How to attach files to code interpreter in new foundry multi-agent workflow

Question

How to attach files to code interpreter in new foundry multi-agent workflow

cheng victor 0

Hi everyone,

I am working on using mult-agent worflow in new foudry to perform generate chart and data analysis.


attachments = [MessageAttachment(     file_id=file_id,     tools=[     	CodeInterpreterToolDefinition(),   ], )]

response = openai_client.responses.create(        
	conversation=conversation.id,        
	input="Could you please create bar chart in TRANSPORTATION sector for the operating profit from the uploaded csv file and provide file to me?",		
	attachment = [attachments ],        
	extra_body={"agent_reference": {"name": agent.name, "type": "agent_reference"}},   
 )

However, i am facing a problem that is create function have no parameters of attachment.

Is anyone can provide suggestion on how to upload document (.csv) to multi-agent workflow and the sub-agent ( Data Analysis Agent / Chart Generation Agent) can utilze the document for code Interpreter execution

Packages:

azure-ai-project==2.0.0b4

Cheers

cheng victor 0 Reputation points

2026-02-26T13:42:10.1233333+00:00

The multi-agent workflow looks following:

Both Sub agents has code-interpreter to excute the csv file
Karnam Venkata Rajeswari 280 Reputation points Microsoft External Staff Moderator

2026-02-28T18:58:42.63+00:00
Hello cheng victor,

Welcome to Microsoft Q&A .Thank you for reaching out with details of your implementation

As asked for suggestions to upload document (.csv) to multi-agent workflow and the sub-agent and based on the provided code snippet review , here is what’s happening behind the hood –

responses.create does not accept attachment. In Azure AI Foundry (Agents), attachments must be added when creating a message in the conversation, not when creating a response (run).

Please try using conversations.messages.create to attach the files

Azure OpenAI in Microsoft Foundry Models REST API preview reference - Microsoft Foundry | Microsoft Learn

While using responses.create

The API does not include an attachment(s) parameter. It triggers the agent to act on the existing conversation state — it does not modify that state. So ,attachment = [attachments ] is invalid for this API.

Since the snippet attaches the file during responses.create, the file would not exist in the conversation, meaning the sub-agent will not see it.

The Code Interpreter tool can only access: o   Files attached to a conversation message o   Files already present in the thread context

Please refer the following:

Use Code Interpreter with Microsoft Foundry agents - Microsoft Foundry | Microsoft Learn

How to use Azure OpenAI Assistants Code Interpreter (classic) - Microsoft Foundry (classic) | Microsoft Learn

Quotas and limits for Foundry Agent Service (classic) - Microsoft Foundry (classic) | Microsoft Learn

Please let me know if you have any questions.

Thank you!

cheng victor 0

Hi Karnam Venkata Rajeswari,

Thank you for your reply. However, the sdk version, conversations class don't have messages, the only one i found is conversations.items.

However, according to the code below, the file will auto inject to the context window, not for code interpreter.


openai_client =  self.project_client.get_openai_client()
content_parts = [{"type": "input_file", "file_id": fid} for fid in file_ids]

            # ✅ Python SDK requires keyword args; wrap your message in items=[...]
            await openai_client.conversations.items.create(
                conversation_id=conversation_id,
                items=[
                    {
                        "type": "message",
                        "role": "user",
                        "content": content_parts,
                    }
                ],
            )

Karnam Venkata Rajeswari 280 Reputation points Microsoft External Staff Moderator

2026-03-02T10:39:50.7533333+00:00

Hello cheng victor,

Thank you for providing the code snippet of the implementation.

After reviewing, it can be seen that implementation is correct in using

openai_client = project_client.get_openai_client() and openai_client.responses.create().

·       The missing step is registering the CSV with the Code Interpreter tool (via file_id) before execution, rather than attempting to pass attachments at response time.

To make a CSV available to the Code Interpreter (including in multi‑agent workflows), the file must be registered before execution in one of the supported ways. The recommended and most reliable approach is to upload the file with FilePurpose.AGENTS and explicitly bind the returned file_id to the Code Interpreter tool via tool_resources when creating each agent (or sub‑agent). This ensures the file is mounted in the Code Interpreter sandbox and is accessible to all agents that share the same tool

While injecting files as input_file or text content only places them in the model context window and does not grant code interpreter runtime access and this approach does not work for CSV execution.

Please refer the below resources for more information

·       How to use Foundry Agent Service Code Interpreter (classic) - Microsoft Foundry (classic) | Microsoft Learn

·       Use Code Interpreter with Microsoft Foundry agents - Microsoft Foundry | Microsoft Learn

·       Azure AI Projects client library for Python | Microsoft Learn

·       Microsoft Foundry Quickstart - Microsoft Foundry | Microsoft Learn

Thank you!
cheng victor 0 Reputation points

2026-03-02T23:11:55.4766667+00:00

Hi Karnam Venkata Rajeswari,

I have looked at your suggestions, but it is not the case for my, because i want to attach the file dynamically in each conversation instead of uploading the file to agent as a fixed file tool.

If updating the agent version everything, it is a bit insane.

What i want is the file will only able to execute for code interpreter when having the same conversation id only.
Karnam Venkata Rajeswari 280 Reputation points Microsoft External Staff Moderator

2026-03-05T10:27:16.31+00:00
Hello cheng victor,

Thank you for mentioning that the case being looked for is to attach the file dynamically in each conversation instead of uploading the file to agent as a fixed file tool.

The issue is likely caused by mixing three similar but different file‑handling mechanisms in Foundry, which leads to confusing the code interpreter execution.

Below are the execution patterns

1.       Model context files (input_file in conversation items)

2.       Agent-tool files (tool_resources bound to Code Interpreter)

3.       Message attachments (classic Assistants pattern)

In the current implementation, the CSV file is added using conversations.items.create with content type set to input_file. This method only injects the file into the model context window, which allows the language model to read the file as text. However, files added this way are not mounted into the code interpreter runtime filesystem, so python code executed by the agent is unable to access the CSV during data analysis.

Use Code Interpreter with Microsoft Foundry agents - Microsoft Foundry | Microsoft Learn

Attempting to pass attachments during responses.create did not work because the Responses API does not modify conversation state. It only runs the agent against the existing conversation, and therefore does not support adding files or attachments at that stage. As a result, attachments passed to responses.create got ignored by design.

https://learn.microsoft.com/en-us/answers/questions/5789844/how-to-attach-files-to-code-interpreter-in-new-fou

So , please consider using the following approac for the usecase - dynamic, conversation‑scoped CSV usage with code interpreter :

Please upload the CSV file normally using the Files API.

Then , attach the file to the conversation message using a message attachment that explicitly references the Code Interpreter tool.

Run the agent using responses.create against the same conversation.

Following this approach:

The file is mounted into the Code Interpreter sandbox.

The file is scoped only to that conversation.

No agent updates or new agent versions are required.

The file is accessible to all sub‑agents in a multi‑agent workflow.

How to use Foundry Agent Service Code Interpreter (classic) - Microsoft Foundry (classic) | Microsoft Learn

The recommended approach for new Foundry (multi-agent + Responses) is per-conversation file binding. If using classic please use the threads/messages approach where attachments are supported on message creation.

As a final check, please ensure that the agent has the code interpreter tool is enabled. Without this, the attached files will not be executed even if they are correctly added to the conversation.

Thank you!
Karnam Venkata Rajeswari 280 Reputation points Microsoft External Staff Moderator

2026-03-06T08:12:29.75+00:00

Hello cheng victor,

Did you get any chance to review the above response?

Do let me know if you have any further queries.

Thank you.