diff --git a/src/main/git/gh-rate-limit-breaker.test.ts b/src/main/git/gh-rate-limit-breaker.test.ts
index 3e136954522..787ad3d1777 100644
--- a/src/main/git/gh-rate-limit-breaker.test.ts
+++ b/src/main/git/gh-rate-limit-breaker.test.ts
@@ -1,5 +1,6 @@
 import { afterEach, describe, expect, it, vi } from 'vitest'
 import {
+  _getGhRateLimitBlockCount,
   _resetGhRateLimitBreaker,
   classifyGhRateLimitBucket,
   createGhRateLimitBlockedError,
@@ -117,6 +118,19 @@ describe('breaker state', () => {
     expect(getGhRateLimitBlockedUntilMs('core', now, 'wsl:ubuntu:github.com')).toBeNull()
   })
 
+  it('bounds retained blocks across user-supplied Enterprise host scopes', () => {
+    const now = Date.now()
+    for (let i = 0; i < 1_200; i += 1) {
+      recordGhPrimaryRateLimit('core', now + 60_000, `native:ghe-${i}.example.test`)
+    }
+
+    expect(_getGhRateLimitBlockCount()).toBe(1024)
+    expect(getGhRateLimitBlockedUntilMs('core', now, 'native:ghe-1199.example.test')).toBe(
+      now + 60_000
+    )
+    expect(getGhRateLimitBlockedUntilMs('core', now, 'native:ghe-0.example.test')).toBeNull()
+  })
+
   it('notifyGhPrimaryRateLimit applies a fallback block and fires the reset probe', () => {
     const probe = vi.fn()
     registerGhRateLimitResetProbe(probe)
diff --git a/src/main/git/gh-rate-limit-breaker.ts b/src/main/git/gh-rate-limit-breaker.ts
index 623555d8133..6da81bab879 100644
--- a/src/main/git/gh-rate-limit-breaker.ts
+++ b/src/main/git/gh-rate-limit-breaker.ts
@@ -57,6 +57,7 @@ export function parseGhRateLimitScopeKey(scope: string): GhRateLimitScopeParts |
 }
 
 const DEFAULT_SCOPE = ghRateLimitScopeKey('native', 'github.com')
+const GH_RATE_LIMIT_BLOCK_MAX_ENTRIES = 1024
 const blockedUntilMsByScopeAndBucket = new Map<string, number>()
 let resetProbe: ((bucket: GhRateLimitBucket, scope: string) => void) | null = null
 
@@ -146,7 +147,18 @@ export function recordGhPrimaryRateLimit(
 ): void {
   const key = breakerKey(bucket, scope)
   const existing = blockedUntilMsByScopeAndBucket.get(key) ?? 0
+  // Why: host scopes can originate from pasted GHES URLs. Refresh insertion
+  // order and cap retained blocks so a stream of failing hosts cannot grow the
+  // main-process map for the lifetime of the app.
+  blockedUntilMsByScopeAndBucket.delete(key)
   blockedUntilMsByScopeAndBucket.set(key, Math.max(existing, blockedUntilMs))
+  while (blockedUntilMsByScopeAndBucket.size > GH_RATE_LIMIT_BLOCK_MAX_ENTRIES) {
+    const oldestKey = blockedUntilMsByScopeAndBucket.keys().next().value
+    if (oldestKey === undefined) {
+      break
+    }
+    blockedUntilMsByScopeAndBucket.delete(oldestKey)
+  }
 }
 
 export function clearGhRateLimitBlock(bucket: GhRateLimitBucket, scope = DEFAULT_SCOPE): void {
@@ -158,6 +170,11 @@ export function getGhRateLimitBlockedUntilMs(
   nowMs: number = Date.now(),
   scope = DEFAULT_SCOPE
 ): number | null {
+  for (const [key, blockedUntil] of blockedUntilMsByScopeAndBucket) {
+    if (blockedUntil <= nowMs) {
+      blockedUntilMsByScopeAndBucket.delete(key)
+    }
+  }
   const key = breakerKey(bucket, scope)
   const blockedUntil = blockedUntilMsByScopeAndBucket.get(key)
   if (blockedUntil === undefined) {
@@ -170,6 +187,11 @@ export function getGhRateLimitBlockedUntilMs(
   return blockedUntil
 }
 
+/** @internal — cache-bound tests only. */
+export function _getGhRateLimitBlockCount(): number {
+  return blockedUntilMsByScopeAndBucket.size
+}
+
 /** Register the (single) callback that refreshes precise reset times after a
  * breaker trip. Registered by the github rate-limit prober at module load. */
 export function registerGhRateLimitResetProbe(
diff --git a/src/main/github/client.ts b/src/main/github/client.ts
index 50617955945..ed643c17ecd 100644
--- a/src/main/github/client.ts
+++ b/src/main/github/client.ts
@@ -2486,10 +2486,6 @@ function parseTrackedUpstreamBranch(upstreamRef: string): TrackedUpstreamBranch
   return parsed
 }
 
-function prOwnerRepoKey(ownerRepo: OwnerRepo): string {
-  return `${ownerRepo.owner.toLowerCase()}/${ownerRepo.repo.toLowerCase()}`
-}
-
 function shouldRetryTrackedUpstreamBranch(
   upstreamBranch: TrackedUpstreamBranch,
   branchName: string,
@@ -2502,7 +2498,7 @@ function shouldRetryTrackedUpstreamBranch(
   if (!headRepo) {
     return true
   }
-  return prOwnerRepoKey(upstreamHeadRepo) !== prOwnerRepoKey(headRepo)
+  return githubRepoIdentityKey(upstreamHeadRepo) !== githubRepoIdentityKey(headRepo)
 }
 
 async function getTrackedUpstreamBranch(
diff --git a/src/main/github/github-repository-identity.ts b/src/main/github/github-repository-identity.ts
index 28b7b0676c7..1996d7b2b54 100644
--- a/src/main/github/github-repository-identity.ts
+++ b/src/main/github/github-repository-identity.ts
@@ -8,6 +8,7 @@ import {
   type GitHubRemoteIdentity
 } from './github-remote-identity-parsing'
 import { isStableMissingGitRemoteError } from './stable-missing-git-remote-error'
+import { githubRepoIdentityKey } from '../../shared/github-repository-identity-key'
 
 export type OwnerRepo = GitHubOwnerRepo
 
@@ -234,7 +235,7 @@ export type PRRepositoryCandidates = {
 }
 
 function ownerRepoKey(ownerRepo: OwnerRepo): string {
-  return `${ownerRepo.owner.toLowerCase()}/${ownerRepo.repo.toLowerCase()}`
+  return githubRepoIdentityKey(ownerRepo)
 }
 
 export async function resolvePRRepositoryCandidates(
diff --git a/src/main/github/rate-limit.ts b/src/main/github/rate-limit.ts
index 6691488f90b..2ca3f5cad43 100644
--- a/src/main/github/rate-limit.ts
+++ b/src/main/github/rate-limit.ts
@@ -195,6 +195,24 @@ const DEFAULT_BREAKER_SCOPE = ghRateLimitScopeKey('native', 'github.com')
 // versa).
 const scopeRefinementInFlight = new Map<string, Promise<void>>()
 const scopeProbeFailureAtMs = new Map<string, number>()
+const SCOPE_PROBE_FAILURE_MAX_ENTRIES = 512
+
+function rememberScopeProbeFailure(scope: string, failedAt: number): void {
+  for (const [key, at] of scopeProbeFailureAtMs) {
+    if (failedAt - at >= RATE_LIMIT_CACHE_TTL_MS) {
+      scopeProbeFailureAtMs.delete(key)
+    }
+  }
+  scopeProbeFailureAtMs.delete(scope)
+  scopeProbeFailureAtMs.set(scope, failedAt)
+  while (scopeProbeFailureAtMs.size > SCOPE_PROBE_FAILURE_MAX_ENTRIES) {
+    const oldestKey = scopeProbeFailureAtMs.keys().next().value
+    if (oldestKey === undefined) {
+      break
+    }
+    scopeProbeFailureAtMs.delete(oldestKey)
+  }
+}
 
 function refineBreakerForScope(scope: string): void {
   // Default scope keeps the existing shared-snapshot refinement path.
@@ -241,7 +259,9 @@ function refineBreakerForScope(scope: string): void {
         release()
       }
     } catch {
-      scopeProbeFailureAtMs.set(scope, Date.now())
+      // Why: GHES hosts can be supplied through pasted project URLs. Bound the
+      // negative cache so repeated failing hosts cannot accumulate forever.
+      rememberScopeProbeFailure(scope, Date.now())
     } finally {
       scopeRefinementInFlight.delete(scope)
     }
diff --git a/src/renderer/src/components/PullRequestPage.tsx b/src/renderer/src/components/PullRequestPage.tsx
index c5a9786cf10..d4c7b5a3b32 100644
--- a/src/renderer/src/components/PullRequestPage.tsx
+++ b/src/renderer/src/components/PullRequestPage.tsx
@@ -223,20 +223,18 @@ import {
 import { translate } from '@/i18n/i18n'
 import { getSettingsForRepoRuntimeOwner } from '@/lib/repo-runtime-owner'
 
-// Why: the item URL is the only owner/repo source present on every work item across the IPC boundary; non-GitHub hosts return null (matching the indicator's suppression).
+// Why: the item URL is the only host-aware repository identity present on every work item across IPC.
 function parseOwnerRepoFromItemUrl(url: string): GitHubOwnerRepo | null {
   try {
     const parsed = new URL(url)
-    if (parsed.hostname !== 'github.com') {
+    if ((parsed.protocol !== 'https:' && parsed.protocol !== 'http:') || !parsed.host) {
       return null
     }
     const segments = parsed.pathname.split('/').filter(Boolean)
     if (segments.length < 2) {
       return null
     }
-    // Why: the URL proves the host. Leaving it off lets the main process stamp
-    // a GHES origin's host onto what is provably a github.com repo.
-    return { owner: segments[0], repo: segments[1], host: 'github.com' }
+    return { owner: segments[0], repo: segments[1], host: parsed.host }
   } catch {
     return null
   }
@@ -287,6 +285,7 @@ function normalizeItemDialogTab(
 export type PullRequestPageProjectOrigin = {
   owner: string
   repo: string
+  host?: string
   number: number
   type: 'issue' | 'pr'
   projectId: string
@@ -563,7 +562,8 @@ function PRAssigneesPanel({
     slugOwner,
     slugRepo,
     assigneeLogins,
-    sourceSettings
+    sourceSettings,
+    projectOrigin?.host ?? assigneeSlug?.host
   )
   const repoAssigneesByPath = useRepoAssignees(repoPath, item.repoId, sourceSettings)
   const repoAssignees = slugOwner && slugRepo ? repoAssigneesBySlug : repoAssigneesByPath
@@ -841,7 +841,8 @@ function PRReviewersPanel({
     open && reviewSlug ? reviewSlug.owner : null,
     open && reviewSlug ? reviewSlug.repo : null,
     reviewerSeedUsers.map((user) => user.login),
-    sourceSettings
+    sourceSettings,
+    reviewSlug?.host
   )
   const reviewerMetadataByPath = useRepoAssignees(
     open && !reviewSlug ? repoPath : null,
@@ -3249,7 +3250,10 @@ function ConversationTab({
 
   const bodySlug = useMemo(() => parseOwnerRepoFromItemUrl(item.url), [item.url])
   const markdownGitHubRepo = useMemo(
-    () => (projectOrigin ? { owner: projectOrigin.owner, repo: projectOrigin.repo } : bodySlug),
+    () =>
+      projectOrigin
+        ? { owner: projectOrigin.owner, repo: projectOrigin.repo, host: projectOrigin.host }
+        : bodySlug,
     [bodySlug, projectOrigin]
   )
   const canEditBody =
@@ -5491,6 +5495,7 @@ async function runIssueUpdate(args: {
     const updateArgs = {
       owner: args.projectOrigin.owner,
       repo: args.projectOrigin.repo,
+      ...(args.projectOrigin.host ? { host: args.projectOrigin.host } : {}),
       number: args.number,
       updates: args.updates
     }
@@ -5571,7 +5576,11 @@ async function runWorkItemBodyUpdate(args: {
 }): Promise<void> {
   if (args.item.type === 'pr') {
     const targetSlug = args.projectOrigin
-      ? { owner: args.projectOrigin.owner, repo: args.projectOrigin.repo }
+      ? {
+          owner: args.projectOrigin.owner,
+          repo: args.projectOrigin.repo,
+          host: args.projectOrigin.host
+        }
       : args.parsedSlug
     if (!targetSlug) {
       throw new Error('No GitHub repository context available for this pull request.')
@@ -5584,6 +5593,7 @@ async function runWorkItemBodyUpdate(args: {
     const updateArgs = {
       owner: targetSlug.owner,
       repo: targetSlug.repo,
+      ...(targetSlug.host ? { host: targetSlug.host } : {}),
       number: args.item.number,
       updates: { body: args.body }
     }
@@ -5643,6 +5653,7 @@ async function runPullRequestStateUpdate(args: {
     const updateArgs = {
       owner: args.projectOrigin.owner,
       repo: args.projectOrigin.repo,
+      ...(args.projectOrigin.host ? { host: args.projectOrigin.host } : {}),
       number: args.number,
       updates: args.updates
     }
@@ -5785,14 +5796,25 @@ function GHEditSection({
     projectOrigin ? null : repoId,
     sourceSettings
   )
-  const repoLabelsBySlug = useRepoLabelsBySlug(slugOwner, slugRepo, sourceSettings)
+  const repoLabelsBySlug = useRepoLabelsBySlug(
+    slugOwner,
+    slugRepo,
+    sourceSettings,
+    projectOrigin?.host
+  )
   const repoLabels = projectOrigin ? repoLabelsBySlug : repoLabelsByPath
   const repoAssigneesByPath = useRepoAssignees(
     projectOrigin ? null : repoPath,
     projectOrigin ? null : repoId,
     sourceSettings
   )
-  const repoAssigneesBySlug = useRepoAssigneesBySlug(slugOwner, slugRepo, assignees, sourceSettings)
+  const repoAssigneesBySlug = useRepoAssigneesBySlug(
+    slugOwner,
+    slugRepo,
+    assignees,
+    sourceSettings,
+    projectOrigin?.host
+  )
   const repoAssignees = projectOrigin ? repoAssigneesBySlug : repoAssigneesByPath
 
   // Why: sync local assignees on item change / detail resolve, but skip if the user made an optimistic edit so we don't clobber in-flight changes.
diff --git a/src/renderer/src/components/TaskPage.tsx b/src/renderer/src/components/TaskPage.tsx
index d0186a1b1a4..5ed37ea6912 100644
--- a/src/renderer/src/components/TaskPage.tsx
+++ b/src/renderer/src/components/TaskPage.tsx
@@ -1180,6 +1180,7 @@ function GHStatusCell({
               {
                 owner: parsedOwnerRepo.owner,
                 repo: parsedOwnerRepo.repo,
+                ...(parsedOwnerRepo.host ? { host: parsedOwnerRepo.host } : {}),
                 number: item.number,
                 updates
               },
@@ -1188,6 +1189,7 @@ function GHStatusCell({
           : window.api.gh.updateIssueBySlug({
               owner: parsedOwnerRepo.owner,
               repo: parsedOwnerRepo.repo,
+              ...(parsedOwnerRepo.host ? { host: parsedOwnerRepo.host } : {}),
               number: item.number,
               updates
             })
@@ -1795,7 +1797,8 @@ function GHAssigneesCell({
     open ? owner : null,
     open ? repoName : null,
     seedLogins,
-    sourceSettings
+    sourceSettings,
+    parsed?.slug.host
   )
 
   const toggleAssignee = useCallback(
@@ -1819,6 +1822,7 @@ function GHAssigneesCell({
           const args = {
             owner,
             repo: repoName,
+            ...(parsed?.slug.host ? { host: parsed.slug.host } : {}),
             number: item.number,
             updates
           }
@@ -2188,7 +2192,8 @@ function PRReviewCell({
     open && reviewSlug ? reviewSlug.owner : null,
     open && reviewSlug ? reviewSlug.repo : null,
     reviewerSeedUsers.map((user) => user.login),
-    sourceSettings
+    sourceSettings,
+    reviewSlug?.host
   )
 
   const authorLogin = item.author?.toLowerCase() ?? null
diff --git a/src/renderer/src/components/github-enterprise-slug-routing-boundary.test.ts b/src/renderer/src/components/github-enterprise-slug-routing-boundary.test.ts
new file mode 100644
index 00000000000..4247fd80d0d
--- /dev/null
+++ b/src/renderer/src/components/github-enterprise-slug-routing-boundary.test.ts
@@ -0,0 +1,54 @@
+import { readFileSync } from 'node:fs'
+import { join } from 'node:path'
+import { describe, expect, it } from 'vitest'
+
+function componentSource(relativePath: string): string {
+  return readFileSync(join(__dirname, relativePath), 'utf8')
+}
+
+function sourceBetween(source: string, startPattern: string, endPattern: string): string {
+  const start = source.indexOf(startPattern)
+  expect(start).toBeGreaterThanOrEqual(0)
+  const end = source.indexOf(endPattern, start + startPattern.length)
+  expect(end).toBeGreaterThan(start)
+  return source.slice(start, end)
+}
+
+describe('GitHub Enterprise slug routing boundaries', () => {
+  it('keeps work-item URL hosts on TaskPage metadata and issue mutations', () => {
+    const source = componentSource('TaskPage.tsx')
+    const statusSection = sourceBetween(source, 'function GHStatusCell', 'function formatPRDelta')
+    const assigneeSection = sourceBetween(
+      source,
+      'function GHAssigneesCell',
+      'function getChecksLabel'
+    )
+
+    expect(statusSection).toContain(
+      '...(parsedOwnerRepo.host ? { host: parsedOwnerRepo.host } : {})'
+    )
+    expect(assigneeSection).toContain('parsed?.slug.host')
+    expect(assigneeSection).toContain('...(parsed?.slug.host ? { host: parsed.slug.host } : {})')
+  })
+
+  it('keeps PR base-repository hosts on checks-sidebar comment writes', () => {
+    const source = componentSource('right-sidebar/ChecksPanel.tsx')
+    const conversationSection = sourceBetween(
+      source,
+      'const handleEditComment = useCallback',
+      'const handleReplyToComment = useCallback'
+    )
+
+    expect(conversationSection).toContain('...(pr.prRepo.host ? { host: pr.prRepo.host } : {})')
+    expect(conversationSection).toContain('updateIssueCommentBySlug({')
+    expect(conversationSection).toContain('deleteIssueCommentBySlug({')
+  })
+
+  it('keeps the primary repository host on task filter metadata reads', () => {
+    const source = componentSource('github/PRFilterDropdowns.tsx')
+
+    expect(source).toContain('useRepoLabelsBySlug(')
+    expect(source).toContain('useRepoAssigneesBySlug(')
+    expect(source.match(/primarySlug\?\.host/g)).toHaveLength(2)
+  })
+})
diff --git a/src/renderer/src/components/github-item-dialog-source-boundary.test.ts b/src/renderer/src/components/github-item-dialog-source-boundary.test.ts
index 951e22d6651..6851fdb3a2a 100644
--- a/src/renderer/src/components/github-item-dialog-source-boundary.test.ts
+++ b/src/renderer/src/components/github-item-dialog-source-boundary.test.ts
@@ -57,7 +57,8 @@ describe('GitHubItemDialog source host boundaries', () => {
 
     expect(section).toContain('getTaskSourceRuntimeSettings(sourceContext)')
     expect(section).toContain('useRepoLabels(')
-    expect(section).toContain('useRepoLabelsBySlug(slugOwner, slugRepo, sourceSettings)')
+    expect(section).toContain('useRepoLabelsBySlug(')
+    expect(section).toContain('projectOrigin?.host')
     expect(section).toContain('useRepoAssignees(')
     expect(section).toContain('useRepoAssigneesBySlug(')
     expect(section).toContain('sourceSettings')
diff --git a/src/renderer/src/components/github-project/GhAuthErrorHelp.test.ts b/src/renderer/src/components/github-project/GhAuthErrorHelp.test.ts
new file mode 100644
index 00000000000..da666d54523
--- /dev/null
+++ b/src/renderer/src/components/github-project/GhAuthErrorHelp.test.ts
@@ -0,0 +1,60 @@
+import { describe, expect, it, vi } from 'vitest'
+import type { GhAuthDiagnostic } from '../../../../shared/github-auth-types'
+
+vi.mock('@/i18n/i18n', () => ({
+  translate: (_key: string, fallback: string) => fallback
+}))
+
+import { buildRemediation } from './GhAuthErrorHelp'
+
+function diagnostic(overrides: Partial<GhAuthDiagnostic> = {}): GhAuthDiagnostic {
+  return {
+    ghAvailable: true,
+    activeAccount: {
+      host: 'ghe.acme.test:8443',
+      user: 'alice',
+      active: true,
+      envToken: null,
+      source: 'keyring',
+      scopes: ['project', 'read:org', 'repo']
+    },
+    accounts: [],
+    envTokenInProcess: null,
+    missingScopes: [],
+    requiredScopes: ['project', 'read:org', 'repo'],
+    hasKeyringFallback: false,
+    requiredHost: 'ghe.acme.test:8443',
+    requiredHostAuthenticated: true,
+    ...overrides
+  }
+}
+
+describe('GitHub Project auth remediation host routing', () => {
+  it('uses the requested GHES host while the diagnostic is still loading', () => {
+    expect(
+      buildRemediation('Sign in required.', 'auth_required', null, 'ghe.acme.test:8443').commands
+    ).toEqual([
+      {
+        label: 'Copy command',
+        command: 'gh auth login --hostname ghe.acme.test:8443'
+      }
+    ])
+    expect(
+      buildRemediation('Missing scope.', 'scope_missing', null, 'ghe.acme.test:8443').commands
+    ).toEqual([
+      {
+        label: 'Copy command',
+        command: 'gh auth refresh --hostname ghe.acme.test:8443 -s project -s read:org -s repo'
+      }
+    ])
+  })
+
+  it('keeps the GHES host on best-effort refresh advice after diagnostics complete', () => {
+    expect(buildRemediation('Access denied.', 'scope_missing', diagnostic()).commands).toEqual([
+      {
+        label: 'Copy refresh command',
+        command: 'gh auth refresh --hostname ghe.acme.test:8443 -s project -s read:org -s repo'
+      }
+    ])
+  })
+})
diff --git a/src/renderer/src/components/github-project/GhAuthErrorHelp.tsx b/src/renderer/src/components/github-project/GhAuthErrorHelp.tsx
index 84e0d16876c..30d1ea61b16 100644
--- a/src/renderer/src/components/github-project/GhAuthErrorHelp.tsx
+++ b/src/renderer/src/components/github-project/GhAuthErrorHelp.tsx
@@ -122,10 +122,11 @@ type Remediation = {
   docsUrl?: string
 }
 
-function buildRemediation(
+export function buildRemediation(
   errorMessage: string,
   kind: AuthErrorKind,
-  diag: GhAuthDiagnostic | null
+  diag: GhAuthDiagnostic | null,
+  requestedHost?: string
 ): Remediation {
   // Diagnostic still loading or unavailable — fall back to the canned advice
   // so the UI never gets worse than the pre-diagnosis behavior.
@@ -138,7 +139,10 @@ function buildRemediation(
             'auto.components.github.project.GhAuthErrorHelp.b436c586d1',
             'Copy command'
           ),
-          command: kind === 'auth_required' ? LOGIN_CMD : REFRESH_CMD
+          command:
+            kind === 'auth_required'
+              ? loginCommandForHost(requestedHost)
+              : refreshCommandForHost(requestedHost)
         }
       ]
     }
@@ -173,7 +177,7 @@ function buildRemediation(
             'auto.components.github.project.GhAuthErrorHelp.9c2da6353b',
             'Copy login command'
           ),
-          command: LOGIN_CMD
+          command: loginCommandForHost(diag.requiredHost ?? requestedHost)
         }
       ],
       docsUrl: 'https://cli.github.com/'
@@ -264,7 +268,7 @@ function buildRemediation(
           'auto.components.github.project.GhAuthErrorHelp.3fefeebde4',
           'Copy refresh command'
         ),
-        command: REFRESH_CMD
+        command: refreshCommandForHost(diag.requiredHost ?? requestedHost)
       }
     ],
     docsUrl:
@@ -299,7 +303,7 @@ export function GhAuthErrorHelp({
     }
   }, [host])
 
-  const remedy = buildRemediation(error.message, error.type, diag)
+  const remedy = buildRemediation(error.message, error.type, diag, host)
   const docsUrl = remedy.docsUrl
 
   if (variant === 'banner') {
diff --git a/src/renderer/src/components/github-project/ProjectPicker.tsx b/src/renderer/src/components/github-project/ProjectPicker.tsx
index 2bd7d516eca..a4d54b3a71e 100644
--- a/src/renderer/src/components/github-project/ProjectPicker.tsx
+++ b/src/renderer/src/components/github-project/ProjectPicker.tsx
@@ -814,6 +814,7 @@ function AuthErrorBanner({ error }: { error: GitHubProjectViewError }): React.JS
       <GhAuthErrorHelp
         error={error as GitHubProjectViewError & { type: 'auth_required' | 'scope_missing' }}
         variant="banner"
+        host="github.com"
       />
     )
   }
diff --git a/src/renderer/src/components/github-project/ProjectViewWrapper.tsx b/src/renderer/src/components/github-project/ProjectViewWrapper.tsx
index 7d7af9bcd95..4e5c6b48a87 100644
--- a/src/renderer/src/components/github-project/ProjectViewWrapper.tsx
+++ b/src/renderer/src/components/github-project/ProjectViewWrapper.tsx
@@ -906,6 +906,7 @@ export default function ProjectViewWrapper({ selectedRepoIds }: Props): React.JS
         <ErrorState
           error={error.error}
           totalCount={error.totalCount}
+          host={activeProject.host}
           onOpenInGitHub={() => {
             if (selectedViewUrl) {
               void window.api.shell.openUrl(selectedViewUrl)
@@ -1262,10 +1263,12 @@ function ViewTabStrip({
 function ErrorState({
   error,
   totalCount,
+  host,
   onOpenInGitHub
 }: {
   error: GitHubProjectViewError
   totalCount?: number
+  host?: string
   onOpenInGitHub: () => void
 }): React.JSX.Element {
   // Auth/scope errors get a richer `gh auth status` remediation UI; bail early before the generic block.
@@ -1274,6 +1277,7 @@ function ErrorState({
       <div className="flex flex-1 flex-col items-start gap-3 p-6 text-sm">
         <GhAuthErrorHelp
           error={error as GitHubProjectViewError & { type: 'auth_required' | 'scope_missing' }}
+          host={host}
         />
         <Button size="sm" variant="outline" onClick={onOpenInGitHub}>
           <ExternalLink className="mr-1 size-3.5" />{' '}
diff --git a/src/renderer/src/components/github/IssueSourceIndicator.tsx b/src/renderer/src/components/github/IssueSourceIndicator.tsx
index a5ce266f60f..bb3411a2fde 100644
--- a/src/renderer/src/components/github/IssueSourceIndicator.tsx
+++ b/src/renderer/src/components/github/IssueSourceIndicator.tsx
@@ -2,6 +2,7 @@ import React from 'react'
 import type { GitHubOwnerRepo } from '../../../../shared/types'
 import RepoBadgeLabel from '@/components/repo/RepoBadgeLabel'
 import { cn } from '@/lib/utils'
+import { githubRepoIdentityKey } from '../../../../shared/github-repository-identity-key'
 
 export type IssueSourceIndicatorProps = {
   /** Resolved issue-source owner/repo. `null` means the source hasn't been
@@ -39,13 +40,9 @@ export function sameGitHubOwnerRepo(
   if (!left || !right) {
     return false
   }
-  // Why: GitHub treats owner/repo names case-insensitively, so remotes with
-  // different casing (e.g. StablyAI/Orca vs stablyai/orca) resolve to the
-  // same repo and must suppress the indicator.
-  return (
-    left.owner.toLowerCase() === right.owner.toLowerCase() &&
-    left.repo.toLowerCase() === right.repo.toLowerCase()
-  )
+  // Why: names are case-insensitive, but the same slug on github.com and GHES
+  // identifies different repositories and must not suppress source routing.
+  return githubRepoIdentityKey(left) === githubRepoIdentityKey(right)
 }
 
 /**
diff --git a/src/renderer/src/components/github/PRFilterDropdowns.tsx b/src/renderer/src/components/github/PRFilterDropdowns.tsx
index 6085b8e750e..4a682c2fdd7 100644
--- a/src/renderer/src/components/github/PRFilterDropdowns.tsx
+++ b/src/renderer/src/components/github/PRFilterDropdowns.tsx
@@ -86,13 +86,15 @@ export default function PRFilterDropdowns({
   const labelsState = useRepoLabelsBySlug(
     popoverOpen ? owner : null,
     popoverOpen ? repo : null,
-    settings
+    settings,
+    primarySlug?.host
   )
   const assigneesState = useRepoAssigneesBySlug(
     popoverOpen ? owner : null,
     popoverOpen ? repo : null,
     undefined,
-    settings
+    settings,
+    primarySlug?.host
   )
 
   // Why: surface @me as a first-class option even though it's not a real
diff --git a/src/renderer/src/components/pull-request-page-host-boundary.test.ts b/src/renderer/src/components/pull-request-page-host-boundary.test.ts
index 89d0dc14f57..cc83a16e6f8 100644
--- a/src/renderer/src/components/pull-request-page-host-boundary.test.ts
+++ b/src/renderer/src/components/pull-request-page-host-boundary.test.ts
@@ -48,7 +48,8 @@ describe('PullRequestPage host boundaries', () => {
     expect(section).toContain('getSettingsForRepoRuntimeOwner(s, item.repoId ?? repoId ?? null)')
     expect(section).toContain('getTaskSourceRuntimeSettings(sourceContext)')
     expect(section).toContain('useRepoLabels(')
-    expect(section).toContain('useRepoLabelsBySlug(slugOwner, slugRepo, sourceSettings)')
+    expect(section).toContain('useRepoLabelsBySlug(')
+    expect(section).toContain('projectOrigin?.host')
     expect(section).toContain('useRepoAssignees(')
     expect(section).toContain('useRepoAssigneesBySlug(')
     expect(section).toContain('sourceSettings')
@@ -267,6 +268,10 @@ describe('PullRequestPage host boundaries', () => {
     expect(editHelperSection).toContain("'github.updatePRState'")
     expect(editHelperSection).toContain("'github.project.updateIssueBySlug'")
     expect(editHelperSection).toContain("'github.project.updatePullRequestBySlug'")
+    expect(editHelperSection).toContain(
+      '...(args.projectOrigin.host ? { host: args.projectOrigin.host } : {})'
+    )
+    expect(editHelperSection).toContain('...(targetSlug.host ? { host: targetSlug.host } : {})')
     expect(editHelperSection).toContain('sourceContext?: TaskSourceContext | null')
     expect(editHelperSection).toContain("args.sourceContext?.provider === 'github'")
     expect(editHelperSection).toContain('getTaskSourceRuntimeSettings(args.sourceContext)')
diff --git a/src/renderer/src/components/right-sidebar/ChecksPanel.tsx b/src/renderer/src/components/right-sidebar/ChecksPanel.tsx
index fb1a8857aca..91afcb2295a 100644
--- a/src/renderer/src/components/right-sidebar/ChecksPanel.tsx
+++ b/src/renderer/src/components/right-sidebar/ChecksPanel.tsx
@@ -2758,6 +2758,7 @@ export default function ChecksPanel(): React.JSX.Element {
       const result = await window.api.gh.updateIssueCommentBySlug({
         owner: pr.prRepo.owner,
         repo: pr.prRepo.repo,
+        ...(pr.prRepo.host ? { host: pr.prRepo.host } : {}),
         commentId: comment.id,
         body
       })
@@ -2793,6 +2794,7 @@ export default function ChecksPanel(): React.JSX.Element {
       const result = await window.api.gh.deleteIssueCommentBySlug({
         owner: pr.prRepo.owner,
         repo: pr.prRepo.repo,
+        ...(pr.prRepo.host ? { host: pr.prRepo.host } : {}),
         commentId: comment.id
       })
       if (!result.ok) {
diff --git a/src/renderer/src/store/slices/github.test.ts b/src/renderer/src/store/slices/github.test.ts
index 3f6c2b32bb4..bf9a86e99ec 100644
--- a/src/renderer/src/store/slices/github.test.ts
+++ b/src/renderer/src/store/slices/github.test.ts
@@ -7199,6 +7199,12 @@ describe('IssueSourceIndicator suppression', () => {
     expect(
       sameGitHubOwnerRepo({ owner: 'StablyAI', repo: 'Orca' }, { owner: 'stablyai', repo: 'orca' })
     ).toBe(true)
+    expect(
+      sameGitHubOwnerRepo(
+        { owner: 'stablyai', repo: 'orca', host: 'github.com' },
+        { owner: 'stablyai', repo: 'orca', host: 'ghe.example.test' }
+      )
+    ).toBe(false)
     expect(sameGitHubOwnerRepo({ owner: 'a', repo: 'r' }, { owner: 'b', repo: 'r' })).toBe(false)
 
     // null on either side → element renders as null (empty render)
diff --git a/src/shared/github-project-identity.test.ts b/src/shared/github-project-identity.test.ts
index 09d2f7f90d8..40c96a316dd 100644
--- a/src/shared/github-project-identity.test.ts
+++ b/src/shared/github-project-identity.test.ts
@@ -7,6 +7,9 @@ describe('GitHub project identity', () => {
 
     expect(githubProjectIdentityKey(project)).toBe('organization:acme:7')
     expect(githubProjectIdentityKey({ ...project, host: 'github.com' })).toBe('organization:acme:7')
+    expect(githubProjectIdentityKey({ ...project, host: ' GitHub.com ' })).toBe(
+      'organization:acme:7'
+    )
     expect(githubProjectIdentityKey({ ...project, host: 'GHE.EXAMPLE:8443' })).toBe(
       'ghe.example:8443:organization:acme:7'
     )
diff --git a/src/shared/github-project-identity.ts b/src/shared/github-project-identity.ts
index 426d8e837b3..dbe7c478504 100644
--- a/src/shared/github-project-identity.ts
+++ b/src/shared/github-project-identity.ts
@@ -11,9 +11,8 @@ export type GitHubProjectIdentity = {
  * legacy shape so existing github.com project preferences survive upgrades. */
 export function githubProjectIdentityKey(project: GitHubProjectIdentity): string {
   const projectKey = `${project.ownerType}:${project.owner.toLowerCase()}:${project.number}`
-  return project.host && !isDefaultGitHubHost(project.host)
-    ? `${project.host.toLowerCase()}:${projectKey}`
-    : projectKey
+  const host = project.host?.trim().toLowerCase()
+  return host && !isDefaultGitHubHost(host) ? `${host}:${projectKey}` : projectKey
 }
 
 /** Project API calls must pin github.com too; otherwise process GH_HOST can
diff --git a/src/shared/github-repository-identity-key.test.ts b/src/shared/github-repository-identity-key.test.ts
new file mode 100644
index 00000000000..ef51d276889
--- /dev/null
+++ b/src/shared/github-repository-identity-key.test.ts
@@ -0,0 +1,14 @@
+import { describe, expect, it } from 'vitest'
+import { githubRepoIdentityKey, isDefaultGitHubHost } from './github-repository-identity-key'
+
+describe('GitHub repository identity', () => {
+  it('normalizes case and harmless surrounding whitespace without merging GHES hosts', () => {
+    expect(isDefaultGitHubHost(' GitHub.com ')).toBe(true)
+    expect(githubRepoIdentityKey({ owner: 'Acme', repo: 'Widgets', host: ' GitHub.com ' })).toBe(
+      'acme/widgets'
+    )
+    expect(
+      githubRepoIdentityKey({ owner: 'Acme', repo: 'Widgets', host: ' GHE.EXAMPLE:8443 ' })
+    ).toBe('ghe.example:8443/acme/widgets')
+  })
+})
diff --git a/src/shared/github-repository-identity-key.ts b/src/shared/github-repository-identity-key.ts
index b8631ac404b..df9b8152982 100644
--- a/src/shared/github-repository-identity-key.ts
+++ b/src/shared/github-repository-identity-key.ts
@@ -2,7 +2,7 @@
 // support — cache identity, quota scoping, and exec-host routing must all
 // agree on it, so the predicate lives here once.
 export function isDefaultGitHubHost(host?: string): boolean {
-  return !host || host.toLowerCase() === 'github.com'
+  return !host?.trim() || host.trim().toLowerCase() === 'github.com'
 }
 
 // Why: cache keys and equality checks for GitHub repos must include the host,
@@ -14,5 +14,6 @@ export function githubRepoIdentityKey(repo: {
   host?: string
 }): string {
   const slug = `${repo.owner.toLowerCase()}/${repo.repo.toLowerCase()}`
-  return repo.host && !isDefaultGitHubHost(repo.host) ? `${repo.host.toLowerCase()}/${slug}` : slug
+  const host = repo.host?.trim().toLowerCase()
+  return host && !isDefaultGitHubHost(host) ? `${host}/${slug}` : slug
 }