Cross Domain · format · Google IDL — used pervasively across CNCF projects, not itself LF-governed

Protocol Buffers

Protocol Buffers (protobuf) is Google’s language- and platform-neutral mechanism for serializing structured data, defined by a .proto schema and encoded as a compact binary format. It is the interface definition language and wire format underneath gRPC, prized for efficient, strongly-typed communication between services.

protobuf.dev/The standard

Google IDL — used pervasively across CNCF projects, not itself LF-governedGoverning body · Not Linux Foundation governed

proto3 / proto2 plus EditionsCurrent version

Yes — Protocol BuffersMachine-readable schema · open

16providers in the catalog

Also known as Protobuf, protobuf, Proto, Google Protocol Buffers.

Providers that carry Protocol Buffers 16

These providers' own APIs.json profiles carry Protocol Buffers as a tag — the provider's statement that the standard is part of what it does. APIs.io has not verified the implementation on this page; the de facto profiles on this site are where that measurement exists. Ordered by Kin Score.

Bufstrong · 65.3 AGNTCYdeveloping · 48.9 AgiBotdeveloping · 47.1 gRPCdeveloping · 43.9 EngFlowdeveloping · 43.3 Aalyriathin · 36.3 Hailothin · 33.3 Science Corporationthin · 33.1 TypeSpecthin · 31.1 Kratosthin · 29.3 Protocol Buffersemerging · 26.0 Kitexemerging · 23.1 Twirpemerging · 22.4 Connect-RPCemerging · 15.0 Utilidataemerging · 11.5 Binary Formatminimal · 6.3

Reading

The Open Source Community Tooling Built on Protocol Buffers 2020-06-11
REST and gRPC Side by Side In New Google Endpoints Documentation 2018-04-18
API Design Industry Guide: gRPC, Open Source RPC Framework 2017-09-28

Read from the API Evangelist standards directory, facts verified 2026-08-17. Provider links come from the catalog's own identity tags and are rebuilt nightly. If this page is wrong about a standard or a provider, say so.