YouTube integration · v1

YouTube API for uploading Shorts

YouTube is the one network here that will not take a URL. It wants the video bytes over a resumable session — PostMCP fetches, uploads and publishes them for you.

Get an API key Read the quickstart

Endpoint: POST /api/tools/create_post
Platform value: "youtube"
Auth: x-api-key or Bearer token
Upstream: YouTube Data API v3

Overview

What the YouTube Shorts API gives you

Publishing a Short through the YouTube Data API means opening a resumable upload session with the video metadata, reading the Location header it returns, and PUTting the file to that URL. Nothing about it resembles a normal JSON post, and nothing else on this list works that way.

"Shorts" is also not a separate endpoint. A video becomes a Short because of what it is — vertical or square, three minutes or less — not because of a flag you set. PostMCP checks the file before it spends the quota, splits your copy into a title and a description, turns hashtags into video tags and appends #Shorts so YouTube classifies it correctly.

Video upload from a URL

You pass a mediaUrl. The engine fetches the file, opens the resumable session and streams the bytes — the part of the API you would otherwise write yourself.

Title from the first line

The first non-empty line of your copy becomes the video title, trimmed to YouTube’s 100 characters. Angle brackets are stripped, because a stray <3 in a title fails the whole upload.

Description and #Shorts tagging

The full body becomes the description, capped at 5,000 characters, with #Shorts appended when you have not already tagged it.

Hashtags become video tags

Hashtags in the copy are lifted into the tags array, where YouTube actually reads them, and trimmed to fit the 500-character tag ceiling.

Pre-flight format check

A still image or a missing attachment is rejected before the upload starts, so a bad post costs one request rather than 1,600 units of daily quota.

Scheduled publication

Queue a Short by date and time alongside every other connected network.

Common uses

Turn a product clip into a Short and cross-post the announcement to X and LinkedIn in the same call.
Let an agent publish a weekly Short with the title and hashtags written from a plain-English brief.
Schedule a run of Shorts across a launch week without keeping a Google token alive yourself.
Repurpose an existing vertical video from your CDN by passing its URL, with no local upload step.

Quickstart

Post to YouTube Shorts in three steps

Connect the account once, grab an API key, then send a single request. The same body works from a shell, a server, or an AI agent.

1
Connect your YouTube Shorts account
Open the dashboard, choose YouTube Shorts and complete the hosted connect flow. Credentials are encrypted into the user vault and never returned to your client.
2
Create an API key
Generate a key from the dashboard. Send it as x-api-key, as an Authorization: Bearer header, or as an apikey query parameter on the MCP transport.
3
Send your first post
POST to /api/tools/create_post with platforms: ["youtube"]. Set publishImmediately to broadcast now, or supply scheduleDate and scheduleTime to queue it.

POST /api/tools/create_post

curl -X POST "https://api.postmcpai.com/api/tools/create_post" \
  -H "Content-Type: application/json" \
  -H "x-api-key: $POSTMCPAI_API_KEY" \
  -d '{"content":"Shipping something new today. Built with PostMCP AI.","platforms":["youtube"],"publishImmediately":true}'

Response — 200 OK

{
  "success": true,
  "message": "Post created and queued successfully",
  "post": {
    "id": "66a50c89e4b019a2b72f",
    "content": "Shipping something new today. Built with PostMCP AI.",
    "platforms": [
      "youtube"
    ],
    "status": "published"
  }
}

Reference

YouTube Shorts API endpoints

Every endpoint is a POST against the base URL https://api.postmcpai.com. The same seven operations cover all connected networks — set the platform value to "youtube" to target YouTube Shorts.

Operation	Endpoint	What it does
preflight_post	POST/api/tools/preflight_post	Dry-run copy against limits, targets and credits before publishing.
create_post	POST/api/tools/create_post	Schedule a post or broadcast it immediately.
publish_post_now	POST/api/tools/publish_post_now	Force a queued post out ahead of its slot, or retry the profiles that failed.
list_posts	POST/api/tools/list_posts	Read the queue — scheduled, published, draft and failed — with counts.
get_post	POST/api/tools/get_post	Read one post, with per-profile delivery state and live URLs.
update_post	POST/api/tools/update_post	Edit copy, targets, schedule or status before publication.
reschedule_post	POST/api/tools/reschedule_post	Move a post to another slot, keeping its copy and targets.
reset_stuck_post	POST/api/tools/reset_stuck_post	Release a post left stuck mid-publish so it can be retried.
delete_post	POST/api/tools/delete_post	Remove a scheduled or draft post from the queue.
get_connected_accounts	POST/api/tools/get_connected_accounts	List connected profiles, handles and page IDs per platform.
get_account_health	POST/api/tools/get_account_health	Find connections whose token expired or is about to.
list_brandings	POST/api/tools/list_brandings	Read the workspace brand kits used to keep copy and visuals on-brand.
generate_image	POST/api/tools/generate_image	Generate a post image and get back a hosted URL for mediaUrl.
list_workspaces	POST/api/tools/list_workspaces	List the workspaces on this key, with the id to scope other calls to.
get_user_info	POST/api/tools/get_user_info	Read plan tier, publishing credits and AI token balance.

create_post parameters

Field	Type	Required	Description
content	string	Yes	Text body of the post. Truncation rules are enforced by the destination network, not by PostMCP.
targetAccounts	array[object]	Yes	The profiles that receive the post. Each entry takes platform and profileId (from get_connected_accounts). Only the profiles listed here are posted to.
platforms	array[string]	Optional	Shorthand for whole networks — linkedin, twitter, facebook, instagram, threads, bluesky, youtube. Each one expands to every connected profile on it, so prefer targetAccounts unless you mean that fan-out. Optional when targetAccounts is given.
publishImmediately	boolean	Optional	When true the post is broadcast on receipt. Defaults to false, which queues it.
scheduleDate	string	Optional	Publication date as YYYY-MM-DD. Required when publishImmediately is false.
scheduleTime	string	Optional	Publication time as HH:MM on a 24-hour clock. Required when publishImmediately is false.
timezone	string	Optional	IANA zone the schedule above is written in, e.g. Asia/Kolkata. Omit it and the wall-clock slot resolves as UTC, which is rarely what "10am" meant.
mediaUrl	string	Optional	Publicly reachable image or video URL. PostMCP fetches it and re-uploads it in the format the network expects. Required, and must be a video, when the post targets YouTube.
workspaceId	string	Optional	Workspace to post from, taken from list_workspaces. Omitted, the call resolves to the default workspace on the key.

Authentication

YouTube Shorts OAuth and API keys

Two layers of auth sit under every request: the YouTube Shorts credential you grant once during connect, and the PostMCP API key your code sends on each call.

Step 1

Consent on Google

The channel owner signs in with Google and grants the upload and read-only scopes. Offline access is requested so a refresh token comes back.

Step 2

Scopes verified at the callback

The granted scope list is checked for youtube.upload. A consent screen where that box was unticked is rejected there and then.

Step 3

Channel resolved

channels?mine=true returns the channel. Its id is stored as the profile id, because that survives a handle change; a Google account with no channel is refused with that reason.

Step 4

Tokens encrypted and refreshed

The refresh token is encrypted into the user vault and exchanged for a fresh access token before every upload.

Scopes requested from YouTube Shorts

Scope	Why it is needed
https://www.googleapis.com/auth/youtube.upload	The only scope that can insert a video. Without it the connection is refused at the callback rather than failing later on a publish.
https://www.googleapis.com/auth/youtube.readonly	Reads the channel title, handle and avatar so the connected profile is named properly instead of showing a bare channel id.

Sending your API key

Header (recommended)x-api-key: pmcp_sec_…

Bearer tokenAuthorization: Bearer pmcp_sec_…

Query (MCP SSE)/mcp?apikey=pmcp_sec_…

Under the hood

How PostMCP publishes to YouTube Shorts

One request from you becomes this sequence server-side. Knowing the shape helps when you are debugging a failed broadcast.

1
Check the media first
The mediaUrl must be present and must look like a video (mp4, mov, webm, …). Anything else fails here, before a byte is transferred.
2
Fetch the video
The file is downloaded with a video-length read window and a 256MB ceiling, and its MIME type derived from the URL and the response.
3
Build the metadata
Title from the first line, description from the body with #Shorts, tags from the hashtags, category "People & Blogs" and an explicit made-for-kids declaration — which YouTube requires.
4
Open the resumable session
The metadata is POSTed with X-Upload-Content-Length and X-Upload-Content-Type; YouTube answers with the upload URL.
5
Send the bytes
The whole file goes in one PUT. Chunking only pays off when a transfer can resume across restarts, which a single publish run cannot do.
6
Record the link
The returned video id is stored and the delivery link is built as youtube.com/shorts/{id}.

Upstream YouTube Shorts calls

Method	Endpoint	Purpose
GET	https://www.googleapis.com/youtube/v3/channels?part=snippet,contentDetails&mine=true	Identifies the channel behind the token and supplies its name, handle and avatar.
POST	https://www.googleapis.com/upload/youtube/v3/videos?uploadType=resumable&part=snippet,status	Opens the resumable session with the snippet and status metadata, returning the upload URL in the Location header.
PUT	{resumable upload URL}	Sends the video bytes and returns the published video id.

Direct YouTube Shorts API vs PostMCP

Aspect	Calling YouTube Shorts directly	With PostMCP
Upload protocol	Open a resumable session, read the Location header, PUT the bytes	One `mediaUrl` field
Getting the video	You host and stream the file yourself	Fetched from your URL, size and type checked
Title and description	Two separate fields you have to split and truncate	First line becomes the title, the body becomes the description
Shorts classification	No flag exists — you have to get the file right	Format checked up front, `#Shorts` appended for you
Tokens	Refresh the Google access token before each call	Encrypted, refreshed per broadcast
Scheduling	Not part of the Data API	Same queue as every other network

Constraints

YouTube Shorts limits and supported media

These ceilings are set by YouTube Shorts, not by PostMCP. Your content field is forwarded unchanged, so the network enforces them rather than silently truncating.

Title100 characters, from the first line

Description5,000 characters

Tags500 characters across the whole list

Video lengthUp to 3 minutes to qualify as a Short

Aspect ratioVertical or square

File sizeUp to 256MB

Formatsmp4, mov, webm and other common video types

Daily quota1,600 units per upload against the app quota

Troubleshooting

Common YouTube Shorts API errors

Failures are recorded per platform on the post record, so a multi-network broadcast that partially succeeds tells you exactly which leg failed and why.

Code	Message	Likely cause	Fix
quotaExceeded	The request cannot be completed because you have exceeded your quota	Each upload costs 1,600 of the application’s 10,000 daily units, so roughly six uploads a day exhausts a default project.	This is an application-wide limit, not a limit on your channel. It resets at midnight Pacific — reschedule the post for tomorrow and retry it then.
mediaRequired	YouTube Shorts needs a video	The post carried no attachment, or the attachment was a still image.	Attach a vertical clip of three minutes or less. The check runs before the upload, so nothing is spent.
invalidTitle	Video title rejected	YouTube refuses titles containing angle brackets.	Handled for you — the brackets are stripped from the first line before it is sent.
forbidden	The request is not properly authorized	The `youtube.upload` scope was not granted, or the refresh token was revoked in the Google account.	Reconnect the channel and leave every requested permission ticked.
uploadLimitExceeded	The user has exceeded the number of videos they may upload	YouTube applies its own per-channel daily upload ceiling, separate from the API quota.	Space the Shorts out across days using the scheduler.

Model Context Protocol

Post to YouTube Shorts from an AI agent

The same seven operations are exposed as MCP tools. Point Claude Desktop, Cursor, or any MCP client at the server and your agent can publish to YouTube Shorts directly.

claude_desktop_config.json

{
  "mcpServers": {
    "postmcpai": {
      "command": "npx",
      "args": ["-y", "@postmcpai/server"],
      "env": {
        "POSTMCPAI_API_KEY": "pmcp_sec_YOUR_SECRET_KEY",
        "POSTMCPAI_API_URL": "https://api.postmcpai.com"
      }
    }
  }
}

Prompt the agent directly

With the server connected, natural language is enough — the agent picks the tool and fills the arguments:

“Draft a YouTube Shorts post about today’s release and schedule it for 9:30am tomorrow.”

Full MCP tool reference AI agent guides

FAQ

YouTube Shorts API questions

How do I upload a YouTube Short with the API?

POST to https://api.postmcpai.com/api/tools/create_post with platforms: ["youtube"], your content and a mediaUrl pointing at a vertical video. PostMCP fetches the file, opens the resumable upload session and publishes it to the connected channel.

Is there a separate Shorts API?

No. A video is treated as a Short because of what it is — vertical or square and three minutes or under — not because of any flag. PostMCP checks the file before uploading and appends #Shorts so YouTube classifies it.

Where do the title and description come from?

The first non-empty line of your copy becomes the title, trimmed to 100 characters, and the full body becomes the description, capped at 5,000. Hashtags in the copy also become video tags.

Can I post an image to YouTube?

No, and the request is rejected before anything is uploaded. YouTube only takes video, so a post without a video attachment fails its pre-flight check rather than burning upload quota.

What does "quota exceeded" mean on a YouTube post?

Every upload costs 1,600 units of a Google project’s 10,000 daily units, so about six uploads exhaust a default quota. It is a limit on the application rather than on your channel, and it resets at midnight Pacific time.

Which permissions does connecting a channel need?

youtube.upload to publish and youtube.readonly to read the channel name and avatar. If the upload permission is unticked on the Google consent screen, the connection is refused right there instead of failing on a later publish.

Other social media APIs

LinkedIn API

One authenticated POST publishes to a LinkedIn profile or company page. PostMCP owns the OAuth dance, the image upload handshake and the versioned LinkedIn REST calls underneath.

Read the reference

X (Twitter) API

Send one request and PostMCP handles Twitter API v2 for you — PKCE OAuth, the three-step chunked media upload, refresh tokens and the final tweet call.

Read the reference

Facebook API

Publish text and photo posts to every Facebook Page you manage from one endpoint. PostMCP resolves page access tokens and calls Graph API v26.0 for you.

Read the reference

Instagram API

Instagram publishing is a two-phase asynchronous flow. PostMCP creates the media container, polls it to FINISHED and publishes it — you send a caption and a media URL.

Read the reference

Threads API

Threads processes every post asynchronously, even plain text. PostMCP creates the container, polls it to FINISHED and publishes — one call from your side.

Read the reference

Bluesky API

Bluesky is not OAuth — it is a session against an AT Protocol server. PostMCP refreshes that session, uploads image blobs and writes the feed record for you.

Read the reference

Start posting to YouTube Shorts today

Connect the account, take an API key and send your first request in under five minutes — from a shell, your backend, or an AI agent.

Get your API key See pricing

What the YouTube Shorts API gives you

Video upload from a URL

Title from the first line

Description and #Shorts tagging

Hashtags become video tags

Pre-flight format check

Scheduled publication

Common uses

Post to YouTube Shorts in three steps

Connect your YouTube Shorts account

Create an API key

Send your first post

YouTube Shorts API endpoints

create_post parameters

YouTube Shorts OAuth and API keys

Consent on Google

Scopes verified at the callback

Channel resolved

Tokens encrypted and refreshed

Scopes requested from YouTube Shorts

Sending your API key

How PostMCP publishes to YouTube Shorts

Check the media first

Fetch the video

Build the metadata

Open the resumable session

Send the bytes

Record the link

Upstream YouTube Shorts calls

Direct YouTube Shorts API vs PostMCP

YouTube Shorts limits and supported media

Common YouTube Shorts API errors

Post to YouTube Shorts from an AI agent

Prompt the agent directly

YouTube Shorts API questions

How do I upload a YouTube Short with the API?

Is there a separate Shorts API?

Where do the title and description come from?

Can I post an image to YouTube?

What does "quota exceeded" mean on a YouTube post?

Which permissions does connecting a channel need?

Other social media APIs

Start posting to YouTube Shorts today