FlashAttention

license

BSD-3-Clause(OSI)

source

public

core-gated

ungated

BSD-3-Clause license body confirmed. The repository is public and unarchived and builds the whole product, and the README describes no paid tier, enterprise edition or license-gated build beside it, so source is public and the core ungated.

• https://github.com/Dao-AILab/flash-attention/blob/main/LICENSE recorded 2026-08-18

  LICENSE file is the verbatim BSD-3-Clause text

• https://api.github.com/repos/Dao-AILab/flash-attention recorded 2026-08-18

  Repo metadata - license spdx_id BSD-3-Clause, private false, archived false, default branch main - for Dao-AILab/flash-attention.

• https://github.com/Dao-AILab/flash-attention/blob/main/README.md recorded 2026-08-18

  README describes the official implementation of FlashAttention and FlashAttention-2, IO-aware exact attention, with the papers, benchmarks and Hopper-specific kernels beside it, with no paid tier, enterprise edition or license-key-gated build beside it.

402,966 PyPI downloads of `flash-attn` in the trailing 30 days, which lands in the 100K-1M band of the software usage scale, level 3.

• https://pypistats.org/api/packages/flash-attn/recent recorded 2026-08-18

  last_month downloads = 402,966 for flash-attn

Banded on the category feature matrix as performance-critical kernel and operator library. Placed two bands below the apache-tvm anchor, on a matrix that bands on how much of the model-to-hardware transformation pipeline a product performs, over how many inputs and targets.

• https://github.com/Dao-AILab/flash-attention/blob/main/README.md recorded 2026-08-18

  README still documents the official implementation of FlashAttention and FlashAttention-2, IO-aware exact attention, with the papers, benchmarks and Hopper-specific kernels beside it.