fix(input-format): field not editable race condition

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/editor/components/sub-block/components/starter/input-format.tsx

@@ -1,5 +1,4 @@
 import { useCallback, useRef } from 'react'
-import { generateId } from '@sim/utils/id'
 import { Plus } from 'lucide-react'
 import { Trash } from '@/components/emcn/icons/trash'
 import 'prismjs/components/prism-json'
@@ -21,6 +20,7 @@ import {
 } from '@/components/emcn'
 import { cn } from '@/lib/core/utils/cn'
 import { handleKeyboardActivation } from '@/lib/core/utils/keyboard'
+import { createDefaultInputFormatField } from '@/lib/workflows/input-format'
 import { formatDisplayText } from '@/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/editor/components/sub-block/components/formatted-text'
 import { TagDropdown } from '@/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/editor/components/sub-block/components/tag-dropdown/tag-dropdown'
 import { getActiveWorkflowSearchHighlight } from '@/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/editor/components/sub-block/components/workflow-search-highlight'
@@ -74,18 +74,6 @@ const BOOLEAN_OPTIONS: ComboboxOption[] = [
   { label: 'false', value: 'false' },
 ]
 
-/**
- * Creates a new field with default values
- */
-const createDefaultField = (): Field => ({
-  id: generateId(),
-  name: '',
-  type: 'string',
-  value: '',
-  description: '',
-  collapsed: false,
-})
-
 /**
  * Validates and sanitizes field names by removing control characters and quotes
  */
@@ -127,8 +115,17 @@ export function FieldFormat({
     disabled,
   })
 
+  /**
+   * Stable fallback field used while the store value is still empty (e.g. a
+   * newly added block). Caching it in a ref keeps the field id constant across
+   * renders, so the inputs don't remount on each keystroke and edits commit to
+   * the same id instead of a freshly generated one.
+   */
+  const fallbackFieldRef = useRef<Field | null>(null)
+  const fallbackField = (fallbackFieldRef.current ??= createDefaultInputFormatField())
+
   const value = isPreview ? previewValue : storeValue
-  const fields: Field[] = Array.isArray(value) && value.length > 0 ? value : [createDefaultField()]
+  const fields: Field[] = Array.isArray(value) && value.length > 0 ? value : [fallbackField]
   const isReadOnly = isPreview || disabled
 
   const renderFieldLabel = (label: string) => <Label>{label}</Label>
@@ -138,7 +135,7 @@ export function FieldFormat({
    */
   const addField = () => {
     if (isReadOnly) return
-    setStoreValue([...fields, createDefaultField()])
+    setStoreValue([...fields, createDefaultInputFormatField()])
   }
 
   /**
@@ -148,15 +145,19 @@ export function FieldFormat({
     if (isReadOnly) return
 
     if (fields.length === 1) {
-      setStoreValue([createDefaultField()])
+      setStoreValue([createDefaultInputFormatField()])
       return
     }
 
     setStoreValue(fields.filter((field) => field.id !== id))
   }
 
-  const storeValueRef = useRef(storeValue)
-  storeValueRef.current = storeValue
+  /**
+   * Mirrors the rendered fields (store value or stable fallback) so updateField
+   * always commits against the same ids the UI is currently showing.
+   */
+  const fieldsRef = useRef(fields)
+  fieldsRef.current = fields
 
   const isReadOnlyRef = useRef(isReadOnly)
   isReadOnlyRef.current = isReadOnly
@@ -173,14 +174,8 @@ export function FieldFormat({
           ? validateFieldName(fieldValue)
           : fieldValue
 
-      const currentStoreValue = storeValueRef.current
-      const currentFields: Field[] =
-        Array.isArray(currentStoreValue) && currentStoreValue.length > 0
-          ? currentStoreValue
-          : [createDefaultField()]
-
       setStoreValueRef.current(
-        currentFields.map((f) => (f.id === id ? { ...f, [fieldKey]: updatedValue } : f))
+        fieldsRef.current.map((f) => (f.id === id ? { ...f, [fieldKey]: updatedValue } : f))
       )
     },
     []

apps/sim/lib/workflows/defaults.ts

@@ -1,5 +1,6 @@
 import { generateId } from '@sim/utils/id'
 import { getEffectiveBlockOutputs } from '@/lib/workflows/blocks/block-outputs'
+import { createDefaultInputFormatField } from '@/lib/workflows/input-format'
 import { getBlock } from '@/blocks'
 import type { BlockConfig, SubBlockConfig } from '@/blocks/types'
 import type { BlockState, SubBlockState, WorkflowState } from '@/stores/workflows/workflow/types'
@@ -39,15 +40,7 @@ function resolveInitialValue(subBlock: SubBlockConfig): unknown {
   }
 
   if (subBlock.type === 'input-format') {
-    return [
-      {
-        id: generateId(),
-        name: '',
-        type: 'string',
-        value: '',
-        collapsed: false,
-      },
-    ]
+    return [createDefaultInputFormatField()]
   }
 
   if (subBlock.type === 'table') {

apps/sim/lib/workflows/input-format.test.ts

@@ -1,5 +1,6 @@
 import { describe, expect, it } from 'vitest'
 import {
+  createDefaultInputFormatField,
   extractInputFieldsFromBlocks,
   normalizeInputFormatValue,
 } from '@/lib/workflows/input-format'
@@ -227,3 +228,28 @@ describe('normalizeInputFormatValue', () => {
     expect(normalizeInputFormatValue(input)).toEqual(input)
   })
 })
+
+describe('createDefaultInputFormatField', () => {
+  it.concurrent('creates an empty field with the canonical default shape', () => {
+    const field = createDefaultInputFormatField()
+    expect(field).toEqual({
+      id: expect.any(String),
+      name: '',
+      type: 'string',
+      value: '',
+      collapsed: false,
+    })
+    expect(field.id.length).toBeGreaterThan(0)
+  })
+
+  it.concurrent('omits description so it is not persisted by default', () => {
+    expect('description' in createDefaultInputFormatField()).toBe(false)
+  })
+
+  it.concurrent('returns a fresh id and a new object on each call', () => {
+    const first = createDefaultInputFormatField()
+    const second = createDefaultInputFormatField()
+    expect(first.id).not.toBe(second.id)
+    expect(first).not.toBe(second)
+  })
+})

apps/sim/lib/workflows/input-format.ts

@@ -1,3 +1,4 @@
+import { generateId } from '@sim/utils/id'
 import { isInputDefinitionTrigger } from '@/lib/workflows/triggers/input-definition-triggers'
 import type { InputFormatField } from '@/lib/workflows/types'
 
@@ -10,6 +11,36 @@ export interface WorkflowInputField {
   description?: string
 }
 
+/**
+ * Stateful input-format field as stored in sub-block values: the editor's
+ * per-row shape, including the editor-only `id` and `collapsed` fields. Stricter
+ * than the wire-level {@link InputFormatField} (required `name`/`type`/`value`).
+ */
+interface InputFormatFieldState {
+  id: string
+  name: string
+  type: 'string' | 'number' | 'boolean' | 'object' | 'array' | 'file[]'
+  value: string
+  description?: string
+  collapsed: boolean
+}
+
+/**
+ * Creates a new empty input-format field with a fresh id.
+ *
+ * Single source of truth for the default field shape used when seeding
+ * input-format / response-format sub-blocks and when adding rows in the editor.
+ */
+export function createDefaultInputFormatField(): InputFormatFieldState {
+  return {
+    id: generateId(),
+    name: '',
+    type: 'string',
+    value: '',
+    collapsed: false,
+  }
+}
+
 /**
  * Extracts input fields from workflow blocks.
  * Finds the trigger block (start_trigger, input_trigger, or starter) and extracts its inputFormat.

apps/sim/stores/workflows/utils.ts

@@ -4,6 +4,7 @@ import type { Edge } from 'reactflow'
 import { DEFAULT_DUPLICATE_OFFSET } from '@/lib/workflows/autolayout/constants'
 import { getEffectiveBlockOutputs } from '@/lib/workflows/blocks/block-outputs'
 import { remapConditionBlockIds, remapConditionEdgeHandle } from '@/lib/workflows/condition-ids'
+import { createDefaultInputFormatField } from '@/lib/workflows/input-format'
 import { buildDefaultCanonicalModes } from '@/lib/workflows/subblocks/visibility'
 import { hasTriggerCapability } from '@/lib/workflows/triggers/trigger-utils'
 import { getBlock } from '@/blocks'
@@ -151,15 +152,7 @@ export function prepareBlockState(options: PrepareBlockStateOptions): BlockState
       } else if (subBlock.defaultValue !== undefined) {
         initialValue = subBlock.defaultValue
       } else if (subBlock.type === 'input-format' || subBlock.type === 'response-format') {
-        initialValue = [
-          {
-            id: generateId(),
-            name: '',
-            type: 'string',
-            value: '',
-            collapsed: false,
-          },
-        ]
+        initialValue = [createDefaultInputFormatField()]
       } else if (subBlock.type === 'table') {
         initialValue = []
       }

apps/sim/stores/workflows/workflow/store.ts

@@ -1,5 +1,4 @@
 import { createLogger } from '@sim/logger'
-import { toError } from '@sim/utils/errors'
 import { generateId } from '@sim/utils/id'
 import type { Edge } from 'reactflow'
 import { create } from 'zustand'
@@ -9,7 +8,6 @@ import {
   getDynamicHandleSubblockType,
   isDynamicHandleSubblock,
 } from '@/lib/workflows/dynamic-handle-topology'
-import type { SubBlockConfig } from '@/blocks/types'
 import { normalizeName, RESERVED_BLOCK_NAMES } from '@/executor/constants'
 import { useSubBlockStore } from '@/stores/workflows/subblock/store'
 import {
@@ -37,72 +35,6 @@ import { normalizeWorkflowState } from '@/stores/workflows/workflow/validation'
 
 const logger = createLogger('WorkflowStore')
 
-/**
- * Creates a deep clone of an initial sub-block value to avoid shared references.
- *
- * @param value - The value to clone.
- * @returns A cloned value suitable for initializing sub-block state.
- */
-function cloneInitialSubblockValue(value: unknown): unknown {
-  if (Array.isArray(value)) {
-    return value.map((item) => cloneInitialSubblockValue(item))
-  }
-
-  if (value && typeof value === 'object') {
-    return Object.entries(value as Record<string, unknown>).reduce<Record<string, unknown>>(
-      (acc, [key, entry]) => {
-        acc[key] = cloneInitialSubblockValue(entry)
-        return acc
-      },
-      {}
-    )
-  }
-
-  return value ?? null
-}
-
-/**
- * Resolves the initial value for a sub-block based on its configuration.
- *
- * @param config - The sub-block configuration.
- * @returns The resolved initial value or null when no defaults are defined.
- */
-function resolveInitialSubblockValue(config: SubBlockConfig): unknown {
-  if (typeof config.value === 'function') {
-    try {
-      const resolved = config.value({})
-      return cloneInitialSubblockValue(resolved)
-    } catch (error) {
-      logger.warn('Failed to resolve dynamic sub-block default value', {
-        subBlockId: config.id,
-        error: toError(error).message,
-      })
-    }
-  }
-
-  if (config.defaultValue !== undefined) {
-    return cloneInitialSubblockValue(config.defaultValue)
-  }
-
-  if (config.type === 'input-format') {
-    return [
-      {
-        id: generateId(),
-        name: '',
-        type: 'string',
-        value: '',
-        collapsed: false,
-      },
-    ]
-  }
-
-  if (config.type === 'table') {
-    return []
-  }
-
-  return null
-}
-
 const initialState = {
   currentWorkflowId: null,
   blocks: {},