fix(knowledge): validate tag slots and share the tag-name length limit

apps/sim/app/api/knowledge/[id]/documents/[documentId]/tag-definitions/route.ts

@@ -5,7 +5,7 @@ import { saveDocumentTagDefinitionsContract } from '@/lib/api/contracts/knowledg
 import { parseRequest } from '@/lib/api/server'
 import { getSession } from '@/lib/auth'
 import { withRouteHandler } from '@/lib/core/utils/with-route-handler'
-import { SUPPORTED_FIELD_TYPES } from '@/lib/knowledge/constants'
+import { getFieldTypeForSlot, SUPPORTED_FIELD_TYPES } from '@/lib/knowledge/constants'
 import {
   cleanupUnusedTagDefinitions,
   createOrUpdateTagDefinitionsBulk,
@@ -114,6 +114,16 @@ export const POST = withRouteHandler(
             { status: 400 }
           )
         }
+        /**
+         * Slot validity only, not slot/field-type agreement: this route also renames
+         * existing definitions, which resend whatever pair is already stored.
+         */
+        if (getFieldTypeForSlot(def.tagSlot) === null) {
+          return NextResponse.json(
+            { error: 'Invalid request data', details: `Unsupported tag slot: ${def.tagSlot}` },
+            { status: 400 }
+          )
+        }
       }
 
       const bulkData: BulkTagDefinitionsData = {

apps/sim/app/api/knowledge/[id]/tag-definitions/route.test.ts

@@ -23,6 +23,7 @@ vi.mock('@/lib/knowledge/tags/service', () => ({
 
 vi.mock('@/app/api/knowledge/utils', () => knowledgeApiUtilsMock)
 
+import { KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH } from '@/lib/knowledge/constants'
 import { GET, POST } from '@/app/api/knowledge/[id]/tag-definitions/route'
 
 const KB_ID = 'kb-victim'
@@ -140,5 +141,64 @@ describe('Knowledge Base Tag Definitions API Route', () => {
       expect(mockCheckKnowledgeBaseWriteAccess).not.toHaveBeenCalled()
       expect(mockCreateTagDefinition).not.toHaveBeenCalled()
     })
+
+    it('rejects a tag slot this schema has no column for', async () => {
+      authenticateAs('user-1', 'session')
+      mockCheckKnowledgeBaseWriteAccess.mockResolvedValue(granted)
+
+      const response = await POST(
+        createMockRequest('POST', { ...CREATE_BODY, tagSlot: 'tag99' }),
+        params()
+      )
+
+      expect(response.status).toBe(400)
+      expect(mockCreateTagDefinition).not.toHaveBeenCalled()
+    })
+
+    it('rejects a slot that belongs to a different field type', async () => {
+      authenticateAs('user-1', 'session')
+      mockCheckKnowledgeBaseWriteAccess.mockResolvedValue(granted)
+
+      const response = await POST(
+        createMockRequest('POST', {
+          tagSlot: 'number1',
+          displayName: 'Mismatch',
+          fieldType: 'text',
+        }),
+        params()
+      )
+
+      expect(response.status).toBe(400)
+      expect(mockCreateTagDefinition).not.toHaveBeenCalled()
+    })
+
+    it('rejects an unsupported field type', async () => {
+      authenticateAs('user-1', 'session')
+      mockCheckKnowledgeBaseWriteAccess.mockResolvedValue(granted)
+
+      const response = await POST(
+        createMockRequest('POST', { ...CREATE_BODY, fieldType: 'nonsense' }),
+        params()
+      )
+
+      expect(response.status).toBe(400)
+      expect(mockCreateTagDefinition).not.toHaveBeenCalled()
+    })
+
+    it('rejects a display name longer than the shared limit', async () => {
+      authenticateAs('user-1', 'session')
+      mockCheckKnowledgeBaseWriteAccess.mockResolvedValue(granted)
+
+      const response = await POST(
+        createMockRequest('POST', {
+          ...CREATE_BODY,
+          displayName: 'a'.repeat(KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH + 1),
+        }),
+        params()
+      )
+
+      expect(response.status).toBe(400)
+      expect(mockCreateTagDefinition).not.toHaveBeenCalled()
+    })
   })
 })

apps/sim/app/api/knowledge/[id]/tag-definitions/route.ts

@@ -5,7 +5,7 @@ import { createTagDefinitionContract } from '@/lib/api/contracts/knowledge'
 import { parseRequest } from '@/lib/api/server'
 import { checkSessionOrInternalAuth } from '@/lib/auth/hybrid'
 import { withRouteHandler } from '@/lib/core/utils/with-route-handler'
-import { SUPPORTED_FIELD_TYPES } from '@/lib/knowledge/constants'
+import { isValidSlotForFieldType } from '@/lib/knowledge/constants'
 import { createTagDefinition, getTagDefinitions } from '@/lib/knowledge/tags/service'
 import { checkKnowledgeBaseAccess, checkKnowledgeBaseWriteAccess } from '@/app/api/knowledge/utils'
 
@@ -76,9 +76,18 @@ export const POST = withRouteHandler(
       if (!parsed.success) return parsed.response
 
       const validatedData = parsed.data.body
-      if (!(SUPPORTED_FIELD_TYPES as readonly string[]).includes(validatedData.fieldType)) {
+      /**
+       * The contract types `tagSlot` and `fieldType` as plain strings because
+       * tightening them to enums cascades into UI form state types, so the pair is
+       * checked here. Nothing downstream enforces it: the slot column is `text`
+       * (its Drizzle `enum` is types-only) and the service casts before inserting.
+       */
+      if (!isValidSlotForFieldType(validatedData.tagSlot, validatedData.fieldType)) {
         return NextResponse.json(
-          { error: 'Invalid request data', details: 'Invalid field type' },
+          {
+            error: 'Invalid request data',
+            details: `Tag slot "${validatedData.tagSlot}" is not valid for field type "${validatedData.fieldType}"`,
+          },
           { status: 400 }
         )
       }

apps/sim/app/workspace/[workspaceId]/knowledge/[id]/[documentId]/components/document-tags-modal/document-tags-modal.tsx

@@ -18,7 +18,13 @@ import {
 } from '@sim/emcn'
 import { createLogger } from '@sim/logger'
 import { formatDate } from '@sim/utils/formatting'
-import { ALL_TAG_SLOTS, type AllTagSlot, MAX_TAG_SLOTS } from '@/lib/knowledge/constants'
+import {
+  ALL_TAG_SLOTS,
+  type AllTagSlot,
+  FIELD_TYPE_LABELS,
+  KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH,
+  MAX_TAG_SLOTS,
+} from '@/lib/knowledge/constants'
 import type { DocumentTag } from '@/lib/knowledge/tags/types'
 import type { DocumentData } from '@/lib/knowledge/types'
 import {
@@ -30,14 +36,6 @@ import { useNextAvailableSlotMutation, useUpdateDocumentTags } from '@/hooks/que
 
 const logger = createLogger('DocumentTagsModal')
 
-/** Field type display labels */
-const FIELD_TYPE_LABELS: Record<string, string> = {
-  text: 'Text',
-  number: 'Number',
-  date: 'Date',
-  boolean: 'Boolean',
-}
-
 /**
  * Gets the appropriate value when changing field types.
  * Clears value when type changes to allow placeholder to show.
@@ -462,6 +460,7 @@ export function DocumentTagsModal({
                             setEditTagForm({ ...editTagForm, displayName: e.target.value })
                           }
                           placeholder='Enter tag name'
+                          maxLength={KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH}
                           error={tagNameConflict}
                           onKeyDown={(e) => {
                             if (e.key === 'Enter' && canSaveTag) {
@@ -615,6 +614,7 @@ export function DocumentTagsModal({
                         setEditTagForm({ ...editTagForm, displayName: e.target.value })
                       }
                       placeholder='Enter tag name'
+                      maxLength={KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH}
                       error={tagNameConflict}
                       onKeyDown={(e) => {
                         if (e.key === 'Enter' && canSaveTag) {

apps/sim/app/workspace/[workspaceId]/knowledge/[id]/components/base-tags-modal/base-tags-modal.tsx

@@ -17,7 +17,12 @@ import {
 } from '@sim/emcn'
 import { createLogger } from '@sim/logger'
 import type { TagUsageData } from '@/lib/api/contracts/knowledge'
-import { SUPPORTED_FIELD_TYPES, TAG_SLOT_CONFIG } from '@/lib/knowledge/constants'
+import {
+  FIELD_TYPE_LABELS,
+  KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH,
+  SUPPORTED_FIELD_TYPES,
+  TAG_SLOT_CONFIG,
+} from '@/lib/knowledge/constants'
 import { getDocumentIcon } from '@/app/workspace/[workspaceId]/knowledge/components'
 import {
   type TagDefinition,
@@ -31,13 +36,6 @@ import {
 
 const logger = createLogger('BaseTagsModal')
 
-const FIELD_TYPE_LABELS: Record<string, string> = {
-  text: 'Text',
-  number: 'Number',
-  date: 'Date',
-  boolean: 'Boolean',
-}
-
 interface DocumentListProps {
   documents: Array<{ id: string; name: string; tagValue: string }>
   totalCount: number
@@ -154,7 +152,9 @@ export function BaseTagsModal({ open, onOpenChange, knowledgeBaseId }: BaseTagsM
     isCreatingTag && !createTagMutation.isPending && hasTagNameConflict(createTagForm.displayName)
 
   const canSaveTag = () => {
-    return createTagForm.displayName.trim() && !hasTagNameConflict(createTagForm.displayName)
+    return (
+      createTagForm.displayName.trim().length > 0 && !hasTagNameConflict(createTagForm.displayName)
+    )
   }
 
   const getSlotUsageByFieldType = (fieldType: string): { used: number; max: number } => {
@@ -331,6 +331,7 @@ export function BaseTagsModal({ open, onOpenChange, knowledgeBaseId }: BaseTagsM
                         setCreateTagForm({ ...createTagForm, displayName: e.target.value })
                       }
                       placeholder='Enter tag name'
+                      maxLength={KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH}
                       error={Boolean(tagNameConflict)}
                       onKeyDown={(e) => {
                         if (e.key === 'Enter' && canSaveTag()) {

apps/sim/lib/api/contracts/knowledge/tags.ts

@@ -6,20 +6,27 @@ import {
   successResponseSchema,
 } from '@/lib/api/contracts/knowledge/shared'
 import { defineRouteContract } from '@/lib/api/contracts/types'
+import { KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH } from '@/lib/knowledge/constants'
 
 export const nextAvailableSlotQuerySchema = z.object({
   fieldType: z.string().min(1),
 })
 
 export const createTagDefinitionBodySchema = z.object({
   tagSlot: z.string().min(1, 'Tag slot is required'),
-  displayName: z.string().min(1, 'Display name is required'),
+  displayName: z
+    .string()
+    .min(1, 'Display name is required')
+    .max(KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH, 'Display name too long'),
   fieldType: z.string().min(1, 'Invalid field type'),
 })
 
 export const documentTagDefinitionInputSchema = z.object({
   tagSlot: z.string().min(1, 'Tag slot is required'),
-  displayName: z.string().min(1, 'Display name is required').max(100, 'Display name too long'),
+  displayName: z
+    .string()
+    .min(1, 'Display name is required')
+    .max(KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH, 'Display name too long'),
   fieldType: z.string().default('text'),
   _originalDisplayName: z.string().optional(),
 })

apps/sim/lib/copilot/tools/server/knowledge/knowledge-base.ts

@@ -22,6 +22,7 @@ import {
   type ServerToolContext,
 } from '@/lib/copilot/tools/server/base-tool'
 import { getInternalApiBaseUrl } from '@/lib/core/utils/urls'
+import { KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH } from '@/lib/knowledge/constants'
 import {
   createSingleDocument,
   deleteDocument,
@@ -705,6 +706,12 @@ export const knowledgeBaseServerTool: BaseServerTool<KnowledgeBaseArgs, Knowledg
               message: 'tagDisplayName is required for create_tag operation',
             }
           }
+          if (args.tagDisplayName.length > KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH) {
+            return {
+              success: false,
+              message: `tagDisplayName must be ${KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH} characters or less`,
+            }
+          }
 
           const writeAccess = await checkKnowledgeBaseWriteAccess(
             args.knowledgeBaseId,
@@ -777,6 +784,15 @@ export const knowledgeBaseServerTool: BaseServerTool<KnowledgeBaseArgs, Knowledg
               message: 'At least one of tagDisplayName or tagFieldType is required for update_tag',
             }
           }
+          if (
+            updateData.displayName &&
+            updateData.displayName.length > KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH
+          ) {
+            return {
+              success: false,
+              message: `tagDisplayName must be ${KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH} characters or less`,
+            }
+          }
 
           const existingTag = await getTagDefinitionById(args.tagDefinitionId)
           if (!existingTag) {

apps/sim/lib/knowledge/constants.ts

@@ -43,6 +43,12 @@ export type TagSlot = (typeof TAG_SLOTS)[number]
 /** Type for all tag slots */
 export type AllTagSlot = (typeof ALL_TAG_SLOTS)[number]
 
+/**
+ * Max character length for a tag display name, enforced on every write path (UI,
+ * create API, bulk document API, copilot tools).
+ */
+export const KNOWLEDGE_TAG_DISPLAY_NAME_MAX_LENGTH = 100
+
 /** Type for number tag slots */
 export type NumberTagSlot = (typeof TAG_SLOT_CONFIG.number.slots)[number]