How Instagram Publishing Works with Postproxy
Instagram's publishing model
Instagram's Graph API uses a two-step container-based publishing flow: you first create a media container with your image or video, wait for it to process, then publish the container to the user's feed. For carousels, each item needs its own container, then a parent container wraps them all. Postproxy collapses this into a single API call — send your media URLs, text, and platform parameters, and the container orchestration happens behind the scenes.
Reels, Stories, and feed posts in one request
Instagram treats Reels, Stories, and feed posts as different publishing flows with different endpoint requirements and media constraints. Reels require video under 15 minutes, Stories expire after 24 hours and don't support text-only posts, and feed posts allow carousels of up to 10 items. With Postproxy you set a format parameter — post, reel, or story — and the API handles the routing and validation for each format automatically.
Common gotchas Postproxy handles for you
Instagram's API is notoriously strict about media formats. Images must be JPEG, and videos need specific codec and aspect ratio requirements that differ by format. The API also rate-limits container creation separately from publishing, and container processing is asynchronous — you need to poll for completion before publishing. Postproxy validates media constraints before uploading, manages the async polling loop, and retries on transient failures so your integration doesn't need to handle these edge cases.
Collaborators, covers, and first comments
Instagram-specific features like tagging collaborators on Reels, setting custom cover images, and posting a first comment immediately after publishing all require separate API calls or additional parameters in the container creation step. Postproxy exposes these as simple fields in the platform-specific parameters object — set collaborators, cover_url, or first_comment and they're applied as part of the same publish request.
