---
title: lingbotworld2
---

<div class="python-reference">
<a id="fastvideo.models.dits.lingbotworld2-classes"></a>
<a id="fastvideo.models.dits.lingbotworld2.LingBotWorld2CausalFastTransformer3DModel-functions"></a>
<a id="fastvideo.models.dits.lingbotworld2"></a>

<h2 id="fastvideo.models.dits.lingbotworld2.LingBotWorld2CausalFastTransformer3DModel"><code>fastvideo.models.dits.lingbotworld2.LingBotWorld2CausalFastTransformer3DModel</code></h2>
<pre class="doc-signature"><code>LingBotWorld2CausalFastTransformer3DModel(config: LingBotWorld2CausalFastVideoConfig, hf_config: dict&#91;str, Any&#93;)</code></pre>
<p>Released LingBot World 2 14B causal-fast model with native FastVideo loading.</p>

<h3 id="fastvideo.models.dits.lingbotworld2.LingBotWorld2CausalFastTransformer3DModel.forward"><code>fastvideo.models.dits.lingbotworld2.LingBotWorld2CausalFastTransformer3DModel.forward</code></h3>
<pre class="doc-signature"><code>forward(hidden_states: torch.Tensor | list&#91;torch.Tensor&#93; | None = None, encoder_hidden_states: torch.Tensor | list&#91;torch.Tensor&#93; | None = None, timestep: torch.Tensor | None = None, encoder_hidden_states_image: torch.Tensor | list&#91;torch.Tensor&#93; | None = None, guidance = None, *, x: list&#91;torch.Tensor&#93; | None = None, t: torch.Tensor | None = None, context: list&#91;torch.Tensor&#93; | torch.Tensor | None = None, seq_len: int | None = None, y: list&#91;torch.Tensor&#93; | None = None, dit_cond_dict: dict&#91;str, Any&#93; | None = None, kv_cache: list&#91;dict&#93; | None = None, crossattn_cache: list&#91;dict&#93; | None = None, current_start: int = 0, max_attention_size: int = 1000000, frame_seqlen: int | None = None, cross_attn_first_call: bool | None = None, **kwargs) -&gt; list&#91;torch.Tensor&#93;</code></pre>
<p>Run one cached causal-fast DiT forward using the released LingBot World 2 ABI.</p>
<h3 id="fastvideo.models.dits.lingbotworld2.LingBotWorld2CausalFastTransformer3DModel.unpatchify"><code>fastvideo.models.dits.lingbotworld2.LingBotWorld2CausalFastTransformer3DModel.unpatchify</code></h3>
<pre class="doc-signature"><code>unpatchify(x: torch.Tensor, grid_sizes: torch.Tensor) -&gt; list&#91;torch.Tensor&#93;</code></pre>
<p>Reconstruct latent videos from flattened patch tokens.</p>
<h3 id="fastvideo.models.dits.lingbotworld2.LingBotWorld2CausalFastTransformer3DModel.init_weights"><code>fastvideo.models.dits.lingbotworld2.LingBotWorld2CausalFastTransformer3DModel.init_weights</code></h3>
<pre class="doc-signature"><code>init_weights() -&gt; None</code></pre>
<p>Initialize modules for non-meta construction; checkpoint load overwrites them.</p>
</div>

<h2>Submodules</h2>
<ul>
<li><a href="/FastVideo/api/fastvideo/models/dits/lingbotworld2/cam_utils">cam_utils</a></li>
<li><a href="/FastVideo/api/fastvideo/models/dits/lingbotworld2/causal_fast">causal_fast</a></li>
</ul>
