{"record":{"id":"db1f6d1df8d25915","repo":"keras-team/keras","slug":"flash-attention-is-not-supported-in-numpy-backend-db1f6d","errorCode":null,"errorMessage":"Flash attention is not supported in numpy backend.","messagePattern":"Flash attention is not supported in numpy backend\\.","errorType":"exception","errorClass":"ValueError","httpStatus":null,"severity":"error","filePath":"keras/src/backend/numpy/ops/nn.py","lineNumber":1427,"sourceCode":"    encoded = encoded.astype(encoded_dtype)\n    return encoded\n\n\ndef dot_product_attention(\n    query,\n    key,\n    value,\n    bias=None,\n    mask=None,\n    scale=None,\n    is_causal=False,\n    flash_attention=None,\n    attn_logits_soft_cap=None,\n):\n    if flash_attention is None:\n        flash_attention = False\n    if flash_attention:\n        raise ValueError(\"Flash attention is not supported in numpy backend.\")\n\n    # Ref: jax.nn.dot_product_attention\n    # https://github.com/jax-ml/jax/blob/jax-v0.4.32/jax/_src/nn/functions.py#L828\n    # Not support `query_seq_lengths` and `key_value_seq_lengths` args\n    query = convert_to_tensor(query)\n    key = convert_to_tensor(key)\n    value = convert_to_tensor(value)\n    if len(query.shape) != 4:\n        raise ValueError(\n            \"`dot_product_attention` only supports 4D inputs. \"\n            f\"Received: query.shape={query.shape}, key.shape={key.shape}, \"\n            f\"value.shape={value.shape}.\"\n        )\n    compute_dtype = backend.result_type(query.dtype, key.dtype, value.dtype)\n    query = cast(query, compute_dtype)\n    key = cast(key, compute_dtype)\n    value = cast(value, compute_dtype)\n    if bias is not None:","sourceCodeStart":1409,"sourceCodeEnd":1445,"githubUrl":"https://github.com/keras-team/keras/blob/7a34a03db60bf60042242d6a556fc3be119046a5/keras/src/backend/numpy/ops/nn.py#L1409-L1445","documentation":"Error \"Flash attention is not supported in numpy backend.\" thrown in keras-team/keras.","triggerScenarios":"Thrown at keras/src/backend/numpy/ops/nn.py:1427 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"7a34a03db60bf60042242d6a556fc3be119046a5","analyzedAt":"2026-08-25T21:25:25.994Z","schemaVersion":2},"datasetVersion":"2026-08-26T02:17:13.382Z"}