diff --git a/.github/workflows/longbridge-api-probe.yml b/.github/workflows/longbridge-api-probe.yml
new file mode 100644
index 0000000..3295703
--- /dev/null
+++ b/.github/workflows/longbridge-api-probe.yml
@@ -0,0 +1,114 @@
+name: LongBridge API Probe
+
+on:
+  workflow_dispatch:
+    inputs:
+      qpk_ref:
+        description: "QuantPlatformKit ref containing the probe test"
+        required: false
+        default: "main"
+        type: string
+      symbol:
+        description: "US symbol to use for the probe"
+        required: false
+        default: "SOXX.US"
+        type: string
+      limit_price:
+        description: "Low buy limit price used by the cancellable probe order"
+        required: false
+        default: "0.01"
+        type: string
+
+env:
+  GCP_PROJECT_ID: longbridgequant
+  GCP_WORKLOAD_IDENTITY_PROVIDER: projects/252919773759/locations/global/workloadIdentityPools/github-actions/providers/github-main
+  GCP_WORKLOAD_IDENTITY_SERVICE_ACCOUNT: longbridge-platform-deploy@longbridgequant.iam.gserviceaccount.com
+
+jobs:
+  hk-fractional-order:
+    name: Probe HK Simulated Fractional Orders
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write
+    environment: longbridge-hk
+    env:
+      LONGPORT_APP_KEY_SECRET_NAME: ${{ vars.LONGPORT_APP_KEY_SECRET_NAME }}
+      LONGPORT_APP_SECRET_SECRET_NAME: ${{ vars.LONGPORT_APP_SECRET_SECRET_NAME }}
+      LONGPORT_SECRET_NAME: ${{ vars.LONGPORT_SECRET_NAME }}
+    steps:
+      - name: Validate inputs
+        run: |
+          set -euo pipefail
+
+          missing_vars=()
+          for var_name in LONGPORT_APP_KEY_SECRET_NAME LONGPORT_APP_SECRET_SECRET_NAME LONGPORT_SECRET_NAME; do
+            if [ -z "${!var_name:-}" ]; then
+              missing_vars+=("${var_name}")
+            fi
+          done
+
+          if [ "${#missing_vars[@]}" -gt 0 ]; then
+            printf 'Missing longbridge-hk variables:\n' >&2
+            printf '  - %s\n' "${missing_vars[@]}" >&2
+            exit 1
+          fi
+
+      - name: Checkout QuantPlatformKit
+        uses: actions/checkout@v6
+        with:
+          repository: QuantStrategyLab/QuantPlatformKit
+          ref: ${{ inputs.qpk_ref }}
+          path: quant-platform-kit
+
+      - name: Set up Python
+        uses: actions/setup-python@v6
+        with:
+          python-version: "3.12"
+
+      - name: Authenticate to Google Cloud
+        uses: google-github-actions/auth@v3
+        with:
+          workload_identity_provider: ${{ env.GCP_WORKLOAD_IDENTITY_PROVIDER }}
+          service_account: ${{ env.GCP_WORKLOAD_IDENTITY_SERVICE_ACCOUNT }}
+
+      - name: Set up gcloud
+        uses: google-github-actions/setup-gcloud@v3
+        with:
+          project_id: ${{ env.GCP_PROJECT_ID }}
+          version: ">= 416.0.0"
+
+      - name: Export LongPort credentials
+        run: |
+          set -euo pipefail
+
+          longport_app_key="$(gcloud secrets versions access latest --secret="${LONGPORT_APP_KEY_SECRET_NAME}")"
+          longport_app_secret="$(gcloud secrets versions access latest --secret="${LONGPORT_APP_SECRET_SECRET_NAME}")"
+          longport_access_token="$(gcloud secrets versions access latest --secret="${LONGPORT_SECRET_NAME}")"
+
+          echo "::add-mask::${longport_app_key}"
+          echo "::add-mask::${longport_app_secret}"
+          echo "::add-mask::${longport_access_token}"
+
+          {
+            echo "LONGPORT_APP_KEY=${longport_app_key}"
+            echo "LONGPORT_APP_SECRET=${longport_app_secret}"
+            echo "LONGPORT_ACCESS_TOKEN=${longport_access_token}"
+          } >> "$GITHUB_ENV"
+
+      - name: Install probe dependencies
+        run: |
+          set -euo pipefail
+
+          python -m pip install --upgrade pip
+          python -m pip install -e quant-platform-kit pytest longport
+
+      - name: Run HK simulated fractional order probe
+        env:
+          LONGBRIDGE_API_PROBE: "1"
+          LONGBRIDGE_API_PROBE_SYMBOL: ${{ inputs.symbol }}
+          LONGBRIDGE_API_PROBE_LIMIT_PRICE: ${{ inputs.limit_price }}
+        run: |
+          set -euo pipefail
+
+          python -m pytest quant-platform-kit/tests/test_longbridge_fractional_order_api_probe.py -q -s
diff --git a/README.md b/README.md
index a6e3a96..6d174fa 100644
--- a/README.md
+++ b/README.md
@@ -146,6 +146,11 @@ Important:
 - If you later rename or move this repository, rebuild the GitHub source binding in Google Cloud for both triggers instead of assuming the existing source binding will follow the rename.
 - For the shared deployment model and trigger migration checklist, see [`QuantPlatformKit/docs/deployment_model.md`](../QuantPlatformKit/docs/deployment_model.md).
 
+### Manual API probes
+
+- `.github/workflows/longbridge-api-probe.yml` can be triggered manually against the `longbridge-hk` GitHub Environment. It checks out a selected `QuantPlatformKit` ref and runs the skipped LongBridge fractional-order API probe with HK simulated-account credentials from Secret Manager.
+- The probe is for broker API validation only. It does not run on normal CI or `main` pushes.
+
 ### Quick deploy
 
 1. Enable **Cloud Run** and **Secret Manager API** in GCP.
@@ -299,6 +304,11 @@ Secret Manager 中需存在 `LONGPORT_SECRET_NAME` 指定的密钥（默认: `lo
 - 如果后面改 GitHub 仓库名或再次迁组织，Google Cloud 里的两个 trigger 都要重新选择 GitHub 来源，不要假设旧绑定会自动跟过去。
 - 统一部署模型和触发器迁移清单见 [`QuantPlatformKit/docs/deployment_model.md`](../QuantPlatformKit/docs/deployment_model.md)。
 
+### 手动 API probe
+
+- `.github/workflows/longbridge-api-probe.yml` 可手动触发，固定使用 `longbridge-hk` GitHub Environment。它会 checkout 指定的 `QuantPlatformKit` ref，并用 Secret Manager 中的 HK 模拟盘 LongPort 凭证运行默认跳过的碎股下单 API probe。
+- 这个 probe 只用于券商 API 验证，不会进入普通 CI 或 `main` push 流程。
+
 ### 快速部署
 
 1. 在 GCP 中启用 **Cloud Run** 和 **Secret Manager API**。
diff --git a/tests/test_longbridge_api_probe_workflow.py b/tests/test_longbridge_api_probe_workflow.py
new file mode 100644
index 0000000..4b2f29f
--- /dev/null
+++ b/tests/test_longbridge_api_probe_workflow.py
@@ -0,0 +1,32 @@
+import unittest
+from pathlib import Path
+
+
+class LongBridgeApiProbeWorkflowTests(unittest.TestCase):
+    def test_workflow_uses_hk_environment_and_gcp_secrets(self) -> None:
+        workflow = Path(".github/workflows/longbridge-api-probe.yml").read_text(encoding="utf-8")
+
+        self.assertIn("name: LongBridge API Probe", workflow)
+        self.assertIn("workflow_dispatch:", workflow)
+        self.assertIn("environment: longbridge-hk", workflow)
+        self.assertIn("id-token: write", workflow)
+        self.assertIn("repository: QuantStrategyLab/QuantPlatformKit", workflow)
+        self.assertIn("ref: ${{ inputs.qpk_ref }}", workflow)
+        self.assertIn("google-github-actions/auth@v3", workflow)
+        self.assertIn("google-github-actions/setup-gcloud@v3", workflow)
+        self.assertIn("LONGPORT_APP_KEY_SECRET_NAME: ${{ vars.LONGPORT_APP_KEY_SECRET_NAME }}", workflow)
+        self.assertIn("LONGPORT_APP_SECRET_SECRET_NAME: ${{ vars.LONGPORT_APP_SECRET_SECRET_NAME }}", workflow)
+        self.assertIn("LONGPORT_SECRET_NAME: ${{ vars.LONGPORT_SECRET_NAME }}", workflow)
+        self.assertIn('gcloud secrets versions access latest --secret="${LONGPORT_APP_KEY_SECRET_NAME}"', workflow)
+        self.assertIn(
+            'gcloud secrets versions access latest --secret="${LONGPORT_APP_SECRET_SECRET_NAME}"',
+            workflow,
+        )
+        self.assertIn('gcloud secrets versions access latest --secret="${LONGPORT_SECRET_NAME}"', workflow)
+        self.assertIn("python -m pip install -e quant-platform-kit pytest longport", workflow)
+        self.assertIn('LONGBRIDGE_API_PROBE: "1"', workflow)
+        self.assertIn("test_longbridge_fractional_order_api_probe.py", workflow)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/tests/test_longbridge_api_probe_workflow.sh b/tests/test_longbridge_api_probe_workflow.sh
new file mode 100755
index 0000000..bafc9ae
--- /dev/null
+++ b/tests/test_longbridge_api_probe_workflow.sh
@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_dir="$(cd "$(dirname "$0")/.." && pwd)"
+workflow_file="$repo_dir/.github/workflows/longbridge-api-probe.yml"
+
+grep -Fq "name: LongBridge API Probe" "$workflow_file"
+grep -Fq "workflow_dispatch:" "$workflow_file"
+grep -Fq "environment: longbridge-hk" "$workflow_file"
+grep -Fq "id-token: write" "$workflow_file"
+grep -Fq "repository: QuantStrategyLab/QuantPlatformKit" "$workflow_file"
+grep -Fq "ref: \${{ inputs.qpk_ref }}" "$workflow_file"
+grep -Fq "google-github-actions/auth@v3" "$workflow_file"
+grep -Fq "google-github-actions/setup-gcloud@v3" "$workflow_file"
+grep -Fq "LONGPORT_APP_KEY_SECRET_NAME: \${{ vars.LONGPORT_APP_KEY_SECRET_NAME }}" "$workflow_file"
+grep -Fq "LONGPORT_APP_SECRET_SECRET_NAME: \${{ vars.LONGPORT_APP_SECRET_SECRET_NAME }}" "$workflow_file"
+grep -Fq "LONGPORT_SECRET_NAME: \${{ vars.LONGPORT_SECRET_NAME }}" "$workflow_file"
+grep -Fq 'gcloud secrets versions access latest --secret="${LONGPORT_APP_KEY_SECRET_NAME}"' "$workflow_file"
+grep -Fq 'gcloud secrets versions access latest --secret="${LONGPORT_APP_SECRET_SECRET_NAME}"' "$workflow_file"
+grep -Fq 'gcloud secrets versions access latest --secret="${LONGPORT_SECRET_NAME}"' "$workflow_file"
+grep -Fq "python -m pip install -e quant-platform-kit pytest longport" "$workflow_file"
+grep -Fq 'LONGBRIDGE_API_PROBE: "1"' "$workflow_file"
+grep -Fq "test_longbridge_fractional_order_api_probe.py" "$workflow_file"