Post to Facebook from Grok Build
Grok Build can post to your Page on Facebook through ClipSpeed. Add the ClipSpeed server with one config block, sign in, and then ask Grok Build to post to your Page, pick the time, and apply Facebook's settings, without leaving xAI's coding agent and CLI. Facebook is coming next on ClipSpeed's rail; this page describes how it works and says so.
Keep a human in the loop: Grok Build shows the plan and asks before anything is public. Posting today: YouTube, TikTok, Instagram, X (Twitter) and LinkedIn.
Also try
How to post Facebook from Grok Build
Add ClipSpeed as an HTTP MCP server in Grok Build's configuration, complete the sign-in, and the tools appear. Connect Facebook in ClipSpeed, then describe the post. Setup takes about a minute.
# One-time setup: Grok Build MCP config
{
"mcpServers": {
"clipspeed": { "url": "https://api.clipspeed.ai/mcp" }
}
}
# Then ask Grok Build:
> Post the launch paragraph to the Facebook Page at 10am with the blog link
Grok Build: Preview — nothing booked yet. Facebook — text with one URL. Book it?ClipSpeed has not yet run an end-to-end check inside Grok Build. The server is standard MCP over HTTP; the configuration shape above is the common one and Grok Build's documentation is the reference for the file location.
- Add the clipspeed server with the URL to Grok Build's MCP configuration (see its docs for the file location).
- Start Grok Build; complete the ClipSpeed sign-in when prompted, or use an API key header.
- Ask it to list your channels.
- Connect Facebook in the ClipSpeed app, or ask Grok Build for a connect link: it is private, valid for ten minutes, and Facebook signs you in itself.
What can Grok Build do on Facebook?
On Facebook, Grok Build can post text, images and video to a Facebook Page, with vertical video as a Reel. Every booking runs through the same rules as the ClipSpeed app.
Text, Image and Video posts
Facebook takes text, image and video through ClipSpeed. Video: MP4 or MOV up to 1 GB; vertical video surfaces as a Reel on the Page. Image: JPG or PNG up to 25 MB.
63,206 characters, checked at booking
Facebook's own arithmetic. Too long is refused with the real count, never trimmed at send time.
Exact time or refused
Name the minute and Grok Build books it, or you are told why not and offered the next open slot. A booked Facebook post is never moved behind your back.
Preview before anything posts
preview: true runs the whole booking and writes nothing. Grok Build shows the plan, with each slot and the day's remaining cap, and books only on your yes.
Clips cut in the same session
Submit a video or stream link, get captioned 9:16 clips with a viral score, and post the best as native video on Facebook. No download, no re-upload.
Pacing and numbers
Planned: Text and image posts on Facebook are at least 60 minutes apart, up to 5 a day. Video on Facebook is at least 4 hours apart, up to 4 a day under your plan. After a post goes out, Grok Build can read back views and engagement where Facebook provides them.
How does Grok Build post to Facebook through ClipSpeed?
You describe what you want in plain language and Grok Build makes the ClipSpeed calls. A typical conversation has three beats.
Find your Facebook channel
Ask Grok Build whether Facebook is connected. It calls list_channels and reads platform_settings, so it also knows what Facebook accepts and the limits before you write a word.
Compose within the rules
Describe the post. Grok Build drafts within Facebook's limits; mention a clip or a file and it attaches it.
Schedule or publish
Name a time, or say now. The slot is booked exactly or refused with the next open one, and the reply carries the id you can cancel or edit by.
Facebook settings reference
These are the schedule_post fields that apply to Facebook. Mention any of them in plain language and Grok Build sets them; the server checks them at booking. Fields marked planned land with the Facebook release.
| Field | Type | Required | What it does on Facebook |
|---|---|---|---|
platforms | string[] | Yes | Include "facebook". Up to ten platforms per call; each books its own slot. |
text | string | Yes for a text post | Facebook's limit is 63,206 characters. The first link becomes a preview card. |
hashtags | string[] | No | Appended to the text. |
media_kind | text | image | video | No | Detected from the file when omitted. |
clip_id or media_url | string | No | A ClipSpeed clip or a public link to an image or video. Vertical video surfaces as a Reel. |
scheduled_at | ISO 8601 | No | Exact or refused with the next open slot. |
preview | boolean | No | Plan only. |
Common Facebook configurations
Ask Grok Build for any of these and it applies the matching settings.
Page post with a link card
Reel from a clip
Image post
Preview a week
Example prompts for Facebook in Grok Build
Type these into xAI's coding agent and CLI. Grok Build calls ClipSpeed and confirms before publishing.
Post Facebook with a scheduled time
Post the launch paragraph to the Facebook Page at 10am with the blog link. Keep the text under 63,206 characters. Preview first.
Cut the clips, then post the best
Clip this link, keep the top three by viral score, and schedule them to Facebook at 11am, 3pm and 7pm tomorrow. Show me the plan before booking.
Check and adjust the Facebook calendar
What is scheduled on Facebook this week? Cancel tomorrow's post and tell me the next open Facebook slot on Friday.
Facebook limits and gotchas to know
Facebook enforces a few rules that Grok Build and ClipSpeed respect automatically, but knowing them helps you phrase requests.
- Facebook Pages only. Meta retired the Groups publishing API, so no scheduler can post to a Group on your behalf; personal profiles are not available to apps either.
- Vertical 9:16 video posted to a Page surfaces as a Reel. Landscape video posts as a standard Page video.
- The character limit is enormous (63,206), but the feed truncates long posts behind 'see more' at a few lines. Lead with the point.
- Facebook is the next rail on ClipSpeed's scheduler. Until it posts, the status badge on this page says so and no booking to Facebook is accepted.
- Planned pacing: five text or image posts a day an hour apart, video four hours apart.
| Rule | |
|---|---|
| Accepts | Text, Image, Video |
| Text limit | 63,206 characters |
| Title | No title field |
| Links in the caption | Kept; the first link becomes a preview card |
| Pacing | Planned: Text and image posts on Facebook are at least 60 minutes apart, up to 5 a day. Video on Facebook is at least 4 hours apart, up to 4 a day under your plan. |
| Formats | Image: JPG or PNG up to 25 MB. Video: MP4 or MOV up to 1 GB; vertical video surfaces as a Reel on the Page. Aspect: any; 9:16 for Reels |
| Status | Coming next on ClipSpeed's rail; bookings are refused with a plain message until then |
What Postiz-style schedulers cannot do
Cut the clips first
Grok Build does not need finished video to start. Hand it a YouTube link, a podcast, a stream VOD or a local export. ClipSpeed finds the moments, cuts them to 9:16 with word-by-word captions, scores each one 0 to 100 for shareability, and returns them in the same conversation. Grok Build picks by score, writes the caption from the transcript, and books the clips on Facebook. Three tool calls, one approval, no download and no re-upload.
- Clips arrive with a title written from the hook, a transcript and a viral score, so the agent can choose and caption without watching the footage.
- Live streams can be clipped while they are still on air; the agent books the highlights for the next morning before the stream ends.
- Every clip is already hosted, so
schedule_posttakes its id directly. Nothing moves through your laptop.
submit_to_clipspeedPaste the link. ClipSpeed starts the job and returns a project id.check_clipsPoll with the project id. Back come the finished 9:16 clips with titles, transcripts, viral scores and preview links.schedule_postPass the clip id, the platforms, a caption and a time. Grok Build shows the plan with preview: true, you say yes, it books.generate_image or generate_videoDescribe the shot. ClipSpeed runs it on the model that fits (Seedance, Kling, Veo, Nano Banana Pro, GPT Image and others) and quotes the credits first.wait_for_generationReturns the hosted result link and a preview the agent can show you.schedule_post with media_urlThe result link goes straight into the booking on Facebook. The caption, the time and the file are approved together.The other half nobody else has
Generate the image or video, then post it
A product shot for Instagram, a 16:9 announcement graphic for X, a six-second opener before a clip: Grok Build can make an image or a short video with ClipSpeed's image and video models and book the result in the same reply. There is no separate design tool, no export, no upload page. The generated file is hosted, so media_url is the only thing the booking needs.
- The price in credits is quoted before anything renders, within the per-generation and daily caps you set in Settings.
- Results are previewed in the conversation, so you approve the picture and the post at once.
- Images post as JPG, PNG or WebP up to 25 MB; video posts as MP4, MOV or WebM up to 1 GB.
What is Grok Build?
Grok Build is xAI's coding agent and command-line tool. It runs tasks in your project and can call MCP servers. With ClipSpeed added, it can clip a video, generate media and schedule posts.
How ClipSpeed works with Grok Build
- Connects over HTTP
- Reads platform rules
- Exact-or-refused booking
preview: true- Same tools everywhere
Grok Build vs Grok Bot vs Grok: Grok Build (terminal), Grok Bot (cloud, always on), Grok (x and grok.com). This page is about Grok Build; the Grok Build guide compares them.
{
"mcpServers": {
"clipspeed": {
"url": "https://api.clipspeed.ai/mcp"
// or: "headers": { "Authorization": "Bearer csai_live_..." }
}
}
}# What the agent reads at connect time (tool descriptions, abridged)
list_channels Connected platforms, what each accepts, limits, your time zone
connect_channel A private 10-minute link to connect one platform
platform_settings Limits, title rules, link handling, pacing per platform
schedule_post clip_id | text | media_url → platforms[], scheduled_at, preview
list_scheduled_posts Scheduled, sending, posted, failed — with post links
update_scheduled_post Edit copy while still scheduled (the time never moves)
cancel_scheduled_post Cancel; undoable 72 h in the app
post_analytics Views, likes, comments, shares where the platform gives them
submit_to_clipspeed Start clipping a video or stream link → projectId
check_clips Finished 9:16 clips with titles, transcripts, viral scores
generate_image / generate_video / wait_for_generation
# Facebook: text/image/video · text 63,206Post to Facebook and other platforms from Grok Build
One request can book the same content to Facebook and other channels, each keeping its own settings and its own slot. Every platform below has its own Grok Build guide.
Also works with
Facebook and Grok Build: frequently asked questions
How do I post to Facebook from Grok Build?
Add the clipspeed server with the URL to Grok Build's MCP configuration (see its docs for the file location). Start Grok Build; complete the ClipSpeed sign-in when prompted, or use an API key header. Connect Facebook in ClipSpeed (or ask Grok Build for a connect link; it is private and valid for ten minutes), then describe the post in plain language. Grok Build reads the Facebook rules, drafts within them, shows the plan and books on your yes. Facebook is coming next; until the badge changes, the booking is refused with a plain message.
What can Grok Build post to Facebook through ClipSpeed?
Post text, images and video to a Facebook Page, with vertical video as a Reel. Facebook takes text, image and video posts. Text is limited to 63,206 characters.
Which Facebook settings can Grok Build control?
The fields in the settings reference above: text, hashtags, media_kind, clip_id or media_url, scheduled_at, preview. Mention any of them in plain language ("unlisted", "tomorrow at 9", "preview first") and Grok Build sets the matching field before it books.
Do I need a Facebook API key or developer account?
No. You connect Facebook to ClipSpeed once through Facebook's own sign-in, and Grok Build talks to ClipSpeed over OAuth. No Facebook developer key, bearer token or password is pasted anywhere.
How many Facebook posts a day can Grok Build schedule?
Planned: Text and image posts on Facebook are at least 60 minutes apart, up to 5 a day. Video on Facebook is at least 4 hours apart, up to 4 a day under your plan. When a time is taken, the booking is refused with the next open slot rather than moved. Ask for preview to see a day's plan and the remaining cap before anything is booked.
Can posts go out to Facebook while I am away?
Yes. Once booked, ClipSpeed publishes at the scheduled minute whether or not Grok Build is open. For unattended runs that decide what to post, use a headless agent such as Claude Code or Codex with the same account.
Is posting to Facebook from Grok Build different from Grok Bot?
The booking is identical: the same rules, the same calendar, the same refusals. What differs is where you work. Grok Build: terminal. Grok Bot: cloud, always on, routines on a cloud computer.