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Buf

Buf is a modern developer platform for Protocol Buffers and gRPC, providing a CLI toolchain, schema registry, and streaming infrastructure. It replaces traditional protoc-based workflows with linting, breaking change detection, code generation, remote plugins, and the Buf Schema Registry (BSR) for centralized schema distribution. Buf also offers Bufstream, a Kafka-compatible streaming platform built on Protobuf. Used by enterprises including EA, Intel, IBM, OpenAI, and Okta.

human only

Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.

Kin Score

API Evangelist profiles Buf the way a machine reads it — 17 machine-readable artifacts across 3 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.

Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Buf scores 33.4/100 (thin), with a separate agent-readiness read of 7/100 (human only). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.

Kin Score

This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 33.4/100 · thin
Contract Quality 0.0 / 25
Developer Ergonomics 3.0 / 20
Commercial Clarity 16.8 / 20
Operational Transparency 4.8 / 13
Governance 0.0 / 12
Discoverability 8.8 / 10
Agent readiness — 7/100 · human only
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 15
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3

How we profile Buf

Each block below is one kind of artifact we hold for Buf. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.

APIs 3

Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.

Individual APIs this provider publishes, each with its own machine-readable definition.

Buf Schema Registry (BSR)

The Buf Schema Registry (BSR) is a centralized repository for managing, distributing, and documenting Protobuf schemas. It provides dependency management, generated SDKs in mult...

Buf CLI

The Buf CLI is a local Protobuf development toolchain providing linting, breaking change detection, code generation, formatting, dependency management, and schema push/pull to t...

Bufstream

Bufstream is a Kafka-compatible streaming platform built on Protocol Buffers. It provides schema enforcement, Iceberg integration, and administrative tooling for managing Kafka-...

Pricing Plans 1

Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the six things the Kin Score reads for commercial clarity.

Published pricing tiers and plan structures.

Buf Plans Pricing

3 plans

PLANS

Rate Limits 1

Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.

Documented rate limits and quota policies.

Buf Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.

Cost, billing, and metering signals for API financial operations.

Buf Finops

FINOPS

Features 6

The notable capabilities this provider advertises, captured as structured features so they can be searched and compared instead of read one landing page at a time.

Notable capabilities this provider offers.

buf lint

buf breaking

buf generate

buf push / buf dep

Reflection API

Language Server Protocol

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Buf Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Use Cases 4

What developers actually build with this provider — captured so the catalogue answers 'what is this for', not just 'what does this expose'.

What developers build with this provider.

Protobuf Schema Management

Code Generation

API Linting and Governance

gRPC and ConnectRPC Development

Resources

Every other property we hold for Buf — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.

Get Started 3

Portal, sign-up, and the first successful call

Documentation 1

Reference material describing how the API behaves

Build 2

SDKs, sample code, and the tooling you integrate with

Access & Security 1

Authentication, authorization, and security posture

Operate 2

Status, limits, changes, and where to get help

Commercial 3

Pricing, plans, and the legal terms of use

← All providers · Data indexed from github.com/api-evangelist/buf · machine-readable index on apis.io