See How to write an Indra Augmentation Proposal for information about the formatting of an IAP proposal. Proposals are to be made via creating a fork of this repository and using a GitHub Pull Request on your document, which if accepted, will then place your draft in the next available number.
A template is available that will let you quickly get started filling out the details of your proposal.
We specifically most especially welcome contributions from developers intending to integrate Indra into their application, though note that such proposals are to be marked as "Integration" in the "type" field, as they will not be implemented, mostly, by us, though they may entail merging extra code into the main repository.
To make a proposal, fork this repository, and add your proposal file with the syntax:
iap-username-short_title_of_proposal.md
to the proposals/ folder.