numpy · seberg · Oct 7, 2025 · Sep 10, 2025 · Sep 11, 2025 · Sep 11, 2025
diff --git a/doc/source/reference/c-api/types-and-structures.rst b/doc/source/reference/c-api/types-and-structures.rst
@@ -728,6 +728,7 @@ PyArrayMethod_Context and PyArrayMethod_Spec
           PyObject *caller;
           struct PyArrayMethodObject_tag *method;
           PyArray_Descr *const *descriptors;
+          void *parameters;
       } PyArrayMethod_Context
 
    .. c:member:: PyObject *caller
@@ -744,6 +745,15 @@ PyArrayMethod_Context and PyArrayMethod_Spec
       An array of descriptors for the ufunc loop, filled in by
       ``resolve_descriptors``. The length of the array is ``nin`` + ``nout``.
 
+   .. c:member:: void *parameters
+
+      A pointer to a structure containing any runtime parameters needed by the
+      loop. This is ``NULL`` if no parameters are needed. The type of the
+      struct is specific to the registered function.
+
+     .. versionchanged:: NumPy 2.4
+        The `parameters` member was added in NumPy 2.4.
+
 .. c:type:: PyArrayMethod_Spec
 
    A struct used to register an ArrayMethod with NumPy. We use the slots

diff --git a/numpy/_core/include/numpy/dtype_api.h b/numpy/_core/include/numpy/dtype_api.h
@@ -119,6 +119,13 @@ typedef struct PyArrayMethod_Context_tag {
      * NPY_ARRAYMETHOD_CONTEXT_FLAGS
      */
     uint64_t flags;
+
+    /*
+     * Optional run-time parameters to pass to the loop (currently used in sorting).
+     * Fixed parameters are expected to be passed via auxdata.
+     */
+    void *parameters;
+
     /* Structure may grow (this is harmless for DType authors) */
  #endif
 } PyArrayMethod_Context;
@@ -489,4 +496,8 @@ typedef PyArray_Descr *(PyArrayDTypeMeta_FinalizeDescriptor)(PyArray_Descr *dtyp
 typedef int(PyArrayDTypeMeta_SetItem)(PyArray_Descr *, PyObject *, char *);
 typedef PyObject *(PyArrayDTypeMeta_GetItem)(PyArray_Descr *, char *);
 
+typedef struct {
+    NPY_SORTKIND flags;
+} PyArrayMethod_SortParameters;
+
 #endif  /* NUMPY_CORE_INCLUDE_NUMPY___DTYPE_API_H_ */
diff --git a/numpy/_core/src/multiarray/dtypemeta.h b/numpy/_core/src/multiarray/dtypemeta.h
@@ -85,6 +85,12 @@ typedef struct {
      * dtype instance for backward compatibility.  (Keep this at end)
      */
     PyArray_ArrFuncs f;
+
+    /*
+     * Hidden slots for the sort and argsort arraymethods.
+     */
+    PyArrayMethodObject *sort_meth;
+    PyArrayMethodObject *argsort_meth;
 } NPY_DType_Slots;
 
 // This must be updated if new slots before within_dtype_castingimpl