diff --git a/.gitea/workflows/obs-ci.yaml b/.gitea/workflows/obs-ci.yaml
new file mode 100644
index 0000000..e256d9f
--- /dev/null
+++ b/.gitea/workflows/obs-ci.yaml
@@ -0,0 +1,53 @@
+name: Trigger OBS build
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+  push:
+    branches:
+      - develop
+  push:
+    tags:
+      - 'v*'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install osc
+        run: sudo apt-get update && sudo apt-get install -y osc
+
+      - name: Configure osc
+        env:
+          OBS_USER: ${{ secrets.OBS_USER }}
+          OBS_PASS: ${{ secrets.OBS_PASS }}
+        run: |
+          mkdir -p ~/.config/osc
+          cat >~/.config/osc/oscrc <<EOF
+          [general]
+          apiurl = https://obs.example.com
+          [https://obs.example.com]
+          user = $OBS_USER
+          pass = $OBS_PASS
+          EOF
+
+      - name: Decide target project
+        id: prep
+        run: |
+          if [[ "${{ gitea.event_name }}" == "pull_request" ]]; then
+            echo "project=CI:${{ gitea.repository }}:PR-${{ gitea.pr_number }}" >>$GITHUB_OUTPUT
+          elif [[ "${{ gitea.ref_type }}" == "tag" ]]; then
+            tag=${{ gitea.ref_name }}
+            echo "project=Unstable:${{ gitea.repository }}:$tag" >>$GITHUB_OUTPUT
+          else
+            echo "project=CI:${{ gitea.repository }}-develop" >>$GITHUB_OUTPUT
+          fi
+
+      - name: Branch & submit
+        run: |
+          proj='${{ steps.prep.outputs.project }}'
+          osc api "/source/$proj?cmd=branch" || true
+          osc up
+          osc ci -m "Auto build via Gitea Actions"
diff --git a/.obs/workflows.yml b/.obs/workflows.yml
new file mode 100644
index 0000000..de620d0
--- /dev/null
+++ b/.obs/workflows.yml
@@ -0,0 +1,21 @@
+name: obs
+
+workflows:
+  test_build:
+    trigger: pull_request
+    project: "CI:${{ repo }}:PR-${{ pr.number }}"
+    repositories:
+      - local_develop
+
+  commit_build:
+    trigger: push
+    branch: develop
+    project: "CI:${{ repo }}-develop"
+    repositories:
+      - local_develop
+
+  tag_build:
+    trigger: tag
+    project: "Unstable:${{ repo }}:${{ tag }}"
+    repositories:
+      - local_unstable
diff --git a/README.md b/README.md
index e69de29..a3e5b25 100644
--- a/README.md
+++ b/README.md
@@ -0,0 +1,3 @@
+# demo-hello
+
+最小可跑通的 Gitea + OBS CI 示例仓库。
diff --git a/debian/changelog b/debian/changelog
new file mode 100644
index 0000000..d9e473b
--- /dev/null
+++ b/debian/changelog
@@ -0,0 +1,5 @@
+hello (0.1-1) unstable; urgency=medium
+
+  * Initial release
+
+ -- Demo Maintainer <demo@example.com>  Tue, 27 May 2025 16:19:19
diff --git a/debian/compat b/debian/compat
new file mode 100644
index 0000000..b1bd38b
--- /dev/null
+++ b/debian/compat
@@ -0,0 +1 @@
+13
diff --git a/debian/control b/debian/control
new file mode 100644
index 0000000..ddeac0c
--- /dev/null
+++ b/debian/control
@@ -0,0 +1,13 @@
+Source: hello
+Section: misc
+Priority: optional
+Maintainer: Demo Maintainer <demo@example.com>
+Build-Depends: debhelper-compat (= 13)
+Standards-Version: 4.6.2
+Homepage: https://example.com/hello
+
+Package: hello
+Architecture: any
+Depends: ${shlibs:Depends}, ${misc:Depends}
+Description: Hello World demo program
+ A minimal program that prints “Hello, world!” on the command line.
diff --git a/debian/rules b/debian/rules
new file mode 100644
index 0000000..9677726
--- /dev/null
+++ b/debian/rules
@@ -0,0 +1,3 @@
+#!/usr/bin/make -f
+%:
+    dh $@
diff --git a/src/hello.c b/src/hello.c
new file mode 100644
index 0000000..e54e11d
--- /dev/null
+++ b/src/hello.c
@@ -0,0 +1,5 @@
+#include <stdio.h>
+int main(void) {
+    puts("Hello, world!");
+    return 0;
+}