Comfy-Org/ComfyUI · error · ValueError

Reference mode '{MODE_AUDIO}' requires at least one referenc

Error message

Reference mode '{MODE_AUDIO}' requires at least one reference_audio input (or switch to '{MODE_TEXT}').

What it means

In 'audio reference' mode (MODE_AUDIO) the Seed-OSS audio node requires at least one connected reference_audio input, because the mode's whole purpose is timbre/sound transfer from clips. With an empty audio_indices list the node fails fast rather than sending a request the provider would reject.

Source

Thrown at comfy_api_nodes/nodes_bytedance.py:3165

def validate_seed_audio_inputs(
    text_prompt: str,
    mode: str,
    audio_indices: list[int],
    has_image: bool,
    preset_voice: str | None = None,
) -> None:
    validate_string(text_prompt, field_name="text_prompt", min_length=1, max_length=3000)
    max_tag = max_audio_tag(text_prompt)

    if mode == MODE_TEXT:
        if max_tag:
            raise ValueError(
                f"The prompt references @Audio{max_tag}, but reference mode is '{MODE_TEXT}'. "
                f"Switch to '{MODE_AUDIO}' and connect the reference clip(s)."
            )
    elif mode == MODE_AUDIO:
        if not audio_indices:
            raise ValueError(
                f"Reference mode '{MODE_AUDIO}' requires at least one reference_audio input "
                f"(or switch to '{MODE_TEXT}')."
            )
        if audio_indices != list(range(1, len(audio_indices) + 1)):
            raise ValueError(
                "Connect reference_audio inputs in order without gaps: reference_audio_1, then _2, then _3."
            )
        if max_tag > len(audio_indices):
            raise ValueError(
                f"The prompt references @Audio{max_tag}, but only {len(audio_indices)} "
                f"reference audio(s) are connected."
            )
    elif mode == MODE_IMAGE:
        if not has_image:
            raise ValueError(f"Reference mode '{MODE_IMAGE}' requires a reference_image input.")
        if max_tag:
            raise ValueError(
                f"@AudioN tags are not used in '{MODE_IMAGE}' mode; the prompt should contain "

View on GitHub (pinned to 1c6d8d45b3)

Solutions

1. Connect at least one audio clip to reference_audio_1.
2. Or switch the mode back to 'text only' if no reference is intended.

if mode == MODE_AUDIO and not audio_indices:
    raise ValueError("audio reference mode needs at least one reference_audio input")

When it happens

Trigger: Setting mode='audio reference' on the audio node while no reference_audio inputs are connected (audio_indices is empty).

Common situations: Flipping the mode widget to try voice transfer without wiring clips; disconnected audio branch after graph edits.

Related errors

• Either first_frame or first_frame_asset_id is required.
• At least one reference image or video or asset is required.
• The prompt references @Audio{max_tag}, but reference mode is
• Connect reference_audio inputs in order without gaps: refere
• Reference mode '{MODE_IMAGE}' requires a reference_image inp

AI-assisted analysis of Comfy-Org/ComfyUI@1c6d8d45b3 (2026-08-14). Data as JSON: /api/errors/3fef38bde3cb83f4. Report an issue: GitHub.