diff --git a/src/specify_cli/integrations/claude/__init__.py b/src/specify_cli/integrations/claude/__init__.py
index 31972c4b0..5a619a6a5 100644
--- a/src/specify_cli/integrations/claude/__init__.py
+++ b/src/specify_cli/integrations/claude/__init__.py
@@ -148,6 +148,35 @@ def _inject_frontmatter_flag(content: str, key: str, value: str = "true") -> str
             out.append(line)
         return "".join(out)
 
+    @staticmethod
+    def ensure_claude_md(project_root: Path) -> Path | None:
+        """Create a minimal root ``CLAUDE.md`` if missing.
+
+        Claude Code expects ``CLAUDE.md`` at the project root; this file
+        acts as a bridge to ``.specify/memory/constitution.md``.
+        Returns the path if created, ``None`` otherwise.
+        """
+        constitution = project_root / ".specify" / "memory" / "constitution.md"
+        claude_file = project_root / "CLAUDE.md"
+        if claude_file.exists() or not constitution.exists():
+            return None
+
+        content = (
+            "## Claude's Role\n"
+            "Read `.specify/memory/constitution.md` first. It is the authoritative source of truth for this project. "
+            "Everything in it is non-negotiable.\n\n"
+            "## SpecKit Commands\n"
+            "- `/speckit.specify` — generate spec\n"
+            "- `/speckit.plan` — generate plan\n"
+            "- `/speckit.tasks` — generate task list\n"
+            "- `/speckit.implement` — execute plan\n\n"
+            "## On Ambiguity\n"
+            "If a spec is missing, incomplete, or conflicts with the constitution — stop and ask. "
+            "Do not infer. Do not proceed.\n\n"
+        )
+        claude_file.write_text(content, encoding="utf-8")
+        return claude_file
+
     def setup(
         self,
         project_root: Path,
@@ -155,9 +184,15 @@ def setup(
         parsed_options: dict[str, Any] | None = None,
         **opts: Any,
     ) -> list[Path]:
-        """Install Claude skills, then inject user-invocable, disable-model-invocation, and argument-hint."""
+        """Install Claude skills, create CLAUDE.md, then inject frontmatter flags and argument-hints."""
         created = super().setup(project_root, manifest, parsed_options, **opts)
 
+        # Create root CLAUDE.md pointing to the constitution
+        claude_md = self.ensure_claude_md(project_root)
+        if claude_md is not None:
+            created.append(claude_md)
+            self.record_file_in_manifest(claude_md, project_root, manifest)
+
         # Post-process generated skill files
         skills_dir = self.skills_dest(project_root).resolve()
 
diff --git a/tests/integrations/test_integration_claude.py b/tests/integrations/test_integration_claude.py
index 7fd69df17..9b1e940f8 100644
--- a/tests/integrations/test_integration_claude.py
+++ b/tests/integrations/test_integration_claude.py
@@ -286,6 +286,76 @@ def test_claude_preset_creates_new_skill_without_commands_dir(self, tmp_path):
         assert "speckit-research" in metadata.get("registered_skills", [])
 
 
+class TestClaudeMdCreation:
+    """Verify that CLAUDE.md is created during setup when constitution exists."""
+
+    def test_setup_creates_claude_md_when_constitution_exists(self, tmp_path):
+        integration = get_integration("claude")
+        constitution = tmp_path / ".specify" / "memory" / "constitution.md"
+        constitution.parent.mkdir(parents=True, exist_ok=True)
+        constitution.write_text("# Constitution\n", encoding="utf-8")
+
+        manifest = IntegrationManifest("claude", tmp_path)
+        created = integration.setup(tmp_path, manifest, script_type="sh")
+
+        claude_md = tmp_path / "CLAUDE.md"
+        assert claude_md.exists()
+        content = claude_md.read_text(encoding="utf-8")
+        assert ".specify/memory/constitution.md" in content
+        assert claude_md in created
+
+    def test_setup_skips_claude_md_when_constitution_missing(self, tmp_path):
+        integration = get_integration("claude")
+        manifest = IntegrationManifest("claude", tmp_path)
+        integration.setup(tmp_path, manifest, script_type="sh")
+
+        assert not (tmp_path / "CLAUDE.md").exists()
+
+    def test_setup_preserves_existing_claude_md(self, tmp_path):
+        integration = get_integration("claude")
+        constitution = tmp_path / ".specify" / "memory" / "constitution.md"
+        constitution.parent.mkdir(parents=True, exist_ok=True)
+        constitution.write_text("# Constitution\n", encoding="utf-8")
+
+        claude_md = tmp_path / "CLAUDE.md"
+        claude_md.write_text("# Custom content\n", encoding="utf-8")
+
+        manifest = IntegrationManifest("claude", tmp_path)
+        integration.setup(tmp_path, manifest, script_type="sh")
+
+        assert claude_md.read_text(encoding="utf-8") == "# Custom content\n"
+
+    def test_init_cli_creates_claude_md(self, tmp_path):
+        from typer.testing import CliRunner
+        from specify_cli import app
+
+        project = tmp_path / "claude-md-test"
+        project.mkdir()
+
+        # Pre-create constitution so ensure_claude_md has something to gate on
+        constitution = project / ".specify" / "memory" / "constitution.md"
+        constitution.parent.mkdir(parents=True, exist_ok=True)
+        constitution.write_text("# Constitution\n", encoding="utf-8")
+
+        old_cwd = os.getcwd()
+        try:
+            os.chdir(project)
+            runner = CliRunner()
+            result = runner.invoke(
+                app,
+                ["init", "--here", "--force", "--ai", "claude", "--script", "sh", "--no-git", "--ignore-agent-tools"],
+                catch_exceptions=False,
+            )
+        finally:
+            os.chdir(old_cwd)
+
+        assert result.exit_code == 0, result.output
+        claude_md = project / "CLAUDE.md"
+        assert claude_md.exists()
+        content = claude_md.read_text(encoding="utf-8")
+        assert ".specify/memory/constitution.md" in content
+
+
 class TestClaudeArgumentHints:
     """Verify that argument-hint frontmatter is injected for Claude skills."""