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Hadron

hadron-project.github.io

Self-hosted
Visit hadron-project.github.io
Spec score 7.1 #17 of 27 in Event Streaming Platforms

What it is

Hadron is an open-source, self-hosted distributed data-storage and messaging system for ingesting events and coordinating multi-stage workflows. Streams are append-only logs with absolute ordering within each partition and horizontal scaling. Pipelines orchestrate stages over Stream data and can begin when an event matches a configured trigger. Exchanges handle ephemeral messages, while Endpoints provide general-purpose RPC handlers. Streams, pipeline inputs and outputs, and ephemeral messages use the CloudEvents 1.0 model. Hadron is designed for Kubernetes and installed with Helm and Kubernetes configuration resources; the quick start requires Helm 3.7.0 or later for OCI usage. Stream availability continues while at least one partition runs. Retention can use a configurable time policy, defaulting to seven days, or retain data indefinitely. Producers and Consumers may be written in any language, with an official Rust client and CLI. Components expose Prometheus metrics over HTTP, including Prometheus scraping and OTEL collector integrations. Token-based access creates JWTs signed by the Operator’s private RSA key, with resource-level permissions. External CLI access is still in progress, and Hadron Cloud is under construction.

Spec sheet

Purpose
Hadron is a distributed event storage and messaging system for ingesting events and working with them in multi-stage workflows.Read 11 Oct 2026 · hadron-project.github.io
Product
Hadron is a distributed data storage system for ingesting events and working with them in multi-stage structured workflows.Read 4 Oct 2026 · hadron-project.github.io
Intended users
The guide presents Hadron for distributed applications with many microservices and event or telemetry signals, and includes a local development use case.Read 11 Oct 2026 · hadron-project.github.io
Access control
Hadron authenticates with Tokens that produce JWTs signed with the Operator's private RSA key, with permissions configurable by resource.Read 4 Oct 2026 · hadron-project.github.io
Authentication
Hadron authentication uses Tokens that the Operator processes into JWTs stored in Kubernetes Secrets.Read 11 Oct 2026 · hadron-project.github.io
CLI access limit
The CLI documentation says access from outside the Kubernetes cluster is in progress.Read 11 Oct 2026 · hadron-project.github.io
Client library
The official clients page lists a Rust client and says client libraries for other languages are planned as Hadron matures.Read 11 Oct 2026 · hadron-project.github.io
Clients
Producers and Consumers can be written in any language, and the project maintains a shared Rust client and a CLI.Read 4 Oct 2026 · hadron-project.github.io
Event format
Hadron uses CloudEvents 1.0 for data entering and leaving the system.Read 11 Oct 2026 · hadron-project.github.io
External access
The CLI documentation says access from outside the Kubernetes cluster is in progress.Read 4 Oct 2026 · hadron-project.github.io
Hosted service
The quick start describes Hadron Cloud as under construction and the hosted, fully managed option.Read 4 Oct 2026 · hadron-project.github.io
Hosted service status
The quick start describes Hadron Cloud as under construction and hosted by the Hadron project team.Read 11 Oct 2026 · hadron-project.github.io
Installation
The quick start installs the Hadron Operator with Helm and requires Helm version 3.7.0 or later for OCI usage.Read 11 Oct 2026 · hadron-project.github.io
Kubernetes
Hadron is designed to run in Kubernetes, and its Operator manages cluster lifecycle tasks including upgrades, horizontal scaling, and access control.Read 11 Oct 2026 · hadron-project.github.io
Messaging and RPC
Hadron describes Exchanges as ephemeral messaging between processes and Endpoints as general-purpose RPC handlers.Read 11 Oct 2026 · hadron-project.github.io
Monitoring
Hadron components expose Prometheus metrics over HTTP, with documented integration options including Prometheus scraping and the OTEL collector.Read 4 Oct 2026 · hadron-project.github.io
Pipelines
Pipelines orchestrate multi-stage workflows for Stream data, triggered when an event type matches a Pipeline trigger.Read 11 Oct 2026 · hadron-project.github.io
Retention
Stream data retention supports a configurable time policy that defaults to seven days, or an indefinite retain policy.Read 4 Oct 2026 · hadron-project.github.io
Scaling and availability
The documentation says Streams can scale horizontally and remain available when at least one partition is running.Read 4 Oct 2026 · hadron-project.github.io
Streams
Streams are append-only immutable logs with absolute ordering per partition and configurable retention, which defaults to seven days.Read 11 Oct 2026 · hadron-project.github.io
TLS setup
The quick start says cert-manager is optional and simplifies TLS certificate setup for Hadron's validating webhooks.Read 4 Oct 2026 · hadron-project.github.io

Strong points and limits

Strong points

  • Append-only, ordered Streams
  • Horizontal Stream scaling
  • Multi-stage Pipeline workflows
  • CloudEvents 1.0 event model
  • Prometheus and OTEL monitoring options

Limits

  • Self-hosted Kubernetes deployment required
  • External CLI access is in progress
  • Hadron Cloud is under construction
  • Official shared client is Rust

Who it suits

Hadron suits teams running distributed applications with many microservices and event or telemetry signals. It is intended for Kubernetes operators comfortable with self-hosted deployment and event-driven workflows.

Verdict

Hadron specifies a Kubernetes-based foundation for durable event streams, workflow pipelines, messaging, RPC, monitoring, and token authentication. Teams must provide their own deployment and account for unfinished external access and hosted-service status.

Where Specifiction places it

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