> ## Documentation Index > Fetch the complete documentation index at: https://docs.comfy.org/llms.txt > Use this file to discover all available pages before exploring further. # TextGenerateLTX2Prompt - ComfyUI Built-in Node Documentation > The TextGenerateLTX2Prompt node expands a short user prompt into a detailed, audio-visual description suitable for generating video with the LTX-2 series of video models. The TextGenerateLTX2Prompt node expands a short user prompt into a detailed, audio-visual description suitable for generating video with the LTX-2 series of video models. It automatically adds task-specific system instructions, sends the formatted prompt to a language model, and returns the enhanced text. When an optional reference image is supplied, the node switches to image-to-video mode and expands the prompt starting from that image's content. ## Inputs ### Common Inputs | Parameter | Description | Data Type | Required | Range | | - | - | - | - | - | | `clip` | The CLIP model used for text encoding. The node checks the model's tokenizer name to select the matching instructions: Gemma 4 based models use the LTX-2.4 format, while other models use the LTX-2 (Gemma 3) format. | CLIP | Yes | - | | `prompt` | The raw text input describing the scene or concept to be expanded into a detailed video generation prompt. | STRING | Yes | - | | `image` | An optional input image used as the first frame of the video. When provided, the node switches to image-to-video mode and uses a system prompt that expands the user prompt based on the image's content. | IMAGE | No | - | | `video` | An optional video input used as additional context. Passed to the language model as an image batch; assumed to be 24 FPS and subsampled to 1 FPS internally. | IMAGE | No | - | | `audio` | An optional audio input that can be used as additional context for generation. | AUDIO | No | - | | `max_length` | The maximum number of tokens the language model is allowed to generate (default: 512). | INT | Yes | 1 to 32768 | | `sampling_mode` | Controls whether random sampling is used during text generation. When set to `"on"`, the sampling parameters below become available; with `"off"` the node generates text without random sampling. | DYNAMIC\_COMBO | Yes | `"on"`
`"off"` | | `thinking` | When enabled, the model is instructed to reason before answering. Any reasoning block is returned on the `thinking` output instead of in `generated_text` (default: False). | BOOLEAN | No | True/False | | `use_default_template` | When enabled, the node uses the default chat template for formatting (default: True). Advanced setting. | BOOLEAN | No | True/False | | `mtp` | Speculative decoding with the checkpoint's multi-token-prediction head. Has no effect without MTP weights. `"auto"` adapts the draft depth, `"2"` to `"5"` pin it. Sampled output stays correctly distributed but differs from non-MTP output for the same seed (default: `"auto"`). | COMBO | No | `"auto"`
`"off"`
`"2"`
`"3"`
`"4"`
`"5"` | | `system_prompt` | Replaces the built-in LTX-2 system prompt. When left empty, the node uses its own instructions: the image-to-video prompt when an `image` is connected, otherwise the text-to-video prompt. Connect a STRING input instead of typing in the node (default: empty). | STRING | No | - | ### Sampling Parameters (when `sampling_mode` is "on") | Parameter | Description | Data Type | Required | Range | | - | - | - | - | - | | `temperature` | Controls the randomness of the output. Lower values make the output more predictable, higher values make it more creative (default: 0.7). | FLOAT | Yes | 0.01 to 2.0 | | `top_k` | Limits the sampling pool to the top K most likely next tokens. A value of 0 disables this filter (default: 64). | INT | Yes | 0 to 1000 | | `top_p` | Uses nucleus sampling: it keeps the smallest set of most likely tokens whose cumulative probability reaches this value. (default: 0.95) | FLOAT | Yes | 0.0 to 1.0 | | `min_p` | Sets a minimum probability threshold for tokens to be considered (default: 0.05). | FLOAT | Yes | 0.0 to 1.0 | | `repetition_penalty` | Penalizes tokens that have already been generated to reduce repetition. A value of 1.0 applies no penalty (default: 1.05). | FLOAT | Yes | 0.0 to 5.0 | | `seed` | A number used to initialize the random number generator for reproducible results (default: 0). | INT | Yes | 0 to 18446744073709551615 | | `presence_penalty` | Penalizes new tokens based on whether they have appeared in the text so far, encouraging the model to talk about new topics (default: 0.0). | FLOAT | No | 0.0 to 5.0 | **Note:** The sampling parameters above are only active and visible in the node interface when `sampling_mode` is set to "on". When it is set to "off", no sampling parameters are available and the node generates text without random sampling. **Note:** The behavior of the node changes based on its inputs: * If an `image` is provided, the generated prompt is formatted for an image-to-video task using a system prompt that describes how to expand the prompt based on the image's content. If no image is provided, the formatting is for a text-to-video task using a system prompt that expands the prompt into a detailed video generation description. * If the CLIP tokenizer's name contains "gemma4", the node uses the LTX-2.4 system prompts and the Gemma 4 chat format. Otherwise, it uses the LTX-2 (Gemma 3) system prompts and chat format. * When `thinking` is enabled with a Gemma 4 model, the model is opened on its reasoning channel; when disabled, the model is opened directly on the final-answer channel. For non-Gemma 4 models, `thinking` is passed through to the underlying generation step. * A `system_prompt` replaces the built-in instructions for the selected mode (image-to-video or text-to-video); when it is empty, the built-in prompt is used. * Any reasoning block is returned on the `thinking` output instead of `generated_text`. * If the language model produces no usable text, the node returns the original `prompt` instead. ## Outputs | Output Name | Description | Data Type | | - | - | - | | `generated_text` | The enhanced video-generation prompt produced by the language model, with any reasoning block separated out into the `thinking` output. If the result is empty, the original user prompt is returned. | STRING | | `thinking` | The reasoning block the model produced, with the opening `` tag removed. Empty when the model produced no reasoning block; with Gemma 4 models a reasoning block is only expected when `thinking` is enabled. | STRING | > This documentation was AI-generated. If you find any errors or have suggestions for improvement, please feel free to contribute! [Edit on GitHub](https://github.com/Comfy-Org/embedded-docs/blob/main/comfyui_embedded_docs/docs/TextGenerateLTX2Prompt/en.md) *** **Source fingerprint (SHA-256):** `a601a8bff65e8ee148d09f04ac0afc201dbc9ba5e09a65856400e9be37e085bb` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.