diff --git a/pkg/agentic/mirror_test.go b/pkg/agentic/mirror_test.go
new file mode 100644
index 0000000..229f870
--- /dev/null
+++ b/pkg/agentic/mirror_test.go
@@ -0,0 +1,357 @@
+// SPDX-License-Identifier: EUPL-1.2
+
+package agentic
+
+import (
+	"os/exec"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// initBareRepo creates a minimal git repo with one commit and returns its path.
+func initBareRepo(t *testing.T) string {
+	t.Helper()
+	dir := t.TempDir()
+	run := func(args ...string) {
+		t.Helper()
+		cmd := exec.Command(args[0], args[1:]...)
+		cmd.Dir = dir
+		cmd.Env = append(cmd.Environ(),
+			"GIT_AUTHOR_NAME=Test",
+			"GIT_AUTHOR_EMAIL=test@test.com",
+			"GIT_COMMITTER_NAME=Test",
+			"GIT_COMMITTER_EMAIL=test@test.com",
+		)
+		out, err := cmd.CombinedOutput()
+		require.NoError(t, err, "cmd %v failed: %s", args, string(out))
+	}
+	run("git", "init", "-b", "main")
+	run("git", "config", "user.name", "Test")
+	run("git", "config", "user.email", "test@test.com")
+
+	// Create a file and commit
+	require.True(t, fs.Write(filepath.Join(dir, "README.md"), "# Test").OK)
+	run("git", "add", "README.md")
+	run("git", "commit", "-m", "initial commit")
+	return dir
+}
+
+// --- hasRemote ---
+
+func TestHasRemote_Good_OriginExists(t *testing.T) {
+	dir := initBareRepo(t)
+	// origin won't exist for a fresh repo, so add it
+	cmd := exec.Command("git", "remote", "add", "origin", "https://example.com/repo.git")
+	cmd.Dir = dir
+	require.NoError(t, cmd.Run())
+
+	assert.True(t, hasRemote(dir, "origin"))
+}
+
+func TestHasRemote_Good_CustomRemote(t *testing.T) {
+	dir := initBareRepo(t)
+	cmd := exec.Command("git", "remote", "add", "github", "https://github.com/test/repo.git")
+	cmd.Dir = dir
+	require.NoError(t, cmd.Run())
+
+	assert.True(t, hasRemote(dir, "github"))
+}
+
+func TestHasRemote_Bad_NoSuchRemote(t *testing.T) {
+	dir := initBareRepo(t)
+	assert.False(t, hasRemote(dir, "nonexistent"))
+}
+
+func TestHasRemote_Bad_NotAGitRepo(t *testing.T) {
+	dir := t.TempDir() // plain directory, no .git
+	assert.False(t, hasRemote(dir, "origin"))
+}
+
+func TestHasRemote_Ugly_EmptyDir(t *testing.T) {
+	// Empty dir defaults to cwd which may or may not be a repo.
+	// Just ensure no panic.
+	assert.NotPanics(t, func() {
+		hasRemote("", "origin")
+	})
+}
+
+// --- commitsAhead ---
+
+func TestCommitsAhead_Good_OneAhead(t *testing.T) {
+	dir := initBareRepo(t)
+
+	// Create a branch at the current commit to act as "base"
+	run := func(args ...string) {
+		t.Helper()
+		cmd := exec.Command(args[0], args[1:]...)
+		cmd.Dir = dir
+		cmd.Env = append(cmd.Environ(),
+			"GIT_AUTHOR_NAME=Test",
+			"GIT_AUTHOR_EMAIL=test@test.com",
+			"GIT_COMMITTER_NAME=Test",
+			"GIT_COMMITTER_EMAIL=test@test.com",
+		)
+		out, err := cmd.CombinedOutput()
+		require.NoError(t, err, "cmd %v failed: %s", args, string(out))
+	}
+
+	run("git", "branch", "base")
+
+	// Add a commit on main
+	require.True(t, fs.Write(filepath.Join(dir, "new.txt"), "data").OK)
+	run("git", "add", "new.txt")
+	run("git", "commit", "-m", "second commit")
+
+	ahead := commitsAhead(dir, "base", "main")
+	assert.Equal(t, 1, ahead)
+}
+
+func TestCommitsAhead_Good_ThreeAhead(t *testing.T) {
+	dir := initBareRepo(t)
+	run := func(args ...string) {
+		t.Helper()
+		cmd := exec.Command(args[0], args[1:]...)
+		cmd.Dir = dir
+		cmd.Env = append(cmd.Environ(),
+			"GIT_AUTHOR_NAME=Test",
+			"GIT_AUTHOR_EMAIL=test@test.com",
+			"GIT_COMMITTER_NAME=Test",
+			"GIT_COMMITTER_EMAIL=test@test.com",
+		)
+		out, err := cmd.CombinedOutput()
+		require.NoError(t, err, "cmd %v failed: %s", args, string(out))
+	}
+
+	run("git", "branch", "base")
+
+	for i := 0; i < 3; i++ {
+		name := filepath.Join(dir, "file"+string(rune('a'+i))+".txt")
+		require.True(t, fs.Write(name, "content").OK)
+		run("git", "add", ".")
+		run("git", "commit", "-m", "commit "+string(rune('0'+i)))
+	}
+
+	ahead := commitsAhead(dir, "base", "main")
+	assert.Equal(t, 3, ahead)
+}
+
+func TestCommitsAhead_Good_ZeroAhead(t *testing.T) {
+	dir := initBareRepo(t)
+	// Same ref on both sides
+	ahead := commitsAhead(dir, "main", "main")
+	assert.Equal(t, 0, ahead)
+}
+
+func TestCommitsAhead_Bad_InvalidRef(t *testing.T) {
+	dir := initBareRepo(t)
+	ahead := commitsAhead(dir, "nonexistent-ref", "main")
+	assert.Equal(t, 0, ahead)
+}
+
+func TestCommitsAhead_Bad_NotARepo(t *testing.T) {
+	ahead := commitsAhead(t.TempDir(), "main", "dev")
+	assert.Equal(t, 0, ahead)
+}
+
+func TestCommitsAhead_Ugly_EmptyDir(t *testing.T) {
+	ahead := commitsAhead("", "a", "b")
+	assert.Equal(t, 0, ahead)
+}
+
+// --- filesChanged ---
+
+func TestFilesChanged_Good_OneFile(t *testing.T) {
+	dir := initBareRepo(t)
+	run := func(args ...string) {
+		t.Helper()
+		cmd := exec.Command(args[0], args[1:]...)
+		cmd.Dir = dir
+		cmd.Env = append(cmd.Environ(),
+			"GIT_AUTHOR_NAME=Test",
+			"GIT_AUTHOR_EMAIL=test@test.com",
+			"GIT_COMMITTER_NAME=Test",
+			"GIT_COMMITTER_EMAIL=test@test.com",
+		)
+		out, err := cmd.CombinedOutput()
+		require.NoError(t, err, "cmd %v failed: %s", args, string(out))
+	}
+
+	run("git", "branch", "base")
+
+	require.True(t, fs.Write(filepath.Join(dir, "changed.txt"), "new").OK)
+	run("git", "add", "changed.txt")
+	run("git", "commit", "-m", "add file")
+
+	files := filesChanged(dir, "base", "main")
+	assert.Equal(t, 1, files)
+}
+
+func TestFilesChanged_Good_MultipleFiles(t *testing.T) {
+	dir := initBareRepo(t)
+	run := func(args ...string) {
+		t.Helper()
+		cmd := exec.Command(args[0], args[1:]...)
+		cmd.Dir = dir
+		cmd.Env = append(cmd.Environ(),
+			"GIT_AUTHOR_NAME=Test",
+			"GIT_AUTHOR_EMAIL=test@test.com",
+			"GIT_COMMITTER_NAME=Test",
+			"GIT_COMMITTER_EMAIL=test@test.com",
+		)
+		out, err := cmd.CombinedOutput()
+		require.NoError(t, err, "cmd %v failed: %s", args, string(out))
+	}
+
+	run("git", "branch", "base")
+
+	for _, name := range []string{"a.go", "b.go", "c.go"} {
+		require.True(t, fs.Write(filepath.Join(dir, name), "package main").OK)
+	}
+	run("git", "add", ".")
+	run("git", "commit", "-m", "add three files")
+
+	files := filesChanged(dir, "base", "main")
+	assert.Equal(t, 3, files)
+}
+
+func TestFilesChanged_Good_NoChanges(t *testing.T) {
+	dir := initBareRepo(t)
+	files := filesChanged(dir, "main", "main")
+	assert.Equal(t, 0, files)
+}
+
+func TestFilesChanged_Bad_InvalidRef(t *testing.T) {
+	dir := initBareRepo(t)
+	files := filesChanged(dir, "nonexistent", "main")
+	assert.Equal(t, 0, files)
+}
+
+func TestFilesChanged_Bad_NotARepo(t *testing.T) {
+	files := filesChanged(t.TempDir(), "main", "dev")
+	assert.Equal(t, 0, files)
+}
+
+func TestFilesChanged_Ugly_EmptyDir(t *testing.T) {
+	files := filesChanged("", "a", "b")
+	assert.Equal(t, 0, files)
+}
+
+// --- extractJSONField (extending existing 91% coverage) ---
+
+func TestExtractJSONField_Good_ArrayFirstItem(t *testing.T) {
+	json := `[{"url":"https://github.com/test/pr/1","title":"Fix bug"}]`
+	assert.Equal(t, "https://github.com/test/pr/1", extractJSONField(json, "url"))
+}
+
+func TestExtractJSONField_Good_ObjectField(t *testing.T) {
+	json := `{"name":"test-repo","status":"active"}`
+	assert.Equal(t, "test-repo", extractJSONField(json, "name"))
+}
+
+func TestExtractJSONField_Good_ArrayMultipleItems(t *testing.T) {
+	json := `[{"id":"first"},{"id":"second"}]`
+	// Should return the first match
+	assert.Equal(t, "first", extractJSONField(json, "id"))
+}
+
+func TestExtractJSONField_Bad_EmptyJSON(t *testing.T) {
+	assert.Equal(t, "", extractJSONField("", "url"))
+}
+
+func TestExtractJSONField_Bad_EmptyField(t *testing.T) {
+	assert.Equal(t, "", extractJSONField(`{"url":"test"}`, ""))
+}
+
+func TestExtractJSONField_Bad_FieldNotFound(t *testing.T) {
+	json := `{"name":"test"}`
+	assert.Equal(t, "", extractJSONField(json, "missing"))
+}
+
+func TestExtractJSONField_Bad_InvalidJSON(t *testing.T) {
+	assert.Equal(t, "", extractJSONField("not json at all", "url"))
+}
+
+func TestExtractJSONField_Ugly_EmptyArray(t *testing.T) {
+	assert.Equal(t, "", extractJSONField("[]", "url"))
+}
+
+func TestExtractJSONField_Ugly_EmptyObject(t *testing.T) {
+	assert.Equal(t, "", extractJSONField("{}", "url"))
+}
+
+func TestExtractJSONField_Ugly_NumericValue(t *testing.T) {
+	// Field exists but is not a string — should return ""
+	json := `{"count":42}`
+	assert.Equal(t, "", extractJSONField(json, "count"))
+}
+
+func TestExtractJSONField_Ugly_NullValue(t *testing.T) {
+	json := `{"url":null}`
+	assert.Equal(t, "", extractJSONField(json, "url"))
+}
+
+// --- DefaultBranch ---
+
+func TestDefaultBranch_Good_MainBranch(t *testing.T) {
+	dir := initBareRepo(t)
+	// initBareRepo creates with -b main
+	branch := DefaultBranch(dir)
+	assert.Equal(t, "main", branch)
+}
+
+func TestDefaultBranch_Bad_NotARepo(t *testing.T) {
+	dir := t.TempDir()
+	// Falls back to "main" when detection fails
+	branch := DefaultBranch(dir)
+	assert.Equal(t, "main", branch)
+}
+
+// --- listLocalRepos ---
+
+func TestListLocalRepos_Good_FindsRepos(t *testing.T) {
+	base := t.TempDir()
+
+	// Create two git repos under base
+	for _, name := range []string{"repo-a", "repo-b"} {
+		repoDir := filepath.Join(base, name)
+		cmd := exec.Command("git", "init", repoDir)
+		require.NoError(t, cmd.Run())
+	}
+
+	// Create a non-repo directory
+	require.True(t, fs.EnsureDir(filepath.Join(base, "not-a-repo")).OK)
+
+	s := &PrepSubsystem{}
+	repos := s.listLocalRepos(base)
+	assert.Contains(t, repos, "repo-a")
+	assert.Contains(t, repos, "repo-b")
+	assert.NotContains(t, repos, "not-a-repo")
+}
+
+func TestListLocalRepos_Bad_EmptyDir(t *testing.T) {
+	base := t.TempDir()
+	s := &PrepSubsystem{}
+	repos := s.listLocalRepos(base)
+	assert.Empty(t, repos)
+}
+
+func TestListLocalRepos_Bad_NonExistentDir(t *testing.T) {
+	s := &PrepSubsystem{}
+	repos := s.listLocalRepos("/nonexistent/path/that/doesnt/exist")
+	assert.Nil(t, repos)
+}
+
+// --- GitHubOrg ---
+
+func TestGitHubOrg_Good_Default(t *testing.T) {
+	t.Setenv("GITHUB_ORG", "")
+	assert.Equal(t, "dAppCore", GitHubOrg())
+}
+
+func TestGitHubOrg_Good_Custom(t *testing.T) {
+	t.Setenv("GITHUB_ORG", "my-org")
+	assert.Equal(t, "my-org", GitHubOrg())
+}