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Default behaviors (and how to replace them)

See also: Bootstrap and execution · Opt-in subsystems · Limits and constraints · Back to the index

Orkeon's DI defaults follow one principle: no implicit magic. Nothing calls an LLM you did not configure, nothing persists where you did not point it, and every deliberately-minimal default announces itself with a one-time Warning that names the remediation. This page is the inventory of those defaults — what each one does, how it tells you it is active, and the exact gesture to replace it.

Most registrations below use TryAdd: registering your own implementation before AddOrkeonApplication() / AddOrkeonInfrastructure() wins, with no other change. The exceptions are called out in their row — a service registered unconditionally (AddScoped/AddSingleton) is replaced by registering yours after the Orkeon call.

The defaults that warn on first use

Service	Default	What it actually does	Replace it with
IAgentPlanner	AgentPlannerService	Emits the same fixed 4-step plan for every task (confidence 0.8). Refinement and validation are real; plan creation ignores the task content.	services.AddSingleton<IAgentPlanner, YourPlanner>(); — an LLM-backed planner is a study item for V1.x.
ITaskDelegator	NullTaskDelegator	Denies every delegation request; FindBestAgentForTaskAsync returns the first available agent. Hierarchical/Autonomous delegation stays inert until replaced.	services.AddSingleton<ITaskDelegator, YourDelegator>();
IKnowledgeStore	InMemoryKnowledgeStore	Working in-memory store (store/retrieve/delete are real, nothing persists) — but SearchAsync ignores the query and returns the first stored entries.	Enable the RAG subsystem (AddOrkeonRag(configuration)) and use its ingestion/retrieval, or register your own store.
ILlmCache	NullLlmCache	A cache that always misses — changes cost, not correctness.	services.AddSingleton<ILlmCache, YourCache>();
IYamlDiffService	NullYamlDiffService	Diffing is an optional observability nicety.	Register your own implementation.
ITemplateInstantiator	NullTemplateInstantiator	Also throws NotSupportedException when actually used — louder than any log.	Register your own implementation.
IToolRegistry	InMemoryToolRegistry	Empty registry; the runner host replaces it with the DI-backed ServiceProviderToolRegistry. Crews that reference tools fail loudly under StrictTools.	services.AddSingleton<IToolRegistry, ServiceProviderToolRegistry>();
IMemorySystem	InMemoryMemorySystem	Real in-memory implementation — correct, just not persistent.	Configure a persistent provider (Memory:Provider).
IAgentSelectionService (FirstFit)	SimpleAgentSelectionService	Picks the first available agent — the explicit safe fallback.	Set OrkeonApplicationOptions.AgentSelectionStrategy to Skill (lexical) or Embedding (semantic — requires a real embedding provider), via AddOrkeonApplication(o => …) or services.Configure<OrkeonApplicationOptions>(…).
IEmbeddingProvider	resolution chain	Local BGE (when AddOrkeonLocalEmbeddings() is registered) → remote provider from Orkeon:Embeddings → fail-fast at first use with an actionable exception. Never a silent hash fallback.	Register AddOrkeonLocalEmbeddings() or configure Orkeon:Embeddings.

IAgentExecutionService is not on this list on purpose: AddOrkeonApplication() registers the real AgentExecutionService unconditionally (AddScoped). The NullAgentExecutionService stub only wins in a container wired with AddOrkeonInfrastructure() alone (its registration is TryAddScoped). To substitute your own in a standard bootstrap, register it after AddOrkeonApplication().

The genuinely silent defaults

These are harmless by construction and stay at Debug or emit nothing:

Service	Default	Why silence is fine
Step/task callbacks	Null*Callback	No-op observability hooks; Debug by design.
IMemoryScope	NullMemoryScope	Explicit "no memory in this context" marker — asked for, not fallen into.
IMemoryProvider	config-driven factory	Falls back to the in-memory provider when Memory:Provider is unset; an unrecognized type does warn.

Fully-functional TryAdd defaults (e.g. IPathValidator → PathValidator) are not listed here on purpose: they are the real implementation, not a stand-in — replace them the same way (register yours before the Orkeon call), but nothing announces them because nothing is missing.

Why it works this way

A framework that silently swaps in an LLM call, a network dependency, or a persistent store behind a default would be making decisions that belong to you. The trade-off is that a freshly-bootstrapped host does less than a fully configured one — and says so in the log, once per service, with the fix in the message. If you see one of these warnings in production, it is never noise: it means a capability you probably expect is running on its minimal stand-in.