The other thread also mentions Prismic being read-only as the reason for not supporting POST. If that is the concern, you can now use HTTP QUERY for read-only idempotent requests. Is that something you could support?
Thanks for following up, and for the pointer to the HTTP QUERY method. Here’s where things stand today:
The GraphQL API is deprecated. It remains available for existing projects, but it’s no longer recommended for new ones, so we don’t plan to add POST or QUERY support to it.
The Content API (REST v2) is the recommended way to query Prismic. It’s GET-based, with query options passed as URL parameters. The Content API reference covers the details.
For Apollo Kotlin users, this means GraphQL requests to Prismic will continue to need GET. For new projects, we’d point people to the Content API.