Large-file upload

Publish a large local video (e.g. a file on the user's computer) when there is no public mediaUrl.

User intents

"Upload a video from my computer to YouTube." "I have a big local file — give me an upload link."

Required information

The target channel (connectionId).
Nothing about the file itself — the browser upload page reads file name, MIME type, and size automatically.

Preconditions

An active connection with a valid token.
The user can open a browser upload page.

Tool sequence

Create an upload session

create_assignment_upload_session with connectionId only. It returns a sessionId and an uploadPageUrl.

Hand the upload page to the user

Give the user the uploadPageUrl and ask them to upload the file there.

Poll the session

get_assignment_upload_session with sessionId until status is completed.

Create the assignment

create_assignment with uploadSessionId (and no mediaUrl/fileContent), plus type and payload.

⚠️

Do not ask the user for file name, MIME type, or size, and never invent placeholder metadata — the browser detects it from the selected file.

REST alternative

Upload-session endpoints back these MCP tools; for direct REST publishing with a public URL use POST /api/v1/assignments. See the Assignments reference.

Recovery paths

Session expired, cancelled, or consumed — create a new session; do not reuse it.
create_assignment before completed — wait; only publish once the session status is completed.
Token expired — re-authorize via get_oauth_connect_url.

Example prompt → result

"Upload a local video to my 'Tech Reviews' channel, title 'Behind the scenes', public."

Result: the agent returns an upload link; after upload completes, it creates a published assignment from the session.

Common mistakes

Asking the user for a mediaUrl when they explicitly want a local/browser upload.
Publishing from a session whose status is not yet completed.

Connect a channel Retry a failed assignment