Publish to Pages With a Meta Muse Connector for Facebook Posting

One field decides whether a Meta Muse connector for Facebook posting works on the first call, and it is pageId. Every other network in the AdaptlyPost API is addressed by a connection ID. Facebook is addressed by the Page, because Facebook publishes to Pages rather than to profiles. Muse writes the client code itself from a public spec, so the whole job is making sure it reads that one field before it schedules anything.

The short version: give Muse the spec at post.adaptlypost.com/post/api/v1/openapi.json, tell it to call GET /social-accounts and print the Facebook page IDs before publishing, then paste an adaptly_ token into the secure credential prompt. facebookConfigs requires pageId, and the top-level pageIds array accepts either that page id or the account id.

What is a Meta Muse connector for Facebook posting?

A Meta Muse connector for Facebook posting is a custom connector that schedules Page posts from a chat message, addressed by pageId rather than by a connection ID. The full Meta Muse connector guide covers what Muse builds on its VM and where the token goes. Parallel's hands-on test of 14 September 2026 found no "add MCP server" setting in Muse, so the Custom Connector path is the route in, and Meta states plainly that it does not review custom connectors or how they use your information.

Does Muse already post to my Facebook Page on its own?

Meta documents that Facebook, Instagram and Threads connect to Muse automatically when the accounts share an Accounts Centre, and documents no publishing action through that link. Meta's Chief AI Officer Alexandr Wang listed Facebook, including Marketplace, among the services you can connect Muse to in a post on 8 September 2026. Neither that post nor the help centre says Muse publishes a Page post, and as of 20 September 2026 no Meta page enumerates the actions.

Accounts Centre links a personal Facebook account. A Page you manage is a separate object with its own id and its own publishing permission. Publishing to the Page your business runs is a different job, which is the argument for pointing Muse at a scheduler.

Why does Facebook use pageId instead of a connection ID?

Each connected Facebook account in AdaptlyPost is one Page. The spec says so of the account id: it "identifies the connected page and is not the Facebook page id", which is why FacebookPostConfig requires pageId while the other configs require connectionId. Its other two fields are postType and videoTitle. The other eight networks take a connection ID. YouTubePostConfig carries its own videoTitle, capped at 100 characters against Facebook's 255, and Pinterest and TikTok carry title.

Eight of the nine networks take a connection ID, so a client written from the spec has one shape to copy and one exception to notice. A post that sends connectionId for Facebook publishes everywhere else and fails on Facebook alone.

You:  Post this launch video to the main Page tomorrow at 2pm,
      title it "Autumn release walkthrough".
 
Muse: GET  /social-accounts            -> reads pageId for "Main Page"
      POST /upload-urls                -> presigned URL for the video
      PUT  the file
      POST /social-posts
        platforms: [FACEBOOK]
        contentType: VIDEO
        pageIds: ["1015..."]
        facebookConfigs: [{ pageId: "1015...", postType: "FEED",
                            videoTitle: "Autumn release walkthrough" }]
        mediaUrls: ["https://..."]
        scheduledAt: "2026-09-21T14:00:00"
        timezone: "Europe/Kyiv"

What do I paste into Muse to build it?

The paste is the spec URL, the Facebook field name and one instruction that stops Muse publishing on the first run.

Build a custom connector for AdaptlyPost from the public OpenAPI spec at
https://post.adaptlypost.com/post/api/v1/openapi.json.
 
Facebook is the exception in this API. facebookConfigs requires pageId, and
the top-level array is pageIds, which accepts either the page id or the
account id. There is no facebookConnectionIds array.
 
Do not publish anything yet. Call GET /social-accounts first and show me every
Facebook Page with its page ID.

What can the connector publish to a Page?

The connector publishes Feed posts, Reels and Stories to any connected Page through facebookConfigs[].postType, with videoTitle on video posts. pageIds is an array, so one call to POST /social-posts reaches every Page you name, and platformTexts carries a different caption per network in the same request.

One POST /social-posts/bulk call is where the connector stops being a novelty. It accepts 1 to 100 posts in one call, so a franchise with twelve location Pages gets a month of posts from one sentence rather than from twelve sessions of clicking.

What breaks on Facebook specifically?

The pageId mix-up breaks quietly, which is what makes it the first thing to check. On a post sent to all nine networks at once, eight publish and Facebook does not, and GET /social-posts/{id}/results is the only place that shows up, because results come back per platform. Tell Muse to read that endpoint after every publish, and POST /social-posts/{id}/retry takes a required platformIds array, so you hand it the failed platform's id from that results call and nothing else republishes.

Three more Facebook-specific failures are worth knowing. A Page whose stored token Facebook later rejects still appears in GET /social-accounts, with status set to unauthorized and unauthorizedReason carrying Facebook's own message. Posts to it come back as a 400 until it is reconnected in the dashboard. postType: REEL is a video post type, so a Reel needs contentType: VIDEO and a video in mediaUrls. And a personal profile is not a publishable target, so a reader who connected only a profile gets an empty Facebook list.

One failure belongs to Muse rather than to Facebook. Parallel reported on 14 September 2026 that a custom connector Muse builds is saved as a reusable skill that persists across conversations, and no one has published what that saved skill does when it holds a wrong field name. Correct it in the conversation and have Muse re-read the accounts endpoint. If you would rather run this on a configured template than on a spec paste, the Grok bot template for Facebook posting covers the identical pageId path, and multi-platform posting covers the other eight networks.

Frequently asked questions

Can Muse post to a Facebook Page without a custom connector?

Meta documents no publishing action for the Facebook account that links to Muse automatically through Accounts Centre. As of 20 September 2026 the help centre describes the connection and never enumerates what Muse does with it, so the connector is the documented path to a Page post.

Does the connector work with a personal Facebook profile?

The connector needs a Page. Facebook's publishing API does not accept personal profiles, so only a Page carries the pageId that facebookConfigs requires. Connect the Page in AdaptlyPost and it appears in GET /social-accounts with a pageId Muse can address.

Why did my post publish everywhere except Facebook?

The call sent connectionId for Facebook instead of the pageId that facebookConfigs requires. Ask Muse to re-read GET /social-accounts, confirm the page ID out loud, then call POST /social-posts/{id}/retry with only the Facebook platform id so the networks that already published do not post twice.

Can Muse post to a Facebook Group or to Marketplace?

AdaptlyPost publishes to Pages, and Groups and Marketplace are not in the spec's Facebook surface. Alexandr Wang's post of 8 September 2026 names Facebook including Marketplace among the things Muse connects to, and Meta documents no publishing action through that link as of 20 September 2026, so treat Marketplace as connected rather than publishable.

What happens to a scheduled Page post if I revoke the token?

Revoking the adaptly_ token stops AdaptlyPost accepting calls from Muse, and posts already queued in AdaptlyPost publish on schedule because the queue is AdaptlyPost's, not Muse's. The pillar guide covers Meta's no-review position and the credential store.

How do I find the page ID Muse needs for Facebook?

Ask Muse to call GET /social-accounts and print every Facebook Page with its page ID before it publishes anything. The account id is not the Facebook page id, but the top-level pageIds array accepts either one. facebookConfigs still requires pageId, so read that field back rather than guessing.

Can Muse schedule Reels and Stories to a Facebook Page?

The connector covers Feed posts, Reels and Stories through facebookConfigs[].postType. A Reel is a video post type, so it needs contentType: VIDEO and a video in mediaUrls. Video posts also take a videoTitle.

Can one request post to several Facebook Pages at once?

Every Page you name in the pageIds array gets the post from a single POST /social-posts call. platformTexts lets each network carry its own caption in the same request. For many posts at once, POST /social-posts/bulk accepts 1 to 100 per call.

What does an unauthorized Facebook Page mean in GET /social-accounts?

Facebook rejected the stored token for that Page. The Page still appears in the list with status set to unauthorized, and unauthorizedReason carries Facebook's own message. Posts to it come back as a 400 until you reconnect it in the dashboard.

Does Muse remember the connector between conversations?

Parallel reported on 14 September 2026 that a custom connector Muse builds is saved as a reusable skill that persists across conversations. No one has published what a saved skill does when it holds a wrong field name, so treat a bad first run as something to check rather than something a later conversation fixes on its own. Correct it in the conversation and have Muse re-read the accounts endpoint.

Create an AdaptlyPost API token and hand Muse the spec, or read the agent setup brief first. API access is included on Creator, Pro and Enterprise, and on the 7-day trial.

Sources: Meta's Muse connectors help article, Alexandr Wang's connector post of 8 September 2026 on X, Parallel's custom integrations write-up (14 September 2026), and the AdaptlyPost OpenAPI spec. Checked 20 September 2026.