diff --git a/apps/x/apps/main/src/ipc.ts b/apps/x/apps/main/src/ipc.ts
index bbeb3164..79645f8f 100644
--- a/apps/x/apps/main/src/ipc.ts
+++ b/apps/x/apps/main/src/ipc.ts
@@ -15,7 +15,11 @@ import { bus } from '@x/core/dist/runs/bus.js';
 import { serviceBus } from '@x/core/dist/services/service_bus.js';
 import type { FSWatcher } from 'chokidar';
 import fs from 'node:fs/promises';
+import { exec } from 'node:child_process';
+import { promisify } from 'node:util';
 import z from 'zod';
+
+const execAsync = promisify(exec);
 import { RunEvent } from '@x/shared/dist/runs.js';
 import { ServiceEvent } from '@x/shared/dist/service-events.js';
 import container from '@x/core/dist/di/container.js';
@@ -397,13 +401,27 @@ export function setupIpcHandlers() {
     'slack:getConfig': async () => {
       const repo = container.resolve<ISlackConfigRepo>('slackConfigRepo');
       const config = await repo.getConfig();
-      return { enabled: config.enabled };
+      return { enabled: config.enabled, workspaces: config.workspaces };
     },
     'slack:setConfig': async (_event, args) => {
       const repo = container.resolve<ISlackConfigRepo>('slackConfigRepo');
-      await repo.setConfig({ enabled: args.enabled });
+      await repo.setConfig({ enabled: args.enabled, workspaces: args.workspaces });
       return { success: true };
     },
+    'slack:listWorkspaces': async () => {
+      try {
+        const { stdout } = await execAsync('agent-slack auth whoami', { timeout: 10000 });
+        const parsed = JSON.parse(stdout);
+        const workspaces = (parsed.workspaces || []).map((w: { workspace_url?: string; workspace_name?: string }) => ({
+          url: w.workspace_url || '',
+          name: w.workspace_name || '',
+        }));
+        return { workspaces };
+      } catch (err: unknown) {
+        const message = err instanceof Error ? err.message : 'Failed to list Slack workspaces';
+        return { workspaces: [], error: message };
+      }
+    },
     'onboarding:getStatus': async () => {
       // Show onboarding if it hasn't been completed yet
       const complete = isOnboardingComplete();
diff --git a/apps/x/apps/renderer/src/components/connectors-popover.tsx b/apps/x/apps/renderer/src/components/connectors-popover.tsx
index 26fb3c04..78aee6e4 100644
--- a/apps/x/apps/renderer/src/components/connectors-popover.tsx
+++ b/apps/x/apps/renderer/src/components/connectors-popover.tsx
@@ -57,6 +57,12 @@ export function ConnectorsPopover({ children, tooltip, open: openProp, onOpenCha
   // Slack state (agent-slack CLI)
   const [slackEnabled, setSlackEnabled] = useState(false)
   const [slackLoading, setSlackLoading] = useState(true)
+  const [slackWorkspaces, setSlackWorkspaces] = useState<Array<{ url: string; name: string }>>([])
+  const [slackAvailableWorkspaces, setSlackAvailableWorkspaces] = useState<Array<{ url: string; name: string }>>([])
+  const [slackSelectedUrls, setSlackSelectedUrls] = useState<Set<string>>(new Set())
+  const [slackPickerOpen, setSlackPickerOpen] = useState(false)
+  const [slackDiscovering, setSlackDiscovering] = useState(false)
+  const [slackDiscoverError, setSlackDiscoverError] = useState<string | null>(null)
 
   // Load available providers on mount
   useEffect(() => {
@@ -110,21 +116,67 @@ export function ConnectorsPopover({ children, tooltip, open: openProp, onOpenCha
       setSlackLoading(true)
       const result = await window.ipc.invoke('slack:getConfig', null)
       setSlackEnabled(result.enabled)
+      setSlackWorkspaces(result.workspaces || [])
     } catch (error) {
       console.error('Failed to load Slack config:', error)
       setSlackEnabled(false)
+      setSlackWorkspaces([])
     } finally {
       setSlackLoading(false)
     }
   }, [])
 
-  // Update Slack config
-  const handleSlackToggle = useCallback(async (enabled: boolean) => {
+  // Enable Slack: discover workspaces
+  const handleSlackEnable = useCallback(async () => {
+    setSlackDiscovering(true)
+    setSlackDiscoverError(null)
+    try {
+      const result = await window.ipc.invoke('slack:listWorkspaces', null)
+      if (result.error || result.workspaces.length === 0) {
+        setSlackDiscoverError(result.error || 'No Slack workspaces found. Set up with: agent-slack auth import-desktop')
+        setSlackAvailableWorkspaces([])
+        setSlackPickerOpen(true)
+      } else {
+        setSlackAvailableWorkspaces(result.workspaces)
+        setSlackSelectedUrls(new Set(result.workspaces.map((w: { url: string }) => w.url)))
+        setSlackPickerOpen(true)
+      }
+    } catch (error) {
+      console.error('Failed to discover Slack workspaces:', error)
+      setSlackDiscoverError('Failed to discover Slack workspaces')
+      setSlackPickerOpen(true)
+    } finally {
+      setSlackDiscovering(false)
+    }
+  }, [])
+
+  // Save selected Slack workspaces
+  const handleSlackSaveWorkspaces = useCallback(async () => {
+    const selected = slackAvailableWorkspaces.filter(w => slackSelectedUrls.has(w.url))
     try {
       setSlackLoading(true)
-      await window.ipc.invoke('slack:setConfig', { enabled })
-      setSlackEnabled(enabled)
-      toast.success(enabled ? 'Slack enabled' : 'Slack disabled')
+      await window.ipc.invoke('slack:setConfig', { enabled: true, workspaces: selected })
+      setSlackEnabled(true)
+      setSlackWorkspaces(selected)
+      setSlackPickerOpen(false)
+      toast.success('Slack enabled')
+    } catch (error) {
+      console.error('Failed to save Slack config:', error)
+      toast.error('Failed to save Slack settings')
+    } finally {
+      setSlackLoading(false)
+    }
+  }, [slackAvailableWorkspaces, slackSelectedUrls])
+
+  // Disable Slack
+  const handleSlackDisable = useCallback(async () => {
+    try {
+      setSlackLoading(true)
+      await window.ipc.invoke('slack:setConfig', { enabled: false, workspaces: [] })
+      setSlackEnabled(false)
+      setSlackWorkspaces([])
+      setSlackPickerOpen(false)
+      toast.success('Slack disabled')
     } catch (error) {
       console.error('Failed to update Slack config:', error)
       toast.error('Failed to update Slack settings')
@@ -505,28 +557,84 @@ export function ConnectorsPopover({ children, tooltip, open: openProp, onOpenCha
               </div>
 
               {/* Slack */}
-              <div className="flex items-center justify-between gap-3 rounded-md px-3 py-2 hover:bg-accent">
-                <div className="flex items-center gap-3 min-w-0">
-                  <div className="flex size-8 items-center justify-center rounded-md bg-muted">
-                    <MessageSquare className="size-4" />
+              <div className="rounded-md px-3 py-2 hover:bg-accent">
+                <div className="flex items-center justify-between gap-3">
+                  <div className="flex items-center gap-3 min-w-0">
+                    <div className="flex size-8 items-center justify-center rounded-md bg-muted">
+                      <MessageSquare className="size-4" />
+                    </div>
+                    <div className="flex flex-col min-w-0">
+                      <span className="text-sm font-medium truncate">Slack</span>
+                      {slackEnabled && slackWorkspaces.length > 0 ? (
+                        <span className="text-xs text-muted-foreground truncate">
+                          {slackWorkspaces.map(w => w.name).join(', ')}
+                        </span>
+                      ) : (
+                        <span className="text-xs text-muted-foreground truncate">
+                          Send messages and view channels
+                        </span>
+                      )}
+                    </div>
                   </div>
-                  <div className="flex flex-col min-w-0">
-                    <span className="text-sm font-medium truncate">Slack</span>
-                    <span className="text-xs text-muted-foreground truncate">
-                      Send messages and view channels
-                    </span>
+                  <div className="shrink-0 flex items-center gap-2">
+                    {(slackLoading || slackDiscovering) && (
+                      <Loader2 className="size-3 animate-spin" />
+                    )}
+                    {slackEnabled ? (
+                      <Switch
+                        checked={true}
+                        onCheckedChange={() => handleSlackDisable()}
+                        disabled={slackLoading}
+                      />
+                    ) : (
+                      <Button
+                        variant="default"
+                        size="sm"
+                        onClick={handleSlackEnable}
+                        disabled={slackLoading || slackDiscovering}
+                        className="h-7 px-2 text-xs"
+                      >
+                        Enable
+                      </Button>
+                    )}
                   </div>
                 </div>
-                <div className="shrink-0 flex items-center gap-2">
-                  {slackLoading && (
-                    <Loader2 className="size-3 animate-spin" />
-                  )}
-                  <Switch
-                    checked={slackEnabled}
-                    onCheckedChange={handleSlackToggle}
-                    disabled={slackLoading}
-                  />
-                </div>
+                {slackPickerOpen && (
+                  <div className="mt-2 ml-11 space-y-2">
+                    {slackDiscoverError ? (
+                      <p className="text-xs text-muted-foreground">{slackDiscoverError}</p>
+                    ) : (
+                      <>
+                        {slackAvailableWorkspaces.map(w => (
+                          <label key={w.url} className="flex items-center gap-2 text-sm cursor-pointer">
+                            <input
+                              type="checkbox"
+                              checked={slackSelectedUrls.has(w.url)}
+                              onChange={(e) => {
+                                setSlackSelectedUrls(prev => {
+                                  const next = new Set(prev)
+                                  if (e.target.checked) next.add(w.url)
+                                  else next.delete(w.url)
+                                  return next
+                                })
+                              }}
+                              className="rounded border-border"
+                            />
+                            <span className="truncate">{w.name}</span>
+                          </label>
+                        ))}
+                        <Button
+                          size="sm"
+                          onClick={handleSlackSaveWorkspaces}
+                          disabled={slackSelectedUrls.size === 0 || slackLoading}
+                          className="h-7 px-3 text-xs"
+                        >
+                          Save
+                        </Button>
+                      </>
+                    )}
+                  </div>
+                )}
               </div>
             </>
           )}
diff --git a/apps/x/apps/renderer/src/components/onboarding-modal.tsx b/apps/x/apps/renderer/src/components/onboarding-modal.tsx
index ff3d18d1..464d8b96 100644
--- a/apps/x/apps/renderer/src/components/onboarding-modal.tsx
+++ b/apps/x/apps/renderer/src/components/onboarding-modal.tsx
@@ -81,6 +81,12 @@ export function OnboardingModal({ open, onComplete }: OnboardingModalProps) {
   // Slack state (agent-slack CLI)
   const [slackEnabled, setSlackEnabled] = useState(false)
   const [slackLoading, setSlackLoading] = useState(true)
+  const [slackWorkspaces, setSlackWorkspaces] = useState<Array<{ url: string; name: string }>>([])
+  const [slackAvailableWorkspaces, setSlackAvailableWorkspaces] = useState<Array<{ url: string; name: string }>>([])
+  const [slackSelectedUrls, setSlackSelectedUrls] = useState<Set<string>>(new Set())
+  const [slackPickerOpen, setSlackPickerOpen] = useState(false)
+  const [slackDiscovering, setSlackDiscovering] = useState(false)
+  const [slackDiscoverError, setSlackDiscoverError] = useState<string | null>(null)
 
   const updateProviderConfig = useCallback(
     (provider: LlmProviderFlavor, updates: Partial<{ apiKey: string; baseURL: string; model: string }>) => {
@@ -214,21 +220,67 @@ export function OnboardingModal({ open, onComplete }: OnboardingModalProps) {
       setSlackLoading(true)
       const result = await window.ipc.invoke('slack:getConfig', null)
       setSlackEnabled(result.enabled)
+      setSlackWorkspaces(result.workspaces || [])
     } catch (error) {
       console.error('Failed to load Slack config:', error)
       setSlackEnabled(false)
+      setSlackWorkspaces([])
     } finally {
       setSlackLoading(false)
     }
   }, [])
 
-  // Update Slack config
-  const handleSlackToggle = useCallback(async (enabled: boolean) => {
+  // Enable Slack: discover workspaces
+  const handleSlackEnable = useCallback(async () => {
+    setSlackDiscovering(true)
+    setSlackDiscoverError(null)
+    try {
+      const result = await window.ipc.invoke('slack:listWorkspaces', null)
+      if (result.error || result.workspaces.length === 0) {
+        setSlackDiscoverError(result.error || 'No Slack workspaces found. Set up with: agent-slack auth import-desktop')
+        setSlackAvailableWorkspaces([])
+        setSlackPickerOpen(true)
+      } else {
+        setSlackAvailableWorkspaces(result.workspaces)
+        setSlackSelectedUrls(new Set(result.workspaces.map((w: { url: string }) => w.url)))
+        setSlackPickerOpen(true)
+      }
+    } catch (error) {
+      console.error('Failed to discover Slack workspaces:', error)
+      setSlackDiscoverError('Failed to discover Slack workspaces')
+      setSlackPickerOpen(true)
+    } finally {
+      setSlackDiscovering(false)
+    }
+  }, [])
+
+  // Save selected Slack workspaces
+  const handleSlackSaveWorkspaces = useCallback(async () => {
+    const selected = slackAvailableWorkspaces.filter(w => slackSelectedUrls.has(w.url))
     try {
       setSlackLoading(true)
-      await window.ipc.invoke('slack:setConfig', { enabled })
-      setSlackEnabled(enabled)
-      toast.success(enabled ? 'Slack enabled' : 'Slack disabled')
+      await window.ipc.invoke('slack:setConfig', { enabled: true, workspaces: selected })
+      setSlackEnabled(true)
+      setSlackWorkspaces(selected)
+      setSlackPickerOpen(false)
+      toast.success('Slack enabled')
+    } catch (error) {
+      console.error('Failed to save Slack config:', error)
+      toast.error('Failed to save Slack settings')
+    } finally {
+      setSlackLoading(false)
+    }
+  }, [slackAvailableWorkspaces, slackSelectedUrls])
+
+  // Disable Slack
+  const handleSlackDisable = useCallback(async () => {
+    try {
+      setSlackLoading(true)
+      await window.ipc.invoke('slack:setConfig', { enabled: false, workspaces: [] })
+      setSlackEnabled(false)
+      setSlackWorkspaces([])
+      setSlackPickerOpen(false)
+      toast.success('Slack disabled')
     } catch (error) {
       console.error('Failed to update Slack config:', error)
       toast.error('Failed to update Slack settings')
@@ -492,28 +544,82 @@ export function OnboardingModal({ open, onComplete }: OnboardingModalProps) {
 
   // Render Slack row
   const renderSlackRow = () => (
-    <div className="flex items-center justify-between gap-3 rounded-md px-3 py-3 hover:bg-accent">
-      <div className="flex items-center gap-3 min-w-0">
-        <div className="flex size-10 items-center justify-center rounded-md bg-muted">
-          <MessageSquare className="size-5" />
+    <div className="rounded-md px-3 py-3 hover:bg-accent">
+      <div className="flex items-center justify-between gap-3">
+        <div className="flex items-center gap-3 min-w-0">
+          <div className="flex size-10 items-center justify-center rounded-md bg-muted">
+            <MessageSquare className="size-5" />
+          </div>
+          <div className="flex flex-col min-w-0">
+            <span className="text-sm font-medium truncate">Slack</span>
+            {slackEnabled && slackWorkspaces.length > 0 ? (
+              <span className="text-xs text-muted-foreground truncate">
+                {slackWorkspaces.map(w => w.name).join(', ')}
+              </span>
+            ) : (
+              <span className="text-xs text-muted-foreground truncate">
+                Send messages and view channels
+              </span>
+            )}
+          </div>
         </div>
-        <div className="flex flex-col min-w-0">
-          <span className="text-sm font-medium truncate">Slack</span>
-          <span className="text-xs text-muted-foreground truncate">
-            Send messages and view channels
-          </span>
+        <div className="shrink-0 flex items-center gap-2">
+          {(slackLoading || slackDiscovering) && (
+            <Loader2 className="size-3 animate-spin" />
+          )}
+          {slackEnabled ? (
+            <Switch
+              checked={true}
+              onCheckedChange={() => handleSlackDisable()}
+              disabled={slackLoading}
+            />
+          ) : (
+            <Button
+              variant="default"
+              size="sm"
+              onClick={handleSlackEnable}
+              disabled={slackLoading || slackDiscovering}
+            >
+              Enable
+            </Button>
+          )}
         </div>
       </div>
-      <div className="shrink-0 flex items-center gap-2">
-        {slackLoading && (
-          <Loader2 className="size-3 animate-spin" />
-        )}
-        <Switch
-          checked={slackEnabled}
-          onCheckedChange={handleSlackToggle}
-          disabled={slackLoading}
-        />
-      </div>
+      {slackPickerOpen && (
+        <div className="mt-2 ml-13 space-y-2">
+          {slackDiscoverError ? (
+            <p className="text-xs text-muted-foreground">{slackDiscoverError}</p>
+          ) : (
+            <>
+              {slackAvailableWorkspaces.map(w => (
+                <label key={w.url} className="flex items-center gap-2 text-sm cursor-pointer">
+                  <input
+                    type="checkbox"
+                    checked={slackSelectedUrls.has(w.url)}
+                    onChange={(e) => {
+                      setSlackSelectedUrls(prev => {
+                        const next = new Set(prev)
+                        if (e.target.checked) next.add(w.url)
+                        else next.delete(w.url)
+                        return next
+                      })
+                    }}
+                    className="rounded border-border"
+                  />
+                  <span className="truncate">{w.name}</span>
+                </label>
+              ))}
+              <Button
+                size="sm"
+                onClick={handleSlackSaveWorkspaces}
+                disabled={slackSelectedUrls.size === 0 || slackLoading}
+              >
+                Save
+              </Button>
+            </>
+          )}
+        </div>
+      )}
     </div>
   )
 
diff --git a/apps/x/packages/core/src/application/assistant/skills/slack/skill.ts b/apps/x/packages/core/src/application/assistant/skills/slack/skill.ts
index 8b6b09d6..afb3ce0d 100644
--- a/apps/x/packages/core/src/application/assistant/skills/slack/skill.ts
+++ b/apps/x/packages/core/src/application/assistant/skills/slack/skill.ts
@@ -83,13 +83,15 @@ agent-slack canvas get F01234567 --workspace https://team.slack.com
 
 ## 3. Multi-Workspace
 
-If the user has multiple workspaces configured, use \`--workspace <url>\` to disambiguate:
+**Important:** The user has chosen which workspaces to use. Before your first Slack operation, read \`~/.rowboat/config/slack.json\` to see the selected workspaces. Only interact with workspaces listed in that config — ignore any other authenticated workspaces.
+
+If the selected workspace list contains multiple entries, use \`--workspace <url>\` to disambiguate:
 
 \`\`\`
 agent-slack message list "#general" --workspace https://team.slack.com
 \`\`\`
 
-Use \`agent-slack auth whoami\` to see all configured workspaces.
+If only one workspace is selected, always use \`--workspace\` with its URL to avoid ambiguity with other authenticated workspaces.
 
 ---
 
diff --git a/apps/x/packages/core/src/slack/repo.ts b/apps/x/packages/core/src/slack/repo.ts
index 3cb9ce99..2e29b57a 100644
--- a/apps/x/packages/core/src/slack/repo.ts
+++ b/apps/x/packages/core/src/slack/repo.ts
@@ -10,7 +10,7 @@ export interface ISlackConfigRepo {
 
 export class FSSlackConfigRepo implements ISlackConfigRepo {
     private readonly configPath = path.join(WorkDir, 'config', 'slack.json');
-    private readonly defaultConfig: SlackConfig = { enabled: false };
+    private readonly defaultConfig: SlackConfig = { enabled: false, workspaces: [] };
 
     constructor() {
         this.ensureConfigFile();
diff --git a/apps/x/packages/core/src/slack/types.ts b/apps/x/packages/core/src/slack/types.ts
index bfd1fe07..64917084 100644
--- a/apps/x/packages/core/src/slack/types.ts
+++ b/apps/x/packages/core/src/slack/types.ts
@@ -1,6 +1,13 @@
 import z from "zod";
 
+export const SlackWorkspace = z.object({
+    url: z.string(),
+    name: z.string(),
+});
+export type SlackWorkspace = z.infer<typeof SlackWorkspace>;
+
 export const SlackConfig = z.object({
     enabled: z.boolean(),
+    workspaces: z.array(SlackWorkspace).default([]),
 });
 export type SlackConfig = z.infer<typeof SlackConfig>;
diff --git a/apps/x/packages/shared/src/ipc.ts b/apps/x/packages/shared/src/ipc.ts
index 04791f9c..8c018438 100644
--- a/apps/x/packages/shared/src/ipc.ts
+++ b/apps/x/packages/shared/src/ipc.ts
@@ -274,16 +274,25 @@ const ipcSchemas = {
     req: z.null(),
     res: z.object({
       enabled: z.boolean(),
+      workspaces: z.array(z.object({ url: z.string(), name: z.string() })),
     }),
   },
   'slack:setConfig': {
     req: z.object({
       enabled: z.boolean(),
+      workspaces: z.array(z.object({ url: z.string(), name: z.string() })),
     }),
     res: z.object({
       success: z.literal(true),
     }),
   },
+  'slack:listWorkspaces': {
+    req: z.null(),
+    res: z.object({
+      workspaces: z.array(z.object({ url: z.string(), name: z.string() })),
+      error: z.string().optional(),
+    }),
+  },
   'onboarding:getStatus': {
     req: z.null(),
     res: z.object({