Retrieve a container file
Returns the metadata of a single file in a container.
Authorizations
API key as bearer token in Authorization header
Path Parameters
The canonical container id, exactly as returned in a bash/shell tool result — a restarted session has its own -r<nonce>-suffixed id. A session-derived id is always sess_ + the sanitized session key, which is not necessarily the raw session id that was sent.
"sess_abc123"
Container file id (cfile_ + base64url of the file path).
"cfile_b3V0L3JlcG9ydC5jc3Y"
Response
The container file.
File size in bytes.
123
The container the file belongs to — echoes the container_id path parameter (OpenAI field name).
"sess_abc123"
Unix timestamp (seconds) when the file was last synced.
1755640000
Container file id: cfile_ + base64url of the file path.
"cfile_b3V0L3JlcG9ydC5jc3Y"
container.file "container.file"
Container-relative file path.
"out/report.csv"
Container files are always produced by the assistant sandbox.
assistant "assistant"