Prompt
When a new file lands in the Dropbox folder "Instagram ready", use the filename as the topic, write a 2-sentence caption with ChatGPT by Zapier, upload the image, and send it as an Instagram draft.How to do it
- Connect Instagram and mint a key In https://app.socialhandoff.com, open Connections, connect an Instagram professional account (Business or Creator). Then create an agent key named Zapier scoped to Instagram with draft permission.
- Set up the trigger Pick a trigger such as a new file in a Dropbox or Google Drive folder, and add a step that writes the caption, for example ChatGPT by Zapier.
- Import media by URL Add a Webhooks by Zapier Custom Request: POST https://app.socialhandoff.com/v1/media/import with JSON {"url": public https link, "alt": description} for the JPEG image, Reel, or carousel (up to 10 items). No multipart needed. Keep the id it returns for the next step.
- Create the post Add a Webhooks by Zapier Custom Request: POST https://app.socialhandoff.com/v1/posts with a bearer header and JSON body {"body": caption, "networks": ["instagram"], "mode": "submit", "mediaIds": [the uploaded ids]}. The post lands in the approval inbox.
- Review and approve Check the caption, hashtag count, and alt text on the approval card. On approval, the post publishes; if Instagram's daily quota is full, it is deferred by an hour.
Example draft
Fresh from the studio: the autumn collection, glazed in a rust red we have been testing all summer. Every piece is thrown and fired by hand, so no two are quite the same. #ceramics #handmade #pottery #autumn [Image: JPEG from the Dropbox folder, alt text: "Rust red ceramic mugs on a wooden shelf"]
Gotchas
- Images must be JPEG (up to 8 MB). A PNG screenshot is not accepted, so convert it before upload.
- Zapier may retry a failed step. Send an idempotencyKey built from the trigger record's id so a retry returns the same draft instead of a second one.
- Captions allow 2,200 characters, 30 hashtags, and 20 mentions. A thread is joined into one caption, so a 5-part draft becomes one long caption.
- Account type: Professional accounts only (Business or Creator). Personal accounts cannot publish through the API.
- Media: Every post needs an image or video. Text-only posts are not possible on Instagram.
- Image files: JPEG only, up to 8 MB. Convert PNG or WebP before posting.
- Reels: Video posts publish as Reels, from MP4 or MOV files.
Frequently asked questions
Does it work with a personal Instagram account?
No. Instagram only allows publishing through its API for professional accounts, Business or Creator. Switching is free in the Instagram app settings.
Is there a native Zapier app?
Not today. Webhooks by Zapier calls the REST API with a bearer header: one JSON request imports the media by URL, another creates the draft.
Can I post Reels?
Yes. Attach an MP4 or MOV video and it publishes as a Reel with your caption.