adding FunctionMessage to Ollama for being compatible with Langgraph

[QHLe]

Checked

• I searched existing ideas and did not find a similar one
• I added a very descriptive title
• I've clearly described the feature request and motivation for it

Feature request

support FunctionMessage, ToolMessage and the role function, tool

Motivation

when using Ollama with Langgraph, I got the following error.
ValueError: Received unsupported message type for Ollama.

Proposal (If applicable)

No response

[QHLe]

after adding

elif isinstance(message, FunctionMessage):
    role = "function"

to _convert_messages_to_ollama_messages in chat_models/ollama.py

I got the message ValueError: Ollama call failed with status code 400. Details: invalid role: function, role must be one of [system, user, assistant]

where do I have to adapt the code?

[tomascribb10]

I have the same problem, have you been able to solve it?

[QHLe]

I guess ollama doesn't support the role function. The error is avoided by setting the role = "assistant".