diff --git a/app/w/[id]/components/workflow-block/components/sub-block/components/dropdown.tsx b/app/w/[id]/components/workflow-block/components/sub-block/components/dropdown.tsx
index b3fdc352cc..10bb122da2 100644
--- a/app/w/[id]/components/workflow-block/components/sub-block/components/dropdown.tsx
+++ b/app/w/[id]/components/workflow-block/components/sub-block/components/dropdown.tsx
@@ -9,7 +9,7 @@ import {
 import { useSubBlockValue } from '../hooks/use-sub-block-value'
 
 interface DropdownProps {
-  options: string[]
+  options: Array<string | { label: string; id: string }>
   defaultValue?: string
   blockId: string
   subBlockId: string
@@ -21,14 +21,24 @@ export function Dropdown({ options, defaultValue, blockId, subBlockId }: Dropdow
   // Set the value to the first option if it's not set
   useEffect(() => {
     if (!value && options.length > 0) {
-      setValue(defaultValue ?? options[0])
+      const firstOption = options[0]
+      const firstValue = typeof firstOption === 'string' ? firstOption : firstOption.id
+      setValue(firstValue)
     }
   }, [value, options, defaultValue, setValue])
 
+  const getOptionValue = (option: string | { label: string; id: string }) => {
+    return typeof option === 'string' ? option : option.id
+  }
+
+  const getOptionLabel = (option: string | { label: string; id: string }) => {
+    return typeof option === 'string' ? option : option.label
+  }
+
   return (
     <Select
       value={value as string | undefined}
-      defaultValue={defaultValue ?? options[0]}
+      defaultValue={defaultValue ?? getOptionValue(options[0])}
       onValueChange={(value) => setValue(value)}
     >
       <SelectTrigger className="text-left">
@@ -36,8 +46,8 @@ export function Dropdown({ options, defaultValue, blockId, subBlockId }: Dropdow
       </SelectTrigger>
       <SelectContent>
         {options.map((option) => (
-          <SelectItem key={option} value={option}>
-            {option}
+          <SelectItem key={getOptionValue(option)} value={getOptionValue(option)}>
+            {getOptionLabel(option)}
           </SelectItem>
         ))}
       </SelectContent>
diff --git a/app/w/[id]/components/workflow-block/components/sub-block/sub-block.tsx b/app/w/[id]/components/workflow-block/components/sub-block/sub-block.tsx
index 8b33c0b253..9cc5525fe8 100644
--- a/app/w/[id]/components/workflow-block/components/sub-block/sub-block.tsx
+++ b/app/w/[id]/components/workflow-block/components/sub-block/sub-block.tsx
@@ -10,6 +10,7 @@ import { SliderInput } from './components/slider-input'
 import { Switch } from './components/switch'
 import { Table } from './components/table'
 import { ToolInput } from './components/tool-input'
+import { useSubBlockValue } from './hooks/use-sub-block-value'
 
 interface SubBlockProps {
   blockId: string
@@ -18,10 +19,18 @@ interface SubBlockProps {
 }
 
 export function SubBlock({ blockId, config, isConnecting }: SubBlockProps) {
+  const [fieldValue] = useSubBlockValue(blockId, config.condition?.field || '')
+
   const handleMouseDown = (e: React.MouseEvent) => {
     e.stopPropagation()
   }
 
+  // Check if the sub-block should be rendered based on its condition
+  const shouldRender = () => {
+    if (!config.condition) return true
+    return fieldValue === config.condition.value
+  }
+
   const renderInput = () => {
     switch (config.type) {
       case 'short-input':
@@ -99,6 +108,10 @@ export function SubBlock({ blockId, config, isConnecting }: SubBlockProps) {
     }
   }
 
+  if (!shouldRender()) {
+    return null
+  }
+
   return (
     <div className="space-y-1" onMouseDown={handleMouseDown}>
       {config.type !== 'switch' && <Label>{config.title}</Label>}
diff --git a/blocks/blocks/gmail.ts b/blocks/blocks/gmail.ts
new file mode 100644
index 0000000000..64aabfd64f
--- /dev/null
+++ b/blocks/blocks/gmail.ts
@@ -0,0 +1,128 @@
+import { GmailIcon } from '@/components/icons'
+import { GmailToolResponse } from '@/tools/gmail/types'
+import { BlockConfig } from '../types'
+
+export const GmailBlock: BlockConfig<GmailToolResponse> = {
+  type: 'gmail_block',
+  toolbar: {
+    title: 'Gmail',
+    description: 'Send, read, and search Gmail messages',
+    bgColor: '#EA4335', // Gmail red color
+    icon: GmailIcon,
+    category: 'tools',
+  },
+  tools: {
+    access: ['gmail_send', 'gmail_read', 'gmail_search'],
+    config: {
+      tool: (params) => {
+        switch (params.operation) {
+          case 'send_gmail':
+            return 'gmail_send'
+          case 'read_gmail':
+            return 'gmail_read'
+          case 'search_gmail':
+            return 'gmail_search'
+          default:
+            throw new Error(`Invalid Gmail operation: ${params.operation}`)
+        }
+      },
+    },
+  },
+  workflow: {
+    inputs: {
+      operation: { type: 'string', required: true },
+      accessToken: { type: 'string', required: true },
+      // Send operation inputs
+      to: { type: 'string', required: false },
+      subject: { type: 'string', required: false },
+      body: { type: 'string', required: false },
+      // Read operation inputs
+      messageId: { type: 'string', required: false },
+      // Search operation inputs
+      query: { type: 'string', required: false },
+      maxResults: { type: 'number', required: false },
+    },
+    outputs: {
+      response: {
+        type: {
+          content: 'string',
+          metadata: 'json',
+        },
+      },
+    },
+    subBlocks: [
+      // Operation selector
+      {
+        id: 'operation',
+        title: 'Operation',
+        type: 'dropdown',
+        layout: 'full',
+        options: [
+          { label: 'Send Email', id: 'send_gmail' },
+          { label: 'Read Email', id: 'read_gmail' },
+          { label: 'Search Emails', id: 'search_gmail' },
+        ],
+      },
+      // OAuth Token
+      {
+        id: 'accessToken',
+        title: 'Access Token',
+        type: 'short-input',
+        layout: 'full',
+        placeholder: 'Enter Gmail OAuth token',
+        password: true,
+      },
+      // Send Email Fields
+      {
+        id: 'to',
+        title: 'To',
+        type: 'short-input',
+        layout: 'full',
+        placeholder: 'Recipient email address',
+        condition: { field: 'operation', value: 'send_gmail' },
+      },
+      {
+        id: 'subject',
+        title: 'Subject',
+        type: 'short-input',
+        layout: 'full',
+        placeholder: 'Email subject',
+        condition: { field: 'operation', value: 'send_gmail' },
+      },
+      {
+        id: 'body',
+        title: 'Body',
+        type: 'long-input',
+        layout: 'full',
+        placeholder: 'Email content',
+        condition: { field: 'operation', value: 'send_gmail' },
+      },
+      // Read Email Fields
+      {
+        id: 'messageId',
+        title: 'Message ID',
+        type: 'short-input',
+        layout: 'full',
+        placeholder: 'Enter message ID to read',
+        condition: { field: 'operation', value: 'read_gmail' },
+      },
+      // Search Fields
+      {
+        id: 'query',
+        title: 'Search Query',
+        type: 'short-input',
+        layout: 'full',
+        placeholder: 'Enter search terms',
+        condition: { field: 'operation', value: 'search_gmail' },
+      },
+      {
+        id: 'maxResults',
+        title: 'Max Results',
+        type: 'short-input',
+        layout: 'full',
+        placeholder: 'Maximum number of results (default: 10)',
+        condition: { field: 'operation', value: 'search_gmail' },
+      },
+    ],
+  },
+}
diff --git a/blocks/blocks/notion.ts b/blocks/blocks/notion.ts
index 06b7b64cef..b2152a29e9 100644
--- a/blocks/blocks/notion.ts
+++ b/blocks/blocks/notion.ts
@@ -15,7 +15,7 @@ export const NotionBlock: BlockConfig<NotionResponse> = {
     access: ['notion_read', 'notion_write'],
     config: {
       tool: (params) => {
-        return params.operation === 'write' ? 'notion_write' : 'notion_read'
+        return params.operation === 'write_notion' ? 'notion_write' : 'notion_read'
       },
     },
   },
@@ -40,7 +40,10 @@ export const NotionBlock: BlockConfig<NotionResponse> = {
         title: 'Operation',
         type: 'dropdown',
         layout: 'full',
-        options: ['read', 'write'],
+        options: [
+          { label: 'Read Page', id: 'read_notion' },
+          { label: 'Write Page', id: 'write_notion' },
+        ],
       },
       {
         id: 'pageId',
@@ -55,6 +58,7 @@ export const NotionBlock: BlockConfig<NotionResponse> = {
         type: 'long-input',
         layout: 'full',
         placeholder: 'Enter content to write (for write operation)',
+        condition: { field: 'operation', value: 'write_notion' },
       },
       {
         id: 'apiKey',
diff --git a/blocks/index.ts b/blocks/index.ts
index 2080dfaf9f..6aeee6c161 100644
--- a/blocks/index.ts
+++ b/blocks/index.ts
@@ -6,6 +6,7 @@ import { CrewAIVisionBlock } from './blocks/crewai'
 import { FirecrawlScrapeBlock } from './blocks/firecrawl'
 import { FunctionBlock } from './blocks/function'
 import { GitHubBlock } from './blocks/github'
+import { GmailBlock } from './blocks/gmail'
 import { JinaBlock } from './blocks/jina'
 import { NotionBlock } from './blocks/notion'
 import { RouterBlock } from './blocks/router'
@@ -34,6 +35,7 @@ export {
   RouterBlock,
   YouTubeSearchBlock,
   NotionBlock,
+  GmailBlock,
 }
 
 // Registry of all block configurations
@@ -54,6 +56,7 @@ const blocks: Record<string, BlockConfig> = {
   tavily_extract: TavilyExtractBlock,
   youtube_search: YouTubeSearchBlock,
   notion_reader: NotionBlock,
+  gmail_block: GmailBlock,
 }
 
 // Build a reverse mapping of tools to block types
diff --git a/blocks/types.ts b/blocks/types.ts
index 5fa81845cb..835196f1d0 100644
--- a/blocks/types.ts
+++ b/blocks/types.ts
@@ -78,6 +78,10 @@ export interface SubBlockConfig {
   hidden?: boolean
   value?: (params: Record<string, any>) => string
   minimizable?: boolean
+  condition?: {
+    field: string
+    value: string | number | boolean
+  }
 }
 
 export interface BlockConfig<T extends ToolResponse = ToolResponse> {
diff --git a/tools/gmail/read.ts b/tools/gmail/read.ts
new file mode 100644
index 0000000000..7f3f4e57ae
--- /dev/null
+++ b/tools/gmail/read.ts
@@ -0,0 +1,88 @@
+import { ToolConfig } from '../types'
+import { GmailMessage, GmailReadParams, GmailToolResponse } from './types'
+
+const GMAIL_API_BASE = 'https://gmail.googleapis.com/gmail/v1/users/me'
+
+export const gmailReadTool: ToolConfig<GmailReadParams, GmailToolResponse> = {
+  id: 'gmail_read',
+  name: 'Gmail Read',
+  description: 'Read emails from Gmail',
+  version: '1.0.0',
+
+  params: {
+    accessToken: {
+      type: 'string',
+      required: true,
+      requiredForToolCall: true,
+      description: 'OAuth access token for Gmail API',
+    },
+    messageId: {
+      type: 'string',
+      required: true,
+      requiredForToolCall: true,
+      description: 'ID of the message to read',
+    },
+  },
+
+  request: {
+    url: (params: GmailReadParams) => `${GMAIL_API_BASE}/messages/${params.messageId}`,
+    method: 'GET',
+    headers: (params: GmailReadParams) => ({
+      Authorization: `Bearer ${params.accessToken}`,
+      'Content-Type': 'application/json',
+    }),
+  },
+
+  transformResponse: async (response) => {
+    const data = await response.json()
+
+    if (!response.ok) {
+      throw new Error(data.error?.message || 'Failed to read email')
+    }
+
+    const message = data as GmailMessage
+    const headers = message.payload.headers
+    const subject = headers.find((h) => h.name.toLowerCase() === 'subject')?.value
+    const from = headers.find((h) => h.name.toLowerCase() === 'from')?.value
+    const to = headers.find((h) => h.name.toLowerCase() === 'to')?.value
+
+    let body = ''
+    if (message.payload.body?.data) {
+      body = Buffer.from(message.payload.body.data, 'base64').toString()
+    } else if (message.payload.parts) {
+      const textPart = message.payload.parts.find((p) => p.mimeType === 'text/plain')
+      if (textPart?.body?.data) {
+        body = Buffer.from(textPart.body.data, 'base64').toString()
+      }
+    }
+
+    return {
+      success: true,
+      output: {
+        content: body,
+        metadata: {
+          id: message.id,
+          threadId: message.threadId,
+          labelIds: message.labelIds,
+          from,
+          to,
+          subject,
+        },
+      },
+    }
+  },
+
+  transformError: (error) => {
+    // Handle Google API error format
+    if (error.error?.message) {
+      if (error.error.message.includes('invalid authentication credentials')) {
+        return 'Invalid or expired access token. Please reauthenticate.'
+      }
+      if (error.error.message.includes('quota')) {
+        return 'Gmail API quota exceeded. Please try again later.'
+      }
+      return error.error.message
+    }
+    return error.message || 'An unexpected error occurred while reading email'
+  },
+}
diff --git a/tools/gmail/search.ts b/tools/gmail/search.ts
new file mode 100644
index 0000000000..82db1f3c19
--- /dev/null
+++ b/tools/gmail/search.ts
@@ -0,0 +1,82 @@
+import { ToolConfig } from '../types'
+import { GmailSearchParams, GmailToolResponse } from './types'
+
+const GMAIL_API_BASE = 'https://gmail.googleapis.com/gmail/v1/users/me'
+
+export const gmailSearchTool: ToolConfig<GmailSearchParams, GmailToolResponse> = {
+  id: 'gmail_search',
+  name: 'Gmail Search',
+  description: 'Search emails in Gmail',
+  version: '1.0.0',
+
+  params: {
+    accessToken: {
+      type: 'string',
+      required: true,
+      requiredForToolCall: true,
+      description: 'OAuth access token for Gmail API',
+    },
+    query: {
+      type: 'string',
+      required: true,
+      description: 'Search query for emails',
+    },
+    maxResults: {
+      type: 'number',
+      required: false,
+      description: 'Maximum number of results to return',
+    },
+  },
+
+  request: {
+    url: (params: GmailSearchParams) => {
+      const searchParams = new URLSearchParams()
+      searchParams.append('q', params.query)
+      if (params.maxResults) {
+        searchParams.append('maxResults', params.maxResults.toString())
+      }
+      return `${GMAIL_API_BASE}/messages?${searchParams.toString()}`
+    },
+    method: 'GET',
+    headers: (params: GmailSearchParams) => ({
+      Authorization: `Bearer ${params.accessToken}`,
+      'Content-Type': 'application/json',
+    }),
+  },
+
+  transformResponse: async (response) => {
+    const data = await response.json()
+
+    if (!response.ok) {
+      throw new Error(data.error?.message || 'Failed to search emails')
+    }
+
+    return {
+      success: true,
+      output: {
+        content: `Found ${data.messages?.length || 0} messages`,
+        metadata: {
+          results:
+            data.messages?.map((msg: any) => ({
+              id: msg.id,
+              threadId: msg.threadId,
+            })) || [],
+        },
+      },
+    }
+  },
+
+  transformError: (error) => {
+    // Handle Google API error format
+    if (error.error?.message) {
+      if (error.error.message.includes('invalid authentication credentials')) {
+        return 'Invalid or expired access token. Please reauthenticate.'
+      }
+      if (error.error.message.includes('quota')) {
+        return 'Gmail API quota exceeded. Please try again later.'
+      }
+      return error.error.message
+    }
+    return error.message || 'An unexpected error occurred while searching emails'
+  },
+}
diff --git a/tools/gmail/send.ts b/tools/gmail/send.ts
new file mode 100644
index 0000000000..e3660b18d9
--- /dev/null
+++ b/tools/gmail/send.ts
@@ -0,0 +1,93 @@
+import { ToolConfig } from '../types'
+import { GmailSendParams, GmailToolResponse } from './types'
+
+const GMAIL_API_BASE = 'https://gmail.googleapis.com/gmail/v1/users/me'
+
+export const gmailSendTool: ToolConfig<GmailSendParams, GmailToolResponse> = {
+  id: 'gmail_send',
+  name: 'Gmail Send',
+  description: 'Send emails using Gmail',
+  version: '1.0.0',
+
+  params: {
+    accessToken: {
+      type: 'string',
+      required: true,
+      requiredForToolCall: true,
+      description: 'OAuth access token for Gmail API',
+    },
+    to: {
+      type: 'string',
+      required: true,
+      requiredForToolCall: true,
+      description: 'Recipient email address',
+    },
+    subject: {
+      type: 'string',
+      required: true,
+      description: 'Email subject',
+    },
+    body: {
+      type: 'string',
+      required: true,
+      description: 'Email body content',
+    },
+  },
+
+  request: {
+    url: () => `${GMAIL_API_BASE}/messages/send`,
+    method: 'POST',
+    headers: (params: GmailSendParams) => ({
+      Authorization: `Bearer ${params.accessToken}`,
+      'Content-Type': 'application/json',
+    }),
+    body: (params: GmailSendParams): Record<string, any> => {
+      const email = [
+        'Content-Type: text/plain; charset="UTF-8"',
+        'MIME-Version: 1.0',
+        `To: ${params.to}`,
+        `Subject: ${params.subject}`,
+        '',
+        params.body,
+      ].join('\n')
+
+      return {
+        raw: Buffer.from(email).toString('base64url'),
+      }
+    },
+  },
+
+  transformResponse: async (response) => {
+    const data = await response.json()
+
+    if (!response.ok) {
+      throw new Error(data.error?.message || 'Failed to send email')
+    }
+
+    return {
+      success: true,
+      output: {
+        content: 'Email sent successfully',
+        metadata: {
+          id: data.id,
+          threadId: data.threadId,
+          labelIds: data.labelIds,
+        },
+      },
+    }
+  },
+
+  transformError: (error) => {
+    // Handle Google API error format
+    if (error.error?.message) {
+      if (error.error.message.includes('invalid authentication credentials')) {
+        return 'Invalid or expired access token. Please reauthenticate.'
+      }
+      if (error.error.message.includes('quota')) {
+        return 'Gmail API quota exceeded. Please try again later.'
+      }
+      return error.error.message
+    }
+    return error.message || 'An unexpected error occurred while sending email'
+  },
+}
diff --git a/tools/gmail/types.ts b/tools/gmail/types.ts
new file mode 100644
index 0000000000..2ef6b7a8eb
--- /dev/null
+++ b/tools/gmail/types.ts
@@ -0,0 +1,78 @@
+import { ToolResponse } from '../types'
+
+// Base parameters shared by all operations
+interface BaseGmailParams {
+  accessToken: string
+}
+
+// Send operation parameters
+export interface GmailSendParams extends BaseGmailParams {
+  to: string
+  subject: string
+  body: string
+}
+
+// Read operation parameters
+export interface GmailReadParams extends BaseGmailParams {
+  messageId: string
+}
+
+// Search operation parameters
+export interface GmailSearchParams extends BaseGmailParams {
+  query: string
+  maxResults?: number
+}
+
+// Union type for all Gmail tool parameters
+export type GmailToolParams = GmailSendParams | GmailReadParams | GmailSearchParams
+
+// Response metadata
+interface BaseGmailMetadata {
+  id?: string
+  threadId?: string
+  labelIds?: string[]
+}
+
+interface EmailMetadata extends BaseGmailMetadata {
+  from?: string
+  to?: string
+  subject?: string
+}
+
+interface SearchMetadata extends BaseGmailMetadata {
+  results: Array<{
+    id: string
+    threadId: string
+  }>
+}
+
+// Response format
+export interface GmailToolResponse extends ToolResponse {
+  output: {
+    content: string
+    metadata: EmailMetadata | SearchMetadata
+  }
+}
+
+// Email Message Interface
+export interface GmailMessage {
+  id: string
+  threadId: string
+  labelIds: string[]
+  snippet: string
+  payload: {
+    headers: Array<{
+      name: string
+      value: string
+    }>
+    body: {
+      data?: string
+    }
+    parts?: Array<{
+      mimeType: string
+      body: {
+        data?: string
+      }
+    }>
+  }
+}
diff --git a/tools/index.ts b/tools/index.ts
index d397d5eb6a..65f1f28b65 100644
--- a/tools/index.ts
+++ b/tools/index.ts
@@ -5,6 +5,9 @@ import { reasonerTool as deepseekReasoner } from './deepseek/reasoner'
 import { scrapeTool } from './firecrawl/scrape'
 import { functionExecuteTool as functionExecute } from './function/execute'
 import { repoInfoTool } from './github/repo'
+import { gmailReadTool } from './gmail/read'
+import { gmailSearchTool } from './gmail/search'
+import { gmailSendTool } from './gmail/send'
 import { chatTool as googleChat } from './google/chat'
 import { requestTool as httpRequest } from './http/request'
 import { contactsTool as hubspotContacts } from './hubspot/contacts'
@@ -44,6 +47,9 @@ export const tools: Record<string, ToolConfig> = {
   youtube_search: youtubeSearchTool,
   notion_read: notionReadTool,
   notion_write: notionWriteTool,
+  gmail_send: gmailSendTool,
+  gmail_read: gmailReadTool,
+  gmail_search: gmailSearchTool,
 }
 
 // Get a tool by its ID