.. _neuron-2-27-0-nki: .. meta:: :description: The official release notes for the AWS Neuron Kernel Interface (NKI) component, version 2.27.0. Release date: 12/19/2025. AWS Neuron SDK 2.27.0: Neuron Kernel Interface (NKI) release notes =================================================================== **Date of release**: December 19, 2025 .. contents:: In this release :local: :depth: 2 * Go back to the :ref:`AWS Neuron 2.27.0 release notes home ` What's New ---------- This release introduces NKI Beta 2, featuring the new :doc:`NKI Compiler ` and significant enhancements to the NKI language constructs and APIs, including changes to existing APIs. For information about the different NKI Beta versions, see :doc:`About NKI Beta Versions `. To take advantage of Beta 2 with the new compiler, import the ``nki.*`` namespace in your code and annotate your top-level kernel function with ``@nki.jit``. **Backward Compatibility and Migration** Neuron 2.27 supports both the ``neuronxcc.nki.*`` and ``nki.*`` namespaces side by side, allowing existing Beta 1 kernels to continue working seamlessly. However, Neuron 2.27 will be the last release to include support for the ``neuronxcc.nki.*`` namespace. Starting with Neuron 2.28, this namespace will no longer be supported. The new ``nki.*`` namespace introduces changes to NKI APIs and language constructs. We encourage customers to migrate existing kernels from ``neuronxcc.nki.*`` to the new ``nki.*`` namespace. A kernel migration guide is available in the Neuron 2.27 documentation to assist with this transition. New nki.language APIs ^^^^^^^^^^^^^^^^^^^^^ * :doc:`nki.language.device_print ` New nki.isa APIs ^^^^^^^^^^^^^^^^ * :doc:`nki.isa.dma_compute ` * :doc:`nki.isa.quantize_mx ` * :doc:`nki.isa.nc_matmul ` * :doc:`nki.isa.nc_n_gather ` [used to be ``nl.gather_flattened`` with free partition limited to 512] * :doc:`nki.isa.rand2 ` * :doc:`nki.isa.rand_set_state ` * :doc:`nki.isa.rand_get_state ` * :doc:`nki.isa.set_rng_seed ` * :doc:`nki.isa.rng ` New dtypes ^^^^^^^^^^^^^^ * :doc:`nki.language.float8_e5m2_x4 ` * :doc:`nki.language.float4_e2m1fn_x4 ` * :doc:`nki.language.float8_e4m3fn_x4 ` Changes to Existing APIs ^^^^^^^^^^^^^^^^^^^^^^^^ * Several nki.language APIs have been removed in NKI Beta 2 * All nki.isa APIs have ``dst`` as an input param * All nki.isa APIs removed ``dtype`` and ``mask`` support * :doc:`nki.isa.memset ` — removed ``shape`` positional arg , since we have ``dst`` * :doc:`nki.isa.affine_select ` — instead of ``pred``, we now take ``pattern`` and ``cmp_op`` params * :doc:`nki.isa.iota ` — ``expr`` replaced with ``pattern`` and ``offset`` * :doc:`nki.isa.nc_stream_shuffle ` - ``src`` and ``dst`` order changed Documentation Updates ^^^^^^^^^^^^^^^^^^^^^^ * Restructured NKI Documentation to align with workflows * Added :doc:`Trainium3 Architecture Guide for NKI ` * Added :doc:`About Neuron Kernel Interface (NKI) ` * Added :doc:`NKI Environment Setup Guide ` * Added :doc:`Get Started with NKI ` * Added :doc:`NKI Language Guide ` * Added :doc:`About the NKI Compiler ` * Added :doc:`About NKI Beta Versions ` * Added :doc:`MXFP Matrix Multiplication with NKI ` * Updated :doc:`Matrix Multiplication Tutorial ` * Updated :doc:`Profile a NKI Kernel ` * Updated :doc:`NKI APIs ` * Updated :doc:`NKI Library docs ` * Removed NKI Error Guide Known issues ------------ * :doc:`nki.isa.nc_matmul ` - ``is_moving_onezero`` was incorrectly named ``is_moving_zero`` in this release * NKI ISA semantic checks are not available with Beta 2, workaround is to reference the API docs * NKI Collectives are not available with Beta 2 * nki.benchmark and nki.profile are not available