BerriAI/litellm · error · ValueError

Unsupported prompt: {prompt_integration}

Error message

Unsupported prompt: {prompt_integration}

What it means

Prompt registration guard: the prompt_integration value present in litellm_params has no initializer in the prompt_initializer_registry, i.e. the named integration is unknown/unsupported by this build; raised as ValueError with the unsupported value embedded.

Source

Thrown at litellm/proxy/prompts/prompt_registry.py:142

        if isinstance(litellm_params_data, dict):
            litellm_params = PromptLiteLLMParams(**litellm_params_data)
        else:
            litellm_params = litellm_params_data

        prompt_integration: Final = litellm_params.prompt_integration
        if prompt_integration is None:
            raise ValueError("prompt_integration is required")

        initializer: Final = prompt_initializer_registry.get(prompt_integration)

        if initializer:
            custom_prompt_callback = initializer(litellm_params, prompt)
            if not isinstance(custom_prompt_callback, CustomPromptManagement):
                raise ValueError(f"CustomPromptManagement is required, got {type(custom_prompt_callback)}")
            litellm.logging_callback_manager.add_litellm_callback(custom_prompt_callback)
        else:
            raise ValueError(f"Unsupported prompt: {prompt_integration}")

        parsed_prompt: Final = PromptSpec(
            prompt_id=prompt_id,
            litellm_params=litellm_params,
            prompt_info=prompt.prompt_info or PromptInfo(prompt_type="config"),
            created_at=prompt.created_at,
            updated_at=prompt.updated_at,
        )

        # store references to the prompt in memory
        self.IN_MEMORY_PROMPTS[prompt_id] = parsed_prompt
        self.prompt_id_to_custom_prompt[prompt_id] = custom_prompt_callback

        return parsed_prompt

    def get_prompt_by_id(self, prompt_id: str) -> PromptSpec | None:
        """
        Get a prompt by its ID from memory

View on GitHub (pinned to 77b7c6c40c)

Solutions

1. Use a supported prompt integration (e.g. dotprompt, langfuse, or a registered custom integration).

When it happens

Trigger: Thrown at litellm/proxy/prompts/prompt_registry.py:142 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of BerriAI/litellm@77b7c6c40c (2026-08-18). Data as JSON: /api/errors/1b0851c1c4d70619. Report an issue: GitHub.