diff --git a/.github/workflows/handle-new-mails.yml b/.github/workflows/handle-new-mails.yml
index 0332090..c37f2d9 100644
--- a/.github/workflows/handle-new-mails.yml
+++ b/.github/workflows/handle-new-mails.yml
@@ -10,31 +10,35 @@ concurrency:
 jobs:
   handle-new-mails:
     runs-on: ubuntu-latest
+    if: vars.CONFIG != ''
 
     steps:
     - uses: actions/create-github-app-token@v1
-      id: gitgitgadget-git-token
+      id: pr-repo-token
       with:
         app-id: ${{ secrets.GITGITGADGET_GITHUB_APP_ID }}
         private-key: ${{ secrets.GITGITGADGET_GITHUB_APP_PRIVATE_KEY }}
-        owner: gitgitgadget
-        repositories: git
+        owner: ${{ fromJSON(vars.CONFIG).repo.owner }}
+        repositories: ${{ fromJSON(vars.CONFIG).repo.name }}
     - uses: actions/create-github-app-token@v1
-      id: git-git-token
+      if: ${{ contains(fromJSON(vars.CONFIG).repo.owners, fromJSON(vars.CONFIG).repo.baseOwner) }}
+      id: upstream-repo-token
       with:
         app-id: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_ID }}
         private-key: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_PRIVATE_KEY }}
-        owner: git
-        repositories: git
+        owner: ${{ fromJSON(vars.CONFIG).repo.baseOwner }}
+        repositories: ${{ fromJSON(vars.CONFIG).repo.name }}
     - uses: actions/create-github-app-token@v1
-      id: dscho-git-token
+      if: ${{ contains(fromJSON(vars.CONFIG).repo.owners, fromJSON(vars.CONFIG).repo.testOwner) }}
+      id: test-repo-token
       with:
         app-id: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_ID }}
         private-key: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_PRIVATE_KEY }}
-        owner: dscho
-        repositories: git
+        owner: ${{ fromJSON(vars.CONFIG).repo.testOwner }}
+        repositories: ${{ fromJSON(vars.CONFIG).repo.name }}
     - uses: gitgitgadget/gitgitgadget/handle-new-mails@v1
       with:
-        pr-repo-token: ${{ steps.gitgitgadget-git-token.outputs.token }}
-        upstream-repo-token: ${{ steps.git-git-token.outputs.token }}
-        test-repo-token: ${{ steps.dscho-git-token.outputs.token }}
+        config: ${{ vars.CONFIG }}
+        pr-repo-token: ${{ steps.pr-repo-token.outputs.token }}
+        upstream-repo-token: ${{ steps.upstream-repo-token.outputs.token }}
+        test-repo-token: ${{ steps.test-repo-token.outputs.token }}
diff --git a/.github/workflows/handle-pr-comment.yml b/.github/workflows/handle-pr-comment.yml
index 31e3cec..9d4fe6a 100644
--- a/.github/workflows/handle-pr-comment.yml
+++ b/.github/workflows/handle-pr-comment.yml
@@ -19,29 +19,32 @@ concurrency:
 jobs:
   handle-pr-comment:
     runs-on: ubuntu-latest
+    if: vars.CONFIG != ''
 
     steps:
     - uses: actions/create-github-app-token@v1
-      id: gitgitgadget-git-token
+      id: pr-repo-token
       with:
         app-id: ${{ secrets.GITGITGADGET_GITHUB_APP_ID }}
         private-key: ${{ secrets.GITGITGADGET_GITHUB_APP_PRIVATE_KEY }}
-        owner: gitgitgadget
-        repositories: git
+        owner: ${{ fromJSON(vars.CONFIG).repo.owner }}
+        repositories: ${{ fromJSON(vars.CONFIG).repo.name }}
     - uses: actions/create-github-app-token@v1
-      id: git-git-token
+      if: ${{ contains(fromJSON(vars.CONFIG).repo.owners, fromJSON(vars.CONFIG).repo.baseOwner) }}
+      id: upstream-repo-token
       with:
         app-id: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_ID }}
         private-key: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_PRIVATE_KEY }}
-        owner: git
-        repositories: git
+        owner: ${{ fromJSON(vars.CONFIG).repo.baseOwner }}
+        repositories: ${{ fromJSON(vars.CONFIG).repo.name }}
     - uses: actions/create-github-app-token@v1
-      id: dscho-git-token
+      if: ${{ contains(fromJSON(vars.CONFIG).repo.owners, fromJSON(vars.CONFIG).repo.testOwner) }}
+      id: test-repo-token
       with:
         app-id: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_ID }}
         private-key: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_PRIVATE_KEY }}
-        owner: dscho
-        repositories: git
+        owner: ${{ fromJSON(vars.CONFIG).repo.testOwner }}
+        repositories: ${{ fromJSON(vars.CONFIG).repo.name }}
     - name: create a check run
       id: create-check-run
       run: |
@@ -66,9 +69,9 @@ jobs:
         echo "repo=$repo" >> $GITHUB_OUTPUT
 
         export GH_TOKEN="$(case "$repo" in
-          gitgitgadget/git) echo "${{ steps.gitgitgadget-git-token.outputs.token }}";;
-          git/git) echo "${{ steps.git-git-token.outputs.token }}";;
-          dscho/git) echo "${{ steps.dscho-git-token.outputs.token }}";;
+          '${{ fromJSON(vars.CONFIG).repo.owner }}/${{ fromJSON(vars.CONFIG).repo.name }}') echo "${{ steps.pr-repo-token.outputs.token }}";;
+          '${{ fromJSON(vars.CONFIG).repo.baseOwner }}/${{ fromJSON(vars.CONFIG).repo.name }}') echo "${{ steps.upstream-repo-token.outputs.token }}";;
+          '${{ fromJSON(vars.CONFIG).repo.testOwner }}/${{ fromJSON(vars.CONFIG).repo.name }}') echo "${{ steps.test-repo-token.outputs.token }}";;
           *) echo "${{ secrets.GITHUB_TOKEN }}";;
           esac
         )"
@@ -84,20 +87,21 @@ jobs:
         echo "check_run_id=$check_run_id" >> $GITHUB_OUTPUT
     - uses: gitgitgadget/gitgitgadget/handle-pr-comment@v1
       with:
-        pr-repo-token: ${{ steps.gitgitgadget-git-token.outputs.token }}
-        upstream-repo-token: ${{ steps.git-git-token.outputs.token }}
-        test-repo-token: ${{ steps.dscho-git-token.outputs.token }}
-        smtp-host: smtp.gmail.com
-        smtp-user: gitgitgadget@gmail.com
+        config: ${{ vars.CONFIG }}
+        pr-repo-token: ${{ steps.pr-repo-token.outputs.token }}
+        upstream-repo-token: ${{ steps.upstream-repo-token.outputs.token }}
+        test-repo-token: ${{ steps.test-repo-token.outputs.token }}
+        smtp-host: '${{ fromJSON(vars.CONFIG).mail.smtpHost }}'
+        smtp-user: '${{ fromJSON(vars.CONFIG).mail.smtpUser }}'
         smtp-pass: "${{ secrets.GITGITGADGET_SMTP_PASS }}"
         pr-comment-url: ${{ env.PR_COMMENT_URL }}
     - name: update the check run
       if: always() && steps.create-check-run.outputs.check_run_id != ''
       run: |
         export GH_TOKEN="$(case "${{ steps.create-check-run.outputs.repo }}" in
-          gitgitgadget/git) echo "${{ steps.gitgitgadget-git-token.outputs.token }}";;
-          git/git) echo "${{ steps.git-git-token.outputs.token }}";;
-          dscho/git) echo "${{ steps.dscho-git-token.outputs.token }}";;
+          '${{ fromJSON(vars.CONFIG).repo.owner }}/${{ fromJSON(vars.CONFIG).repo.name }}') echo "${{ steps.pr-repo-token.outputs.token }}";;
+          '${{ fromJSON(vars.CONFIG).repo.baseOwner }}/${{ fromJSON(vars.CONFIG).repo.name }}') echo "${{ steps.upstream-repo-token.outputs.token }}";;
+          '${{ fromJSON(vars.CONFIG).repo.testOwner }}/${{ fromJSON(vars.CONFIG).repo.name }}') echo "${{ steps.test-repo-token.outputs.token }}";;
           *) echo "${{ secrets.GITHUB_TOKEN }}";;
           esac
         )"
diff --git a/.github/workflows/handle-pr-push.yml b/.github/workflows/handle-pr-push.yml
index 6ef1c96..4e78716 100644
--- a/.github/workflows/handle-pr-push.yml
+++ b/.github/workflows/handle-pr-push.yml
@@ -19,29 +19,32 @@ concurrency:
 jobs:
   handle-pr-push:
     runs-on: ubuntu-latest
+    if: vars.CONFIG != ''
 
     steps:
     - uses: actions/create-github-app-token@v1
-      id: gitgitgadget-git-token
+      id: pr-repo-token
       with:
         app-id: ${{ secrets.GITGITGADGET_GITHUB_APP_ID }}
         private-key: ${{ secrets.GITGITGADGET_GITHUB_APP_PRIVATE_KEY }}
-        owner: gitgitgadget
-        repositories: git
+        owner: ${{ fromJSON(vars.CONFIG).repo.owner }}
+        repositories: ${{ fromJSON(vars.CONFIG).repo.name }}
     - uses: actions/create-github-app-token@v1
-      id: git-git-token
+      if: ${{ contains(fromJSON(vars.CONFIG).repo.owners, fromJSON(vars.CONFIG).repo.baseOwner) }}
+      id: upstream-repo-token
       with:
         app-id: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_ID }}
         private-key: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_PRIVATE_KEY }}
-        owner: git
-        repositories: git
+        owner: ${{ fromJSON(vars.CONFIG).repo.baseOwner }}
+        repositories: ${{ fromJSON(vars.CONFIG).repo.name }}
     - uses: actions/create-github-app-token@v1
-      id: dscho-git-token
+      if: ${{ contains(fromJSON(vars.CONFIG).repo.owners, fromJSON(vars.CONFIG).repo.testOwner) }}
+      id: test-repo-token
       with:
         app-id: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_ID }}
         private-key: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_PRIVATE_KEY }}
-        owner: dscho
-        repositories: git
+        owner: ${{ fromJSON(vars.CONFIG).repo.testOwner }}
+        repositories: ${{ fromJSON(vars.CONFIG).repo.name }}
     - name: create a check run
       id: create-check-run
       run: |
@@ -64,9 +67,9 @@ jobs:
         echo "repo=$repo" >> $GITHUB_OUTPUT
 
         export GH_TOKEN="$(case "$repo" in
-          gitgitgadget/git) echo "${{ steps.gitgitgadget-git-token.outputs.token }}";;
-          git/git) echo "${{ steps.git-git-token.outputs.token }}";;
-          dscho/git) echo "${{ steps.dscho-git-token.outputs.token }}";;
+          '${{ fromJSON(vars.CONFIG).repo.owner }}/${{ fromJSON(vars.CONFIG).repo.name }}') echo "${{ steps.pr-repo-token.outputs.token }}";;
+          '${{ fromJSON(vars.CONFIG).repo.baseOwner }}/${{ fromJSON(vars.CONFIG).repo.name }}') echo "${{ steps.upstream-repo-token.outputs.token }}";;
+          '${{ fromJSON(vars.CONFIG).repo.testOwner }}/${{ fromJSON(vars.CONFIG).repo.name }}') echo "${{ steps.test-repo-token.outputs.token }}";;
           *) echo "${{ secrets.GITHUB_TOKEN }}";;
           esac
         )"
@@ -82,17 +85,18 @@ jobs:
         echo "check_run_id=$check_run_id" >> $GITHUB_OUTPUT
     - uses: gitgitgadget/gitgitgadget/handle-pr-push@v1
       with:
-        pr-repo-token: ${{ steps.gitgitgadget-git-token.outputs.token }}
-        upstream-repo-token: ${{ steps.git-git-token.outputs.token }}
-        test-repo-token: ${{ steps.dscho-git-token.outputs.token }}
+        config: ${{ vars.CONFIG }}
+        pr-repo-token: ${{ steps.pr-repo-token.outputs.token }}
+        upstream-repo-token: ${{ steps.upstream-repo-token.outputs.token }}
+        test-repo-token: ${{ steps.test-repo-token.outputs.token }}
         pr-url: ${{ env.PR_URL }}
     - name: update the check run
       if: always() && steps.create-check-run.outputs.check_run_id != ''
       run: |
         export GH_TOKEN="$(case "${{ steps.create-check-run.outputs.repo }}" in
-          gitgitgadget/git) echo "${{ steps.gitgitgadget-git-token.outputs.token }}";;
-          git/git) echo "${{ steps.git-git-token.outputs.token }}";;
-          dscho/git) echo "${{ steps.dscho-git-token.outputs.token }}";;
+          '${{ fromJSON(vars.CONFIG).repo.owner }}/${{ fromJSON(vars.CONFIG).repo.name }}') echo "${{ steps.pr-repo-token.outputs.token }}";;
+          '${{ fromJSON(vars.CONFIG).repo.baseOwner }}/${{ fromJSON(vars.CONFIG).repo.name }}') echo "${{ steps.upstream-repo-token.outputs.token }}";;
+          '${{ fromJSON(vars.CONFIG).repo.testOwner }}/${{ fromJSON(vars.CONFIG).repo.name }}') echo "${{ steps.test-repo-token.outputs.token }}";;
           *) echo "${{ secrets.GITHUB_TOKEN }}";;
           esac
         )"
diff --git a/.github/workflows/initialize-git-notes.yml b/.github/workflows/initialize-git-notes.yml
new file mode 100644
index 0000000..4e1715e
--- /dev/null
+++ b/.github/workflows/initialize-git-notes.yml
@@ -0,0 +1,25 @@
+name: Initialize Git notes
+
+# This workflow is expected to be triggered manually, exactly once, when
+# GitGitGadget is first used with a new `pr-repo`.
+
+on:
+  workflow_dispatch:
+
+jobs:
+  initialize-git-notes:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/create-github-app-token@v1
+      id: pr-repo-token
+      with:
+        app-id: ${{ secrets.GITGITGADGET_GITHUB_APP_ID }}
+        private-key: ${{ secrets.GITGITGADGET_GITHUB_APP_PRIVATE_KEY }}
+        owner: ${{ fromJSON(vars.CONFIG).repo.owner }}
+        repositories: ${{ fromJSON(vars.CONFIG).repo.name }}
+    - uses: gitgitgadget/gitgitgadget/initialize-git-notes@v1
+      with:
+        config: ${{ vars.CONFIG }}
+        pr-repo-token: ${{ steps.pr-repo-token.outputs.token }}
+        initial-user: ${{ github.actor }}
diff --git a/.github/workflows/sync-mailing-list-mirror.yml b/.github/workflows/sync-mailing-list-mirror.yml
index b08b856..81c1d90 100644
--- a/.github/workflows/sync-mailing-list-mirror.yml
+++ b/.github/workflows/sync-mailing-list-mirror.yml
@@ -6,9 +6,9 @@ on:
     - cron:  "*/5 * * * *"
 
 env:
-  LORE_EPOCH: 1 # also adjust SOURCE_REPOSITORY
-  SOURCE_REPOSITORY: https://lore.kernel.org/git/1 # LORE_EPOCH
-  TARGET_GITHUB_REPOSITORY: gitgitgadget/git-mailing-list-mirror
+  MIRROR_REF: ${{ fromJSON(vars.CONFIG).mailrepo.mirrorRef }}
+  SOURCE_REPOSITORY: ${{ fromJSON(vars.CONFIG).mailrepo.url }}${{ fromJSON(vars.CONFIG).mailrepo.public_inbox_epoch }}
+  TARGET_GITHUB_REPOSITORY: ${{ fromJSON(vars.CONFIG).mailrepo.owner }}/${{ fromJSON(vars.CONFIG).mailrepo.name }}
 
 concurrency:
   group: sync-mailing-list-mirror
@@ -27,16 +27,16 @@ jobs:
         echo "org=${TARGET_GITHUB_REPOSITORY%%/*}" >>$GITHUB_OUTPUT &&
         echo "repo=${TARGET_GITHUB_REPOSITORY#*/}" >>$GITHUB_OUTPUT &&
         source="$(git ls-remote "$SOURCE_REPOSITORY" master)" &&
-        target="$(git ls-remote https://github.com/"$TARGET_GITHUB_REPOSITORY" lore-$LORE_EPOCH)" &&
+        target="$(git ls-remote https://github.com/"$TARGET_GITHUB_REPOSITORY" "$MIRROR_REF")" &&
         echo "result=$(test "${source%%	*}" = "${target%%	*}" && echo false || echo true)" >>$GITHUB_OUTPUT
     - name: Partial clone
       if: steps.needs-update.outputs.result == 'true'
       run: |
-        git clone --bare --depth=1 -b lore-$LORE_EPOCH --filter=blob:none https://github.com/$TARGET_GITHUB_REPOSITORY .
+        git clone --bare --depth=1 -b "${MIRROR_REF#refs/heads/}" --filter=blob:none https://github.com/$TARGET_GITHUB_REPOSITORY .
     - name: Update from lore.kernel.org
       if: steps.needs-update.outputs.result == 'true'
       run: |
-        git fetch "$SOURCE_REPOSITORY" refs/heads/master:refs/heads/lore-$LORE_EPOCH
+        git fetch "$SOURCE_REPOSITORY" refs/heads/master:"$MIRROR_REF"
     - name: obtain installation token
       if: steps.needs-update.outputs.result == 'true'
       uses: actions/create-github-app-token@v2
@@ -51,4 +51,4 @@ jobs:
       env:
         GITHUB_TOKEN: ${{ steps.token.outputs.token }}
       run: |
-        git push https://$GITHUB_ACTOR:$GITHUB_TOKEN@github.com/$TARGET_GITHUB_REPOSITORY lore-$LORE_EPOCH
+        git push https://$GITHUB_ACTOR:$GITHUB_TOKEN@github.com/$TARGET_GITHUB_REPOSITORY "$MIRROR_REF"
diff --git a/.github/workflows/sync-upstream-branches.yml b/.github/workflows/sync-upstream-branches.yml
index f1c39de..68530bd 100644
--- a/.github/workflows/sync-upstream-branches.yml
+++ b/.github/workflows/sync-upstream-branches.yml
@@ -16,13 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        spec:
-          - sourceRepo: j6t/git-gui
-            targetRepo: gitgitgadget/git
-            targetRefNamespace: git-gui/
-          - sourceRepo: gitster/git
-            targetRepo: gitgitgadget/git
-            sourceRefRegex: "^refs/heads/(maint-\\d|[a-z][a-z]/)"
+        spec: ${{ fromJSON(vars.CONFIG).syncUpstreamBranches }}
 
     steps:
       - name: check which refs need to be synchronized
diff --git a/.github/workflows/update-mail-to-commit-notes.yml b/.github/workflows/update-mail-to-commit-notes.yml
index bedc4c8..5937e64 100644
--- a/.github/workflows/update-mail-to-commit-notes.yml
+++ b/.github/workflows/update-mail-to-commit-notes.yml
@@ -11,15 +11,17 @@ concurrency:
 jobs:
   update-mail-to-commit-notes:
     runs-on: ubuntu-latest
+    if: vars.CONFIG != ''
 
     steps:
     - uses: actions/create-github-app-token@v1
-      id: gitgitgadget-git-token
+      id: pr-repo-token
       with:
         app-id: ${{ secrets.GITGITGADGET_GITHUB_APP_ID }}
         private-key: ${{ secrets.GITGITGADGET_GITHUB_APP_PRIVATE_KEY }}
-        owner: gitgitgadget
-        repositories: git
+        owner: ${{ fromJSON(vars.CONFIG).repo.owner }}
+        repositories: ${{ fromJSON(vars.CONFIG).repo.name }}
     - uses: gitgitgadget/gitgitgadget/update-mail-to-commit-notes@v1
       with:
-        pr-repo-token: ${{ steps.gitgitgadget-git-token.outputs.token }}
+        config: ${{ vars.CONFIG }}
+        pr-repo-token: ${{ steps.pr-repo-token.outputs.token }}
diff --git a/.github/workflows/update-prs.yml b/.github/workflows/update-prs.yml
index 6de7cb1..1637aa3 100644
--- a/.github/workflows/update-prs.yml
+++ b/.github/workflows/update-prs.yml
@@ -10,31 +10,35 @@ concurrency:
 jobs:
   update-prs:
     runs-on: ubuntu-latest
+    if: vars.CONFIG != ''
 
     steps:
     - uses: actions/create-github-app-token@v1
-      id: gitgitgadget-git-token
+      id: pr-repo-token
       with:
         app-id: ${{ secrets.GITGITGADGET_GITHUB_APP_ID }}
         private-key: ${{ secrets.GITGITGADGET_GITHUB_APP_PRIVATE_KEY }}
-        owner: gitgitgadget
-        repositories: git
+        owner: ${{ fromJSON(vars.CONFIG).repo.owner }}
+        repositories: ${{ fromJSON(vars.CONFIG).repo.name }}
     - uses: actions/create-github-app-token@v1
-      id: git-git-token
+      if: ${{ contains(fromJSON(vars.CONFIG).repo.owners, fromJSON(vars.CONFIG).repo.baseOwner) }}
+      id: upstream-repo-token
       with:
         app-id: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_ID }}
         private-key: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_PRIVATE_KEY }}
-        owner: git
-        repositories: git
+        owner: ${{ fromJSON(vars.CONFIG).repo.baseOwner }}
+        repositories: ${{ fromJSON(vars.CONFIG).repo.name }}
     - uses: actions/create-github-app-token@v1
-      id: dscho-git-token
+      if: ${{ contains(fromJSON(vars.CONFIG).repo.owners, fromJSON(vars.CONFIG).repo.testOwner) }}
+      id: test-repo-token
       with:
         app-id: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_ID }}
         private-key: ${{ secrets.GITGITGADGET_GIT_GITHUB_APP_PRIVATE_KEY }}
-        owner: dscho
-        repositories: git
+        owner: ${{ fromJSON(vars.CONFIG).repo.testOwner }}
+        repositories: ${{ fromJSON(vars.CONFIG).repo.name }}
     - uses: gitgitgadget/gitgitgadget/update-prs@v1
       with:
-        pr-repo-token: ${{ steps.gitgitgadget-git-token.outputs.token }}
-        upstream-repo-token: ${{ steps.git-git-token.outputs.token }}
-        test-repo-token: ${{ steps.dscho-git-token.outputs.token }}
+        config: ${{ vars.CONFIG }}
+        pr-repo-token: ${{ steps.pr-repo-token.outputs.token }}
+        upstream-repo-token: ${{ steps.upstream-repo-token.outputs.token }}
+        test-repo-token: ${{ steps.test-repo-token.outputs.token }}