feat(gmail): add edit draft and update label tools

apps/docs/content/docs/en/tools/gmail.mdx

@@ -90,6 +90,34 @@ Draft emails using Gmail. Returns API-aligned fields only.
 | `threadId` | string | Gmail thread ID |
 | `labelIds` | array | Email labels |
 
+### `gmail_edit_draft`
+
+Update an existing Gmail draft in place without deleting and recreating it.
+
+#### Input
+
+| Parameter | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `draftId` | string | Yes | ID of the draft to update \(from Gmail List Drafts or Gmail Get Draft\) |
+| `to` | string | Yes | Recipient email address |
+| `subject` | string | No | Email subject |
+| `body` | string | Yes | Email body content |
+| `contentType` | string | No | Content type for the email body \(text or html\) |
+| `threadId` | string | No | Thread ID to associate the draft with \(for threading\) |
+| `replyToMessageId` | string | No | Gmail message ID to reply to - use the "id" field from Gmail Read results \(not the RFC "messageId"\) |
+| `cc` | string | No | CC recipients \(comma-separated\) |
+| `bcc` | string | No | BCC recipients \(comma-separated\) |
+| `attachments` | file[] | No | Files to attach to the email draft |
+
+#### Output
+
+| Parameter | Type | Description |
+| --------- | ---- | ----------- |
+| `draftId` | string | Draft ID |
+| `messageId` | string | Gmail message ID for the draft |
+| `threadId` | string | Gmail thread ID |
+| `labelIds` | array | Email labels |
+
 ### `gmail_read`
 
 Read emails from Gmail. Returns API-aligned fields only.

apps/docs/content/docs/en/tools/outlook.mdx

@@ -56,7 +56,6 @@ Send emails using Outlook
 | `body` | string | Yes | Email body content |
 | `contentType` | string | No | Content type for the email body \(text or html\) |
 | `replyToMessageId` | string | No | Message ID to reply to \(for threading\) |
-| `conversationId` | string | No | Conversation ID for threading |
 | `cc` | string | No | CC recipients \(comma-separated\) |
 | `bcc` | string | No | BCC recipients \(comma-separated\) |
 | `attachments` | file[] | No | Files to attach to the email |

apps/sim/app/(landing)/integrations/data/integrations.json

@@ -4662,6 +4662,10 @@
         "name": "Draft Email",
         "description": "Draft emails using Gmail"
       },
+      {
+        "name": "Edit Draft",
+        "description": "Update an existing Gmail draft in place without deleting and recreating it."
+      },
       {
         "name": "Search Email",
         "description": "Search emails in Gmail"
@@ -4699,7 +4703,7 @@
         "description": "Remove label(s) from a Gmail message"
       }
     ],
-    "operationCount": 12,
+    "operationCount": 13,
     "triggers": [
       {
         "id": "gmail_poller",

apps/sim/app/api/tools/gmail/edit-draft/route.ts

@@ -0,0 +1,180 @@
+import { createLogger } from '@sim/logger'
+import { type NextRequest, NextResponse } from 'next/server'
+import { gmailEditDraftContract } from '@/lib/api/contracts/google-tools'
+import { parseRequest } from '@/lib/api/server'
+import { checkInternalAuth } from '@/lib/auth/hybrid'
+import { generateRequestId } from '@/lib/core/utils/request'
+import { withRouteHandler } from '@/lib/core/utils/with-route-handler'
+import { processFilesToUserFiles } from '@/lib/uploads/utils/file-utils'
+import { downloadFileFromStorage } from '@/lib/uploads/utils/file-utils.server'
+import {
+  base64UrlEncode,
+  buildMimeMessage,
+  buildSimpleEmailMessage,
+  fetchThreadingHeaders,
+  GMAIL_API_BASE,
+} from '@/tools/gmail/utils'
+
+export const dynamic = 'force-dynamic'
+
+const logger = createLogger('GmailEditDraftAPI')
+
+export const POST = withRouteHandler(async (request: NextRequest) => {
+  const requestId = generateRequestId()
+
+  try {
+    const authResult = await checkInternalAuth(request, { requireWorkflowId: false })
+
+    if (!authResult.success) {
+      logger.warn(`[${requestId}] Unauthorized Gmail edit draft attempt: ${authResult.error}`)
+      return NextResponse.json(
+        {
+          success: false,
+          error: authResult.error || 'Authentication required',
+        },
+        { status: 401 }
+      )
+    }
+
+    logger.info(
+      `[${requestId}] Authenticated Gmail edit draft request via ${authResult.authType}`,
+      { userId: authResult.userId }
+    )
+
+    const parsed = await parseRequest(gmailEditDraftContract, request, {})
+    if (!parsed.success) return parsed.response
+    const validatedData = parsed.data.body
+
+    logger.info(`[${requestId}] Updating Gmail draft`, {
+      draftId: validatedData.draftId,
+      to: validatedData.to,
+      hasAttachments: !!(validatedData.attachments && validatedData.attachments.length > 0),
+      attachmentCount: validatedData.attachments?.length || 0,
+    })
+
+    const threadingHeaders = validatedData.replyToMessageId
+      ? await fetchThreadingHeaders(validatedData.replyToMessageId, validatedData.accessToken)
+      : {}
+
+    const originalMessageId = threadingHeaders.messageId
+    const originalReferences = threadingHeaders.references
+    const originalSubject = threadingHeaders.subject
+
+    let rawMessage: string | undefined
+
+    if (validatedData.attachments && validatedData.attachments.length > 0) {
+      const rawAttachments = validatedData.attachments
+      const attachments = processFilesToUserFiles(rawAttachments, requestId, logger)
+
+      if (attachments.length > 0) {
+        const totalSize = attachments.reduce((sum, file) => sum + file.size, 0)
+        const maxSize = 25 * 1024 * 1024
+
+        if (totalSize > maxSize) {
+          const sizeMB = (totalSize / (1024 * 1024)).toFixed(2)
+          return NextResponse.json(
+            {
+              success: false,
+              error: `Total attachment size (${sizeMB}MB) exceeds Gmail's limit of 25MB`,
+            },
+            { status: 400 }
+          )
+        }
+
+        const attachmentBuffers = await Promise.all(
+          attachments.map(async (file) => {
+            const buffer = await downloadFileFromStorage(file, requestId, logger)
+            return {
+              filename: file.name,
+              mimeType: file.type || 'application/octet-stream',
+              content: buffer,
+            }
+          })
+        )
+
+        const mimeMessage = buildMimeMessage({
+          to: validatedData.to,
+          cc: validatedData.cc ?? undefined,
+          bcc: validatedData.bcc ?? undefined,
+          subject: validatedData.subject || originalSubject || '',
+          body: validatedData.body,
+          contentType: validatedData.contentType || 'text',
+          inReplyTo: originalMessageId,
+          references: originalReferences,
+          attachments: attachmentBuffers,
+        })
+
+        rawMessage = base64UrlEncode(mimeMessage)
+      }
+    }
+
+    if (!rawMessage) {
+      rawMessage = buildSimpleEmailMessage({
+        to: validatedData.to,
+        cc: validatedData.cc,
+        bcc: validatedData.bcc,
+        subject: validatedData.subject || originalSubject,
+        body: validatedData.body,
+        contentType: validatedData.contentType || 'text',
+        inReplyTo: originalMessageId,
+        references: originalReferences,
+      })
+    }
+
+    const draftMessage: { raw: string; threadId?: string } = { raw: rawMessage }
+    if (validatedData.threadId) {
+      draftMessage.threadId = validatedData.threadId
+    }
+
+    const gmailResponse = await fetch(
+      `${GMAIL_API_BASE}/drafts/${encodeURIComponent(validatedData.draftId)}`,
+      {
+        method: 'PUT',
+        headers: {
+          Authorization: `Bearer ${validatedData.accessToken}`,
+          'Content-Type': 'application/json',
+        },
+        body: JSON.stringify({
+          id: validatedData.draftId,
+          message: draftMessage,
+        }),
+      }
+    )
+
+    if (!gmailResponse.ok) {
+      const errorText = await gmailResponse.text()
+      logger.error(`[${requestId}] Gmail API error:`, errorText)
+      return NextResponse.json(
+        {
+          success: false,
+          error: `Gmail API error: ${gmailResponse.statusText}`,
+        },
+        { status: gmailResponse.status }
+      )
+    }
+
+    const data = await gmailResponse.json()
+
+    logger.info(`[${requestId}] Draft updated successfully`, { draftId: data.id })
+
+    return NextResponse.json({
+      success: true,
+      output: {
+        draftId: data.id ?? null,
+        messageId: data.message?.id ?? null,
+        threadId: data.message?.threadId ?? null,
+        labelIds: data.message?.labelIds ?? null,
+      },
+    })
+  } catch (error) {
+    logger.error(`[${requestId}] Error updating Gmail draft:`, error)
+
+    return NextResponse.json(
+      {
+        success: false,
+        error: error instanceof Error ? error.message : 'Internal server error',
+      },
+      { status: 500 }
+    )
+  }
+})