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FabrCore 2.0 · Release and package availability

These guides track the current 2.0 source. Stable 2.0.0 publication is pending; package commands show the release target. Until it is published, follow the source quick start or use a matching available prerelease set. Release migration · Runtime modes

MODULE 01 · LESSON 1.5

Understand what you just configured

Keep host settings, models and agent behavior in the right resources.

Lesson 5 of 86 · FabrCore 2.0

Overview

appsettings.json configures infrastructure; fabrcore.json configures the standard local model store; AgentConfiguration configures an instance. This separation prevents a model switch from accidentally becoming a cluster configuration change. Environment variables use double underscores only for settings in the .NET configuration system.

Infrastructure, model catalog, instance

appsettings.json controls how the process is hosted: URLs, clustering and optional services. fabrcore.json is the standard local model catalog: model names, provider settings and API-key aliases. AgentConfiguration says what one instance uses: AgentType, Models, Plugins and Args. Putting an instance setting into the model catalog does not cause the instance to consume it.

How to diagnose a change that had no effect

First identify which component reads the value and when it reads it. A process startup option may require a restart; a proxy's initialization may cache its selected model or tools. A cloud publication is a new configuration resource, not proof that every existing object has reconstructed itself. Environment variables affect the .NET configuration pipeline; they do not automatically rewrite an independently loaded model file.

Inspect the three configuration layers

Download the Operations Desk source. The README lists project setup, package prerequisites and local ports.

  1. Compare the three configuration examples. Keep ConnectionStrings at the root and runtime sections under FabrCore.
  2. Set a non-secret Host option with an environment variable and inspect the effective result. Keep model credentials in the model-store path or use a supported remote store.
  3. Restart the standalone process. Recreate the instance and compare its history with the previous process.
Three resources and their consumers 
appsettings.json
  FabrCore:HostUrl -> Host HTTP address
  FabrCore:Orleans -> clustering/provider setup

fabrcore.json (or Cloud Server configuration payload)
  ModelConfigurations[].Name -> named model lookup
  ApiKeys[].Alias -> credential lookup

AgentConfiguration (one provisioned instance)
  AgentType -> installed class alias
  Models -> model catalog Name
  Plugins / Tools / Args -> selected behavior

Make one change at a time

  1. Locate HostUrl in the Host settings, default in the model catalog, and Models in the instance definition. Explain the link from Models to the catalog's Name before changing anything.
  2. Change a harmless instance setting on a disposable instance and use the supported reconfiguration path. Read the instance configuration back and verify the value belongs to that instance, not every agent.
  3. If changing a startup option, restart the Host and verify the new effective value. Repeat the echo check after restarting; standalone instances may need to be created again.

You now have a way to locate configuration errors: wrong document, wrong alias, wrong instance, or a consumer that has not reloaded. The three files/resources serve different lifetimes.

If the result is different

An agent or plugin setting in the root of fabrcore.json is not automatically applied. Addon-specific loaders, such as the Copilot addon, document their own exceptions.

Go deeper

Explore the related documentation.