API
Under Technique, API covers how systems expose and consume programmatic interfaces—contracts for moving data and invoking behavior across process and network boundaries.
In this subcategory: style and protocol choices for service interfaces—REST (default for HTTP APIs), gRPC (RPC/protobuf where it fits), GraphQL (query layer; hold for new greenfield work in our garden). Related: OpenAPI for describing and documenting HTTP APIs; RPC as the broader pattern gRPC builds on.
Garden stance: adopt REST with OpenAPI specs for most HTTP services. assess gRPC for internal high-performance or tooling-shaped RPC (e.g. provider plugins). hold GraphQL unless you have a concrete hyper-scale or client-heterogeneity problem it solves better than REST + OpenAPI.
Tag an item here when the note is about an API style or protocol, not a specific product SDK or agent tool surface.