How to call chain with functions

[morfeusys]

I'm not sure this was covered in docs already, but I'm stuck with how can I call any chain (for example conversationalchain) with functions?

I've found that some sort of calloptions could be used, but not found how. Also seems that modelKwargs cannot be used for that, because once I pass functions to this param, chain returns the response that doesn't involve functions at all.

[siisee11]

Will this be helpful? #1646

[morfeusys]

@siisee11 looks like that it doesn't cover the case I've described... There is a separated agent type, but what I need is to call chain (not a model itself) with my own functions, not involving agent with tools..

[morfeusys]

Looks like the problem here in the https://github.com/hwchase17/langchainjs/blob/5661b2d07c1dd1ea2c2c8296a314d5cadcb52985/langchain/src/chat_models/openai.ts#L301

"functions" from Kwargs are overwriten each time. Need to have a check if functions param was passed in Kwargs

[morfeusys]

Nevertheless, looks like there is no any way to use functions through ConversationChain...

[relvao]

I've been having the same problem. This is the workaround we found. I doubt this is why the outputParser was added to langchain but it's useful in this case

chain.outputParser = {
        parseResultWithPrompt(generations, _promptValue, _runManager) {
          if (generations.length > 1) {
            throw Error('Unexpected number of generations in outputParser')
          }

          const chatGenerationChunk = generations[0]
          if (!chatGenerationChunk.text) {
            const addKwargs = chatGenerationChunk.message?.additional_kwargs
            const fnCall = addKwargs?.function_call
            
            // DO SOMETHING WITH THE fnCall properties

            // memory throws an error about invalid output key if string is empty
            return fnCall?.arguments ?? ' '
          }

          return chatGenerationChunk.text
        }
      }

The other problem I have is that in LLMChain I can't pass a role. It assumes it's always a chat between AI and Human. There doesn't seem to be a way to send a function response. We found a workaround but that one is even more of a hack than this one.

I could potentially help by submitting a PR but given how deep this goes into the lib codebase I'd need some clarity on what is going to be potentially accepted. I feel that the fact that a chain only supports 2 roles (human and AI) and that it always assumes the reply will be plain text is an unavoidable part of the problem.

[ST1LLWATER]

Is any solution found for this? Im trying to use function calling with ConversationChain but I cant get any docs or reference in which I can add function schema of function calls to the chain to have the feature implemented.

[ComeBackTo2016]

I meet the same issue witch I'm trying to add function calling with ConversationalRetrievalChain but failed.

[aaflatooni]

We are having the same issue.
Any updates on this?
Any useful workaround that we could explore?

[GIDDY269]

Any updates on this or any useful workaround??