YouTube

Set up a Google Cloud project for the YouTube Data API, connect channels, and publish videos and Shorts with title, visibility and first comments.

MagicPost uploads to YouTube with the YouTube Data API. You create one Google Cloud project and OAuth client. Each user then connects their own YouTube channel through it.

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What you need

• A Google account that can use the Google Cloud console.
• Your site served over HTTPS.
• Access to Admin → Publishing → Platforms.
• For a custom thumbnail, FFmpeg on the server. See Video processing.

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Set up Google Cloud

1. Create a project and enable the API

   In the Google Cloud console, create a project and enable the YouTube Data API v3 for it.

2. Get the redirect URI from MagicPost

   In MagicPost, go to Admin → Publishing → Platforms and click Add credentials on the YouTube card. Under What to register, copy the Redirect URI and the permissions under Permissions asked for:

   https://your-domain.com/publishing/youtube/callback
   
3. Configure the consent screen

   Set up the OAuth consent screen for External users and add the scopes from the table below.

4. Create the OAuth client

   Create an OAuth client ID of type Web application. Add the redirect URI under Authorized redirect URIs.

5. Copy the keys

   Copy the Client ID and the Client secret.

6. Store them in MagicPost

   Paste them into Client ID and Client secret. Tick Available to users, click Save, then Run checks.

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Permissions MagicPost asks for

Scope	Used for
https://www.googleapis.com/auth/youtube.upload	Uploading videos.
https://www.googleapis.com/auth/youtube.readonly	Reading the channel and its statistics.
https://www.googleapis.com/auth/youtube.force-ssl	Posting first comments.

While the consent screen is in Testing, Google ends every connection after 7 days. Publish the app to In production before users rely on it.

Videos uploaded through a Google project that has not passed YouTube’s API audit are locked to private, whatever visibility the user chose. Request the audit from Google before people publish publicly.

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Connect a YouTube channel

1. Open Channels

   Under Publishing in the sidebar, click Channels.

2. Add the channel

   In Add a channel, click YouTube. Sign in with Google and approve access. Google asks for consent every time, so that it issues a refresh token.

3. Confirm

   You return to Channels with a Channel entry named after the YouTube channel.

A Google account without a YouTube channel cannot be connected. MagicPost answers This Google account has no YouTube channel.

Channels connected before first comments were added lack the youtube.force-ssl scope. They have to reconnect to get first comments.

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What you can publish

YouTube has two post types: Video and Short. Both need a video.

Setting	Video	Short
Description	Up to 5,000 bytes. The characters < and > are not allowed.	Same.
Video formats	mp4, mov, webm, avi, mkv, flv	mp4, mov, webm
Video size	Up to 262,144 MB	Up to 1,024 MB
Video length	1 to 43,200 seconds	1 to 180 seconds
Images	None.	None.
First comment	Yes.	Yes.

• YouTube counts the description in bytes, so characters outside the basic Latin range use more than one.
• Files reach YouTube through the media library. Its default ceiling is 2,048 MB per video, and it accepts mp4, mov, webm, avi and mkv. A larger file, or a format the library does not accept such as flv, cannot be added to the library. See Upload ceilings.
• A Short needs a square or vertical video. A wide one is published as a regular video.
• YouTube refuses videos over 15 minutes until the YouTube account is verified.

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Options

Set these under Settings for the channel in the composer.

Option	Required	On Video	On Short	What it does
Title	Yes	Yes	Yes	Up to 100 characters, without < or >. When empty, the first line of the caption is used, then Untitled video.
Visibility	Yes	Yes	Yes	Public, Unlisted or Private.
Category	No	Yes	No	One of 15 YouTube categories, from Film & Animation to Nonprofits & Activism. People & Blogs is used when none is chosen.
Tags	No	Yes	Yes	Up to 500 characters in total, without < or >.
Made for kids	No	Yes	Yes	Required by law to be set honestly. Turns off comments and personalised ads.
Altered or synthetic content	No	Yes	Yes	For realistic content made or changed with AI. YouTube shows a label.
Thumbnail frame	No	Yes	Yes	Pick a frame of the video as the thumbnail.
Don’t notify subscribers	No	Yes	Yes	Uploads without notifying subscribers.

• MagicPost switches Altered or synthetic content on by itself when any attached media was created with MagicPost’s AI tools.
• Thumbnail frame only works for a verified YouTube account, and the server needs FFmpeg. Otherwise YouTube picks a thumbnail itself. The video stays live either way.

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First comment

The first comment is posted as a top-level comment on the video once YouTube has finished processing it. It is not posted on a video marked Made for kids, because comments are off. If posting it fails, the video stays published and the failure is written to the application log.

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How the upload works

• The file is uploaded in chunks of 8 MB against one upload session. A run that is cut short asks Google how much it has and carries on, so a long video is never sent twice.
• After the upload, MagicPost waits for YouTube to process the video and checks again every minute. A video that is still processing 30 minutes after the upload is treated as published, because it exists and YouTube carries on.

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Connection check

Item	Result
Channel	Connected to NAME.
Long videos	Warns when YouTube does not allow long uploads: Videos over 15 minutes are refused until the YouTube account is verified.
Visibility	Warns when an earlier upload came out private: YouTube keeps this channel’s uploads private until the Google Cloud project behind this app passes YouTube’s API audit. Ask your admin to apply for it. The warning clears when a public upload goes through.
First comments	Warns when the connection lacks youtube.force-ssl: Reconnect this channel so MagicPost can post first comments on new videos.

The same note about private uploads appears in the composer under Settings for the channel.

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Analytics

Level	Figures
Post	Likes, comments and views. A like count the creator hides is read as zero.
Channel	Subscribers (shown as followers), number of videos, and total views.

See Analytics.

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Common errors

This app has used its YouTube upload allowance for today

The Google project’s daily quota is used up. The post is retried after midnight Pacific time, when the allowance resets.

This YouTube channel has reached its daily upload limit

The channel itself hit YouTube’s limit. The post goes out after midnight Pacific time.

Videos stay private

The Google project has not passed YouTube’s API audit. See the warning above and apply for the audit.

Connections end after a week

The OAuth consent screen is still in Testing. Publish it to In production, then reconnect the channels.

YouTube refused the video as a duplicate

The channel already holds a video with the same content. Use a different file.

The video is longer than this YouTube account may upload

Verify the YouTube account to upload videos over 15 minutes.

YouTube refused the video over a copyright claim

YouTube rejected the upload because of a copyright claim. The post fails with that reason.

YouTube could not process the file

Export the video as an H.264 MP4 and try again.

The upload session expired

MagicPost starts the upload again automatically. No action is needed.

Redirect URI mismatch when connecting

The URI under Authorized redirect URIs in Google Cloud differs from the Redirect URI in MagicPost. Copy it again from the setup panel.

Other errors are shown with Google’s own message. See Failed posts.