Back in the early years of Snowplow, we adopted a similar approach for our support of 3rd party webhooks[1] as an event stream source supported natively by Snowplow (https://github.com/snowplow/snowplow). (The important background here is that all events and entities flowing through Snowplow are described using versioned JSON Schema).

We built a kind of Maven Central for 3rd party webhooks' schemas[2], and got to work adding schemas for various popular webhooks, e.g. Sendgrid and Pingdom. But, we never met a single SaaS vendor who was interested in 'adopting' the JSON Schemas for their webhook, let alone publishing versioned JSON Schemas for their whole API. This meant that at Snowplow we have stayed on the hook for keeping these vendors' webhook schema definitions up to date in our registry.

It's a real tragedy of the commons - oceans of developer time wasted on tedious low-leverage work (updating API client code) so that each SaaS vendor can 'move fast and break things'. The ultimate irony is that if these vendors were to adopt, publish and respect versioned schema definitions internally, using something like OpenAPI, they would see huge productivity gains (think enhanced CI/CD testing, auto-gen of client code etc).

1. https://docs.snowplowanalytics.com/docs/getting-started-on-s... 2. https://github.com/snowplow/iglu-central/tree/master/schemas