API registry / Builder.io
Builder.io
No machine-readable spec found (checked the docs site, its llms.txt and common openapi.json paths). The APIs are documented in HTML only: Content API https://www.builder.io/c/docs/content-api, Write API https://www.builder.io/c/docs/write-api and GraphQL Content API https://www.builder.io/c/docs/graphql-api.
Apideck doesn't connect Builder.io yet, so its tools aren't available to your agent here. It's listed for its spec.
Builder.io publishes no machine-readable API spec.