diff --git a/pkg/agentic/prep.go b/pkg/agentic/prep.go
index 1cd2073..0e28c36 100644
--- a/pkg/agentic/prep.go
+++ b/pkg/agentic/prep.go
@@ -620,11 +620,21 @@ func (s *PrepSubsystem) PrepareWorkspace(ctx context.Context, input PrepInput) (
 	return s.prepWorkspace(ctx, nil, input)
 }
 
+// _, out, err := prep.TestPrepWorkspace(ctx, input)
+func (s *PrepSubsystem) TestPrepWorkspace(ctx context.Context, input PrepInput) (*mcp.CallToolResult, PrepOutput, error) {
+	return s.prepWorkspace(ctx, nil, input)
+}
+
 // prompt, memories, consumers := prep.BuildPrompt(ctx, input, "dev", repoPath)
 func (s *PrepSubsystem) BuildPrompt(ctx context.Context, input PrepInput, branch, repoPath string) (string, int, int) {
 	return s.buildPrompt(ctx, input, branch, repoPath)
 }
 
+// prompt, memories, consumers := prep.TestBuildPrompt(ctx, input, "dev", repoPath)
+func (s *PrepSubsystem) TestBuildPrompt(ctx context.Context, input PrepInput, branch, repoPath string) (string, int, int) {
+	return s.buildPrompt(ctx, input, branch, repoPath)
+}
+
 // prompt, memories, consumers := prep.buildPrompt(ctx, input, "dev", "/srv/repos/go-io")
 func (s *PrepSubsystem) buildPrompt(ctx context.Context, input PrepInput, branch, repoPath string) (string, int, int) {
 	b := core.NewBuilder()
diff --git a/pkg/agentic/prep_extra_test.go b/pkg/agentic/prep_extra_test.go
index 0e5d7df..53566e4 100644
--- a/pkg/agentic/prep_extra_test.go
+++ b/pkg/agentic/prep_extra_test.go
@@ -360,6 +360,31 @@ func TestPrep_BuildPrompt_Good_BasicFields(t *testing.T) {
 	assert.Equal(t, 0, consumers)
 }
 
+func TestPrep_TestBuildPrompt_Good_BasicFields(t *testing.T) {
+	dir := t.TempDir()
+	fs.Write(core.JoinPath(dir, "go.mod"), "module test\n\ngo 1.22\n")
+
+	s := &PrepSubsystem{
+		ServiceRuntime: core.NewServiceRuntime(testCore, AgentOptions{}),
+		codePath:       t.TempDir(),
+		backoff:        make(map[string]time.Time),
+		failCount:      make(map[string]int),
+	}
+
+	prompt, memories, consumers := s.TestBuildPrompt(context.Background(), PrepInput{
+		Task: "Fix the tests",
+		Org:  "core",
+		Repo: "go-io",
+	}, "dev", dir)
+
+	assert.Contains(t, prompt, "TASK: Fix the tests")
+	assert.Contains(t, prompt, "REPO: core/go-io on branch dev")
+	assert.Contains(t, prompt, "LANGUAGE: go")
+	assert.Contains(t, prompt, "CONSTRAINTS:")
+	assert.Equal(t, 0, memories)
+	assert.Equal(t, 0, consumers)
+}
+
 func TestPrep_BuildPrompt_Good_WithIssue(t *testing.T) {
 	dir := t.TempDir()
 
@@ -391,6 +416,40 @@ func TestPrep_BuildPrompt_Good_WithIssue(t *testing.T) {
 	assert.Contains(t, prompt, "Steps to reproduce")
 }
 
+func TestPrep_TestBuildPrompt_Bad_EmptyRepoPath(t *testing.T) {
+	s := &PrepSubsystem{
+		ServiceRuntime: core.NewServiceRuntime(testCore, AgentOptions{}),
+		codePath:       t.TempDir(),
+		backoff:        make(map[string]time.Time),
+		failCount:      make(map[string]int),
+	}
+
+	prompt, memories, consumers := s.TestBuildPrompt(context.Background(), PrepInput{
+		Task: "Add unit tests",
+		Org:  "core",
+		Repo: "go-io",
+	}, "dev", "")
+
+	assert.Contains(t, prompt, "TASK: Add unit tests")
+	assert.Equal(t, 0, memories)
+	assert.Equal(t, 0, consumers)
+}
+
+func TestPrep_TestBuildPrompt_Ugly_StillBuildsPrompt(t *testing.T) {
+	s := &PrepSubsystem{
+		ServiceRuntime: core.NewServiceRuntime(testCore, AgentOptions{}),
+		codePath:       t.TempDir(),
+		backoff:        make(map[string]time.Time),
+		failCount:      make(map[string]int),
+	}
+
+	prompt, memories, consumers := s.TestBuildPrompt(context.Background(), PrepInput{}, "", "")
+
+	assert.Contains(t, prompt, "TASK:")
+	assert.Equal(t, 0, memories)
+	assert.Equal(t, 0, consumers)
+}
+
 // --- buildPrompt (naming convention tests) ---
 
 func TestPrep_BuildPromptNaming_Good(t *testing.T) {
diff --git a/pkg/agentic/prep_test.go b/pkg/agentic/prep_test.go
index 7abecb2..ce8b4d2 100644
--- a/pkg/agentic/prep_test.go
+++ b/pkg/agentic/prep_test.go
@@ -988,3 +988,71 @@ func TestPrep_PrepWorkspace_Good(t *testing.T) {
 	assert.NotEmpty(t, out.Branch)
 	assert.Contains(t, out.Branch, "agent/")
 }
+
+func TestPrep_TestPrepWorkspace_Good(t *testing.T) {
+	root := t.TempDir()
+	t.Setenv("CORE_WORKSPACE", root)
+
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte(core.JSONMarshalString(map[string]any{
+			"number": 1,
+			"title":  "Fix tests",
+			"body":   "Tests are broken",
+		})))
+	}))
+	t.Cleanup(srv.Close)
+
+	srcRepo := core.JoinPath(root, "src", "core", "test-repo")
+	gitEnv := []string{"GIT_AUTHOR_NAME=Test", "GIT_AUTHOR_EMAIL=test@test.com", "GIT_COMMITTER_NAME=Test", "GIT_COMMITTER_EMAIL=test@test.com"}
+	run := func(dir string, args ...string) {
+		t.Helper()
+		r := testCore.Process().RunWithEnv(context.Background(), dir, gitEnv, args[0], args[1:]...)
+		require.True(t, r.OK, "cmd %v failed: %s", args, r.Value)
+	}
+	require.True(t, fs.EnsureDir(srcRepo).OK)
+	run(srcRepo, "git", "init", "-b", "main")
+	run(srcRepo, "git", "config", "user.name", "Test")
+	run(srcRepo, "git", "config", "user.email", "test@test.com")
+	require.True(t, fs.Write(core.JoinPath(srcRepo, "README.md"), "# Test").OK)
+	run(srcRepo, "git", "add", "README.md")
+	run(srcRepo, "git", "commit", "-m", "initial commit")
+
+	s := &PrepSubsystem{
+		ServiceRuntime: core.NewServiceRuntime(testCore, AgentOptions{}),
+		forge:          forge.NewForge(srv.URL, "test-token"),
+		codePath:       core.JoinPath(root, "src"),
+		backoff:        make(map[string]time.Time),
+		failCount:      make(map[string]int),
+	}
+
+	_, out, err := s.TestPrepWorkspace(context.Background(), PrepInput{
+		Repo:  "test-repo",
+		Issue: 1,
+		Task:  "Fix tests",
+	})
+	require.NoError(t, err)
+	assert.True(t, out.Success)
+	assert.NotEmpty(t, out.WorkspaceDir)
+}
+
+func TestPrep_TestPrepWorkspace_Bad(t *testing.T) {
+	s := &PrepSubsystem{
+		ServiceRuntime: core.NewServiceRuntime(testCore, AgentOptions{}),
+		backoff:        make(map[string]time.Time),
+		failCount:      make(map[string]int),
+	}
+
+	_, _, err := s.TestPrepWorkspace(context.Background(), PrepInput{Repo: "."})
+	require.Error(t, err)
+}
+
+func TestPrep_TestPrepWorkspace_Ugly(t *testing.T) {
+	s := &PrepSubsystem{
+		ServiceRuntime: core.NewServiceRuntime(testCore, AgentOptions{}),
+		backoff:        make(map[string]time.Time),
+		failCount:      make(map[string]int),
+	}
+
+	_, _, err := s.TestPrepWorkspace(context.Background(), PrepInput{Repo: ".."})
+	require.Error(t, err)
+}