diff --git a/src/cli/handlers/project.ts b/src/cli/handlers/project.ts
index a7bf9ee2abe..7b17e9632dd 100644
--- a/src/cli/handlers/project.ts
+++ b/src/cli/handlers/project.ts
@@ -208,7 +208,8 @@ export const PROJECT_HANDLERS: Record<string, CommandHandler> = {
       client,
       'projectHostSetup.delete',
       {
-        setupId: getRequiredStringFlag(flags, 'setup')
+        setupId: getRequiredStringFlag(flags, 'setup'),
+        force: flags.get('force') === true
       }
     )
     printResult(result, json, formatProjectHostSetupDeleteResult)
diff --git a/src/cli/index-project-setup.test.ts b/src/cli/index-project-setup.test.ts
index f104e45c39a..abc668e5fb9 100644
--- a/src/cli/index-project-setup.test.ts
+++ b/src/cli/index-project-setup.test.ts
@@ -776,7 +776,10 @@ describe('orca cli worktree awareness', () => {
     })
   })
 
-  it('deletes project host setup metadata through the project-first runtime API', async () => {
+  it.each([
+    { flags: [], force: false },
+    { flags: ['--force'], force: true }
+  ])('deletes project host setup metadata with force=$force', async ({ flags, force }) => {
     queueFixtures(
       callMock,
       okFixture('req_project_setup_delete', {
@@ -806,10 +809,11 @@ describe('orca cli worktree awareness', () => {
     )
     vi.spyOn(console, 'log').mockImplementation(() => {})
 
-    await main(['project', 'setup-delete', '--setup', 'setup-gpu', '--json'], '/tmp/repo')
+    await main(['project', 'setup-delete', '--setup', 'setup-gpu', ...flags, '--json'], '/tmp/repo')
 
     expect(callMock).toHaveBeenCalledWith('projectHostSetup.delete', {
-      setupId: 'setup-gpu'
+      setupId: 'setup-gpu',
+      force
     })
   })
 })
diff --git a/src/cli/root-help-text-secondary.ts b/src/cli/root-help-text-secondary.ts
index 4b61499ffc1..c34ab0884af 100644
--- a/src/cli/root-help-text-secondary.ts
+++ b/src/cli/root-help-text-secondary.ts
@@ -74,7 +74,7 @@ export const ROOT_HELP_TEXT_SECONDARY = [
   '  orca project setup-clone --project <id> --host <host-id> --url <clone-url> --destination <path> [--display-name <name>] [--json]',
   '  orca project setup-create --project <id> --host <host-id> [--setup-id <id>] [--path <path>] [--kind git|folder] [--display-name <name>] [--worktree-base-path <path>] [--git-username <name>] [--state ready|not-set-up|setting-up|error|unsupported] [--method imported-existing-folder|cloned|provisioned] [--json]',
   '  orca project setup-update --setup <setup-id> [--display-name <name>] [--path <path>] [--worktree-base-path <path>] [--git-username <name>] [--kind git|folder] [--state ready|not-set-up|setting-up|error|unsupported] [--method legacy-repo|imported-existing-folder|cloned|provisioned] [--json]',
-  '  orca project setup-delete --setup <setup-id> [--json]',
+  '  orca project setup-delete --setup <setup-id> [--force] [--json]',
   '  orca repo list [--json]',
   '  orca repo add --path <path> [--json]',
   '  orca repo show --repo <selector> [--json]',
diff --git a/src/cli/specs/project.ts b/src/cli/specs/project.ts
index 56b33827c4b..064d0188044 100644
--- a/src/cli/specs/project.ts
+++ b/src/cli/specs/project.ts
@@ -115,11 +115,12 @@ export const PROJECT_COMMAND_SPECS: CommandSpec[] = [
     path: ['project', 'setup-delete'],
     destructive: true,
     summary: 'Remove a project host setup',
-    usage: 'orca project setup-delete --setup <setup-id> [--json]',
-    allowedFlags: [...GLOBAL_FLAGS, 'setup'],
+    usage: 'orca project setup-delete --setup <setup-id> [--force] [--json]',
+    allowedFlags: [...GLOBAL_FLAGS, 'setup', 'force'],
     notes: [
       'Independent setups are removed directly.',
-      'Repo-backed setups remove the registered repo compatibility record.'
+      'Repo-backed setups remove the registered repo compatibility record.',
+      'Refuses while the project has open terminals or saved workspace details; --force removes it anyway.'
     ],
     examples: ['orca project setup-delete --setup github:stablyai/orca::gpu --json']
   }
diff --git a/src/main/runtime/orca-runtime-preserved-branch-cleanup.ts b/src/main/runtime/orca-runtime-preserved-branch-cleanup.ts
index be727819a06..18604c368b7 100644
--- a/src/main/runtime/orca-runtime-preserved-branch-cleanup.ts
+++ b/src/main/runtime/orca-runtime-preserved-branch-cleanup.ts
@@ -45,6 +45,7 @@ import { RuntimeWorkspaceSessionController } from './runtime-workspace-session-c
 import { RuntimeAiVaultCommands } from './runtime-ai-vault-commands'
 import { ClaudeAgentTeamsService } from './claude-agent-teams-service'
 import { teardownFolderWorkspacePtys } from './folder-workspace-pty-teardown'
+import { countRepoTerminalsNotKnownExited } from './project-removal-impact'
 
 export class OrcaRuntimeWithPreservedBranchCleanup extends OrcaRuntimeWithTerminalDrivers {
   protected readonly preservedBranchCleanup = new RuntimePreservedBranchCleanup(() =>
@@ -265,7 +266,11 @@ export class OrcaRuntimeWithPreservedBranchCleanup extends OrcaRuntimeWithTermin
       (this as RuntimeCommandSurfaceHost<this>).cloneRepo(url, destination, hostId),
     invalidateResolvedWorktrees: () => this.invalidateResolvedWorktreeCache(),
     invalidateWorktreeScan: (repoId) => this.invalidateWorktreeScanCacheForRepo(repoId),
-    notifyReposChanged: () => this.notifyReposChanged()
+    notifyReposChanged: () => this.notifyReposChanged(),
+    countLiveTerminalsForRepo: (repo) =>
+      countRepoTerminalsNotKnownExited(repo, this.ptysById.values(), (ptyId) =>
+        this.isPtyKnownExited(ptyId)
+      )
   })
 
   protected readonly projectGroups = new RuntimeProjectGroupController({
diff --git a/src/main/runtime/project-host-setup-delete-guard.test.ts b/src/main/runtime/project-host-setup-delete-guard.test.ts
new file mode 100644
index 00000000000..37c2e5d7368
--- /dev/null
+++ b/src/main/runtime/project-host-setup-delete-guard.test.ts
@@ -0,0 +1,150 @@
+// `orca project setup-delete` used to drop a repo-backed project even while its terminals were
+// running and its workspaces had saved details, orphaning both with no warning.
+import { describe, expect, it, vi } from 'vitest'
+import { RuntimeProjectHostSetupController } from './runtime-project-host-setup-controller'
+import { projectHostSetupProjectionFromRepos } from '../../shared/project-host-setup-projection'
+import type { Repo } from '../../shared/repo-types'
+import {
+  countRepoTerminalsNotKnownExited,
+  countRepoWorkspacesWithMetadata
+} from './project-removal-impact'
+
+const repo: Repo = {
+  id: 'repo-1',
+  path: '/work/app',
+  displayName: 'app',
+  badgeColor: 'blue',
+  addedAt: 1,
+  kind: 'git'
+}
+
+function makeController(options: {
+  liveTerminals: number
+  metaIds: string[]
+  canonicalMetaIdsForHost?: string[]
+  targetRepo?: Repo
+}) {
+  const targetRepo = options.targetRepo ?? repo
+  const { projects, setups: projectHostSetups } = projectHostSetupProjectionFromRepos([targetRepo])
+  const deleteProjectHostSetup = vi.fn(() => ({
+    project: projects[0],
+    setup: projectHostSetups[0],
+    repo: targetRepo
+  }))
+  const store = {
+    getProjects: () => projects,
+    getProjectHostSetups: () => projectHostSetups,
+    getAllWorktreeMeta: () =>
+      Object.fromEntries(options.metaIds.map((id) => [id, { hostId: undefined }])),
+    getAllWorktreeMetaForHost: (hostId: string) =>
+      options.canonicalMetaIdsForHost
+        ? Object.fromEntries(options.canonicalMetaIdsForHost.map((id) => [id, { hostId }]))
+        : undefined,
+    deleteProjectHostSetup
+  }
+  const controller = new RuntimeProjectHostSetupController({
+    getStore: () => store as never,
+    listRepos: () => [targetRepo],
+    addRepo: vi.fn(),
+    addRemoteRepo: vi.fn(),
+    cloneRepo: vi.fn(),
+    invalidateResolvedWorktrees: vi.fn(),
+    invalidateWorktreeScan: vi.fn(),
+    notifyReposChanged: vi.fn(),
+    countLiveTerminalsForRepo: () => options.liveTerminals
+  })
+  return { controller, deleteProjectHostSetup, setupId: projectHostSetups[0].id }
+}
+
+describe('project setup delete guard', () => {
+  it('refuses a CLI delete while terminals are live, and deletes with --force', () => {
+    const { controller, deleteProjectHostSetup, setupId } = makeController({
+      liveTerminals: 2,
+      metaIds: []
+    })
+
+    expect(() => controller.deleteSetup({ setupId, force: false })).toThrow(
+      /2 terminals still open.*--force/
+    )
+    expect(deleteProjectHostSetup).not.toHaveBeenCalled()
+
+    controller.deleteSetup({ setupId, force: true })
+    expect(deleteProjectHostSetup).toHaveBeenCalledTimes(1)
+  })
+
+  it('refuses while workspaces have saved details', () => {
+    const { controller, deleteProjectHostSetup, setupId } = makeController({
+      liveTerminals: 0,
+      metaIds: ['repo-1::/work/app', 'other-repo::/work/other']
+    })
+
+    expect(() => controller.deleteSetup({ setupId, force: false })).toThrow(
+      /saved details for 1 workspace\./
+    )
+    expect(deleteProjectHostSetup).not.toHaveBeenCalled()
+  })
+
+  it('sees sibling-host metadata kept only in the host-qualified maps', () => {
+    // Same repo id and path on local and SSH: the raw-id map holds only the local row.
+    const { controller, deleteProjectHostSetup, setupId } = makeController({
+      liveTerminals: 0,
+      metaIds: ['repo-1::/work/app'],
+      canonicalMetaIdsForHost: ['repo-1::/work/app'],
+      targetRepo: { ...repo, connectionId: 'box' }
+    })
+
+    expect(() => controller.deleteSetup({ setupId, force: false })).toThrow(
+      /saved details for 1 workspace\./
+    )
+    expect(deleteProjectHostSetup).not.toHaveBeenCalled()
+  })
+
+  it('deletes an unused project without --force', () => {
+    const { controller, deleteProjectHostSetup, setupId } = makeController({
+      liveTerminals: 0,
+      metaIds: ['other-repo::/work/other']
+    })
+
+    controller.deleteSetup({ setupId, force: false })
+    expect(deleteProjectHostSetup).toHaveBeenCalledTimes(1)
+  })
+
+  it('keeps the unchecked delete for older clients that omit force', () => {
+    const { controller, deleteProjectHostSetup, setupId } = makeController({
+      liveTerminals: 3,
+      metaIds: ['repo-1::/work/app']
+    })
+
+    controller.deleteSetup({ setupId })
+    expect(deleteProjectHostSetup).toHaveBeenCalledTimes(1)
+  })
+})
+
+describe('project removal impact', () => {
+  it('counts only this repo and host, and treats unverifiable terminals as live', () => {
+    const ptys = [
+      { ptyId: 'local-1', worktreeId: 'repo-1::/work/app', connectionId: null },
+      { ptyId: 'local-exited', worktreeId: 'repo-1::/work/app', connectionId: null },
+      { ptyId: 'ssh-1', worktreeId: 'repo-1::/work/app', connectionId: 'box' },
+      { ptyId: 'other-repo', worktreeId: 'repo-10::/work/app', connectionId: null }
+    ]
+    const isKnownExited = (ptyId: string) => ptyId === 'local-exited'
+
+    expect(countRepoTerminalsNotKnownExited(repo, ptys, isKnownExited)).toBe(1)
+    expect(
+      countRepoTerminalsNotKnownExited({ ...repo, connectionId: 'box' }, ptys, isKnownExited)
+    ).toBe(1)
+  })
+
+  it('counts metadata on the repo host only, reading unstamped rows as local', () => {
+    const meta = {
+      'repo-1::/work/app': {},
+      'repo-1::/work/feature': { hostId: 'local' as const },
+      'repo-1::/srv/app': { hostId: 'ssh:box' as const },
+      'repo-10::/work/app': {}
+    }
+
+    expect(countRepoWorkspacesWithMetadata(repo, meta)).toBe(2)
+    expect(countRepoWorkspacesWithMetadata({ ...repo, connectionId: 'box' }, meta)).toBe(1)
+  })
+})
diff --git a/src/main/runtime/project-removal-impact.ts b/src/main/runtime/project-removal-impact.ts
new file mode 100644
index 00000000000..04708e0c490
--- /dev/null
+++ b/src/main/runtime/project-removal-impact.ts
@@ -0,0 +1,73 @@
+import type { Repo } from '../../shared/repo-types'
+import type { WorktreeMeta } from '../../shared/worktree/meta-types'
+import {
+  getRepoExecutionHostId,
+  LOCAL_EXECUTION_HOST_ID,
+  parseExecutionHostId
+} from '../../shared/execution-host'
+import { splitWorktreeId } from '../../shared/worktree/id'
+import { worktreePtyBelongsToHost, type WorktreePtyHostFence } from './worktree-pty-host-fence'
+
+export type ProjectRemovalImpact = {
+  liveTerminals: number
+  workspacesWithMetadata: number
+}
+
+type RepoIdentity = Pick<Repo, 'id' | 'connectionId' | 'executionHostId'>
+
+function repoPtyHostFence(repo: RepoIdentity): WorktreePtyHostFence {
+  const host = parseExecutionHostId(getRepoExecutionHostId(repo))
+  return host?.kind === 'runtime'
+    ? { resolvedRuntimeEnvironmentId: host.environmentId }
+    : { resolvedConnectionId: host?.kind === 'ssh' ? host.targetId : null }
+}
+
+/** Terminals not known to have exited count: a lost-contact PTY may still be running. */
+export function countRepoTerminalsNotKnownExited(
+  repo: RepoIdentity,
+  ptys: Iterable<{ ptyId: string; worktreeId: string; connectionId: string | null }>,
+  isKnownExited: (ptyId: string) => boolean
+): number {
+  const fence = repoPtyHostFence(repo)
+  let count = 0
+  for (const pty of ptys) {
+    if (
+      splitWorktreeId(pty.worktreeId)?.repoId === repo.id &&
+      worktreePtyBelongsToHost(pty.ptyId, pty.connectionId, fence) &&
+      !isKnownExited(pty.ptyId)
+    ) {
+      count += 1
+    }
+  }
+  return count
+}
+
+/** Same host rule as the repo prune: unstamped metadata predates host stamping and is local. */
+export function countRepoWorkspacesWithMetadata(
+  repo: RepoIdentity,
+  metaById: Record<string, Pick<WorktreeMeta, 'hostId'>>
+): number {
+  const hostId = getRepoExecutionHostId(repo)
+  const prefix = `${repo.id}::`
+  return Object.entries(metaById).filter(
+    ([id, meta]) => id.startsWith(prefix) && (meta.hostId ?? LOCAL_EXECUTION_HOST_ID) === hostId
+  ).length
+}
+
+export function describeProjectRemovalRefusal(impact: ProjectRemovalImpact): string | null {
+  const parts: string[] = []
+  if (impact.liveTerminals > 0) {
+    parts.push(
+      `${impact.liveTerminals} terminal${impact.liveTerminals === 1 ? '' : 's'} still open`
+    )
+  }
+  if (impact.workspacesWithMetadata > 0) {
+    parts.push(
+      `saved details for ${impact.workspacesWithMetadata} workspace${impact.workspacesWithMetadata === 1 ? '' : 's'}`
+    )
+  }
+  if (parts.length === 0) {
+    return null
+  }
+  return `This project has ${parts.join(' and ')}. Removing it detaches those terminals from Orca and deletes the saved workspace details. Re-run with --force to remove it anyway.`
+}
diff --git a/src/main/runtime/runtime-project-host-setup-controller.test.ts b/src/main/runtime/runtime-project-host-setup-controller.test.ts
index bb3d928d406..6defe84800b 100644
--- a/src/main/runtime/runtime-project-host-setup-controller.test.ts
+++ b/src/main/runtime/runtime-project-host-setup-controller.test.ts
@@ -43,7 +43,8 @@ function makeController(): {
     cloneRepo,
     invalidateResolvedWorktrees: vi.fn(),
     invalidateWorktreeScan: vi.fn(),
-    notifyReposChanged: vi.fn()
+    notifyReposChanged: vi.fn(),
+    countLiveTerminalsForRepo: () => 0
   })
   return {
     controller,
diff --git a/src/main/runtime/runtime-project-host-setup-controller.ts b/src/main/runtime/runtime-project-host-setup-controller.ts
index bfcbb4e5fe1..c3661f06acd 100644
--- a/src/main/runtime/runtime-project-host-setup-controller.ts
+++ b/src/main/runtime/runtime-project-host-setup-controller.ts
@@ -24,6 +24,11 @@ import { getProjectHostSetupForRepo } from '../../shared/project-host-setup-look
 import { invalidateAuthorizedRootsCache } from '../ipc/filesystem-auth'
 import { prepareLocalWorktreeRootForRepo } from '../worktree-root-preparation'
 import type { RuntimeStore } from './runtime-store-contract'
+import { readAllWorktreeMetaForRepo } from '../persistence/host-qualified-worktree-meta'
+import {
+  countRepoWorkspacesWithMetadata,
+  describeProjectRemovalRefusal
+} from './project-removal-impact'
 
 type RuntimeProjectHostSetupDependencies = {
   getStore: () => RuntimeStore | null
@@ -40,6 +45,7 @@ type RuntimeProjectHostSetupDependencies = {
   invalidateResolvedWorktrees: () => void
   invalidateWorktreeScan: (repoId: string) => void
   notifyReposChanged: () => void
+  countLiveTerminalsForRepo: (repo: Repo) => number
 }
 
 // Why clone alone still refuses: nothing in this process clones onto an SSH host. `cloneRepo` runs
@@ -147,6 +153,9 @@ export class RuntimeProjectHostSetupController {
     if (!store?.deleteProjectHostSetup) {
       throw new Error('runtime_unavailable')
     }
+    if (args.force === false) {
+      this.assertSetupRemovalIsUnused(store, args.setupId)
+    }
     const result = store.deleteProjectHostSetup(args)
     if (!result) {
       throw new Error(`Project host setup not found: ${args.setupId}`)
@@ -154,6 +163,33 @@ export class RuntimeProjectHostSetupController {
     return result
   }
 
+  // Why only for an explicit `force: false`: older clients omit it and must keep their delete.
+  private assertSetupRemovalIsUnused(store: RuntimeStore, setupId: string): void {
+    const setup = this.listSetups().find((entry) => entry.id === setupId)
+    // Same exact-host match the store's delete uses, so a sibling host's row is never measured.
+    const repo = setup?.repoId
+      ? this.deps
+          .listRepos()
+          .find(
+            (entry) => entry.id === setup.repoId && getRepoExecutionHostId(entry) === setup.hostId
+          )
+      : undefined
+    if (!repo) {
+      return
+    }
+    const refusal = describeProjectRemovalRefusal({
+      liveTerminals: this.deps.countLiveTerminalsForRepo(repo),
+      workspacesWithMetadata: countRepoWorkspacesWithMetadata(
+        repo,
+        // Host-qualified read: a same-id, same-path sibling host keeps its rows only in canonical maps.
+        readAllWorktreeMetaForRepo(store, repo)
+      )
+    })
+    if (refusal) {
+      throw new Error(refusal)
+    }
+  }
+
   private completeSetup(
     args: ProjectHostSetupExistingFolderArgs,
     initialRepo: Repo,
diff --git a/src/renderer/src/components/sidebar/RemoveFolderDialog.test.tsx b/src/renderer/src/components/sidebar/RemoveFolderDialog.test.tsx
index 7a5ac841d53..45c04b08a56 100644
--- a/src/renderer/src/components/sidebar/RemoveFolderDialog.test.tsx
+++ b/src/renderer/src/components/sidebar/RemoveFolderDialog.test.tsx
@@ -3,21 +3,30 @@ import type { ReactNode } from 'react'
 import { beforeEach, describe, expect, it, vi } from 'vitest'
 import type { Repo } from '../../../../shared/repo-types'
 
-const mocks = vi.hoisted(() => ({
-  state: {
-    activeModal: 'confirm-remove-folder' as string | null,
-    modalData: {
-      repoId: 'repo-1',
-      displayName: 'Example',
-      hostId: 'ssh:target-1'
-    } as Record<string, unknown>,
-    repos: [] as Repo[],
-    sshTargetLabels: new Map<string, string>(),
-    removedSshTargetLabels: new Map<string, string>(),
-    closeModal: vi.fn(),
-    removeProject: vi.fn()
+const mocks = vi.hoisted(() => {
+  const worktreesByRepo: Record<string, { id: string; hostId?: string }[]> = {}
+  const tabsByWorktree: Record<string, { id: string }[]> = {}
+  const ptyIdsByTabId: Record<string, string[]> = {}
+  return {
+    state: {
+      activeModal: 'confirm-remove-folder' as string | null,
+      modalData: {
+        repoId: 'repo-1',
+        displayName: 'Example',
+        hostId: 'ssh:target-1'
+      } as Record<string, unknown>,
+      repos: [] as Repo[],
+      sshTargetLabels: new Map<string, string>(),
+      removedSshTargetLabels: new Map<string, string>(),
+      worktreesByRepo,
+      detectedWorktreesByRepo: {},
+      tabsByWorktree,
+      ptyIdsByTabId,
+      closeModal: vi.fn(),
+      removeProject: vi.fn()
+    }
   }
-}))
+})
 
 vi.mock('@/store', () => ({
   useAppStore: (selector: (state: typeof mocks.state) => unknown) => selector(mocks.state)
@@ -70,6 +79,9 @@ describe('RemoveFolderDialog', () => {
     }
     mocks.state.sshTargetLabels = new Map([['target-1', 'Persistent host']])
     mocks.state.removedSshTargetLabels = new Map()
+    mocks.state.worktreesByRepo = {}
+    mocks.state.tabsByWorktree = {}
+    mocks.state.ptyIdsByTabId = {}
   })
 
   it('warns that VM recipe cleanup controls file deletion', () => {
@@ -91,4 +103,17 @@ describe('RemoveFolderDialog', () => {
     expect(html).toContain('Its files stay on Persistent host')
     expect(html).not.toContain('VM recipe')
   })
+
+  it('says how many open terminals removal will close', () => {
+    mocks.state.repos = [repo('target-1', 'ssh:target-1')]
+    mocks.state.worktreesByRepo = {
+      'repo-1': [{ id: 'repo-1::/workspace/example', hostId: 'ssh:target-1' }]
+    }
+    mocks.state.tabsByWorktree = { 'repo-1::/workspace/example': [{ id: 'a' }, { id: 'b' }] }
+    mocks.state.ptyIdsByTabId = { a: ['pty-a'], b: ['pty-b'] }
+
+    expect(renderToStaticMarkup(<RemoveFolderDialog />)).toContain(
+      '2 open terminals in this project will be closed.'
+    )
+  })
 })
diff --git a/src/renderer/src/components/sidebar/RemoveFolderDialog.tsx b/src/renderer/src/components/sidebar/RemoveFolderDialog.tsx
index f1b8856e14f..f7b9776a6e8 100644
--- a/src/renderer/src/components/sidebar/RemoveFolderDialog.tsx
+++ b/src/renderer/src/components/sidebar/RemoveFolderDialog.tsx
@@ -15,6 +15,7 @@ import {
   isRuntimeOwnedSshTargetId,
   normalizeExecutionHostId
 } from '../../../../shared/execution-host'
+import { countOpenRepoTerminalTabs } from '@/store/repos/repo-removal'
 
 // Why: interpolated into the sentence so locales control where the name sits;
 // U+0000 cannot appear in a real project name, so the split is unambiguous.
@@ -53,6 +54,23 @@ const RemoveFolderDialog = React.memo(function RemoveFolderDialog() {
     )
   })
 
+  const openTerminalCount = useAppStore((s) =>
+    repoId && hostId ? countOpenRepoTerminalTabs(s, repoId, hostId) : 0
+  )
+  const openTerminalWarning =
+    openTerminalCount === 0
+      ? null
+      : openTerminalCount === 1
+        ? translate(
+            'auto.components.sidebar.RemoveFolderDialog.openTerminalWarningOne',
+            '1 open terminal in this project will be closed.'
+          )
+        : translate(
+            'auto.components.sidebar.RemoveFolderDialog.openTerminalWarningMany',
+            '{{count}} open terminals in this project will be closed.',
+            { count: openTerminalCount }
+          )
+
   // Why: fragment concatenation around the styled name cannot be reordered by
   // SOV locales (#9294). Translate one full sentence with the name as a
   // sentinel token, then split on it to re-apply the inline emphasis.
@@ -104,6 +122,9 @@ const RemoveFolderDialog = React.memo(function RemoveFolderDialog() {
             <span className="break-all font-medium text-foreground">{displayName}</span>
             {descriptionAfterName}
           </DialogDescription>
+          {openTerminalWarning ? (
+            <p className="text-xs font-medium text-foreground">{openTerminalWarning}</p>
+          ) : null}
         </DialogHeader>
         <DialogFooter>
           <Button variant="outline" onClick={() => handleOpenChange(false)}>
diff --git a/src/renderer/src/i18n/locales/en.json b/src/renderer/src/i18n/locales/en.json
index b9893ea9a6f..640f8aace54 100644
--- a/src/renderer/src/i18n/locales/en.json
+++ b/src/renderer/src/i18n/locales/en.json
@@ -5569,7 +5569,9 @@
           "b79b39d865": "Remove Project",
           "removeDescriptionSsh": "This only removes {{name}} from Orca. Its files stay on {{host}} — re-add that SSH host to recover it.",
           "removeDescriptionLocal": "This only removes {{name}} from Orca. It is still on your disk.",
-          "removeDescriptionVmRecipe": "This removes {{name}} from Orca. Its VM recipe determines whether the environment and its files are permanently deleted."
+          "removeDescriptionVmRecipe": "This removes {{name}} from Orca. Its VM recipe determines whether the environment and its files are permanently deleted.",
+          "openTerminalWarningOne": "1 open terminal in this project will be closed.",
+          "openTerminalWarningMany": "{{count}} open terminals in this project will be closed."
         },
         "ScrollToCurrentWorkspaceToolbarButton": {
           "23989bb663": "Reveal active workspace"
diff --git a/src/renderer/src/i18n/locales/es.json b/src/renderer/src/i18n/locales/es.json
index fd461e13613..66e4e29d853 100644
--- a/src/renderer/src/i18n/locales/es.json
+++ b/src/renderer/src/i18n/locales/es.json
@@ -5318,7 +5318,9 @@
           "b79b39d865": "Quitar proyecto",
           "removeDescriptionSsh": "Esto solo elimina {{name}} de Orca. Sus archivos permanecen en {{host}}; vuelve a añadir ese host SSH para recuperarlo.",
           "removeDescriptionLocal": "Esto solo elimina {{name}} de Orca. Sigue estando en tu disco.",
-          "removeDescriptionVmRecipe": "Esto elimina {{name}} de Orca. Su receta de VM determina si el entorno y sus archivos se eliminan permanentemente."
+          "removeDescriptionVmRecipe": "Esto elimina {{name}} de Orca. Su receta de VM determina si el entorno y sus archivos se eliminan permanentemente.",
+          "openTerminalWarningOne": "Se cerrará 1 terminal abierto en este proyecto.",
+          "openTerminalWarningMany": "Se cerrarán {{count}} terminales abiertos en este proyecto."
         },
         "ScrollToCurrentWorkspaceToolbarButton": {
           "23989bb663": "Mostrar espacio de trabajo activo"
diff --git a/src/renderer/src/i18n/locales/fr.json b/src/renderer/src/i18n/locales/fr.json
index 3c20a21befb..68e047432ab 100644
--- a/src/renderer/src/i18n/locales/fr.json
+++ b/src/renderer/src/i18n/locales/fr.json
@@ -5439,7 +5439,9 @@
           "b79b39d865": "Retirer le projet",
           "removeDescriptionSsh": "Ceci retire uniquement {{name}} d'Orca. Ses fichiers restent sur {{host}} — rajoutez cet hôte SSH pour le récupérer.",
           "removeDescriptionLocal": "Ceci retire uniquement {{name}} d'Orca. Il est toujours sur votre disque.",
-          "removeDescriptionVmRecipe": "Ceci retire {{name}} d'Orca. Sa recette de VM détermine si l'environnement et ses fichiers sont définitivement supprimés."
+          "removeDescriptionVmRecipe": "Ceci retire {{name}} d'Orca. Sa recette de VM détermine si l'environnement et ses fichiers sont définitivement supprimés.",
+          "openTerminalWarningOne": "1 terminal ouvert dans ce projet sera fermé.",
+          "openTerminalWarningMany": "{{count}} terminaux ouverts dans ce projet seront fermés."
         },
         "ScrollToCurrentWorkspaceToolbarButton": {
           "23989bb663": "Révéler l'espace de travail actif"
diff --git a/src/renderer/src/i18n/locales/ja.json b/src/renderer/src/i18n/locales/ja.json
index 71a55e8dd37..4b0fea62329 100644
--- a/src/renderer/src/i18n/locales/ja.json
+++ b/src/renderer/src/i18n/locales/ja.json
@@ -5299,7 +5299,9 @@
           "b79b39d865": "プロジェクトの削除",
           "removeDescriptionSsh": "この操作は {{name}} を Orca から削除するだけです。ファイルは {{host}} に残っており、その SSH ホストを再追加すれば復元できます。",
           "removeDescriptionLocal": "この操作は {{name}} を Orca から削除するだけです。ファイルはディスクに残っています。",
-          "removeDescriptionVmRecipe": "これにより、{{name}} が Orca から削除されます。その VM レシピによって、環境とそのファイルが完全に削除されるかどうかが決まります。"
+          "removeDescriptionVmRecipe": "これにより、{{name}} が Orca から削除されます。その VM レシピによって、環境とそのファイルが完全に削除されるかどうかが決まります。",
+          "openTerminalWarningOne": "このプロジェクトで開いているターミナル 1 個が閉じられます。",
+          "openTerminalWarningMany": "このプロジェクトで開いているターミナル {{count}} 個が閉じられます。"
         },
         "ScrollToCurrentWorkspaceToolbarButton": {
           "23989bb663": "アクティブなワークスペースを表示する"
diff --git a/src/renderer/src/i18n/locales/ko.json b/src/renderer/src/i18n/locales/ko.json
index 9139145462a..9a1d925e5ec 100644
--- a/src/renderer/src/i18n/locales/ko.json
+++ b/src/renderer/src/i18n/locales/ko.json
@@ -5299,7 +5299,9 @@
           "b79b39d865": "프로젝트 제거",
           "removeDescriptionSsh": "이 작업은 {{name}}을(를) Orca에서 제거만 합니다. 파일은 {{host}}에 그대로 남아 있으며, 해당 SSH 호스트를 다시 추가하면 복구할 수 있습니다.",
           "removeDescriptionLocal": "이 작업은 {{name}}을(를) Orca에서 제거만 합니다. 파일은 디스크에 그대로 남아 있습니다.",
-          "removeDescriptionVmRecipe": "이렇게 하면 Orca에서 {{name}}이(가) 제거됩니다. 해당 VM 레시피에 따라 환경과 해당 파일이 영구적으로 삭제되는지 여부가 결정됩니다."
+          "removeDescriptionVmRecipe": "이렇게 하면 Orca에서 {{name}}이(가) 제거됩니다. 해당 VM 레시피에 따라 환경과 해당 파일이 영구적으로 삭제되는지 여부가 결정됩니다.",
+          "openTerminalWarningOne": "이 프로젝트에서 열려 있는 터미널 1개가 닫힙니다.",
+          "openTerminalWarningMany": "이 프로젝트에서 열려 있는 터미널 {{count}}개가 닫힙니다."
         },
         "ScrollToCurrentWorkspaceToolbarButton": {
           "23989bb663": "활성 워크스페이스로 이동"
diff --git a/src/renderer/src/i18n/locales/zh.json b/src/renderer/src/i18n/locales/zh.json
index 590cb456dd9..678490ba673 100644
--- a/src/renderer/src/i18n/locales/zh.json
+++ b/src/renderer/src/i18n/locales/zh.json
@@ -5299,7 +5299,9 @@
           "b79b39d865": "删除项目",
           "removeDescriptionSsh": "此操作仅将 {{name}} 从 Orca 中移除。文件仍保留在 {{host}} 上 — 重新添加该 SSH 主机即可恢复。",
           "removeDescriptionLocal": "此操作仅将 {{name}} 从 Orca 中移除。文件仍保留在您的磁盘上。",
-          "removeDescriptionVmRecipe": "这会从 Orca 中删除 {{name}}。其VM配方决定是否永久删除环境及其文件。"
+          "removeDescriptionVmRecipe": "这会从 Orca 中删除 {{name}}。其VM配方决定是否永久删除环境及其文件。",
+          "openTerminalWarningOne": "此项目中 1 个打开的终端将被关闭。",
+          "openTerminalWarningMany": "此项目中 {{count}} 个打开的终端将被关闭。"
         },
         "ScrollToCurrentWorkspaceToolbarButton": {
           "23989bb663": "显示活动工作区"
diff --git a/src/renderer/src/store/repos/repo-removal.test.ts b/src/renderer/src/store/repos/repo-removal.test.ts
new file mode 100644
index 00000000000..f368cf853fb
--- /dev/null
+++ b/src/renderer/src/store/repos/repo-removal.test.ts
@@ -0,0 +1,25 @@
+import { describe, expect, it } from 'vitest'
+import { countOpenRepoTerminalTabs } from './repo-removal'
+
+describe('countOpenRepoTerminalTabs', () => {
+  it('counts tabs with a PTY on the removed host only', () => {
+    const state = {
+      worktreesByRepo: {
+        'repo-1': [
+          { id: 'repo-1::/a', hostId: 'local' },
+          { id: 'repo-1::/srv/a', hostId: 'ssh:box' }
+        ]
+      },
+      detectedWorktreesByRepo: {},
+      tabsByWorktree: {
+        'repo-1::/a': [{ id: 'tab-live' }, { id: 'tab-no-pty' }],
+        'repo-1::/srv/a': [{ id: 'tab-ssh' }]
+      },
+      ptyIdsByTabId: { 'tab-live': ['pty-1'], 'tab-no-pty': [], 'tab-ssh': ['pty-2'] }
+    }
+
+    expect(countOpenRepoTerminalTabs(state, 'repo-1', 'local')).toBe(1)
+    expect(countOpenRepoTerminalTabs(state, 'repo-1', 'ssh:box')).toBe(1)
+    expect(countOpenRepoTerminalTabs(state, 'repo-2', 'local')).toBe(0)
+  })
+})
diff --git a/src/renderer/src/store/repos/repo-removal.ts b/src/renderer/src/store/repos/repo-removal.ts
index c042d46493f..e1dde15d7cf 100644
--- a/src/renderer/src/store/repos/repo-removal.ts
+++ b/src/renderer/src/store/repos/repo-removal.ts
@@ -32,8 +32,17 @@ export function worktreeBelongsToHost(worktree: { hostId?: string }, hostId: str
   return (worktree.hostId ?? LOCAL_EXECUTION_HOST_ID) === hostId
 }
 
+type HostScopedWorktreeRef = { id: string; hostId?: string }
+
+type RepoWorktreeCatalog = {
+  worktreesByRepo: Readonly<Record<string, readonly HostScopedWorktreeRef[] | undefined>>
+  detectedWorktreesByRepo: Readonly<
+    Record<string, { worktrees: readonly HostScopedWorktreeRef[] } | undefined>
+  >
+}
+
 export function getKnownRepoWorktreeIds(
-  state: AppState,
+  state: RepoWorktreeCatalog,
   projectId: string,
   hostId?: string
 ): string[] {
@@ -51,6 +60,26 @@ export function getKnownRepoWorktreeIds(
   return [...ids]
 }
 
+/** Terminal tabs that removing this project's host row will close. */
+export function countOpenRepoTerminalTabs(
+  state: RepoWorktreeCatalog & {
+    tabsByWorktree: Readonly<Record<string, readonly { id: string }[] | undefined>>
+    ptyIdsByTabId: Readonly<Record<string, readonly string[] | undefined>>
+  },
+  projectId: string,
+  hostId: string
+): number {
+  let count = 0
+  for (const worktreeId of getKnownRepoWorktreeIds(state, projectId, hostId)) {
+    for (const tab of state.tabsByWorktree[worktreeId] ?? []) {
+      if ((state.ptyIdsByTabId[tab.id]?.length ?? 0) > 0) {
+        count += 1
+      }
+    }
+  }
+  return count
+}
+
 export function createRepoRemovalActions(
   set: Parameters<StateCreator<AppState>>[0],
   get: Parameters<StateCreator<AppState>>[1]
diff --git a/src/shared/project-types.ts b/src/shared/project-types.ts
index f5704c504ef..4ef6e522c85 100644
--- a/src/shared/project-types.ts
+++ b/src/shared/project-types.ts
@@ -116,6 +116,8 @@ export type ProjectHostSetupUpdateArgs = {
 
 export type ProjectHostSetupDeleteArgs = {
   setupId: string
+  /** `false` refuses while the project has live terminals or workspace metadata; absent skips the check. */
+  force?: boolean
 }
 
 export type ProjectHostSetupResult = {
diff --git a/src/shared/rpc-contract/project-runtime-params.ts b/src/shared/rpc-contract/project-runtime-params.ts
index 38d9ebff0ba..94fd5d39915 100644
--- a/src/shared/rpc-contract/project-runtime-params.ts
+++ b/src/shared/rpc-contract/project-runtime-params.ts
@@ -91,5 +91,6 @@ export const ProjectHostSetupUpdate = z.object({
 })
 
 export const ProjectHostSetupDelete = z.object({
-  setupId: requiredString('Missing setup ID')
+  setupId: requiredString('Missing setup ID'),
+  force: z.boolean().optional()
 })