'file' message type with data URL should be supported by chat completions

[danielmklein]

Describe the bug

If you run an agent and pass it content that includes an input_file where file is base64-encoded data, like this...

content: [
  {
    type: 'input_file',
    file: "data:application/pdf;base64,JVBER...snip...",
    providerData: {
      filename: "cool-doc.pdf"
    }
  }
],

you hit this error:

openai-agents-js/packages/agents-openai/src/openaiChatCompletionsConverter.ts

Lines 99 to 103 in 1300121

	throw new Error(
	`File uploads are not supported for chat completions: ${JSON.stringify(
	c,
	)}`,
	);

even though the docs and API do support passing such an input file.

It looks like this issue also existed in the python SDK but was fixed: openai/openai-agents-python#893.

Debug information

• Agents SDK version: (e.g. `v0.3.4)
• Node 22.21.1

Repro steps

import { Agent, run } from '@openai/agents';

const agent = new Agent({
  name: 'Assistant',
  instructions: 'You are a helpful assistant.',
});

const result = await run(
  agent,
  [
    {
      role: 'user',
      content: [
        {
          type: 'input_text',
          text: "what does this file say?",
        }
        {
          type: 'input_file',
          file: "data:application/pdf;base64,JVBER...snip...", // replace with a valid base64-encoded pdf
          providerData: {
            filename: "cool-doc.pdf"
          }
        }
      ],
    }
  ],
);`

Expected behavior

I would expect this to successfully pass the file input data to the API without error.