </div>
+  </div>
+
+  <!-- Fallback: plain textarea for unknown types -->
+  <div v-else class="schema-input">
+    <textarea
+      :value="fallbackText"
+      @input="(e) => handleFallbackChange(e.target.value)"
+      class="fallback-input"
+    />
+  </div>
+</template>
+
+<style scoped>
+.schema-input { width: 100%; }
+
+/* Object styles */
+.object-container { display: flex; flex-direction: column; gap: 0.5rem; }
+
+.object-row {
+  display: flex;
+  gap: 0.5rem;
+  align-items: center;
+}
+
+.property-key {
+  width: 120px;
+  padding: 0.3rem 0.5rem;
+  border: 1px solid var(--color-border);
+  border-radius: 4px;
+  background: var(--color-background);
+  font-family: inherit;
+}
+
+.property-key:focus { outline: none; border-color: var(--color-primary); }
+
+.colon { color: var(--color-text-mute); }
+
+.property-value { flex: 1; min-width: 0; }
+
+/* Array styles */
+.array-container { display: flex; flex-direction: column; gap: 0.5rem; }
+
+.array-row {
+  display: flex;
+  gap: 0.5rem;
+  align-items: center;
+}
+
+.array-index {
+  color: var(--color-text-mute);
+  font-family: monospace;
+  font-size: 0.9em;
+  width: 3rem;
+  flex-shrink: 0;
+}
+
+.array-value { flex: 1; min-width: 0; }
+
+.empty-array {
+  color: var(--color-text-mute);
+  font-style: italic;
+  padding: 0.5rem;
+}
+
+.dynamic-item {
+  display: flex;
+  gap: 0.5rem;
+  align-items: center;
+}
+
+.item-type-select {
+  padding: 0.2rem 0.5rem;
+  border: 1px solid var(--color-border);
+  border-radius: 4px;
+  background: var(--color-background);
+  flex-shrink: 0;
+}
+
+/* String styles */
+.string-input {
+  width: 100%;
+  padding: 0.5rem;
+  border: 1px solid var(--color-border);
+  border-radius: 4px;
+  background: var(--color-background);
+  resize: none;
+  font-family: monospace;
+  box-sizing: border-box;
+}
+
+/* Number styles */
+.number-input {
+  width: 100%;
+  padding: 0.5rem;
+  border: 1px solid var(--color-border);
+  border-radius: 4px;
+  background: var(--color-background);
+}
+
+/* Boolean styles */
+.checkbox-label {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  cursor: pointer;
+}
+
+.checkbox-label input { width: 1rem; height: 1rem; }
+
+/* Dynamic styles */
+.dynamic-container { display: flex; flex-direction: column; gap: 0.5rem; }
+
+.dynamic-selector {
+  display: flex;
+  gap: 0.5rem;
+  align-items: center;
+}
+
+.dynamic-selector label { color: var(--color-text-mute); font-size: 0.85em; }
+
+.dynamic-select {
+  padding: 0.2rem 0.5rem;
+  border: 1px solid var(--color-border);
+  border-radius: 4px;
+  background: var(--color-background);
+}
+
+/* Fallback styles */
+.fallback-input {
+  width: 100%;
+  padding: 0.5rem;
+  border: 1px solid var(--color-border);
+  border-radius: 4px;
+  background: var(--color-background);
+  resize: vertical;
+}
+
+/* Buttons */
+.btn-remove {
+  background: var(--color-error);
+  color: white;
+  border: none;
+  border-radius: 4px;
+  width: 1.8rem;
+  height: 1.8rem;
+  font-size: 1.2rem;
+  line-height: 1;
+  cursor: pointer;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  flex-shrink: 0;
+}
+
+.btn-remove:hover { background: #dc2626; }
+
+.btn-add {
+  background: var(--color-muted);
+  color: white;
+  border: none;
+  border-radius: 4px;
+  padding: 0.5rem 1rem;
+  cursor: pointer;
+  font-size: 0.85em;
+}
+</style>
\ No newline at end of file
diff --git a/frontend/src/views/Remotes.vue b/frontend/src/views/Remotes.vue
index 60e5693..665a39c 100644
--- a/frontend/src/views/Remotes.vue
+++ b/frontend/src/views/Remotes.vue
@@ -99,6 +99,7 @@ backend.onAction('remote-call', async ({ requestId, remotename, function: fnName
 
 <script setup>
 import TitleBar from '../components/TitleBar.vue';
+import SchemaInput from '../components/SchemaInput.vue';
 import { ref, reactive, computed, onMounted, onUnmounted } from 'vue';
 import * as backend from '../backend';
 import * as ui from '../ui';
@@ -246,26 +247,38 @@ function toggleFn(row, fn) {
 
 // ---- Calling ----
 
-/** Type-appropriate default argument JSON for a function spec */
-function defaultArgsJson(fn) {
+function buildArgSchema(fn) {
+  const props = fn.parameters?.properties || {};
+  const required = fn.parameters?.required || [];
+
+  return {
+    type: 'object',
+    properties: props,
+    required: required,
+  };
+}
+
+/** Type-appropriate default argument values for a function spec */
+function defaultArgs(fn) {
   const props = fn.parameters?.properties || {};
   const out = {};
   for (const [name, p] of Object.entries(props)) {
-    const type = p.type;
+    // JSON Schema allows type arrays (e.g. ["string", "null"]): use the non-null member
+    const type = Array.isArray(p?.type) ? p.type.find(t => t !== 'null') : p?.type;
     out[name] =
       type === 'string' ? '' :
-      type === 'number' ? 0 :
+      type === 'number' || type === 'integer' ? 0 :
       type === 'boolean' ? false :
       type === 'array' ? [] :
       type === 'object' ? {} : null;
   }
-  return JSON.stringify(out, null, 2);
+  return out;
 }
 
 function callStateFor(row, fn) {
   const key = fnStateKey(row, fn);
   if (!callStates[key]) {
-    callStates[key] = { args: defaultArgsJson(fn), result: null, error: '', busy: false };
+    callStates[key] = { args: defaultArgs(fn), result: null, error: '', busy: false };
   }
   return callStates[key];
 }
@@ -274,19 +287,14 @@ async function doCall(row, fn) {
   const state = callStateFor(row, fn);
   state.result = null;
   state.error = '';
-  let argsParsed;
-  try {
-    argsParsed = state.args.trim() ? JSON.parse(state.args) : {};
-  } catch (e) {
-    state.error = 'Invalid JSON args: ' + e.message;
-    return;
-  }
   state.busy = true;
   try {
+    // state.args is the object edited by SchemaInput (seeded by defaultArgs);
+    // send it as-is — no JSON string handling anymore.
     const response = await backend.sendAction('remote-call', {
       remotename: row.remote.name,
       function: fn.name,
-      args: argsParsed,
+      args: state.args ?? {},
     });
     state.result = response.result;
   } catch (e) {
@@ -497,12 +505,11 @@ function removeArgument(fn, argIdx) {
                   <!-- Callable mode (connected remotes) -->
                   <template v-if="!isEditable(row)">
                     <div class="detail-left">
-                      <label>Arguments (JSON)</label>
-                      <textarea
+                      <label>Arguments</label>
+                      <SchemaInput
                         v-model="callStateFor(row, fn).args"
-                        placeholder='{"param": "value"}'
-                        spellcheck="false"
-                      ></textarea>
+                        :schema="buildArgSchema(fn)"
+                      />
                       <button class="btn btn-primary btn-sm" :disabled="callStateFor(row, fn).busy" @click="doCall(row, fn)">
                         {{ callStateFor(row, fn).busy ? 'Calling...' : 'Execute Call' }}
                       </button>
@@ -622,4 +629,4 @@ function removeArgument(fn, argIdx) {
 .btn-danger { background: var(--color-error, #ef4444); color: #fff; }
 .btn-sm { padding: 0.25em 0.6em; font-size: 0.8em; }
 .btn-xs { padding: 0.15em 0.4em; font-size: 0.75em; }
-</style>
+</style>
\ No newline at end of file