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.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles Apache Pulsar the way a machine reads it — 53 machine-readable artifacts across 8 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 — Apache Pulsar scores 49.4/100 (developing), with a separate agent-readiness read of 44/100 (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.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
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 1
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).
Apache Pulsar Admin REST API
OPEN COLLECTIONPricing 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.
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
RATE LIMITSFinOps 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.
Apache Pulsar Finops
FINOPSFeatures 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...
ASYNCAPISemantic 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
JSON-LDSpectral 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.
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
JSON SCHEMAFunctionConfig
JSON SCHEMAPolicies
JSON SCHEMAPulsarMessage
JSON SCHEMARetentionPolicies
JSON SCHEMATenantInfo
JSON SCHEMATopicStats
JSON SCHEMAApache Pulsar Message
JSON SCHEMAScroll 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
JSON STRUCTUREApache Pulsar Function Config Structure
JSON STRUCTUREApache Pulsar Policies Structure
JSON STRUCTUREApache Pulsar Pulsar Message Structure
JSON STRUCTUREApache Pulsar Retention Policies Structure
JSON STRUCTUREApache Pulsar Tenant Info Structure
JSON STRUCTUREApache Pulsar Topic Stats Structure
JSON STRUCTUREScroll 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.
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.
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 1
The organization behind the API
← All providers · Data indexed from github.com/api-evangelist/apache-pulsar · machine-readable index on apis.io