assafelovic/gpt-researcher · warning · UserWarning

Invalid prompt family: {prompt_family_name}. Please use one

Error message

Invalid prompt family: {prompt_family_name}.
Please use one of the following: {', '.join([enum_value for enum_value in prompt_family_mapping.keys()])}
Using default prompt family: {PromptFamilyEnum.Default.value} prompt.

What it means

UserWarning from get_prompt_family: prompt_family_name is not a key in prompt_family_mapping, so the default PromptFamily is used instead of raising. Your custom prompt family's instructions are silently ignored and stock prompts are applied.

Source

Thrown at gpt_researcher/prompts.py:897

prompt_family_mapping = {
    PromptFamilyEnum.Default.value: PromptFamily,
    PromptFamilyEnum.Granite.value: GranitePromptFamily,
    PromptFamilyEnum.Granite3.value: Granite3PromptFamily,
    PromptFamilyEnum.Granite31.value: Granite3PromptFamily,
    PromptFamilyEnum.Granite32.value: Granite3PromptFamily,
    PromptFamilyEnum.Granite33.value: Granite33PromptFamily,
}


def get_prompt_family(
    prompt_family_name: PromptFamilyEnum | str, config: Config,
) -> PromptFamily:
    """Get a prompt family by name or value."""
    if isinstance(prompt_family_name, PromptFamilyEnum):
        prompt_family_name = prompt_family_name.value
    if prompt_family := prompt_family_mapping.get(prompt_family_name):
        return prompt_family(config)
    warnings.warn(
        f"Invalid prompt family: {prompt_family_name}.\n"
        f"Please use one of the following: {', '.join([enum_value for enum_value in prompt_family_mapping.keys()])}\n"
        f"Using default prompt family: {PromptFamilyEnum.Default.value} prompt.",
        UserWarning,
    )
    return PromptFamily()

View on GitHub (pinned to 6f998577d5)

Solutions

1. Pass a valid PromptFamilyEnum value (e.g. 'default', or whichever families are registered in gpt_researcher/prompts.py prompt_family_mapping).
2. For custom families, register your PromptFamily subclass in prompt_family_mapping or pass the family per its documented registration mechanism for your version.
3. Print list(prompt_family_mapping.keys()) for your installed version to see accepted names.

Example fix

# before
researcher = GPTResearcher(query=q, prompt_family="my-custom")  # not registered
# after
from gpt_researcher.prompts import prompt_family_mapping, PromptFamilyEnum
print(list(prompt_family_mapping))  # pick a valid name
researcher = GPTResearcher(query=q, prompt_family=PromptFamilyEnum.Default.value)

from gpt_researcher.prompts import prompt_family_mapping
if name not in prompt_family_mapping:
    name = "default"

from gpt_researcher.prompts import prompt_family_mapping

def is_valid_prompt_family(name: str) -> bool:
    return name in prompt_family_mapping

When it happens

Trigger: Passing prompt_family="my_family" to GPTResearcher when it isn't registered in prompt_family_mapping, or a typo/case mismatch of a known name; called from GPTResearcher.__init__.

Common situations: Custom prompt families not registered in the mapping after upgrade, renamed built-in families, or string typos; code that passes a class instead of a registered name/value.

Related errors

• EMBEDDING_PROVIDER is deprecated and will be removed soon. U
• LLM_PROVIDER, FAST_LLM_MODEL and SMART_LLM_MODEL are depreca
• Invalid report type: {report_type}. Please use one of the fo
• Cost must be an integer or float
• Embedding provider not found.

AI-assisted analysis of assafelovic/gpt-researcher@6f998577d5 (2026-08-28). Data as JSON: /api/errors/19293306d56d665c. Report an issue: GitHub.