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Apache Pulsar website screenshot

Apache Pulsar

Apache Pulsar is a cloud-native, distributed messaging and streaming platform that provides server-to-server messaging with multi-tenancy, high performance, and geo-replication. It combines messaging and stream processing in a single platform.

agent aware

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 Apache Pulsar the way a machine reads it — 61 machine-readable artifacts across 1 API, 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 — Apache Pulsar scores 32.2/100 (thin), with a separate agent-readiness read of 18/100 (agent aware). 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. Every facet and dimension name is a link: it opens that measurement's page on APIs.io, where the rating runs across the whole catalog — the exact checks that feed it, how every profiled provider distributes on it, and who is at the top of it.

Kin Score Kin Score How this is scored →
scored 2026-09-10 · rubric v0.20.0
Apache Pulsar Kin Score — API readiness rating by API Evangelist

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More shapes, themes and sizes → · Score as JSON · How badges work

How we profile Apache Pulsar

Each block below is one kind of artifact we hold for Apache Pulsar. 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 8

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.

Apache Pulsar Messaging API

Pulsar messaging protocol for producing and consuming messages on topics, with support for multiple subscription types (Exclusive, Shared, Failover, Key_Shared), schema enforcem...

Apache Pulsar Brokers API

The Brokers API from Apache Pulsar — 2 operation(s) for brokers.

Apache Pulsar Clusters API

The Clusters API from Apache Pulsar — 2 operation(s) for clusters.

Apache Pulsar Functions API

The Functions API from Apache Pulsar — 3 operation(s) for functions.

Apache Pulsar Namespaces API

The Namespaces API from Apache Pulsar — 3 operation(s) for namespaces.

Apache Pulsar Subscriptions API

The Subscriptions API from Apache Pulsar — 2 operation(s) for subscriptions.

Apache Pulsar Tenants API

The Tenants API from Apache Pulsar — 2 operation(s) for tenants.

Apache Pulsar Topics API

The Topics API from Apache Pulsar — 4 operation(s) for topics.

Scroll within the panel for all 8 ·

Open Collections 9

Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Scroll within the panel for all 9 ·

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 things the Kin Score reads for access clarity — renamed from commercial clarity in rubric 0.12, because a free statutory interface has access terms and no commercial ones.

Published pricing tiers and plan structures.

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.

Apache Pulsar 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.

Features 7

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.

Multi-Tenancy

Native multi-tenancy with tenant and namespace isolation

Persistent Messaging

Durable message storage with Apache BookKeeper

Geo-Replication

Built-in geo-replication across data centers and clouds

Pulsar Functions

Lightweight serverless compute natively integrated with messaging

Tiered Storage

Offload old data to object storage (S3, GCS) for cost efficiency

Schema Registry

Built-in schema registry for producers and consumers

Multiple Subscription Types

Exclusive, Shared, Failover, and Key_Shared subscription modes

Scroll within the panel for all 7 ·

Event Specifications 1

Not every API is request/response. AsyncAPI describes the event-driven and streaming side — the webhooks and channels — so the asynchronous half of the interface is documented the same way the synchronous half is.

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

Apache Pulsar Messaging API

Apache Pulsar is a cloud-native, multi-tenant, high-performance messaging and streaming platform. This spec describes the messaging patterns for producing and consuming messages...

ASYNCAPI

Semantic Vocabularies 1

JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.

JSON-LD contexts and semantic vocabularies used across these APIs.

Apache Pulsar Context

7 classes · 51 properties

JSON-LD

Spectral Rules 3

Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.

Apache Pulsar API Rules

3 rules · 3 warnings

SPECTRAL

Apache Pulsar API Rules

5 rules · 3 warnings

SPECTRAL

Apache Pulsar API Rules

6 rules · 5 warnings

SPECTRAL

JSON Schema 8

Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.

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

ClusterData

5 properties

JSON SCHEMA

FunctionConfig

12 properties

JSON SCHEMA

Policies

9 properties

JSON SCHEMA

PulsarMessage

12 properties

JSON SCHEMA

RetentionPolicies

2 properties

JSON SCHEMA

TenantInfo

2 properties

JSON SCHEMA

TopicStats

9 properties

JSON SCHEMA

Apache Pulsar Message

12 properties

JSON SCHEMA

Scroll within the panel for all 8 ·

JSON Structure 7

JSON Structure captures the data shapes in a form built for tooling — a complement to JSON Schema that keeps the model machine-legible.

JSON Structure definitions describing this provider's data shapes.

Apache Pulsar Cluster Data Structure

5 properties

JSON STRUCTURE

Apache Pulsar Function Config Structure

12 properties

JSON STRUCTURE

Apache Pulsar Policies Structure

9 properties

JSON STRUCTURE

Apache Pulsar Pulsar Message Structure

12 properties

JSON STRUCTURE

Apache Pulsar Retention Policies Structure

2 properties

JSON STRUCTURE

Apache Pulsar Tenant Info Structure

2 properties

JSON STRUCTURE

Apache Pulsar Topic Stats Structure

9 properties

JSON STRUCTURE

Scroll within the panel for all 7 ·

Examples 7

Real request and response payloads are what turn a spec from abstract into obvious — and they're one of the twelve things an agent needs to call an API correctly on the first try.

Example request and response payloads for these APIs.

Scroll within the panel for all 7 ·

Security Posture 2

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.

Apache Pulsar Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Apache Pulsar Vulnerability Disclosure

security.txt · contact published

SECURITY

Agentic Access 1

An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.

Recommended x-agentic-access execution contracts for AI agents.

Apache Pulsar Agentic Access

29 operations · 13 acting

29 operations · 13 acting

AGENTIC

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.

Real-Time Event Streaming

Stream events between microservices with guaranteed delivery

Message Queue

Use Shared subscription as a traditional message queue

Event Sourcing

Store and replay event streams for event-driven architectures

IoT Data Ingestion

Ingest high-volume IoT telemetry into Pulsar topics

Resources

Every other property we hold for Apache Pulsar — 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.

Documentation 1

Reference material describing how the API behaves

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

Design & Contract 3

Pagination, idempotency, versioning, errors, and events

Build 1

SDKs, sample code, and the tooling you integrate with

Access & Security 2

Authentication, authorization, and security posture

Company 2

The organization behind the API

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

Where this information came from

This is an independent, third-party profile of Apache Pulsar, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.

The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.

Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.

info@apievangelist.com · Read the full data-sourcing policy →
On a security or compliance team? Put security in the subject line and you will get a person, not a form — we will tell you exactly which public URLs this profile was built from.