Pick Your Stack

Not sure which packages you need? Follow this guide to find the right combination for your scenario.

graph TD
    START[What are you building?] --> SIMPLE[Simple dispatcher]
    START --> ES[Event-sourced app]
    START --> DIST[Distributed system]
    START --> SERVERLESS[Serverless function]
    START --> FULL[Full enterprise stack]

    SIMPLE --> |Install| PKG_DISPATCH[Excalibur.Dispatch]

    ES --> DB{Which database?}
    DB --> SQL[SQL Server]
    DB --> PG[PostgreSQL]
    DB --> NOSQL[NoSQL]

    SQL --> |Quick start| PKG_SQL_STARTER[Excalibur.Dispatch.SqlServer]
    SQL --> |Production| PKG_SQL_FULL[Excalibur.SqlServer]
    PG --> |Quick start| PKG_PG_STARTER[Excalibur.Dispatch.Postgres]
    PG --> |Production| PKG_PG_FULL[Excalibur.Postgres]

    ES --> TRANSPORT{Need messaging?}
    TRANSPORT --> RMQ[Excalibur.Dispatch.RabbitMQ]
    TRANSPORT --> KAFKA[Excalibur.Dispatch.Kafka]
    TRANSPORT --> AZURE[Excalibur.Dispatch.Azure]
    TRANSPORT --> AWS_PKG[Excalibur.Dispatch.Aws]

---

Simple Message Dispatcher

Replacing MediatR or building a basic command/query pipeline.

<PackageReference Include="Excalibur.Dispatch" />

services.AddDispatch(dispatch =>
{
    dispatch.AddHandlersFromAssembly(typeof(Program).Assembly);
    dispatch.UseValidation();
});

That's it. No other packages needed. See the Getting Started guide.

---

Event-Sourced Application

Which database?

SQL Server

Quick start — event sourcing + outbox + hosting:

<PackageReference Include="Excalibur.Dispatch.SqlServer" />

Production — adds inbox, sagas, leader election, audit logging, compliance:

<PackageReference Include="Excalibur.SqlServer" />

services.AddExcaliburSqlServer(sql =>
{
    sql.ConnectionString = connectionString;
    sql.UseLeaderElection = true;
    sql.UseAuditLogging = true;
});

PostgreSQL

Quick start — event sourcing + outbox + hosting:

<PackageReference Include="Excalibur.Dispatch.Postgres" />

Production — adds inbox, sagas, leader election, audit logging, compliance:

<PackageReference Include="Excalibur.Postgres" />

services.AddExcaliburPostgres(pg =>
{
    pg.ConnectionString = connectionString;
    pg.UseLeaderElection = true;
    pg.UseAuditLogging = true;
});

CosmosDB / DynamoDB / MongoDB

Install individually — no full-stack metapackage yet:

<PackageReference Include="Excalibur.EventSourcing.CosmosDb" />
<!-- or -->
<PackageReference Include="Excalibur.EventSourcing.DynamoDb" />
<!-- or -->
<PackageReference Include="Excalibur.EventSourcing.MongoDB" />

<!-- Add if you need outbox -->
<PackageReference Include="Excalibur.Outbox.InMemory" />
<!-- Add hosting -->
<PackageReference Include="Excalibur.Hosting.Web" />

---

Adding a Message Transport

Choose a transport for publishing integration events between services:

RabbitMQ

<PackageReference Include="Excalibur.Dispatch.RabbitMQ" />

services.AddDispatchRabbitMQ(rmq =>
{
    rmq.ConnectionString = "amqp://guest:guest@localhost";
});

Bundles: transport + resilience + observability.

Apache Kafka

<PackageReference Include="Excalibur.Dispatch.Kafka" />

services.AddDispatchKafka(kafka =>
{
    kafka.BootstrapServers = "localhost:9092";
});

Bundles: transport + serialization.

Azure Service Bus

<PackageReference Include="Excalibur.Dispatch.Azure" />

services.AddDispatchAzure(azure =>
{
    azure.ConnectionString = "Endpoint=sb://...";
});

Bundles: transport + Azure Key Vault integration.

AWS SQS

<PackageReference Include="Excalibur.Dispatch.Aws" />

services.AddDispatchAws(aws =>
{
    aws.Region = "us-east-1";
});

Bundles: transport + AWS Secrets Manager integration.

Google Pub/Sub

<PackageReference Include="Excalibur.Dispatch.Transport.GooglePubSub" />
<PackageReference Include="Excalibur.Dispatch.Resilience.Polly" />
<PackageReference Include="Excalibur.Dispatch.Observability" />

No metapackage yet — install individually.

---

Distributed System with Sagas

Start with the event-sourcing stack above, then add saga persistence:

<!-- Already have Excalibur.SqlServer or Excalibur.Postgres? Sagas are included. -->

<!-- If using individual packages, add: -->
<PackageReference Include="Excalibur.Saga.SqlServer" />
<!-- or -->
<PackageReference Include="Excalibur.Saga.Postgres" />

---

Serverless Functions

Azure Functions

<PackageReference Include="Excalibur.Dispatch.Hosting.AzureFunctions" />

AWS Lambda

<PackageReference Include="Excalibur.Dispatch.Hosting.AwsLambda" />

Google Cloud Functions

<PackageReference Include="Excalibur.Dispatch.Hosting.GoogleCloudFunctions" />

---

Full Enterprise Production Stack

Complete provider + transport — everything you need:

<!-- Database provider (pick one) -->
<PackageReference Include="Excalibur.SqlServer" />

<!-- Transport (pick one) -->
<PackageReference Include="Excalibur.Dispatch.RabbitMQ" />

<!-- Cross-cutting concerns (opt-in) -->
<PackageReference Include="Excalibur.Dispatch.Security" />
<PackageReference Include="Excalibur.Dispatch.Validation.FluentValidation" />
<PackageReference Include="Excalibur.Dispatch.Caching" />

services.AddExcaliburSqlServer(sql =>
{
    sql.ConnectionString = connectionString;
    sql.UseLeaderElection = true;
    sql.UseAuditLogging = true;
});

services.AddDispatchRabbitMQ(rmq =>
{
    rmq.ConnectionString = "amqp://guest:guest@localhost";
});

services.AddDispatch(dispatch =>
{
    dispatch.AddHandlersFromAssembly(typeof(Program).Assembly);
    dispatch.UseValidation().WithFluentValidation();
    dispatch.UseCaching();
    dispatch.UseSecurity(builder.Configuration);
});

---

Package Tiering

Tier	Purpose	Examples
Feature	Single concern, opt-in	Excalibur.EventSourcing.SqlServer, Excalibur.Inbox.SqlServer
Starter	Get up and running quickly	Excalibur.Dispatch.SqlServer, Excalibur.Dispatch.RabbitMQ
Complete	Everything for a provider	Excalibur.SqlServer, Excalibur.Postgres

Starters bundle the most common features. Complete metapackages bundle everything for a database provider so you don't miss anything.

---

Next Steps

• Package Guide — Full package reference with all 119+ packages
• Getting Started — Build your first Dispatch application
• Core Concepts — Understand the architecture