"Instructor does not support multiple tool calls" Error When Using List[Model]

[andytriboletti]

• [x] This is actually a bug report.
• [x] I have tried searching the documentation and have not found an answer.

What Model are you using?

Llama3.2

Describe the bug When trying to handle multiple files using a List in my model, I'm getting an error about multiple tool calls.

Code:

class CodeFile(BaseModel):
    filename: str
    content: str

class MultiFileResponse(BaseModel):
    files: List[CodeFile]

Error message: Error: Instructor does not support multiple tool calls, use List[Model] instead

What's the correct way to structure a model to handle multiple files when the error suggests using List[Model]? I'm trying to get multiple files (with filename and content) in a single response, but getting the "multiple tool calls" error.

The error message suggests using List[Model], but I'm already using List[CodeFile]. Would appreciate guidance on the correct way to structure this.

To Reproduce

from pydantic import BaseModel
from typing import List
import instructor
from openai import OpenAI

class CodeFile(BaseModel):
    filename: str
    content: str

class MultiFileResponse(BaseModel):
    files: List[CodeFile]

def main():
    client = OpenAI(
        base_url="http://localhost:11434/v1",
        api_key="ollama"
    )

    client = instructor.patch(client)

    try:
        response = client.chat.completions.create(
            model="llama3.2",
            messages=[
                {"role": "system", "content": "You are a Python code generator. Return multiple Python files."},
                {"role": "user", "content": "Generate a fibonacci generator with tests"}
            ],
            response_model=MultiFileResponse
        )
        print("Response:", response)
    except Exception as e:
        print("Error:", e)

if __name__ == "__main__":
    main()

run this script

Expected behavior It outputs some files.

[ivanbelenky]

As in this issue your client is wrognfully created.

if you read closely at the docs you will notice that OpenAI client is being leveraged for Ollama instructor.Instructor instance in this case. Furthermore, it may not be clear as water but the mode is set as instructor.Mode.JSON.

For LLMs without tools mode, not overriding the default TOOLS mode will trigger --> attempt to parse tools responses --> not finding anything --> throwing the error you saw.

Hope this clarifies the issue.