dosubot[bot]
commented
1 month ago The error you're encountering, ValidationException: A conversation must alternate between user and assistant roles, suggests that the conversation flow is not adhering to the required sequence of alternating between user and assistant roles. This issue can arise when multiple tools are invoked simultaneously, causing the conversation to break this sequence.
To address this, you can manage the sequence of tool invocations to ensure they do not execute simultaneously. Dify provides a mechanism to handle this through the use of a variable pool, which stores variables, files, etc., generated during the tool's operation. This allows tools to cooperate with each other and avoid conflicts.
For example, you can save the output of one tool to the variable pool and then use it as input for another tool, ensuring a sequential execution:
# Example: Saving the output of the first tool to the variable pool
result.append(self.create_blob_message(blob=b64decode(image.b64_json),
meta={ 'mime_type': 'image/png' },
save_as=self.VARIABLE_KEY.IMAGE.value))
# Example: Retrieving the output from the variable pool for the second tool
image_binary = self.get_variable_file(self.VARIABLE_KEY.IMAGE)
if not image_binary:
return self.create_text_message('Image not found, please request user to generate image firstly.')This approach ensures that tools are invoked in a sequence, preventing simultaneous execution errors and maintaining the required conversation flow [1].
Additionally, ensure that your conversation logic explicitly alternates between user and assistant roles to comply with the validation requirements.
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crazywoola
YYyp99
ybalbert001
Self Checks
Dify version
0.8.2
Cloud or Self Hosted
Self Hosted (Docker)
Steps to reproduce
When I use the search tool and the web scraping tool, it uses them together, calling both tools simultaneously. Afterwards, the LLM throws an error. [bedrock] Error: ValidationException: A conversation must alternate between user and assistant roles. Make sure the conversation alternates between user and assistant roles and try again.
✔️ Expected Behavior
No response
❌ Actual Behavior
No response