diff --git a/src/mcore_bridge/model/gpts/deepseek_v4.py b/src/mcore_bridge/model/gpts/deepseek_v4.py
index 65c9270..14eb047 100644
--- a/src/mcore_bridge/model/gpts/deepseek_v4.py
+++ b/src/mcore_bridge/model/gpts/deepseek_v4.py
@@ -1,6 +1,7 @@
 # Copyright (c) ModelScope Contributors. All rights reserved.
 import copy
 import torch
+import transformer_engine.pytorch as te
 from contextlib import contextmanager
 from megatron.core import tensor_parallel
 from megatron.core.models.common.embeddings.rope_utils import apply_rotary_pos_emb
@@ -12,6 +13,7 @@
 
 from ..constant import ModelType
 from ..gpt_model import GPTModel
+from ..modules.compressor import Compressor, CSAIndexer
 from ..register import ModelLoader, ModelMeta, register_model
 from ..rope import get_rope_inv_freq
 
@@ -68,6 +70,19 @@ def __init__(self, config, *args, **kwargs):
             super().__init__(config, *args, **kwargs)
         self.layer_type = self.config.hf_config.layer_types[self.layer_number - 1]
         self.rope_layer_type = 'main' if self.layer_type == 'sliding_attention' else 'compress'
+        if getattr(config, 'fp8_param', False):
+            group_proj_in_size = self.query_projection_size // config.o_groups
+            del self.linear_o_group_proj
+            self.linear_o_group_proj = te.GroupedLinear(
+                num_gemms=config.o_groups,
+                in_features=group_proj_in_size,
+                out_features=config.o_lora_rank,
+                bias=False,
+                params_dtype=config.params_dtype,
+            )
+            self._o_group_proj_is_grouped_linear = True
+        else:
+            self._o_group_proj_is_grouped_linear = False
 
     def get_query_key_value_tensors(
         self,
@@ -312,10 +327,23 @@ def forward(
         core_attn_out = core_attn_out.view(seq_len, core_attn_out.size(1), -1)
 
         # Grouped output
-        core_attn_out = core_attn_out.view(core_attn_out.size(0), core_attn_out.size(1), self.o_local_groups, -1)
-        wo_a_weight = self.linear_o_group_proj.view(self.o_local_groups, self.config.o_lora_rank, -1)
-        core_attn_out = torch.einsum('...gd,grd->...gr', core_attn_out, wo_a_weight)
-        core_attn_out = core_attn_out.reshape(*core_attn_out.shape[:-2], -1)
+        if self._o_group_proj_is_grouped_linear:
+            s, b = core_attn_out.size(0), core_attn_out.size(1)
+            # [s, b, G*D] -> [G, s*b, D] -> [G*s*b, D]
+            core_attn_out = core_attn_out.view(s, b, self.o_local_groups, -1)
+            core_attn_out = core_attn_out.permute(2, 0, 1, 3).contiguous()
+            core_attn_out = core_attn_out.reshape(-1, core_attn_out.size(-1))
+            m_splits = [s * b] * self.o_local_groups
+            core_attn_out = self.linear_o_group_proj(core_attn_out, m_splits)
+            # [G*s*b, R] -> [G, s, b, R] -> [s, b, G*R]
+            core_attn_out = core_attn_out.view(self.o_local_groups, s, b, -1)
+            core_attn_out = core_attn_out.permute(1, 2, 0, 3).contiguous()
+            core_attn_out = core_attn_out.reshape(s, b, -1)
+        else:
+            core_attn_out = core_attn_out.view(core_attn_out.size(0), core_attn_out.size(1), self.o_local_groups, -1)
+            wo_a_weight = self.linear_o_group_proj.view(self.o_local_groups, self.config.o_lora_rank, -1)
+            core_attn_out = torch.einsum('...gd,grd->...gr', core_attn_out, wo_a_weight)
+            core_attn_out = core_attn_out.reshape(*core_attn_out.shape[:-2], -1)
 
         # =================
         # Output. [sq, b, h]
@@ -367,6 +395,12 @@ def get_transformer_layer_spec(self, vp_stage: Optional[int] = None):
         transformer_layer_spec = get_transformer_block_with_experimental_attention_variant_spec(self.config, vp_stage)
         for layer_spec in transformer_layer_spec.layer_specs:
             layer_spec.submodules.self_attention.module = DSv4HybridSelfAttention
+            core_attention_submodules = layer_spec.submodules.self_attention.submodules.core_attention.submodules
+            if getattr(core_attention_submodules, 'compressor', None) is not None:
+                core_attention_submodules.compressor.module = Compressor
+            if getattr(core_attention_submodules, 'indexer', None) is not None:
+                core_attention_submodules.indexer.module = CSAIndexer
+                core_attention_submodules.indexer.submodules.compressor.module = Compressor
         return transformer_layer_spec
 
 
@@ -381,6 +415,37 @@ class DeepseekV4Bridge(GPTBridge):
     hf_post_attention_layernorm_key = 'ffn_norm.weight'
     hf_expert_bias_key = 'gate.bias'
 
+    def _set_o_group_proj_grouped(self, mg_attn, hf_state_dict, to_mcore):
+        """Handle GroupedLinear state dict for linear_o_group_proj in fp8 mode.
+
+        HF stores a single wo_a.weight of shape [G*R, D].
+        GroupedLinear stores per-gemm weight{i} each of shape [R, D].
+        """
+        o_groups = self.config.o_groups
+        if to_mcore:
+            hf_weight = hf_state_dict['wo_a.weight'].load()
+            hf_scale_inv = None
+            if 'wo_a.weight_scale_inv' in hf_state_dict:
+                hf_scale_inv = hf_state_dict['wo_a.weight_scale_inv'].load()
+            weights = hf_weight.chunk(o_groups, dim=0)
+            scale_invs = hf_scale_inv.chunk(o_groups, dim=0) if hf_scale_inv is not None else [None] * o_groups
+            for i, (w, s) in enumerate(zip(weights, scale_invs)):
+                param = getattr(mg_attn.linear_o_group_proj, f'weight{i}')
+                self._set_param(param, w, s)
+        else:
+            weights = []
+            scale_invs = []
+            for i in range(o_groups):
+                param = getattr(mg_attn.linear_o_group_proj, f'weight{i}')
+                if self._is_fp8_param(param):
+                    weights.append(param._rowwise_data)
+                    scale_invs.append(param._rowwise_scale_inv)
+                else:
+                    weights.append(param.data)
+            hf_state_dict['wo_a.weight'] = torch.cat(weights, dim=0)
+            if scale_invs:
+                hf_state_dict['wo_a.weight_scale_inv'] = torch.cat(scale_invs, dim=0)
+
     def _convert_hf_state_dict(self, hf_state_dict, to_mcore):
         res = super()._convert_hf_state_dict(hf_state_dict, to_mcore)
         if to_mcore:
@@ -436,7 +501,10 @@ def _set_mla_attn_state(
         else:
             hf_state_dict = {}
         self._set_state_dict(mg_attn, 'linear_proj.weight', hf_state_dict, 'wo_b.weight', to_mcore)
-        self._set_state_dict(mg_attn, 'linear_o_group_proj', hf_state_dict, 'wo_a.weight', to_mcore)
+        if self.config.fp8_param:
+            self._set_o_group_proj_grouped(mg_attn, hf_state_dict, to_mcore)
+        else:
+            self._set_state_dict(mg_attn, 'linear_o_group_proj', hf_state_dict, 'wo_a.weight', to_mcore)
         self._set_state_dict(mg_attn, 'linear_q_down_proj.weight', hf_state_dict, 'wq_a.weight', to_mcore)
         self._set_state_dict(mg_attn, 'linear_q_up_proj.weight', hf_state_dict, 'wq_b.weight', to_mcore)
         self._set_state_dict(mg_attn, 'linear_kv_proj.weight', hf_state_dict, 'wkv.weight', to_mcore)
diff --git a/src/mcore_bridge/model/modules/__init__.py b/src/mcore_bridge/model/modules/__init__.py
index 87b7bc7..edf406d 100644
--- a/src/mcore_bridge/model/modules/__init__.py
+++ b/src/mcore_bridge/model/modules/__init__.py
@@ -1,4 +1,5 @@
 # Copyright (c) ModelScope Contributors. All rights reserved.
+from .compressor import Compressor, CSAIndexer
 from .dsa_indexer import DSAIndexer
 from .gated_delta_net import GatedDeltaNet
 from .gated_self_attention import GatedSelfAttention
diff --git a/src/mcore_bridge/model/modules/compressor.py b/src/mcore_bridge/model/modules/compressor.py
new file mode 100644
index 0000000..897a11c
--- /dev/null
+++ b/src/mcore_bridge/model/modules/compressor.py
@@ -0,0 +1,58 @@
+import transformer_engine
+from megatron.core.transformer.spec_utils import build_module
+
+try:
+    from megatron.core.transformer.experimental_attention_variant.csa import Compressor as McoreCompressor
+    from megatron.core.transformer.experimental_attention_variant.csa import CSAIndexer as McoreCSAIndexer
+except ImportError:
+    McoreCompressor = object
+    McoreCSAIndexer = object
+
+
+class Compressor(McoreCompressor):
+
+    def __init__(self, config, submodules, *args, **kwargs):
+        super().__init__(config, submodules, *args, **kwargs)
+        if getattr(config, 'fp8_param', False):
+            with transformer_engine.pytorch.fp8_model_init(enabled=False):
+                self.linear_wkv = build_module(
+                    submodules.linear_wkv,
+                    config.hidden_size,
+                    self.coff * self.head_dim,
+                    config=config,
+                    init_method=config.init_method,
+                    bias=False,
+                    skip_bias_add=False,
+                    skip_weight_param_allocation=False,
+                    parallel_mode='duplicated',
+                )
+                self.linear_wgate = build_module(
+                    submodules.linear_wgate,
+                    config.hidden_size,
+                    self.coff * self.head_dim,
+                    config=config,
+                    init_method=config.init_method,
+                    bias=False,
+                    skip_bias_add=False,
+                    skip_weight_param_allocation=False,
+                    parallel_mode='duplicated',
+                )
+
+
+class CSAIndexer(McoreCSAIndexer):
+
+    def __init__(self, config, submodules, *args, **kwargs):
+        super().__init__(config, submodules, *args, **kwargs)
+        if getattr(config, 'fp8_param', False):
+            with transformer_engine.pytorch.fp8_model_init(enabled=False):
+                self.linear_weights_proj = build_module(
+                    submodules.linear_weights_proj,
+                    self.hidden_size,
+                    self.index_n_heads,
+                    config=config,
+                    init_method=config.init_method,
+                    bias=False,
+                    skip_bias_add=False,
+                    skip_weight_param_allocation=False,
+                    parallel_mode='duplicated',
+                )
diff --git a/src/mcore_bridge/patcher.py b/src/mcore_bridge/patcher.py
index 9806d38..37390ac 100644
--- a/src/mcore_bridge/patcher.py
+++ b/src/mcore_bridge/patcher.py
@@ -207,6 +207,7 @@ def _apply_rotary_pos_emb_thd(t: torch.Tensor, cu_seqlens: torch.Tensor, freqs:
             logger.warning_once('Using non-batched RoPE, which may affect performance.')
             return _origin_apply_rotary_pos_emb_thd(t, cu_seqlens, freqs, *args, **kwargs)
 
+        kwargs.pop('max_seqlen', None)  # compat megatron-lm dev branch
         return rope_utils._apply_rotary_pos_emb_bshd(t.unsqueeze(1), freqs, *args, **kwargs).squeeze(1)
 
     rope_utils._apply_rotary_pos_emb_thd = _apply_rotary_pos_emb_thd