MartenInstaller

Key: Marten
Default Enabled: ✅ (when added via AddCritterStack())
Package: SaveApis.Utils.CritterStack

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Purpose

Configures Marten as a PostgreSQL-backed document database and event store with multi-tenancy (Conjoined), event sourcing, Wolverine integration, and an async projection daemon.

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What It Does

Builder phase:

• Builds a NpgsqlConnectionString from the Marten configuration section
  • In Development: enables IncludeErrorDetail and LogParameters
• Calls builder.Services.AddMarten(options => { ... }) with:
  • PostgreSQL connection string from configuration
  • System.Text.Json serialization with enums as strings
  • Npgsql logging disabled
  • Identity map for aggregates in both event store and projections
  • Tenancy: TenancyStyle.Conjoined for all documents and events
  • Archived stream partitioning enabled
  • Document metadata: CreatedAt and CorrelationId enabled
  • OpenTelemetry connection tracking at Normal level + event counters
• .UseLightweightSessions() — all sessions are lightweight by default
• .IntegrateWithWolverine() — enables Wolverine/Marten integration for outbox, saga persistence, and event processing
• .AddAsyncDaemon(mode) — starts the projection daemon in the configured mode

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Dependencies

No explicit installer dependencies. Must be registered after CritterStackInstaller (guaranteed by AddCritterStack() registration order).

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Configuration

appsettings.json

{
  "Marten": {
    "Host": "localhost",
    "Port": 5432,
    "Database": "my_service",
    "Username": "postgres",
    "Password": "secret",
    "Mode": "HotCold"
  }
}

Environment Variables

Variable	Type	Default	Required	Description
Marten__Host	string	–	Yes	PostgreSQL host
Marten__Port	int	–	Yes	PostgreSQL port
Marten__Database	string	–	Yes	Database name
Marten__Username	string	–	Yes	Database username
Marten__Password	string	–	Yes	Database password
Marten__Mode	DaemonMode	HotCold	No	Async daemon mode

Example:

Marten__Host=db.example.com
Marten__Port=5432
Marten__Database=my_service_db
Marten__Username=app_user
Marten__Password=s3cr3t
Marten__Mode=HotCold

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DaemonMode Values

Value	Description
HotCold	Leader election — one node runs projections at a time (recommended for multi-instance deployments)
Solo	Always runs projections, regardless of other instances
Disabled	No projection daemon started

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Multi-Tenancy

All documents and events use TenancyStyle.Conjoined, meaning tenant data is stored in the same tables with a tenant identifier column. Queries are automatically scoped to the active tenant via Marten’s session API.

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Notes

• ResourceAutoCreate = All (set by CritterStackInstaller) means Marten will create or migrate all required tables on startup — no manual migrations needed in development.
• In production, consider whether auto-migration on startup is appropriate for your deployment strategy.
• The application name from SaveApisApplication.Name is set on the Npgsql connection for easier identification in PostgreSQL activity views.

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Related

• CritterStack Overview
• CritterStackInstaller — sets JasperFx defaults required by Marten
• WolverineInstaller — integrated with Marten for outbox and event handling