Skip to main content
Pre-release

This release is a pre-release and may not be stable for production use.

Haliax

Build Status Documentation Status License PyPI

Though you don’t seem to be much for listening, it’s best to be careful. If you managed to catch hold of even just a piece of my name, you’d have all manner of power over me.
— Patrick Rothfuss, The Name of the Wind

Haliax is a JAX library for building neural networks with named tensors, in the tradition of Alexander Rush's Tensor Considered Harmful. Named tensors improve the legibility and compositionality of tensor programs by using named axes instead of positional indices as typically used in NumPy, PyTorch, etc.

Despite the focus on legibility, Haliax is also fast, typically about as fast as "pure" JAX code. Haliax is also built to be scalable: it can support Fully-Sharded Data Parallelism (FSDP) and Tensor Parallelism with just a few lines of code. Haliax powers Levanter, our companion library for training large language models and other foundation models, with scale proven up to 70B parameters and up to TPU v4-2048.

Example: Attention

Here's a minimal attention module implementation in Haliax. For a more detailed introduction, please see the Haliax tutorial. (We use the excellent Equinox library for its module system and tree transformations.)

import equinox as eqx
import jax
import jax.numpy as jnp
import haliax as hax
import haliax.nn as hnn

Pos = hax.Axis("position", 1024)  # sequence length
KPos = Pos.alias("key_position")
Head = hax.Axis("head", 8)  # number of attention heads
Key = hax.Axis("key", 64)  # key size
Embed = hax.Axis("embed", 512)  # embedding size

# alternatively:
#Pos, KPos, Head, Key, Embed = hax.make_axes(pos=1024, key_pos=1024, head=8, key=64, embed=512)


def attention_scores(Key, KPos, query, key, mask):
    # how similar is each query to each key
    scores = hax.dot(query, key, axis=Key) / jnp.sqrt(Key.size)

    if mask is not None:
        scores -= 1E9 * (1.0 - mask)

    # convert to probabilities
    scores = haliax.nn.softmax(scores, KPos)
    return scores


def attention(Key, KPos, query, key, value, mask):
    scores = attention_scores(Key, KPos, query, key, mask)
    answers = hax.dot(scores, value, axis=KPos)

    return answers


# Causal Mask means that if pos >= key_pos, then pos can attend to key_pos
causal_mask = hax.arange(Pos).broadcast_axis(KPos) >= hax.arange(KPos)


class Attention(eqx.Module):
    proj_q: hnn.Linear  # [Embed] -> [Head, Key]
    proj_k: hnn.Linear  # [Embed] -> [Head, Key]
    proj_v: hnn.Linear  # [Embed] -> [Head, Key]
    proj_answer: hnn.Linear  # output projection from [Head, Key] -> [Embed]

    @staticmethod
    def init(Embed, Head, Key, *, key):
        k_q, k_k, k_v, k_ans = jax.random.split(key, 4)
        proj_q = hnn.Linear.init(In=Embed, Out=(Head, Key), key=k_q)
        proj_k = hnn.Linear.init(In=Embed, Out=(Head, Key), key=k_k)
        proj_v = hnn.Linear.init(In=Embed, Out=(Head, Key), key=k_v)
        proj_answer = hnn.Linear.init(In=(Head, Key), Out=Embed, key=k_ans)
        return Attention(proj_q, proj_k, proj_v, proj_answer)

    def __call__(self, x, mask=None):
        q = self.proj_q(x)
        # Rename "position" to "key_position" for self attention
        k = self.proj_k(x).rename({"position": "key_position"})
        v = self.proj_v(x).rename({"position": "key_position"})

        answers = attention(Key, KPos, q, k, v, causal_mask)

        x = self.proj_answer(answers)
        return x

Haliax was created by Stanford's Center for Research on Foundation Models (CRFM)'s research engineering team. You can find us in the #levanter channel on the unofficial Jax LLM Discord.

Documentation

Tutorials

These are some tutorials to get you started with Haliax. They are available as Colab notebooks:

API Reference

Haliax's API documentation is available at haliax.readthedocs.io.

Contributing

We welcome contributions! Please see CONTRIBUTING.md for more information. We also have a list of good first issues to help you get started. (If those don't appeal, don't hesitate to reach out to us on Discord!)

License

Haliax is licensed under the Apache License, Version 2.0. See LICENSE for the full license text.

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

marin_haliax-0.2.96.dev33307221957.tar.gz (780.8 kB view details)

Uploaded Source

Built Distribution

If you're not sure about the file name format, learn more about wheel file names.

marin_haliax-0.2.96.dev33307221957-py3-none-any.whl (159.1 kB view details)

Uploaded Python 3

File details

Details for the file marin_haliax-0.2.96.dev33307221957.tar.gz.

File metadata

File hashes

Hashes for marin_haliax-0.2.96.dev33307221957.tar.gz
Algorithm Hash digest
SHA256 e509dcb045e2d6e2ef8be941f9953346a832d7f4a94597e840fead3f4663c341
MD5 974a6691b3a64417a21c192a689cbc33
BLAKE2b-256 9082bdb193fff89089353b0f52c08a962a2aae560c058ee3ea1b99c8071f0ca8

See more details on using hashes here.

Provenance

The following attestation bundles were made for marin_haliax-0.2.96.dev33307221957.tar.gz:

Publisher: marin-release-libs-wheels.yaml on marin-community/marin

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file marin_haliax-0.2.96.dev33307221957-py3-none-any.whl.

File metadata

File hashes

Hashes for marin_haliax-0.2.96.dev33307221957-py3-none-any.whl
Algorithm Hash digest
SHA256 067b8f4b780e307e40f4769de7c4272d80105230283f0e9e53cf71c628923761
MD5 0c0d632357c1f815cc43c6d36fe56b33
BLAKE2b-256 5589637031c7f6437d766bea6d53f51632ef40afa3061d4f932fd2484ef5e4ca

See more details on using hashes here.

Provenance

The following attestation bundles were made for marin_haliax-0.2.96.dev33307221957-py3-none-any.whl:

Publisher: marin-release-libs-wheels.yaml on marin-community/marin

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

Release history Release notifications | RSS feed

This release

0.2.96.dev33307221957 This release

2 files

Anthropic, PBC Visionary sponsor Bloomberg Visionary sponsor Hudson River Trading Visionary sponsor Meta Visionary sponsor NVIDIA Visionary sponsor Microsoft Sustainability sponsor Depot Continuous Integration AWS Cloud computing and Security Sponsor Datadog Monitoring Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page