fix(slack): drain conversation pagination safely

Author: TheodoreSpeaks

apps/docs/content/docs/integrations/slack.mdx

@@ -956,7 +956,7 @@ Rename the Slack agent session associated with a thread.
 
 ### Slack List Channels
 
-List accessible Slack conversations across multiple cursor pages. Credential-group user tokens also return one-to-one and group direct messages.
+List up to 10,000 accessible Slack conversations across as many cursor pages as Slack supplies, capped at 200 provider pages. Credential-group user tokens also return one-to-one and group direct messages.
 
 #### Input
 
@@ -968,13 +968,13 @@ List accessible Slack conversations across multiple cursor pages. Credential-gro
 | `excludeArchived` | boolean | No | Exclude archived channels \(default: true\) |
 | `limit` | number | No | Conversations to request per Slack page \(default: 100, max: 200\) |
 | `cursor` | string | No | Pagination cursor from a previous response.nextCursor to resume from |
-| `maxPages` | number | No | Maximum number of Slack pages to fetch \(default: 10, max: 10\) |
+| `maxPages` | number | No | Maximum number of Slack pages to fetch \(default: 200, max: 200\) |
 
 #### Output
 
 | Parameter | Type | Description |
 | --------- | ---- | ----------- |
-| `channels` | array | Accessible public and private channels, plus direct and group DMs for credential-group user tokens |
+| `channels` | array | Up to 10,000 accessible public and private channels, plus direct and group DMs for credential-group user tokens |
 |   ↳ `id` | string | Conversation ID \(for example, C123, D123, or G123\) |
 |   ↳ `name` | string | Channel or group-DM name; omitted for one-to-one direct messages |
 |   ↳ `is_channel` | boolean | Whether this is a channel |
@@ -1000,7 +1000,7 @@ List accessible Slack conversations across multiple cursor pages. Credential-gro
 |   ↳ `priority` | number | Slack sidebar sort priority |
 | `ids` | array | Conversation IDs for every returned channel or DM |
 | `names` | array | Names of returned channels and group DMs; one-to-one DMs have no name |
-| `count` | number | Total number of conversations returned across all fetched pages |
+| `count` | number | Total number of conversations returned across all fetched pages, up to 10,000 |
 | `hasMore` | boolean | Whether more Slack conversation pages remain beyond the fetched window |
 | `nextCursor` | string | Cursor to fetch the next page; null when there are no more pages |
 | `pages` | number | Number of Slack conversation pages fetched in this invocation |

apps/sim/blocks/blocks/slack.test.ts

@@ -212,8 +212,8 @@ describe('Slack block release', () => {
     expect(() => mapSlackV2Params({ ...values, channelLimit: '201' })).toThrow(
       'Conversations per page must be an integer between 1 and 200'
     )
-    expect(() => mapSlackV2Params({ ...values, channelMaxPages: '11' })).toThrow(
-      'Max pages must be an integer between 1 and 10'
+    expect(() => mapSlackV2Params({ ...values, channelMaxPages: '201' })).toThrow(
+      'Max pages must be an integer between 1 and 200'
     )
     expect(mapSlackV2Params({ ...values, channelLimit: null, channelMaxPages: ' ' })).toMatchObject(
       { limit: 100 }

apps/sim/blocks/blocks/slack.ts

@@ -775,7 +775,7 @@ Do not include any explanations, markdown formatting, or other text outside the
       id: 'channelMaxPages',
       title: 'Max Pages',
       type: 'short-input',
-      placeholder: '10',
+      placeholder: '200',
       condition: {
         field: 'operation',
         value: 'list_channels',
@@ -2155,8 +2155,8 @@ Return ONLY the integer Unix timestamp - no explanations, no quotes, no extra te
               (typeof channelMaxPages !== 'string' || Boolean(channelMaxPages.trim()))
             if (hasChannelMaxPages) {
               const parsedMaxPages = Number(channelMaxPages)
-              if (!Number.isInteger(parsedMaxPages) || parsedMaxPages < 1 || parsedMaxPages > 10) {
-                throw new Error('Max pages must be an integer between 1 and 10')
+              if (!Number.isInteger(parsedMaxPages) || parsedMaxPages < 1 || parsedMaxPages > 200) {
+                throw new Error('Max pages must be an integer between 1 and 200')
               }
               baseParams.maxPages = parsedMaxPages
             }
@@ -2426,7 +2426,7 @@ Return ONLY the integer Unix timestamp - no explanations, no quotes, no extra te
     // List Channels inputs
     includePrivate: { type: 'string', description: 'Include private channels (true/false)' },
     channelLimit: { type: 'string', description: 'Conversations to request per Slack page' },
-    channelMaxPages: { type: 'string', description: 'Maximum Slack pages to fetch (max 10)' },
+    channelMaxPages: { type: 'string', description: 'Maximum Slack pages to fetch (max 200)' },
     // List Members inputs
     memberLimit: { type: 'string', description: 'Maximum number of members to return' },
     // List Users inputs
@@ -2657,7 +2657,7 @@ Return ONLY the integer Unix timestamp - no explanations, no quotes, no extra te
     channels: {
       type: 'json',
       description:
-        'Array of accessible conversation objects. Credential-group user tokens also include direct and group DMs, with type fields (is_channel, is_im, is_mpim) and DM participant field user.',
+        'Array of up to 10,000 accessible conversation objects. Credential-group user tokens also include direct and group DMs, with type fields (is_channel, is_im, is_mpim) and DM participant field user.',
     },
     count: {
       type: 'number',

apps/sim/lib/internal/slack/operations/list-conversations.ts

@@ -6,6 +6,7 @@ import {
   DEFAULT_CONVERSATION_PAGE_LIMIT,
   MAX_CONVERSATION_PAGE_LIMIT,
   MAX_CONVERSATION_PAGES,
+  MAX_CONVERSATIONS,
 } from '@/tools/slack/list_channels'
 import type { SlackListChannelsParams, SlackListChannelsResponse } from '@/tools/slack/types'
 import {
@@ -130,15 +131,16 @@ export const executeSlackListConversationsOperation: InternalToolOperationImplem
   let nextCursor: string | null = null
   let pages = 0
 
-  while (pages < maxPages) {
+  while (pages < maxPages && channels.length < MAX_CONVERSATIONS) {
+    const pageLimit = Math.min(limit, MAX_CONVERSATIONS - channels.length)
     const { data } = await requestSlackApi({
       accessToken,
       method: 'conversations.list',
       httpMethod: 'GET',
       query: {
         types,
         exclude_archived: String(excludeArchived),
-        limit,
+        limit: pageLimit,
         cursor,
       },
       signal,
@@ -148,6 +150,9 @@ export const executeSlackListConversationsOperation: InternalToolOperationImplem
     if (!parsed.channels) {
       throw new Error('Slack returned a malformed conversations list')
     }
+    if (parsed.channels.length > pageLimit) {
+      throw new Error(`Slack returned more than the requested ${pageLimit} conversations`)
+    }
 
     channels.push(...parsed.channels.map(mapSlackConversation))
     pages += 1

apps/sim/tools/generated/tool-metadata.ts

@@ -178,13 +178,60 @@ describe('Slack list channels', () => {
     })
   })
 
+  it('continues beyond ten pages by default until Slack exhausts its cursor', async () => {
+    fetchMock.mockImplementation(async (input) => {
+      const cursor = new URL(String(input)).searchParams.get('cursor')
+      const page = cursor ? Number(cursor.replace('cursor-', '')) : 1
+      return slackResponse({
+        ok: true,
+        channels: [{ id: `C${page}` }],
+        response_metadata: { next_cursor: page < 12 ? `cursor-${page + 1}` : '' },
+      })
+    })
+
+    const result = await executeSlackListConversationsOperation(BASE_PARAMS)
+
+    expect(fetchMock).toHaveBeenCalledTimes(12)
+    expect(result.output).toMatchObject({
+      count: 12,
+      hasMore: false,
+      nextCursor: null,
+      pages: 12,
+    })
+  })
+
+  it('stops at 10,000 conversations and preserves the cursor for resumption', async () => {
+    fetchMock.mockImplementation(async (input) => {
+      const cursor = new URL(String(input)).searchParams.get('cursor')
+      const page = cursor ? Number(cursor.replace('cursor-', '')) : 1
+      return slackResponse({
+        ok: true,
+        channels: Array.from({ length: 200 }, (_, index) => ({ id: `C${page}-${index}` })),
+        response_metadata: { next_cursor: `cursor-${page + 1}` },
+      })
+    })
+
+    const result = await executeSlackListConversationsOperation({
+      ...BASE_PARAMS,
+      limit: 200,
+    })
+
+    expect(fetchMock).toHaveBeenCalledTimes(50)
+    expect(result.output).toMatchObject({
+      count: 10_000,
+      hasMore: true,
+      nextCursor: 'cursor-51',
+      pages: 50,
+    })
+  })
+
   it('fails fast on invalid pagination inputs before a provider request', async () => {
     await expect(
       executeSlackListConversationsOperation({ ...BASE_PARAMS, limit: 0 })
     ).rejects.toThrow('Conversation page size must be an integer between 1 and 200')
     await expect(
-      executeSlackListConversationsOperation({ ...BASE_PARAMS, maxPages: 11 })
-    ).rejects.toThrow('Maximum conversation pages must be an integer between 1 and 10')
+      executeSlackListConversationsOperation({ ...BASE_PARAMS, maxPages: 201 })
+    ).rejects.toThrow('Maximum conversation pages must be an integer between 1 and 200')
     await expect(
       executeSlackListConversationsOperation({ ...BASE_PARAMS, cursor: ' ' })
     ).rejects.toThrow('Pagination cursor is required')
@@ -229,5 +276,16 @@ describe('Slack list channels', () => {
     await expect(
       executeSlackListConversationsOperation({ ...BASE_PARAMS, cursor: 'same-cursor' })
     ).rejects.toThrow('Slack returned a repeated conversation pagination cursor')
+
+    fetchMock.mockResolvedValueOnce(
+      slackResponse({
+        ok: true,
+        channels: [{ id: 'C1' }, { id: 'C2' }],
+        response_metadata: { next_cursor: '' },
+      })
+    )
+    await expect(
+      executeSlackListConversationsOperation({ ...BASE_PARAMS, limit: 1 })
+    ).rejects.toThrow('Slack returned more than the requested 1 conversations')
   })
 })

apps/sim/tools/generated/tool-outputs.ts

@@ -9,8 +9,11 @@ export const DEFAULT_CONVERSATION_PAGE_LIMIT = 100
 /** Slack's recommended upper bound for conversations.list page size. */
 export const MAX_CONVERSATION_PAGE_LIMIT = 200
 
-/** Default and hard cap on Slack conversation pages fetched per invocation. */
-export const MAX_CONVERSATION_PAGES = 10
+/** Default and hard cap on Slack conversation provider pages fetched per invocation. */
+export const MAX_CONVERSATION_PAGES = 200
+
+/** Hard cap on Slack conversations accumulated per invocation. */
+export const MAX_CONVERSATIONS = 10_000
 
 export const slackListChannelsTool: InternalToolConfig<
   SlackListChannelsParams,
@@ -19,8 +22,8 @@ export const slackListChannelsTool: InternalToolConfig<
   id: 'slack_list_channels',
   name: 'Slack List Channels',
   description:
-    'List accessible Slack conversations across multiple cursor pages. Credential-group user tokens also return one-to-one and group direct messages.',
-  version: '1.2.0',
+    'List up to 10,000 accessible Slack conversations across as many cursor pages as Slack supplies, capped at 200 provider pages. Credential-group user tokens also return one-to-one and group direct messages.',
+  version: '1.3.0',
 
   oauth: {
     required: true,
@@ -81,7 +84,7 @@ export const slackListChannelsTool: InternalToolConfig<
       type: 'number',
       required: false,
       visibility: 'user-or-llm',
-      description: 'Maximum number of Slack pages to fetch (default: 10, max: 10)',
+      description: 'Maximum number of Slack pages to fetch (default: 200, max: 200)',
     },
   },
 
@@ -93,7 +96,7 @@ export const slackListChannelsTool: InternalToolConfig<
     channels: {
       type: 'array',
       description:
-        'Accessible public and private channels, plus direct and group DMs for credential-group user tokens',
+        'Up to 10,000 accessible public and private channels, plus direct and group DMs for credential-group user tokens',
       items: {
         type: 'object',
         properties: CONVERSATION_LIST_OUTPUT_PROPERTIES,
@@ -111,7 +114,7 @@ export const slackListChannelsTool: InternalToolConfig<
     },
     count: {
       type: 'number',
-      description: 'Total number of conversations returned across all fetched pages',
+      description: 'Total number of conversations returned across all fetched pages, up to 10,000',
     },
     hasMore: {
       type: 'boolean',

apps/sim/tools/slack/list_channels.test.ts

@@ -1,5 +1,5 @@
 {
-  "updatedAt": "2026-09-06",
+  "updatedAt": "2026-09-07",
   "integrations": [
     {
       "type": "onepassword",
@@ -22205,7 +22205,7 @@
         },
         {
           "name": "List Channels",
-          "description": "List accessible Slack conversations across multiple cursor pages. Credential-group user tokens also return one-to-one and group direct messages."
+          "description": "List up to 10,000 accessible Slack conversations across as many cursor pages as Slack supplies, capped at 200 provider pages. Credential-group user tokens also return one-to-one and group direct messages."
         },
         {
           "name": "List Channel Members",