MCP tool

create_post

Create a post

Creates or changes something · and, like everything an agent creates, it is mailed to the project — and in copilot mode waits for a human in the approval queue.

What it does

Create a post to connected accounts — X/Twitter, Instagram, LinkedIn, Facebook, TikTok, YouTube, Threads, Bluesky, Pinterest. CREATING IT SENDS IT: no scheduled_at publishes now, one publishes then; a project may hold it instead (status says). The answer carries message and approval_link or preview_link. accounts takes each account's ref. Media is media_ids, files (attachments from this conversation) or media_pending: true, which holds the post until the picture arrives — the reply's upload_url takes a POST of the file (upload_curl), or the person adds it in the card; then it goes out on its own unless the project holds agent posts. "next_slot" takes the queue; is_draft saves without sending. Undo: update_post or delete_post before it goes out; take_down_post after, where networks allow.

Arguments

Name	Type	Required	What it is
caption	string	No	The post text. Optional only where no destination prints one: a story, or X/Instagram/LinkedIn publishing media alone. WRITE IT TO FIT EVERY TARGET: one destination over its own limit refuses the WHOLE post and nothing goes out anywhere — X is 280 as X counts it, and list_accounts gives each account its `caption_chars_available`. Words the person wrote are theirs: where they do not fit, say so and ask, never quietly shorten them.
accounts	array	No	Where it posts: each account's `ref` from list_accounts ("x:someone"). LIST EVERY ACCOUNT THIS POST GOES TO — one post, many accounts; a platform that needs different words gets them in platform_configurations.<platform>.caption, never a post of its own. A person reads this request before approving it, and the ref is what they can check. A ref matching nothing refuses the whole post.
social_account_ids	array	No	Deprecated name for `accounts`.
media_ids	array	No	Media ids from upload_media; first is the carousel lead.
files	array	No	Files the user attached to this conversation, as the host hands them over, in post order. They are attached after `media_ids`.
media_pending	boolean	No	The picture is still to come: the person adds it in the approval card. Lets a post for Instagram, TikTok, YouTube or Pinterest be created without media; it goes out once the media is on it (or, on a project that holds agent posts, can be approved then).
scheduled_at	union	No	ISO 8601 with Z or an offset, or "next_slot" for the project's own posting schedule (get_project shows `queue`). Omit to publish now — or, on a project that holds agent posts, as soon as it is approved.
is_draft	boolean	No	Save as a draft: visible in xpost, publishing nowhere until a person sends it.
platform_configurations	record	No	Per-platform options keyed by platform: `caption` is that platform's own text (so one post can say it differently on X and on Instagram), `placement` picks "reels"/"stories" where offered. Which keys each account takes is what get_posting_rules answers. Example: {"instagram": {"placement": "stories"}, "x": {"caption": "the short one"}}
idempotency_key	string	No	Your own id for THIS request, unique to it (not to the subject). A retry with the same key returns the post the first call made, as `repeated: true`, instead of a second post.

Calling it

Any MCP client calls this by name once the connector is added. The address is the same for every tool:

https://xpost.to/api/mcp

A client that has signed in sends the tool name and its arguments:

{
  "name": "create_post",
  "arguments": {
    "caption": "…",
    "accounts": []
  }
}

The other tools

get_projectProject rules and settings list_accountsList connected accounts get_posting_rulesPosting rules per account upload_mediaAttach a picture, video or PDF list_postsList posts delete_postDelete a post update_postEdit a post retry_deliveryRetry a failed delivery take_down_postTake a live post down list_connection_issuesList account connection problems get_delivery_receiptDelivery receipt for a post bulk_postCreate several posts at once get_post_metricsMetrics for a post get_insightsAccount insights get_top_postsTop posts get_best_timesBest times to post

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