fix(workflow): support integration: auto to follow project's initialized AI

src/specify_cli/workflows/engine.py

@@ -715,12 +715,46 @@ def _resolve_inputs(
                     name, provided[name], input_def
                 )
             elif "default" in input_def:
-                resolved[name] = input_def["default"]
+                resolved[name] = self._resolve_default(name, input_def["default"])
             elif input_def.get("required", False):
                 msg = f"Required input {name!r} not provided."
                 raise ValueError(msg)
         return resolved
 
+    def _resolve_default(self, name: str, default: Any) -> Any:
+        """Resolve special default sentinels against project state.
+
+        For the ``integration`` input, ``"auto"`` resolves to the integration
+        recorded in ``.specify/integration.json`` so workflows dispatch to the
+        AI the project was actually initialized with, instead of a hardcoded
+        value baked into the workflow YAML.
+        """
+        if name == "integration" and default == "auto":
+            resolved = self._load_project_integration()
+            if resolved is not None:
+                return resolved
+        return default
+
+    def _load_project_integration(self) -> str | None:
+        """Read the active integration key from ``.specify/integration.json``.
+
+        Returns None when the file is missing or malformed; callers are
+        expected to fall back to a literal default.
+        """
+        path = self.project_root / ".specify" / "integration.json"
+        if not path.is_file():
+            return None
+        try:
+            data = json.loads(path.read_text(encoding="utf-8"))
+        except (json.JSONDecodeError, OSError):
+            return None
+        if not isinstance(data, dict):
+            return None
+        value = data.get("integration")
+        if isinstance(value, str) and value:
+            return value
+        return None
+
     @staticmethod
     def _coerce_input(
         name: str, value: Any, input_def: dict[str, Any]

tests/test_workflows.py

@@ -1495,6 +1495,104 @@ def test_execute_missing_required_input(self, project_dir):
         with pytest.raises(ValueError, match="Required input"):
             engine.execute(definition, {})
 
+    def test_integration_auto_default_uses_project_integration(self, project_dir):
+        """`integration: auto` should resolve to .specify/integration.json's integration."""
+        from specify_cli.workflows.engine import WorkflowEngine, WorkflowDefinition
+
+        specify_dir = project_dir / ".specify"
+        specify_dir.mkdir(parents=True, exist_ok=True)
+        (specify_dir / "integration.json").write_text(
+            json.dumps({"integration": "opencode", "version": "0.7.4"}),
+            encoding="utf-8",
+        )
+
+        definition = WorkflowDefinition.from_string("""
+schema_version: "1.0"
+workflow:
+  id: "auto-default"
+  name: "Auto Default"
+  version: "1.0.0"
+inputs:
+  integration:
+    type: string
+    default: "auto"
+""")
+        engine = WorkflowEngine(project_dir)
+        resolved = engine._resolve_inputs(definition, {})
+        assert resolved["integration"] == "opencode"
+
+    def test_integration_auto_default_falls_back_when_no_integration_json(self, project_dir):
+        """`integration: auto` should keep the literal "auto" when project state is missing.
+
+        The CommandStep / dispatcher is responsible for surfacing a helpful
+        error in that case; the engine itself must not invent an integration.
+        """
+        from specify_cli.workflows.engine import WorkflowEngine, WorkflowDefinition
+
+        definition = WorkflowDefinition.from_string("""
+schema_version: "1.0"
+workflow:
+  id: "auto-fallback"
+  name: "Auto Fallback"
+  version: "1.0.0"
+inputs:
+  integration:
+    type: string
+    default: "auto"
+""")
+        engine = WorkflowEngine(project_dir)
+        resolved = engine._resolve_inputs(definition, {})
+        assert resolved["integration"] == "auto"
+
+    def test_integration_explicit_input_overrides_auto(self, project_dir):
+        """An explicit --input integration=X must win over `auto` even when integration.json exists."""
+        from specify_cli.workflows.engine import WorkflowEngine, WorkflowDefinition
+
+        specify_dir = project_dir / ".specify"
+        specify_dir.mkdir(parents=True, exist_ok=True)
+        (specify_dir / "integration.json").write_text(
+            json.dumps({"integration": "opencode"}),
+            encoding="utf-8",
+        )
+
+        definition = WorkflowDefinition.from_string("""
+schema_version: "1.0"
+workflow:
+  id: "explicit-wins"
+  name: "Explicit Wins"
+  version: "1.0.0"
+inputs:
+  integration:
+    type: string
+    default: "auto"
+""")
+        engine = WorkflowEngine(project_dir)
+        resolved = engine._resolve_inputs(definition, {"integration": "claude"})
+        assert resolved["integration"] == "claude"
+
+    def test_integration_auto_ignores_malformed_integration_json(self, project_dir):
+        """A malformed integration.json must not crash — fall back to the literal default."""
+        from specify_cli.workflows.engine import WorkflowEngine, WorkflowDefinition
+
+        specify_dir = project_dir / ".specify"
+        specify_dir.mkdir(parents=True, exist_ok=True)
+        (specify_dir / "integration.json").write_text("{not json", encoding="utf-8")
+
+        definition = WorkflowDefinition.from_string("""
+schema_version: "1.0"
+workflow:
+  id: "auto-malformed"
+  name: "Auto Malformed"
+  version: "1.0.0"
+inputs:
+  integration:
+    type: string
+    default: "auto"
+""")
+        engine = WorkflowEngine(project_dir)
+        resolved = engine._resolve_inputs(definition, {})
+        assert resolved["integration"] == "auto"
+
 
 # ===== State Persistence Tests =====
 

workflows/speckit/workflow.yml

@@ -18,8 +18,8 @@ inputs:
     prompt: "Describe what you want to build"
   integration:
     type: string
-    default: "copilot"
-    prompt: "Integration to use (e.g. claude, copilot, gemini)"
+    default: "auto"
+    prompt: "Integration to use (e.g. claude, copilot, gemini; 'auto' uses the project's initialized integration)"
   scope:
     type: string
     default: "full"