I'd like to allow users of my mobile website to upload a photo, enter a tag and caption in Mobile Safari, then open Instagram with that image, tag and caption pre-populated.
Based on this documentation, it's possible to pre-populate the image and tag, but the only mention of pre-populating a caption is "To include a pre-filled caption with your photo, you can set the annotation property on the document interaction request to an NSDictionary containing an NSString under the key "InstagramCaption."
Can I use a custom URL, something like: instagram://media?id=999&tag?name=sweet_tag&InstagramCaption?caption='My sweet caption.' to pre-populate an image, tag and caption?
This feature does exist, it just hasn't been added to the documentation yet.
Starting with our next release (2.3.0) you'll be able to pass in a caption parameter to the camera URL hook, like so:
instagram://camera?caption=hello
Make sure it's properly URL-encoded (# should be %23, etc)
Submitted to Apple, so should be out in the near future.
Cheers, -- Mike Krieger Co-founder, Instagram
https://groups.google.com/forum/?fromgroups=#!topic/instagram-api-developers/0lsJyFcfYPw
来源：https://stackoverflow.com/questions/12586775/is-it-possible-to-send-a-caption-annotation-to-instagram-via-its-custom-url-sche