curl -X POST 'https://api.openai.com/v1/containers/container-id/files' \
  -H "Authorization: Bearer $OPENAI_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{}'

# POST /containers/{container_id}/files (OpenAI API)
Base URL: https://api.openai.com/v1
Auth: Authorization; OpenAI API key; required.
Request formats: application/json, multipart/form-data.
Last verified: 2026-10-20

> Create container file

## Critical Gotchas
* The Responses API is the primary interface for new text and tool workflows; Chat Completions remains a separate compatibility API.
* Audio transcription uploads use multipart form data rather than a JSON request body.

## cURL
curl -X POST 'https://api.openai.com/v1/containers/container-id/files' \
  -H "Authorization: Bearer $OPENAI_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{}'

## Parameters
| Name | In | Type | Required | Description |
| :--- | :--- | :--- | :--- | :--- |
| container_id | path | string | Yes | path parameter container_id. |
| file_id | body | string | No | Name of the file to create. |
| file | body | string | No | The File object (not file name) to be uploaded.  |

## Response example
{"id":"string","object":"string"}

---
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POST

POST /containers/{container_id}/files — OpenAI API

OpenAI API key (required); https://api.openai.com/v1

OpenAI API

Create container file

Base URL: https://api.openai.com/v1
Auth: Authorization: Bearer <OPENAI_API_KEY>
Last verified: 2026-10-20 · upstream hash matched

Actions Try in browser→

Agents: curl -H "Accept: text/markdown" this URL
→ 216 tokens · Vary: Accept

Critical gotchas

The Responses API is the primary interface for new text and tool workflows; Chat Completions remains a separate compatibility API.

Audio transcription uploads use multipart form data rather than a JSON request body.

cURL

curl -X POST 'https://api.openai.com/v1/containers/container-id/files' \  -H "Authorization: Bearer $OPENAI_API_KEY" \  -H 'Content-Type: application/json' \  -d '{}'

Parameters

Name	In	Type	Required	Description
container_id	path	string	Yes	path parameter container_id.
file_id	body	string	No	Name of the file to create.
file	body	string	No	The File object (not file name) to be uploaded.

Response 200 OK

{
  "id": "string",
  "object": "string",
  "container_id": "string",
  "created_at": 0,
  "bytes": 0,
  "path": "string",
  "source": "string"
}

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