MLX compatibility: Creation functions

[aaishwarymishra]

Array API	MLX Analog	Status	Blame / Notes	Test Node	Result
arange(start, /, stop=None, step=1, *, dtype=None, device=None)	arange(start, stop, step, dtype=None, *, stream=None)	incompatible	MLX rejects valid calls such as arange(0, None, 1). It also lacks device; defaults and positional constraints differ.	test_arange	Failed
asarray(obj, /, *, dtype=None, device=None, copy=None)	asarray(a, dtype=None, *, copy=None)	partial	copy=False can fail even when given an MLX array of the requested dtype. MLX also lacks device, and dtype is not keyword-only.	test_asarray_arrays	Failed
empty(shape, *, dtype=None, device=None)	empty(shape, dtype=float32, *, stream=None)	undocumented	Implemented by MLX but absent from its documentation. No device; signature/default behavior may differ.	test_empty	Passed
empty_like(x, /, *, dtype=None, device=None)	empty_like(a, /, *, stream=None)	undocumented / partial	Implemented but undocumented. It rejects the standard dtype keyword, including dtype=None; no device. Its error refers to zeros_like, suggesting shared or aliased internals.	test_empty_like	Failed
eye(n_rows, n_cols=None, /, *, k=0, dtype=None, device=None)	eye(n, m=None, k=0, dtype=float32, *, stream=None)	incompatible	Rejects zero-sized output such as eye(0) and large valid offsets such as k=2147483648. No device; positional constraints also differ.	test_eye	Failed
from_dlpack(x, /, *, device=None, copy=None)	from_dlpack(x, /, *, copy=None)	partial	MLX lacks x.device and array_namespace_info().devices(), so the test fails before calling from_dlpack.	test_dlpack.py::test_from_dlpack	Not tested
full(shape, fill_value, *, dtype=None, device=None)	full(shape, vals, dtype=None, *, stream=None)	signature mismatch	fill_value is named vals; dtype is not keyword-only; no device.	test_full	Passed
full_like(x, /, fill_value, *, dtype=None, device=None)	full_like(a, vals, dtype=None, *, stream=None)	signature mismatch	fill_value is named vals; dtype is not keyword-only; no device.	test_full_like	Passed
linspace(start, stop, /, num, *, dtype=None, device=None, endpoint=True)	linspace(start, stop, num=50, dtype=float32, stream=None)	partial	MLX does not support endpoint, causing calls with endpoint=False to fail. It also lacks device; num and dtype constraints differ.	test_linspace	Failed
meshgrid(*arrays, indexing="xy")	meshgrid(*arrays, sparse=False, indexing="xy", stream=None)	return mismatch	MLX returns a list; Array API 2025.12 requires a tuple. Extra optional MLX parameters are not themselves incompatible.	test_meshgrid	Failed
ones(shape, *, dtype=None, device=None)	ones(shape, dtype=float32, *, stream=None)	signature mismatch	dtype is not keyword-only; no device. Tested behavior otherwise passes.	test_ones	Passed
ones_like(x, /, *, dtype=None, device=None)	ones_like(a, /, *, stream=None)	partial	MLX rejects the standard dtype keyword, including dtype=None; it also lacks device.	test_ones_like	Failed
tril(x, /, *, k=0)	tril(x, k, *, stream=None)	signature mismatch	MLX accepts k positionally, whereas the Array API makes it keyword-only. Tested behavior passes.	test_tril	Passed
triu(x, /, *, k=0)	triu(x, k, *, stream=None)	signature mismatch	MLX accepts k positionally, whereas the Array API makes it keyword-only. Tested behavior passes.	test_triu	Passed
zeros(shape, *, dtype=None, device=None)	zeros(shape, dtype=float32, *, stream=None)	signature mismatch	dtype is not keyword-only; no device. Tested behavior otherwise passes.	test_zeros	Passed
zeros_like(x, /, *, dtype=None, device=None)	zeros_like(a, /, *, stream=None)	partial	MLX rejects the standard dtype keyword, including dtype=None; it also lacks device.	test_zeros_like	Failed

[aaishwarymishra]

I wasn't able to run tests on this file mainly because,

• By default mlx arrays are on gpu stream and they dont support float64, many tests failed because of that.
• some tests were checking different datatypes the complex bug also affected these tests.
• No device parameter or method signature mismatch

[ev-br]

No device parameter

This is systemic and is worth noting indeed. Does not block testing at this stage, not more than cupy which does not have device arguments either.

By default mlx arrays are on gpu stream and they dont support float64, many tests failed because of that.

This is a nice observation and runs into a systemic problem in the test suite (cf data-apis/array-api-tests#440).
Meanwhile, can you run tests with set_default_device to CPU? https://ml-explore.github.io/mlx/build/html/python/_autosummary/mlx.core.set_default_device.html
That'd be similar to JAX, data-apis/array-api-tests#368 (comment)

---

Your table is very useful, but is a tad hard to read because the "notes" column runs into the page width, could swap with "Test node" and "result" columns.

And it'd be useful to continue compiling a compatibility table for the rest of the spec in this same issue.

[ev-br]

By default mlx arrays are on gpu stream and they dont support float64, many tests failed because of that.

In addition / as an alternative to setting the MLX default device to CPU, you may run the test suite with the environment variable ARRAY_API_TESTS_SKIP_DTYPES=float64,complex128. Skipping float64 mostly works: if a test fails with this skip and MLX, it'd be helpful to double-check the test failure with the skip and array_api_compat.numpy. If it still fails, the problem is with the test suite (please report it in data-apis/array-api-tests#431). If it passes with numpy and fails with MLX, then report the failure here.

[aaishwarymishra]

• arange: MLX rejects the valid three-argument form when stop=None, e.g. arange(0, None, 1).

• asarray: copy=False fails even when the input is already an MLX array with the requested dtype; MLX claims it cannot
  avoid copying.

• empty_like: MLX does not accept the standard dtype keyword—even dtype=None. The error mentioning zeros_like also
  suggests empty_like is internally aliased or misrouted.

• eye: two issues:

  • Zero-sized dimensions such as eye(0) are rejected.
  • Large valid diagonal offsets such as k=2147483648 overflow or fail MLX’s argument binding.

• linspace: MLX does not implement the endpoint keyword.

• meshgrid: MLX returns a list, but Array API 2025.12 requires a tuple.

• ones_like: MLX does not accept the standard dtype keyword.

• zeros_like: Same missing dtype keyword support.

what I found was the empty and empty_like was implemented on new release, but the docs wasn't updated so I marked them as missing, I will update that, out of 16, 8 passed and 8 failed.

For the from_dlpack its's test is in a separate file and it didn't ran It tried to determine which device to use in two ways:

1. With copy=False, it reads x.device, but MLX arrays do not have that attribute.
2. Otherwise, it call xp.array_namespace_info().devices(),but MLX does not implement array_namespace_info.
   Even if I manually hardcode the MLX device test will fail as mlx does not have device parameter which it is passing.

The two passing tests were:

• test_dlpack.py::test_dlpack_device
• test_dlpack.py::test_dunder_dlpack

Only test_dlpack.py::test_from_dlpack failed.

Details

FAILED array_api_tests/test_creation_functions.py::test_arange - TypeError: arange(): incompatible function arguments. The following argument types are supported:
FAILED array_api_tests/test_creation_functions.py::test_asarray_arrays - ValueError: Unable to avoid copy while creating an array as requested.
FAILED array_api_tests/test_creation_functions.py::test_empty_like - TypeError: zeros_like(): incompatible function arguments. The following argument types are supp...
FAILED array_api_tests/test_creation_functions.py::test_eye - ExceptionGroup: Hypothesis found 2 distinct failures. (2 sub-exceptions)
FAILED array_api_tests/test_creation_functions.py::test_linspace - TypeError: linspace(): incompatible function arguments. The following argument types are suppor...
FAILED array_api_tests/test_creation_functions.py::test_meshgrid - AssertionError: assert <class 'list'> == <class 'tuple'>
FAILED array_api_tests/test_creation_functions.py::test_ones_like - TypeError: ones_like(): incompatible function arguments. The following argument types are suppo...
FAILED array_api_tests/test_creation_functions.py::test_zeros_like - TypeError: zeros_like(): incompatible function arguments. The following argument types are supp...