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.