How to post to Facebook from Google Antigravity
Hand an agent the Page. It schedules the update when the task closes, with the link to whatever shipped.
How do I post to Facebook from Google Antigravity?
Add the planpo.st MCP server to Google Antigravity, connect Facebook once in the dashboard, then ask. The first three steps are one-time.
- 1
Create an API key and add planpo.st to Antigravity
Make a scoped key in planpo.st under Settings. Add the local planpost entry to mcp_config.json, the shared one in ~/.gemini/config or .agents inside a workspace. Antigravity substitutes ${PLANPOST_API_KEY} from the environment, so export the key and leave it out of the file.
- 2
Confirm the server is connected
In the agent panel open the menu, then MCP Servers, then Manage MCP Servers, and check that planpost is listed.
- 3
Connect Facebook
Connect a Facebook Page in the dashboard under Connections. planpo.st publishes to Pages; each Page is one connection, and the agent can produce the connect URL with get_connection_link.
- 4
Know what the post needs
A Facebook post needs text and nothing else. The limit is 63,206 characters, media is optional and no platformSettings are required.
- 5
Ask in the agent panel or the agy CLI
Say what to post and when. Antigravity finds the Facebook connection, creates the post, and tells you whether it was scheduled or kept as a draft, with the reason.
{
"mcpServers": {
"planpost": {
"command": "npx",
"args": ["-y", "planpost-mcp"],
"env": { "PLANPOST_API_KEY": "${PLANPOST_API_KEY}" }
}
}
}Config location: Shared: ~/.gemini/config/mcp_config.json · Per workspace: .agents/mcp_config.json. Replace pk_live_xxx with your own key.
Which transport does Google Antigravity use?
For Antigravity the tested route is the local server in mcp_config.json, with the key substituted from the environment. One entry covers the IDE, the agy CLI and the SDK, because all three read the same file.
- Antigravity substitutes ${VAR_NAME} from the environment, so export PLANPOST_API_KEY in your shell rather than pasting the key into the file.
- In the IDE you can reach the same file via the agent panel: ... menu -> MCP Servers -> Manage MCP Servers -> View raw config.
- Custom servers sit alongside the built-in MCP Store; a server added in the raw config appears with the store-installed ones.
The full walkthrough is on the Google Antigravity setup page.
What can Google Antigravity do on Facebook?
It can publish text posts with a link preview, single photos, multi-photo posts, videos and Reels to a Page, and it can leave a post unpublished as a draft on the Page. It cannot post to a personal profile or publish Facebook Stories.
Text and link
A text post. The first URL in it is attached as the link, which is what makes Facebook draw the preview card.
Photos
One image is a photo post, several are a multi-photo post.
Video or Reel
postType "reel" publishes a Reel. A portrait video of 180 seconds or less is routed to Reels as well.
Draft on the Page
optionalpublishAsDraft creates the post unpublished, for someone to review and publish inside Facebook.
Attachments are optional on Facebook. When a post should carry one, Antigravity can take it from disk: it calls upload_media for a presigned URL, PUTs the file there with a shell command, and passes the returned asset into create_post. Files already uploaded come back from list_media, ready to reuse.
Which settings does a Facebook post take?
Facebook reads two settings, both optional. Which Page receives the post is decided by the connection, not by a setting.
| Field | Allowed values | If you leave it out | Worth knowing |
|---|---|---|---|
| platformSettings.facebook.publishAsDraft | true or false | false, published live | true creates the post unpublished on the Page. It stays there until someone publishes it in Facebook. |
| platformSettings.facebook.isReel | true or false | Set from postType | postType "reel" or "short" sets it. A portrait video up to 180 seconds becomes a Reel without it. |
| postType | "post" or "reel" | "post" | "story" is accepted with a Facebook connection and has no Story publisher behind it, so do not use it for Facebook. |
| platformSettings.facebook.pageId | Not read | The connection's Page | Pick the Page with connectionIds. One connection is one Page. |
| platformContent.facebook | Text, 63,206 characters or fewer | The shared content | In practice the limit is never the problem. |
| media, platformMedia.facebook | Images, or one video | Text post | The first attachment decides the kind of post. With a video first, only that video is used. |
What do I type to post to Facebook from Google Antigravity?
Plain requests work. Each example lists the tool calls Google Antigravity makes in response.
1. Page post with a preview card
You say
Summarize the task you just finished in this workspace. Write a short Facebook Page post about it with the link to the full write-up, and schedule it for tomorrow 08:30.
Tool calls
create_post({ content: "<two or three sentences> https://...", connectionIds: ["<page id>"], schedule: "tomorrow 08:30" })A scheduled text post. At publish the first URL is attached as the link, so the Page shows the preview card and the link is tracked.
2. Leave it as a draft on the Page
You say
Read the spec in docs/feature.md. Prepare a Facebook post from it for the client's Page, but as an unpublished draft there. They want to press publish themselves.
Tool calls
create_post({ content: "<post text>", platformSettings: { facebook: { publishAsDraft: true } }, connectionIds: ["<client page id>"], schedule: "today 15:00" })At 15:00 the post is created on the Page as a draft, not shown to followers. The client finds it in the Page's own tools.
3. A photo set
You say
The image is in the workspace under recordings/still.jpg. Add the three other photos from the same shoot in my library and publish them together on the Page on Saturday 10:00.
Tool calls
upload_media({ filename: "cover.jpg", contentType: "image/jpeg", size: <bytes> })
PUT <file> to the returned URL (shell)
list_media({ type: "image" })
create_post({ content: "<caption>", media: [<4 images>], connectionIds: ["<page id>"], schedule: "saturday 10:00" })One multi-photo post. list_media returns items already shaped for the media array, so they pass straight through.
What stops a Facebook post from Google Antigravity?
The tag on a card is the code that comes back in the tool result.
Pages only
The publisher posts to the Page behind the connection. Personal profiles and groups are not targets.
No Facebook Stories
Stories are published for Instagram. A Facebook connection has no Story path, so a "story" post would go out as an ordinary photo or video.
The first URL becomes the card
In a text post the first link is the one Facebook previews. Put the link you care about first, or keep it to one.
Vertical video goes to Reels
Portrait video of 180 seconds or less is sent as a Reel even with post type "post". Landscape video stays a regular video post.
One video per post
When the first attachment is a video, the rest are ignored. Photos and video do not mix in one post.
63,206 characters
char_limitThe check exists and you will not hit it by accident.
One config, three surfaces
AntigravitySince 2.x the IDE, the agy CLI and the SDK read the same mcp_config.json. Add planpost once and an agent started from any of them has the tools, which also means any of them can post.
Can Google Antigravity tell me what a Facebook post earned?
Yes. Links in Facebook posts are clickable and the first one becomes the preview card, so a tracked link gets clicks that payments can be matched to. get_revenue_overview returns the totals and recent transactions. Pages that sell physical products tend to have Shopify behind them, and that is the integration I would connect first.
Google Antigravity and Facebook: questions people ask
- Can it post to my personal Facebook profile?
- No. It publishes to Facebook Pages. Each connected Page has its own connection ID.
- What does publishAsDraft do?
- It creates the post on the Page unpublished. Nobody sees it until someone publishes it from Facebook's own tools, which suits a client who wants the last click.
- What happens when Antigravity sends a Facebook post that breaks a rule?
- It is told at once. The usual case on Facebook is a Page whose connection has lapsed: the post is kept as a draft and the tool result carries connection_inactive plus the fix, which Antigravity applies with update_post.
- Is planpo.st in Antigravity's MCP Store?
- Not today. It goes in as a custom server through the raw config and then shows up next to the store-installed ones. The Facebook tools work the same either way.
- Can an autonomous agent publish without me?
- It can if the key allows it, so decide that with the key. A key that requires approval turns each Facebook post into a request with an approve link, and the agent can carry on with other work while it waits.
Keep going
Facebook from other agents
Other networks from Antigravity