Feat/Add HunyuanImage-3.0-Instruct ar part support: (#2713)

Signed-off-by: TaffyOfficial <2324465096@qq.com>
Co-authored-by: TaffyOfficial <2324465096@qq.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

examples/offline_inference/hunyuan_image3/prompt_utils.py

@@ -0,0 +1,88 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+"""
+Prompt construction utilities for HunyuanImage-3.0-Instruct examples.
+
+Wraps system_prompt.get_system_prompt() with task-aware presets so that
+examples and tests don't need to manually concatenate system prompts,
+<img>, <think>, and <recaption> tags.
+
+Usage:
+    from prompt_utils import build_prompt
+
+    # IT2I (image editing, think+recaption mode)
+    prompt = build_prompt("Make the petals neon pink", task="it2i_think")
+
+    # I2T (image understanding)
+    prompt = build_prompt("Describe the content of the picture.", task="i2t")
+"""
+
+from __future__ import annotations
+
+from vllm_omni.diffusion.models.hunyuan_image3.system_prompt import (
+    get_system_prompt,
+)
+
+# task → (sys_type, bot_task, trigger_tag)
+# trigger_tag: "<think>", "<recaption>", or None
+_TASK_PRESETS: dict[str, tuple[str, str | None, str | None]] = {
+    # Pure text generation (text → text, no image)
+    "t2t": ("en_unified", None, None),
+    # Image understanding (image → text)
+    "i2t": ("en_unified", None, None),
+    # Image editing (image+text → image), think+recaption mode
+    "it2i_think": ("en_unified", "think", "<think>"),
+    # Image editing, recaption-only mode
+    "it2i_recaption": ("en_unified", "recaption", "<recaption>"),
+    # Text-to-image, think mode
+    "t2i_think": ("en_unified", "think", "<think>"),
+    # Text-to-image, recaption mode
+    "t2i_recaption": ("en_unified", "recaption", "<recaption>"),
+    # Text-to-image, vanilla (no CoT)
+    "t2i_vanilla": ("en_vanilla", "image", None),
+}
+
+
+def build_prompt(
+    user_prompt: str,
+    task: str = "it2i_think",
+    sys_type: str | None = None,
+    custom_system_prompt: str | None = None,
+) -> str:
+    """Build a complete HunyuanImage-3.0 prompt with auto-selected system
+    prompt and mode trigger tags.
+
+    Args:
+        user_prompt: The user's raw instruction or question.
+        task: One of the preset task keys (see _TASK_PRESETS).
+        sys_type: Override the preset's sys_type for get_system_prompt().
+        custom_system_prompt: Custom system prompt text (used when
+            sys_type="custom").
+
+    Returns:
+        Fully formatted prompt string ready for Omni.generate().
+    """
+    if task not in _TASK_PRESETS:
+        raise ValueError(f"Unknown task {task!r}. Choose from: {sorted(_TASK_PRESETS)}")
+
+    preset_sys_type, preset_bot_task, trigger_tag = _TASK_PRESETS[task]
+    effective_sys_type = sys_type or preset_sys_type
+
+    system_prompt = get_system_prompt(effective_sys_type, preset_bot_task, custom_system_prompt)
+    sys_text = system_prompt.strip() if system_prompt else ""
+
+    has_image_input = task.startswith("i2t") or task.startswith("it2i")
+
+    parts = ["<|startoftext|>"]
+    if sys_text:
+        parts.append(sys_text)
+    # Instruct conversation template: \n\nUser: ... \n\nAssistant:
+    parts.append("\n\nUser: ")
+    if has_image_input:
+        parts.append("<img>")
+    parts.append(user_prompt)
+    parts.append("\n\nAssistant: ")
+    if trigger_tag:
+        parts.append(trigger_tag)
+
+    return "".join(parts)