MassTransit

MassTransit is a free, open source distributed application framework for .NET that makes it easy to create applications and services that leverage message-based, loosely-coupled asynchronous communication for higher availability, reliability, and scalability.

MassTransit publishes 1 API on the APIs.io network. Tagged areas include .NET, Event-Driven, Message Bus, Messaging, and Open-Source.

The MassTransit catalog on APIs.io includes 1 Spectral governance ruleset.

MassTransit’s developer surface includes documentation, getting-started guide, GitHub presence, and 4 more developer resources.

🌐 Visit website 📡 Source on GitHub

20.5/100 emerging ▬ flat Agent 3/100 human only Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessFreemium

1 APIs

.NET Event-DrivenMessage BusMessaging Open-Source Sagas

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 20.5/100 · emerging

Contract Quality 3.3 / 25

Developer Ergonomics 5.2 / 20

Access Clarity 3.2 / 20

Operational Transparency 1.7 / 13

Contract Governance 1.2 / 12

Discoverability 5.9 / 10

Agent readiness — 3/100 · human only

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

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

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

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.

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/masstransit: 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 1

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

MassTransit Messaging Framework

MassTransit provides a consistent abstraction on top of message transports like RabbitMQ, Azure Service Bus, and Amazon SQS, with support for sagas, state machines, routing slip...

Pricing Plans 1

Published pricing tiers and plan structures.

Masstransit Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Masstransit Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Masstransit Finops

FINOPS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

MassTransit API Rules

5 rules · 3 warnings 2 info

SPECTRAL

JSON Schema 2

Standalone JSON Schema definitions for this provider's data models.

MassTransit Message Envelope

15 properties

JSON SCHEMA

MassTransit Saga State

8 properties

JSON SCHEMA

Security Posture 1

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

Masstransit Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Resources

Get Started 1

Portal, sign-up, and the first successful call

GettingStarted

GettingStarted

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Build 1

SDKs, sample code, and the tooling you integrate with

GitHub

GitHub

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

Discord

Discord

Company 1

The organization behind the API

Website

Website

Other 1

Properties that don't map to a standard resource type

NuGet

NuGet

Source (apis.yml)

aid: masstransit
name: MassTransit
description: MassTransit is a free, open source distributed application framework for .NET that makes it easy to create applications
  and services that leverage message-based, loosely-coupled asynchronous communication for higher availability, reliability,
  and scalability.
type: Index
deliveryModel:
  model: unknown
  open_source: false
  commercial: false
  callable_host: false
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - none
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  - url: https://masstransit.io/
    status: 307
    note: declared website redirects to https://masstransit.massient.com/ — a different registrable domain (masstransit.io
      -> massient.com), possible rename or acquisition (probed 2026-09-03, roadmap#169)
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/masstransit.png
tags:
- .NET
- Event-Driven
- Message Bus
- Messaging
- Open-Source
- Sagas
tags_raw:
- .NET
- Event-Driven
- Message Bus
- Messaging
- Open Source
- Sagas
url: https://raw.githubusercontent.com/api-evangelist/masstransit/refs/heads/main/apis.yml
created: '2026-03-26'
modified: '2026-04-28'
specificationVersion: '0.23'
apis:
- aid: masstransit:masstransit-messaging
  name: MassTransit Messaging Framework
  description: MassTransit provides a consistent abstraction on top of message transports like RabbitMQ, Azure Service Bus,
    and Amazon SQS, with support for sagas, state machines, routing slip activities, and a standardized message envelope format.
  humanURL: https://masstransit.io/
  tags:
  - .NET
  - Event-Driven
  - Message Bus
  - Messaging
  - Sagas
  properties:
  - type: Documentation
    url: https://masstransit.io/documentation/concepts
  - type: JSONSchema
    url: json-schema/masstransit-message-envelope.json
  - type: JSONSchema
    url: json-schema/masstransit-saga-state.json
common:
- type: DomainSecurity
  url: security/masstransit-domain-security.yml
- type: Website
  url: https://masstransit.io/
- type: Documentation
  url: https://masstransit.io/documentation/concepts
- type: GettingStarted
  url: https://masstransit.io/quick-starts
- type: GitHub
  url: https://github.com/MassTransit/MassTransit
- type: Discord
  url: https://discord.gg/rNpQgYn
- type: NuGet
  url: https://www.nuget.org/packages/MassTransit
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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