Renamed: This project was formerly called Deveel Events. As of 23 May 2026, the NuGet packages have been renamed from Deveel.Events.* to Hermodr.*. The old packages remain published and will be deprecated.

Packages

The framework is split into focused NuGet packages so you only take what you need.

Core packages

Package	Description
Hermodr.Annotations	Attributes for describing event metadata on your data classes
Hermodr.Publisher	Core publisher infrastructure (EventPublisher, EventPublisherBuilder, DI helpers)

Channel packages

Package	Description
Hermodr.Publisher.AzureServiceBus	Publish events to an Azure Service Bus queue or topic
Hermodr.Publisher.RabbitMq	Publish events to a RabbitMQ exchange
Hermodr.Publisher.MassTransit	Publish events through a MassTransit bus
Hermodr.Publisher.Webhook	Deliver events to HTTP webhook endpoints
Hermodr.Publisher.Outbox	Persist events to a transactional outbox for later relay
Hermodr.Publisher.Outbox.EntityFramework	Entity Framework Core repository and helpers for the outbox channel
Hermodr.Amqp.Annotations	AMQP-specific attributes (exchange name, routing key)

Subscriptions package

Package	Description
Hermodr.Subscriptions	In-process event subscription registry and dispatcher

Observability package

Package	Description
Hermodr.Publisher.OpenTelemetry	Distributed tracing with W3C trace context propagation via CloudEvents extensions

Audit Trail packages

Package	Description
Hermodr.AuditTrail	Core contracts for an append-only audit trail (IAuditTrailWriter, IAuditTrailReader<T>, AuditTrailBuilder, AuditTrailStreamQuery)
Hermodr.Publisher.AuditTrail	Publisher integration: AuditTrailPublishChannel and AddAuditTrail() extension method
Hermodr.AuditTrail.InMemory	In-memory storage backend for testing and development
Hermodr.AuditTrail.EntityFramework	Entity Framework Core storage backend (SQL Server, PostgreSQL, SQLite)
Hermodr.AuditTrail.NDJson	NDJson file storage backend with pluggable filesystem (Azure Blob, S3, local disk)

Schema packages

Package	Description
Hermodr.Schema	Core schema model, fluent builder, JSON writer, and schema validation
Hermodr.Schema.Yaml	Export an event schema as a YAML document
Hermodr.Schema.AsyncApi	Export schemas as an AsyncAPI 2.x document (JSON or YAML)

Test package

Package	Description
Hermodr.TestPublisher	In-memory test channel and helpers for unit tests

---

Package Details

Hermodr.Annotations

Contains the [Event] and [EventProperty] attributes used to annotate data-transfer classes with event type metadata. No dependencies except the .NET BCL.

dotnet add package Hermodr.Annotations

---

Hermodr.Publisher

The heart of the framework. Provides:

• EventPublisher
• IEventPublishChannel and IBatchEventPublishChannel
• EventPublisherBuilder for fluent DI registration
• IEventFactory, IEventIdGenerator, and IEventSystemTime extensibility points
• EventPublisherOptions for global defaults
• named publisher pipelines resolved through keyed DI

dotnet add package Hermodr.Publisher

---

Hermodr.Publisher.AzureServiceBus

Azure Service Bus channel implementation. Serialises CloudEvent objects as ServiceBusMessage instances and sends them to a configured queue or topic.

dotnet add package Hermodr.Publisher.AzureServiceBus

---

Hermodr.Publisher.RabbitMq

RabbitMQ channel implementation using the official RabbitMQ.Client library. Supports AMQP exchange/routing-key annotations, publisher confirms, and persistent messages.

dotnet add package Hermodr.Publisher.RabbitMq

---

Hermodr.Publisher.MassTransit

Wraps MassTransit's IPublishEndpoint / ISendEndpointProvider so events can be routed through any MassTransit-supported transport.

dotnet add package Hermodr.Publisher.MassTransit

---

Hermodr.Publisher.Webhook

Delivers events over HTTP to a webhook endpoint. Features HMAC signing (SHA-256/384/512), exponential-backoff retries, configurable headers, and pluggable serialisers.

dotnet add package Hermodr.Publisher.Webhook

---

Hermodr.Publisher.Outbox

Implements the transactional outbox pattern for event publishing. It adds the AddOutbox<TMessage>() builder entry point, outbox relay services, repository abstractions, and message-factory hooks for persisting events before relaying them to a transport-specific publisher pipeline.

dotnet add package Hermodr.Publisher.Outbox

---

Hermodr.Publisher.Outbox.EntityFramework

Adds Entity Framework Core integration for the outbox channel, including DbOutboxMessage, OutboxDbContext, and the WithEntityFramework() registration helper that wires an IOutboxMessageRepository<TMessage> backed by EF Core.

dotnet add package Hermodr.Publisher.Outbox.EntityFramework

---

Hermodr.Amqp.Annotations

Adds [AmqpExchange] and [AmqpRoutingKey] attributes to let you declare per-event-type AMQP routing metadata directly on your data classes. See RabbitMQ — AMQP Annotations for usage details.

dotnet add package Hermodr.Amqp.Annotations

---

Hermodr.Subscriptions

Adds an in-process event subscription registry and dispatcher middleware to the EventPublisher pipeline. Includes:

• IEventSubscription and EventSubscription — the subscription model
• IEventSubscriptionRegistry — default in-memory registry
• IEventSubscriptionResolver — extensibility point for database- or remote-backed resolvers
• EventDispatcher — middleware that queries resolvers and invokes matched handlers
• EventFilter / EventFilterBuilder — composable FilterExpression factory for envelope and data-payload filtering

dotnet add package Hermodr.Subscriptions

---

Hermodr.Publisher.OpenTelemetry

Adds OpenTelemetry instrumentation to the event publishing pipeline. Creates producer and consumer Activity spans, injects W3C traceparent/tracestate as CloudEvents extension attributes on publish, and extracts them on the subscription side to enable end-to-end distributed tracing across service boundaries.

dotnet add package Hermodr.Publisher.OpenTelemetry

See OpenTelemetry Instrumentation for the full guide.

---

Hermodr.Schema

Core schema model. Includes EventSchema, EventSchemaBuilder (fluent API), EventSchemaCreator (reflection-based), IEventSchemaFactory, IEventSchemaWriter, and IEventSchemaValidator.

dotnet add package Hermodr.Schema

---

Hermodr.Schema.Yaml

Adds EventSchemaYamlWriter, which serialises an IEventSchema to a YAML stream using YamlDotNet.

dotnet add package Hermodr.Schema.Yaml

---

Hermodr.Schema.AsyncApi

Exports single or multiple event schemas as a complete AsyncAPI 2.x document (JSON or YAML).

dotnet add package Hermodr.Schema.AsyncApi

---

Hermodr.TestPublisher

An in-memory publish channel for use in unit and integration tests. Invokes a user-supplied callback whenever an event is published, so you can assert on published events without a real transport.

dotnet add package Hermodr.TestPublisher

---

Hermodr.AuditTrail

Core contracts for an append-only audit trail. Provides IAuditTrailWriter, IAuditTrailReader<TEntry>, AuditTrailEntry, AuditTrailStreamQuery, and the AuditTrailBuilder used by the publisher integration.

dotnet add package Hermodr.AuditTrail

---

Hermodr.Publisher.AuditTrail

Publisher integration: AuditTrailPublishChannel and the AddAuditTrail() extension method. Use it together with one of the audit trail storage backends (Hermodr.AuditTrail.InMemory, Hermodr.AuditTrail.EntityFramework, or Hermodr.AuditTrail.NDJson).

dotnet add package Hermodr.Publisher.AuditTrail

---

Hermodr.AuditTrail.InMemory

In-memory storage backend for the audit trail. Suitable for testing and development.

dotnet add package Hermodr.AuditTrail.InMemory

---

Hermodr.AuditTrail.EntityFramework

Entity Framework Core storage backend for the audit trail. Supports SQL Server, PostgreSQL, and SQLite.

dotnet add package Hermodr.AuditTrail.EntityFramework

---

Hermodr.AuditTrail.NDJson

Newline-delimited JSON (NDJSON) file storage backend for the audit trail, with automatic file rolling by size or time interval and retention policies. All I/O is performed through the IFileSystem abstraction from System.IO.Abstractions, so the local disk can be replaced with Azure Blob Storage, Amazon S3, or any other compatible filesystem by registering a different IFileSystem implementation. Reads are asynchronous and non-blocking: files are opened with FileShare.ReadWrite and streamed line-by-line, so a concurrent writer is never blocked and the full file content is never loaded into memory.

builder.Services.AddEventPublisher(o => o.Source = new Uri("https://example.com"))
    .AddAuditTrail(audit => audit.UseNDJson(o =>
    {
        o.DirectoryPath = "./audit-trail";
        o.MaxFileSizeBytes = 10 * 1024 * 1024;
        o.RollInterval = TimeSpan.FromHours(1);
        o.MaxFileCount = 100;
        o.ReadBufferSize = 65_536;  // optional: tune for large files
    }));

dotnet add package Hermodr.AuditTrail.NDJson

See the Audit Trail with NDJson Files sample for a full walkthrough.