Buf

Buf Technologies builds the modern toolchain for Protocol Buffers and gRPC: the buf CLI, the Buf Schema Registry (BSR), Protovalidate, Protobuf-ES and Protobuf-Py, and the Connect protocol, which is now a CNCF project. It replaces protoc-based workflows with linting, breaking-change detection, code generation, remote plugins, policy checks and centralized schema distribution. Buf's own public API is published as Protobuf rather than OpenAPI — 33 services and 85 RPCs served over Connect, gRPC and gRPC-Web at the root of buf.build, Apache-2.0 licensed at github.com/bufbuild/registry-proto — and the same surface is exposed to agents as a remote MCP server at https://buf.build/mcp. Used by enterprises including EA, Intel, IBM, OpenAI and Okta. Bufstream, Buf's Kafka-compatible streaming platform, was acquired by CoreWeave in May 2026 and is no longer a Buf product.

Buf publishes 2 APIs on the APIs.io network. Tagged areas include Code Generation, gRPC, Kafka, Open Source, and Protocol Buffers.

The Buf catalog on APIs.io includes 1 event-driven AsyncAPI specification.

Buf’s developer surface includes documentation, engineering blog, pricing, signup flow, API reference, getting-started guide, support, and 43 more developer resources.

🌐 Visit website 📡 Source on GitHub

65.3/100 strong ▬ flat Agent 49/100 agent ready Front door AI 2/6 trace open core · Apache-2.0 Full breakdown ↓
scored 2026-09-25 · rubric v0.23.0

AccessFreemium

2 APIs 1 MCP Servers 6 Features 4 Use Cases

Code Generation gRPC Kafka Open Source Protocol Buffers Schema Registry SDK Streaming

Kin Score

Kin Score How this is scored →
scored 2026-09-25 · rubric v0.23.0

Composite quality — 65.3/100 · strong

Contract Quality 7.3 / 19

Developer Ergonomics 12.9 / 15

Access Clarity 12.8 / 15

Operational Transparency 9.0 / 10

Contract Governance 1.6 / 9

Discoverability 5.0 / 8

Regulatory Posture 6.8 / 15

Open Source Surface 2.5 / 10

Agent readiness — 49/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 12

Machine-Readable Auth 10 / 10

Idempotency 9 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 6 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 6 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 6 / 6

Agentic Commerce Well-Known Document 0 / 5

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Open Source Surface applies to this provider. This product is open source and we read its repository directly, so Open Source Surface carries 10 points of the composite. It is scored from what the repository actually publishes — a security policy, a contribution guide, a release history, a code of conduct — read live from the provider rather than inferred from our own catalog pointers. This facet adds; nothing was taken away to make room for it. An open-source project is not excused from the commercial facets, because exemption would strip it of the points it does earn. If we have the wrong repository, or this product is not open source, say so on your provider repo and we will drop the facet rather than have you publish against it.

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 75 points between them, because both conditional facets apply and carry 25 points together. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/buf: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 2

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...

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Buf MCP Server

The Buf Schema Registry exposes its public v1 Registry API as MCP tools so an agent can find a module, fetch its schema, and inspect commits and labels without a generated clien...

MCP SERVER

Pricing Plans 1

Published pricing tiers and plan structures.

Buf Plans Pricing

4 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Buf Rate Limits

4 limits

RATE LIMITS

FinOps 1

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

Buf Finops

FINOPS

Features 6

Notable capabilities this provider offers.

buf lint

buf breaking

buf generate

buf push / buf dep

Reflection API

Language Server Protocol

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

Buf Bsr Webhooks

ASYNCAPI

Security Posture 3

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

Buf Authentication

3 schemes

SECURITY

Buf Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Buf Vulnerability Disclosure

Hackerone

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Buf Scopes

OAuth 2.0 · no documented scopes

0 scopes

SCOPES

Use Cases 4

What developers build with this provider.

Protobuf Schema Management

Code Generation

API Linting and Governance

gRPC and ConnectRPC Development

Resources

Get Started 6

Portal, sign-up, and the first successful call

Signup

Signup

Login

SchemaRegistry

DeveloperPortal

GettingStarted

Sandbox

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

MCPServer

AgentSkill

LLMsTxt

WellKnown

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

Lifecycle

Conventions

Idempotency

ErrorCatalog

DataModel

Webhooks

Conformance

Scroll for all 7

Build 6

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubRepository

Packages

SDKs

Go SDK

CLI

Access & Security 6

Authentication, authorization, and security posture

DomainSecurity

Authentication

OAuthScopes

Compliance

VulnerabilityDisclosure

VulnerabilityDisclosure

Security

Security

Operate 9

Status, limits, changes, and where to get help

IssueTracker

Releases

Contact

Community

Support

StatusPage

Deprecation

ChangeLog

RateLimits

Scroll for all 9

Commercial 5

Pricing, plans, and the legal terms of use

License

Pricing

TermsOfService

PrivacyPolicy

Plans

Company 4

The organization behind the API

LinkedIn

Website

Website

Blog

Blog

BlogRSS

BlogRSS

Other 1

Properties that don't map to a standard resource type

Protobuf

Protobuf

Source (apis.yml)

aid: buf
name: Buf
description: 'Buf Technologies builds the modern toolchain for Protocol Buffers and gRPC: the buf CLI, the Buf Schema Registry
  (BSR), Protovalidate, Protobuf-ES and Protobuf-Py, and the Connect protocol, which is now a CNCF project. It replaces protoc-based
  workflows with linting, breaking-change detection, code generation, remote plugins, policy checks and centralized schema
  distribution. Buf''s own public API is published as Protobuf rather than OpenAPI — 33 services and 85 RPCs served over Connect,
  gRPC and gRPC-Web at the root of buf.build, Apache-2.0 licensed at github.com/bufbuild/registry-proto — and the same surface
  is exposed to agents as a remote MCP server at https://buf.build/mcp. Used by enterprises including EA, Intel, IBM, OpenAI
  and Okta. Bufstream, Buf''s Kafka-compatible streaming platform, was acquired by CoreWeave in May 2026 and is no longer
  a Buf product.'
type: Index
deliveryModel:
  model: open-core
  license: Apache-2.0
  open_source: true
  commercial: true
  callable_host: false
  label: Open core · an OSS project plus a commercial hosted product
  confidence: high
  source:
  - license
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/buf.png
url: https://raw.githubusercontent.com/api-evangelist/buf/refs/heads/main/apis.yml
created: '2026-03-25'
modified: '2026-09-13'
specificationVersion: '0.23'
tags:
- Code Generation
- gRPC
- Kafka
- Open Source
- Protocol Buffers
- Schema Registry
- SDK
- Streaming
tags_raw:
- Code Generation
- gRPC
- Kafka
- Open Source
- Protocol Buffers
- Schema Registry
- SDKs
- Streaming
- Open-Source
apis:
- aid: buf:buf-schema-registry
  name: Buf Schema Registry (BSR)
  description: The Buf Schema Registry (BSR) is a centralized repository for managing, distributing, and documenting Protobuf
    schemas. It provides dependency management, generated SDKs in multiple languages, remote plugins for code generation,
    and a Reflection API for runtime schema discovery.
  humanURL: https://buf.build/product/bsr
  tags:
  - Code Generation
  - Protocol Buffers
  - Schema Registry
  - SDK
  tags_raw:
  - Code Generation
  - Protocol Buffers
  - Schema Registry
  - SDKs
  properties:
  - type: Documentation
    url: https://buf.build/docs/bsr/
  - type: GettingStarted
    url: https://buf.build/docs/bsr/quickstart/
  - type: Authentication
    url: authentication/buf-authentication.yml
  - type: APIReference
    url: https://buf.build/docs/bsr/apis/api-access/
  - type: Protobuf
    url: grpc/buf-grpc-index.yml
  - type: MCPServer
    url: mcp/buf-mcp.yml
  - type: ToolCrosswalk
    url: mcp/buf-tool-crosswalk.yml
  - type: OAuthScopes
    url: scopes/buf-scopes.yml
  - type: Conventions
    url: conventions/buf-conventions.yml
  - type: Idempotency
    url: conventions/buf-conventions.yml
  - type: ErrorCatalog
    url: errors/buf-problem-types.yml
  - type: DataModel
    url: data-model/buf-data-model.yml
  - type: RateLimits
    url: rate-limits/buf-rate-limits.yml
  - type: Webhooks
    url: asyncapi/buf-bsr-webhooks.yml
- aid: buf:buf-cli
  name: Buf CLI
  description: The Buf CLI is a local Protobuf development toolchain providing linting, breaking change detection, code generation,
    formatting, dependency management, and schema push/pull to the Buf Schema Registry. It replaces protoc with a faster,
    more developer-friendly interface.
  humanURL: https://buf.build/product/cli
  tags:
  - CLI
  - Code Generation
  - Linting
  - Protocol Buffers
  properties:
  - type: Documentation
    url: https://buf.build/docs/cli/
  - type: GettingStarted
    url: https://buf.build/docs/cli/quickstart/
  - type: GitHubRepository
    url: https://github.com/bufbuild/buf
  - type: CLI
    url: cli/buf-cli.yml
  - type: APIReference
    url: https://buf.build/docs/reference/cli/buf/
common:
- type: IssueTracker
  url: https://github.com/bufbuild/buf/issues
- type: Releases
  url: https://github.com/bufbuild/buf/releases
- type: License
  name: Apache-2.0
  url: https://github.com/bufbuild/buf/blob/main/LICENSE
- type: DomainSecurity
  url: security/buf-domain-security.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/bufbuild
- type: Website
  url: https://buf.build
- type: Documentation
  url: https://buf.build/docs
- type: GitHubOrganization
  url: https://github.com/bufbuild
- type: GitHubRepository
  url: https://github.com/bufbuild/buf
- type: Blog
  url: https://buf.build/blog
- url: https://buf.build/blog/rss.xml
  type: BlogRSS
  description: Discovered RSS/Atom feed for https://buf.build/blog
- type: Pricing
  url: https://buf.build/pricing
- type: Signup
  url: https://buf.build/signup
- type: Login
  url: https://buf.build/login
- type: Contact
  url: https://buf.build/contact
- type: TermsOfService
  url: https://buf.build/legal/terms-of-use
- type: PrivacyPolicy
  url: https://buf.build/legal/privacy-policy
- type: Community
  url: https://buf.build/b/slack
- type: SchemaRegistry
  url: https://buf.build/registry
- type: DeveloperPortal
  url: https://buf.build/docs
- type: APIReference
  url: https://buf.build/docs/bsr/apis/api-access/
- type: GettingStarted
  url: https://buf.build/docs/bsr/quickstart/
- type: Support
  url: https://buf.build/docs/contact/
- type: StatusPage
  url: https://status.buf.build
- type: Lifecycle
  url: lifecycle/buf-lifecycle.yml
- type: Deprecation
  url: lifecycle/buf-lifecycle.yml
- type: ChangeLog
  url: changelog/buf-changelog.yml
- type: Protobuf
  url: grpc/buf-grpc-index.yml
- type: MCPServer
  url: mcp/buf-mcp.yml
- type: AgentSkill
  url: skills/_index.yml
- type: LLMsTxt
  url: llms/buf-llms.txt
- type: Packages
  url: packages/buf-packages.yml
- type: SDKs
  url: packages/buf-packages.yml
- type: Go SDK
  url: https://pkg.go.dev/buf.build/gen/go/bufbuild/registry/connectrpc/go
- type: CLI
  url: cli/buf-cli.yml
- type: Sandbox
  url: sandbox/buf-sandbox.yml
- type: Conventions
  url: conventions/buf-conventions.yml
- type: Idempotency
  url: conventions/buf-conventions.yml
- type: Authentication
  url: authentication/buf-authentication.yml
- type: OAuthScopes
  url: scopes/buf-scopes.yml
- type: ErrorCatalog
  url: errors/buf-problem-types.yml
- type: DataModel
  url: data-model/buf-data-model.yml
- type: RateLimits
  url: rate-limits/buf-rate-limits.yml
- type: Plans
  url: plans/buf-plans-pricing.yml
- type: Webhooks
  url: asyncapi/buf-bsr-webhooks.yml
- type: Conformance
  url: conformance/buf-conformance.yml
- type: Compliance
  url: conformance/buf-conformance.yml
- type: WellKnown
  url: well-known/buf-well-known.yml
- type: VulnerabilityDisclosure
  url: security/buf-vulnerability-disclosure.yml
- type: Security
  url: security/buf-vulnerability-disclosure.yml
- name: Use Cases
  type: UseCases
  data:
  - name: Protobuf Schema Management
    url: https://buf.build/product/bsr
    features:
    - Centralized Schema Registry
    - Module Versioning
    - Dependency Management
    - Schema Discovery
    - API Documentation Generation
    - Breaking Change Prevention
  - name: Code Generation
    url: https://buf.build/docs/generate/
    features:
    - Multi-Language SDK Generation
    - Remote Plugin Execution
    - Go SDK Generation
    - Python SDK Generation
    - TypeScript/npm SDK Generation
    - Java/Maven SDK Generation
    - Rust/Cargo SDK Generation
    - Swift SDK Generation
    - .NET/NuGet SDK Generation
  - name: API Linting and Governance
    url: https://buf.build/docs/lint/
    features:
    - Protobuf Style Enforcement
    - Breaking Change Detection
    - CI/CD Integration
    - Custom Policy Rules
    - Field Deprecation Tracking
  - name: gRPC and ConnectRPC Development
    url: https://connectrpc.com/
    features:
    - gRPC Server Support
    - Connect Protocol
    - Browser-Compatible RPC
    - Mobile Client Support
    - Protovalidate Semantic Validation
- name: Features
  type: Features
  data:
  - name: buf lint
    url: https://buf.build/docs/lint/
    features:
    - Style Guide Enforcement
    - Default and Custom Rules
    - CI/CD Compatible
    - Per-File Ignore Rules
  - name: buf breaking
    url: https://buf.build/docs/breaking/
    features:
    - Breaking Change Detection
    - Wire Compatibility Checks
    - Source Compatibility Checks
    - Git-Based Comparison
  - name: buf generate
    url: https://buf.build/docs/generate/
    features:
    - Multi-Language Code Generation
    - Remote Plugin Support
    - Managed Mode
    - Template Configuration
  - name: buf push / buf dep
    url: https://buf.build/docs/bsr/
    features:
    - Schema Publishing
    - Dependency Resolution
    - Module Locking
    - Version Tagging
  - name: Reflection API
    url: https://buf.build/docs/bsr/reflection/
    features:
    - Runtime Schema Discovery
    - gRPC Server Reflection
    - Prototransform Integration
  - name: Language Server Protocol
    url: https://buf.build/docs/cli/
    features:
    - IDE Integration
    - Inline Linting
    - Autocomplete Support
    - VS Code Compatible
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
x-enrichment:
  date: '2026-09-13'
  status: enriched
  artifacts_added: 87
  pass: local-v3

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