How to post to Instagram from Google Antigravity
An Antigravity agent renders a carousel from a spec document and schedules it to Instagram as part of the same task that wrote the spec.
How do I post to Instagram from Google Antigravity?
Add the planpo.st MCP server to Google Antigravity, connect Instagram 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 ${PLANPOST_API_KEY} from the environment, so export the key and leave it out of the file.
- 2
Confirm the server is connected
In the agent panel open the menu, then MCP Servers, then Manage MCP Servers, and check that planpost is listed.
- 3
Connect Instagram
Connect a professional Instagram account in the dashboard under Connections, either through its linked Facebook Page or with Instagram login. When it asks for permissions, leave publishing ticked or posts will fail later.
- 4
Know what the post needs
An Instagram post needs at least one image or video. Captions run to 2,200 characters. Nothing in platformSettings is required; postType picks between a feed post, a Reel and a Story.
- 5
Ask in the agent panel or the agy CLI
Say what to post and when. Antigravity finds the Instagram connection, creates the post, and tells you whether it was scheduled or kept as a draft, with the reason.
{
"mcpServers": {
"planpost": {
"command": "npx",
"args": ["-y", "planpost-mcp"],
"env": { "PLANPOST_API_KEY": "${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 Instagram?
It can publish single images, carousels of up to 10 items, Reels and Stories, and invite up to 3 collaborators on image and carousel posts. It cannot publish a post without media or make a caption link clickable.
Image or carousel
1 to 10One image is a feed post, two to ten attachments are a carousel. JPEG is what Instagram accepts; PNG files are converted on the way.
Reel
postType "reel" with one video. coverImageTime picks the cover frame, in seconds.
Story
postType "story" with one image or one video.
Collab post
up to 3platformSettings.instagram.collaborators takes Instagram usernames. Works on image and carousel posts.
Instagram needs an image or video on every post, and 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 Instagram post take?
Instagram reads four settings. Two of them, isReel and isStory, are older flags that postType now sets for you, so in practice an agent sends postType plus the two optional ones.
| Field | Allowed values | If you leave it out | Worth knowing |
|---|---|---|---|
| postType | "post", "reel" or "story" | "post" | Takes precedence over the flags below. A vertical video, or one of 90 seconds or less, is published as a Reel even when this says "post". |
| platformSettings.instagram.isReel | true or false | Set from postType | If it disagrees with an explicit postType it is ignored and the response carries post_type_flag_ignored. |
| platformSettings.instagram.isStory | true or false | Set from postType | Same rule as isReel. Prefer postType "story". |
| platformSettings.instagram.coverImageTime | Seconds into the video | Instagram picks the frame | Reels only. 0 counts as not set. |
| platformSettings.instagram.collaborators | Up to 3 usernames, with or without @ | No collaborators | Single-image and carousel posts only. A fourth name is dropped, and the field is not sent for Reels or Stories. |
| media, platformMedia.instagram | 1 to 10 items. JPEG or PNG images, MP4 or MOV video | None, required | No media saves the post as a draft with media_required. More than 10 fails at publish. |
| platformContent.instagram | Caption, 2,200 characters or fewer | The shared content | A URL in the caption returns a link_not_clickable warning. More than 30 hashtags returns hashtags_over_limit. |
What do I type to post to Instagram from Google Antigravity?
Plain requests work. Each example lists the tool calls Google Antigravity makes in response.
1. Carousel from something you wrote
You say
Summarize the task you just finished in this workspace. Turn it into a 6-slide Instagram carousel in my brand kit and schedule it for Wednesday 18:00.
Tool calls
list_brand_kits()
generate_carousel({ content: "<source text>", platform: "instagram", maxSlides: 6 })
render_carousel({ slides: [...], family: "<id>", brandKitId: "<kit id>" })
get_carousel_render({ id: "<render id>" })
create_post({ content: "<caption>", media: [<6 assets>], connectionIds: ["<instagram id>"], schedule: "wednesday 18:00" })Six slides rendered server-side as images, saved to the media library and scheduled as one carousel. The render tops out at 10 slides, which is also Instagram's cap.
2. A Reel with a chosen cover
You say
The clip is in the workspace under recordings/demo.mp4. Schedule it as an Instagram Reel on Friday 19:00 with the cover taken 3 seconds in.
Tool calls
upload_media({ filename: "demo.mp4", contentType: "video/mp4", size: <bytes> })
PUT <file> to the returned URL (shell)
create_post({ content: "<caption>", postType: "reel", platformSettings: { instagram: { coverImageTime: 3 } }, media: [<video>], connectionIds: ["<instagram id>"], schedule: "friday 19:00" })One scheduled Reel. The video has to be MP4 or MOV; anything else is refused with the format named.
3. A collab post
You say
The image is in the workspace under recordings/still.jpg. Post it to Instagram tomorrow 11:00 as a collab with @partnerstudio, caption about the joint launch.
Tool calls
upload_media({ filename: "cover.jpg", contentType: "image/jpeg", size: <bytes> })
PUT <file> to the returned URL (shell)
create_post({ content: "<caption>", platformSettings: { instagram: { collaborators: ["partnerstudio"] } }, media: [<image>], connectionIds: ["<instagram id>"], schedule: "tomorrow 11:00" })An image post that invites the other account as a collaborator. They still have to accept the invite in Instagram before it shows on their profile.
What stops a Instagram post from Google Antigravity?
The tag on a card is the code that comes back in the tool result.
No media, no post
media_requiredA text-only post that targets Instagram is saved as a draft. If the same post also goes to X or LinkedIn, give Instagram its own attachments in platformMedia.instagram.
Image rules
JPEG, at least 320 pixels wide, 8 MB or smaller, aspect ratio between 4:5 and 1.91:1. PNG is converted to JPEG. GIF and WebP are refused.
10 items per carousel
Eleven attachments fail at publish with the count in the error. Trim the set before scheduling.
Short or vertical video becomes a Reel
A portrait video, or any video of 90 seconds or less, is published as a Reel whatever the post type says. Instagram does not take those as feed video.
Caption links do not work
link_not_clickableInstagram shows the URL as plain text. The create call warns about it and still schedules the post.
30 hashtags
hashtags_over_limitPast 30 the response carries a warning with the count.
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 Instagram post earned?
Partly. A caption link on Instagram is not clickable, so a tracked link in a caption has nothing to click and the post earns no attributed revenue from it. The clickable places are the bio link and Story link stickers, and the Instagram guide covers how those are tracked. get_revenue_overview returns totals either way, and for shops selling through Instagram the other end is usually Shopify.
Google Antigravity and Instagram: questions people ask
- Which image formats does it accept for Instagram?
- JPEG, and PNG which is converted to JPEG before upload. GIF and WebP are refused. Images must be at least 320 pixels wide, 8 MB or less, and between 4:5 and 1.91:1.
- Why did my video post as a Reel?
- Because it was vertical or no longer than 90 seconds. Instagram accepts those as Reels only, so the publisher routes them there.
- What happens when Antigravity sends a Instagram post that breaks a rule?
- It is told at once. The usual case on Instagram is a post with no image or video: the post is kept as a draft and the tool result carries media_required 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 Instagram 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 Instagram post into a request with an approve link, and the agent can carry on with other work while it waits.
Keep going
Instagram from other agents
Other networks from Antigravity