diff --git a/.github/workflows/marketplace-identity.yml b/.github/workflows/marketplace-identity.yml
index 6b38003..2be436e 100644
--- a/.github/workflows/marketplace-identity.yml
+++ b/.github/workflows/marketplace-identity.yml
@@ -2,6 +2,12 @@ name: Resolve Marketplace Identity
 
 on:
   workflow_dispatch:
+    inputs:
+      verify_marketplace_access:
+        description: Verify that the managed identity can publish for the configured Publisher
+        required: false
+        default: false
+        type: boolean
 
 permissions:
   contents: read
@@ -55,3 +61,13 @@ jobs:
             ''
             ('`{0}`' -f $profile.id)
           ) | Add-Content -Path $env:GITHUB_STEP_SUMMARY
+      - name: Verify Marketplace publishing permission
+        if: ${{ inputs.verify_marketplace_access }}
+        shell: pwsh
+        env:
+          PUBLISHER: ${{ vars.VSCODE_MARKETPLACE_PUBLISHER }}
+        run: |
+          if ([string]::IsNullOrWhiteSpace($env:PUBLISHER)) {
+            throw 'Set the VSCODE_MARKETPLACE_PUBLISHER repository variable before verifying Marketplace access.'
+          }
+          npx --yes @vscode/vsce@3.9.2 verify-pat --azure-credential $env:PUBLISHER
diff --git a/docs/RELEASING.md b/docs/RELEASING.md
index b6918fd..fa21374 100644
--- a/docs/RELEASING.md
+++ b/docs/RELEASING.md
@@ -87,18 +87,22 @@ az role assignment create \
   --scope "/subscriptions/$SUBSCRIPTION_ID"
 ```
 
-3. 为该身份创建 GitHub Environment 专用的联合凭据。Issuer、Subject 和 Audience 必须逐字一致；Environment 名称由工作流固定为 `marketplace-release`：
+3. 查询仓库当前使用的 OIDC Subject 前缀，再为该身份创建 GitHub Environment 专用的联合凭据。Issuer、Subject 和 Audience 必须与 GitHub 实际签发的断言逐字一致；本仓库使用包含组织与仓库数字 ID 的稳定前缀，Environment 名称固定为 `marketplace-release`：
 
 ```bash
+gh api repos/realSilasYang/CodeBookmark/actions/oidc/customization/sub
+
 az identity federated-credential create \
   --name GitHub-CodeBookmark-marketplace-release \
   --identity-name CodeBookmarkMarketplacePublisher \
   --resource-group CodeBookmark-Publishing \
   --issuer https://token.actions.githubusercontent.com \
-  --subject repo:realSilasYang/CodeBookmark:environment:marketplace-release \
+  --subject repo:realSilasYang@64590265/CodeBookmark@1308408396:environment:marketplace-release \
   --audiences api://AzureADTokenExchange
 ```
 
+不要根据仓库显示名称自行拼接 Subject。若 GitHub 返回的 `sub_claim_prefix` 与上例不同，应以实际返回值加上 `:environment:marketplace-release`；Azure 登录错误中的 `presented assertion subject` 也可以用于逐字核对。
+
 4. 在 GitHub 仓库创建名为 `marketplace-release` 的 Environment。工作流将发布 Job 绑定到此 Environment，因而 OIDC 令牌的 Subject 只能匹配上面的联合凭据：
 
 ```bash
@@ -121,14 +125,24 @@ gh variable set AZURE_TENANT_ID --repo realSilasYang/CodeBookmark --body "<托
 gh variable set AZURE_SUBSCRIPTION_ID --repo realSilasYang/CodeBookmark --body "<Azure subscriptionId>"
 ```
 
-6. 在 GitHub Actions 中手动运行 `Resolve Marketplace Identity` 工作流。它只登录 Entra、调用 Azure DevOps Profile API，并把非机密的 Marketplace identity resource ID 写入运行摘要，不会构建或发布扩展。也可以从终端触发：
+6. 在 GitHub Actions 中手动运行 `Resolve Marketplace Identity` 工作流。它只登录 Entra、调用 Azure DevOps Profile API，并把非机密的 Marketplace identity resource ID 写入运行摘要，不会构建或发布扩展。首次运行不启用权限验证，也可以从终端触发：
 
 ```bash
-gh workflow run marketplace-identity.yml --repo realSilasYang/CodeBookmark
+gh workflow run marketplace-identity.yml \
+  --repo realSilasYang/CodeBookmark \
+  -f verify_marketplace_access=false
 ```
 
 7. 从该工作流的 Summary 复制 identity resource ID，在 [Visual Studio Marketplace 管理页](https://marketplace.visualstudio.com/manage)打开 Publisher `realSilasYang`，使用这个 ID 添加成员并授予 `Contributor` 角色。这里不能使用 Azure 门户中的资源名称、客户端 ID 或对象 ID 代替。只有该身份已经加入 Marketplace Publisher，`--azure-credential` 才有发布权限。
 
+8. 再次运行同一工作流并启用权限验证。它会调用 `vsce verify-pat --azure-credential` 验证托管身份确实具有 Publisher 发布权限，但不会上传或修改扩展；只有本次运行完整成功后，才创建正式版本标签：
+
+```bash
+gh workflow run marketplace-identity.yml \
+  --repo realSilasYang/CodeBookmark \
+  -f verify_marketplace_access=true
+```
+
 `AZURE_CLIENT_ID`、`AZURE_TENANT_ID` 和 `AZURE_SUBSCRIPTION_ID` 是资源标识，不是凭据。`azure/login` 在每次运行时使用 GitHub OIDC 换取短期令牌，`vsce` 再从已登录的 Azure CLI 会话取得该令牌。仓库不需要 Actions Secret；不要添加长期发布令牌或客户端密钥作为兼容路径。
 
 配置完成后，可在创建正式标签前从 Actions 页面手动检查 Release 工作流配置，但不要用虚假版本标签测试发布。正式发布失败时先修正身份、变量或 Publisher 权限，再重新运行原工作流。
diff --git a/scripts/verify-release-readiness.js b/scripts/verify-release-readiness.js
index 7ed8104..6ba2d65 100644
--- a/scripts/verify-release-readiness.js
+++ b/scripts/verify-release-readiness.js
@@ -175,13 +175,20 @@ const marketplaceIdentityWorkflow = read(
   path.join('.github', 'workflows', 'marketplace-identity.yml')
 )
 assert.match(marketplaceIdentityWorkflow, /workflow_dispatch:/)
+assert.match(marketplaceIdentityWorkflow, /verify_marketplace_access:/)
 assert.match(marketplaceIdentityWorkflow, /environment: marketplace-release/)
 assert.match(marketplaceIdentityWorkflow, /id-token: write/)
 assert.match(marketplaceIdentityWorkflow, /uses: azure\/login@v2/)
 assert.match(marketplaceIdentityWorkflow, /app\.vssps\.visualstudio\.com\/_apis\/profile\/profiles\/me/)
 assert.match(marketplaceIdentityWorkflow, /499b84ac-1321-427f-aa17-267ca6975798/)
 assert.match(marketplaceIdentityWorkflow, /GITHUB_STEP_SUMMARY/)
+assert.match(marketplaceIdentityWorkflow, /@vscode\/vsce@3\.9\.2 verify-pat --azure-credential/)
+assert.match(marketplaceIdentityWorkflow, /VSCODE_MARKETPLACE_PUBLISHER/)
 assert.doesNotMatch(marketplaceIdentityWorkflow, /VSCE_PAT|secrets\.|--pat\b/)
+assert.match(
+  read(path.join('docs', 'RELEASING.md')),
+  /repo:realSilasYang@64590265\/CodeBookmark@1308408396:environment:marketplace-release/
+)
 assert.match(releaseWorkflow, /tags:[\s\S]*- v\*/)
 assert.match(releaseWorkflow, /GITHUB_REF_NAME/)
 assert.match(releaseWorkflow, /VSCODE_MARKETPLACE_PUBLISHER/)