Helpers for Arrow C Data & Arrow C Stream interfaces

Clone this repo:
  1. 1690579 feat(r): Improve printing and conversion of buffers (#208) by Dewey Dunnington · 5 days ago main
  2. 1e6ca7e feat: Add `enum ArrowType buffer_data_type` member to `struct ArrowLayout` (#207) by Dewey Dunnington · 6 days ago
  3. dcb33f0 chore(ci): Add Python packaging tools to images + fix s390x build (#206) by Dewey Dunnington · 7 days ago
  4. 30d01a9 fix: clear `release` in `EmptyArrayStream::release_wrapper` (#204) by David Li · 11 days ago
  5. d9f428d refactor: Unify `ArrowArrayView` and `ArrowArray` validation (#201) by Dewey Dunnington · 11 days ago


Codecov test coverage Documentation nanoarrow on GitHub

The nanoarrow library is a set of helper functions to interpret and generate Arrow C Data Interface and Arrow C Stream Interface structures. The library is in active early development and users should update regularly from the main branch of this repository.

Whereas the current suite of Arrow implementations provide the basis for a comprehensive data analysis toolkit, this library is intended to support clients that wish to produce or interpret Arrow C Data and/or Arrow C Stream structures where linking to a higher level Arrow binding is difficult or impossible.

Using the C library

The nanoarrow C library is intended to be copied and vendored. This can be done using CMake or by using the bundled nanoarrow.h/nanorrow.c distribution available in the dist/ directory in this repository. Examples of both can be found in the examples/ directory in this repository.

A simple producer example:

#include "nanoarrow.h"

int make_simple_array(struct ArrowArray* array_out, struct ArrowSchema* schema_out) {
  struct ArrowError error;
  array_out->release = NULL;
  schema_out->release = NULL;

  NANOARROW_RETURN_NOT_OK(ArrowArrayInitFromType(array_out, NANOARROW_TYPE_INT32));

  NANOARROW_RETURN_NOT_OK(ArrowArrayAppendInt(array_out, 1));
  NANOARROW_RETURN_NOT_OK(ArrowArrayAppendInt(array_out, 2));
  NANOARROW_RETURN_NOT_OK(ArrowArrayAppendInt(array_out, 3));
  NANOARROW_RETURN_NOT_OK(ArrowArrayFinishBuildingDefault(array_out, &error));


  return NANOARROW_OK;

A simple consumer example:

#include <stdio.h>

#include "nanoarrow.h"

int print_simple_array(struct ArrowArray* array, struct ArrowSchema* schema) {
  struct ArrowError error;
  struct ArrowArrayView array_view;
  NANOARROW_RETURN_NOT_OK(ArrowArrayViewInitFromSchema(&array_view, schema, &error));

  if (array_view.storage_type != NANOARROW_TYPE_INT32) {
    printf("Array has storage that is not int32\n");

  int result = ArrowArrayViewSetArray(&array_view, array, &error);
  if (result != NANOARROW_OK) {
    return result;

  for (int64_t i = 0; i < array->length; i++) {
    printf("%d\n", (int)ArrowArrayViewGetIntUnsafe(&array_view, i));

  return NANOARROW_OK;