Host Tracking

Methods on TraxBuilder for configuring host identity. All are optional — host tracking works with zero configuration via auto-detection.

SetHostEnvironment

Overrides the auto-detected host environment type.

public TraxBuilder SetHostEnvironment(string environment)

Parameter	Type	Required	Description
`environment`	`string`	Yes	Environment identifier (e.g., `"lambda"`, `"ecs"`, `"my-custom-env"`)

SetHostInstanceId

Overrides the auto-detected host instance ID.

public TraxBuilder SetHostInstanceId(string instanceId)

Parameter	Type	Required	Description
`instanceId`	`string`	Yes	Instance identifier

AddHostLabel

Adds a custom key-value label to the host identity. Labels are stored as JSONB on every metadata record.

public TraxBuilder AddHostLabel(string key, string value)

Parameter	Type	Required	Description
`key`	`string`	Yes	Label key (e.g., `"region"`, `"service"`)
`value`	`string`	Yes	Label value (e.g., `"us-east-1"`)

AddHostLabels

Adds multiple custom labels at once.

public TraxBuilder AddHostLabels(Dictionary<string, string> labels)

Parameter	Type	Required	Description
`labels`	`Dictionary<string, string>`	Yes	Key-value pairs to add

Example

services.AddTrax(trax => trax
    .SetHostEnvironment("ecs")
    .AddHostLabel("region", "us-east-1")
    .AddHostLabel("service", "content-shield")
    .AddEffects(effects => effects
        .UsePostgres(connectionString)
    )
    .AddMediator(assemblies)
);

Remarks

Host identity is detected once at startup and applied to all train executions in the process.
Auto-detection probes environment variables for Lambda, ECS, Kubernetes, and Azure App Service. See Host Tracking for the full detection table.
Duplicate label keys use last-write-wins semantics.
When a remote worker executes a train, host fields are overwritten in StartServiceTrain() so the metadata reflects the actual execution host, not the dispatcher.