Configuration settings

SAIF.NetCore.Clients.UC4 reads exactly two Environment API settings, both in the uc4coreapi section, through IEnvironmentClient; it reads no IConfiguration keys, Web.config/App.config settings, environment variables, or secure settings directly.

Configuration retrieval methods

Method	Class / Interface	Namespace	Usage pattern
IEnvironmentClient.HasSetting(string configKey, string section)	IEnvironmentClient (contract) → BaseEnvironmentClient.HasSetting (runtime)	SAIF.NetCore.Services.Contracts	Called twice from a private EnsureSettingExists helper during construction, with section "uc4coreapi"; a false result throws NotSupportedException. Existence check only — no value check.
IEnvironmentClient.GetSettingValue(string configKey, string section)	IEnvironmentClient → BaseEnvironmentClient.GetSettingValue	SAIF.NetCore.Services.Contracts	Called twice in the constructor, immediately after the existence check, to populate ServiceUrl and ScheduleJobEndpoint. A missing/null value resolves to "" and never throws.

Environment API settings

Settings retrieved via IEnvironmentClient. Both keys live in a single dedicated section, uc4coreapi, read only by UC4Client; there is no wrapping configuration class — UC4Client itself holds the resolved values as public, privately-set properties.

Setting key	Method	Data type	Purpose	Consuming class	Source
uc4coreapi:url	HasSetting then GetSettingValue	string (absolute URL)	Base URL of the UC4 Core API, passed to IHttpJsonClient.SetClientInfo on the first ScheduleJob call; exposed read-only as UC4Client.ServiceUrl. Required — missing key throws NotSupportedException at construction.	UC4Client (ctor, Init)	src/SAIF.NetCore.Clients.UC4/SAIF.NetCore.Clients.UC4/SAIF.NetCore.Clients.UC4/Services/UC4Client.cs
uc4coreapi:schedulejobroute	HasSetting then GetSettingValue	string (relative URL path, expected to end in its own separator)	Relative route prefix for the schedule-job POST; the request resource is {ScheduleJobEndpoint}{jobname}, a direct concatenation with no separator added and no URL-encoding. Exposed read-only as UC4Client.ScheduleJobEndpoint. Required — missing key throws NotSupportedException at construction.	UC4Client (ctor, ScheduleJob)	same file

Both settings are validated for existence only, not for a non-empty or well-formed value (BR-UC4-01, BR-UC4-02). An empty uc4coreapi:url is accepted silently and fails later with UriFormatException on the first ScheduleJob call; an empty uc4coreapi:schedulejobroute causes every POST to target {jobname} alone.

Developer overrides

This library defines no developer override file or flag of its own. It is affected by the transitive SAIF.NetCore.EnvironmentClient developer override mechanism (AppSettings:EnvApiDeveloperSettingsOverride), with an asymmetric effect:

File or flag	When applied	Effect	Source
EnvironmentClient developer settings override file	Developer machine, file present	Can replace the value of uc4coreapi:url / uc4coreapi:schedulejobroute once the key already exists in the Environment API for that track. It does not satisfy the HasSetting existence check performed by EnsureSettingExists — a key entirely absent from the Environment API still throws NotSupportedException, even if the override file defines it (CR-UC4-04).	src/SAIF.NetCore.EnvironmentClient/SAIF.NetCore.EnvironmentClient/SAIF.NetCore.EnvironmentClient/BaseEnvironmentClient.cs

Transitive configuration (from dependencies)

UC4 has no <ProjectReference> and a single PackageReference to SAIF.NetCore.ServiceContracts (contracts only, no configuration reads). Configuration arrives transitively through the runtime implementations of the two injected contracts, which a consuming application must register.

Setting key	Method	Source dependency	Dependency type	Purpose
Registered IEnvironmentClient	DI resolution	SAIF.NetCore.EnvironmentClient (BaseEnvironmentClient / SecureEnvironmentClient)	NuGet (runtime-registered by SAIF.NetCore.ServiceExtensions)	Required constructor dependency; resolves both uc4coreapi settings.
Registered IHttpJsonClient	DI resolution	SAIF.NetCore.HttpClients (HttpJsonClient)	NuGet (runtime-registered by SAIF.NetCore.ServiceExtensions)	Required constructor dependency; sends the schedule-job POST. Reads no configuration of its own; retry/delay come from HttpClientOptions defaults (retry on 401/502/503, 1000 ms, 3 retries), which UC4 never overrides.
EnvironmentApiUrl (environment variable)	Process bootstrap	SAIF.NetCore.EnvironmentClient	NuGet (transitive)	Base URL of the Environment API that serves section uc4coreapi; absent → MissingEnvironmentUrlVariableException before UC4Client can be constructed.
IHostEnvironment.ApplicationName	Host-supplied identity	SAIF.NetCore.EnvironmentClient	NuGet (transitive)	Selects the application/host-qualified Environment API retrieval URL used to look up uc4coreapi:*; whether the underlying settings are published once and shared across applications on the server side, or published separately per consuming application, is unknown**.
AppSettings:ApplicationHost, AppSettings:EnvApiDeveloperOverrideAllowed, AppSettings:EnvApiDeveloperSettingsOverride	IConfiguration bootstrap	SAIF.NetCore.EnvironmentClient	NuGet (transitive)	Determine host → track and hence which uc4coreapi values are returned; enable the developer override described above.
COREAPIENABLED=1	IConfiguration root key	SAIF.NetCore.EnvironmentClient	NuGet (transitive)	Required only if the host registers SecureEnvironmentClient on a non-developer machine; UC4 itself performs no secure reads.
EnvironmentClient:GetHostsByTrack:RetryCount / :RetrySleepMs	IConfiguration (optional)	SAIF.NetCore.EnvironmentClient	NuGet (transitive)	Startup resilience of the environment client that UC4 depends on.

Configuration dependencies

Dependency	Type	Required at	Impact if missing
uc4coreapi:url	Environment API setting (key)	Construction (DI activation)	NotSupportedException; construction aborts.
uc4coreapi:schedulejobroute	Environment API setting (key)	Construction (DI activation)	NotSupportedException; construction aborts.
IEnvironmentClient registration	DI service	Construction (DI container activation)	UC4Client cannot be resolved by the DI container; activation fails immediately with the container's resolution error (constructor parameter). A manual new UC4Client(null, httpJsonClient) is accepted by the unguarded constructor, but fails immediately during construction — not deferred to first use — because the constructor's first statement, EnsureSettingExists, calls env.HasSetting, which throws a NullReferenceException on the null env right away.
IHttpJsonClient registration	DI service	Construction (DI container activation)	UC4Client cannot be resolved by the DI container under normal constructor-injection DI resolution; activation fails immediately (constructor parameter). Only a manual new UC4Client(env, null) is accepted by the unguarded constructor and fails later, on the first ScheduleJob call, with a NullReferenceException.

Key configuration risks: existence-only validation means a malformed or empty uc4coreapi:url is detected late, at the first ScheduleJob call, as a UriFormatException rather than at construction (CR-UC4-01); a uc4coreapi:schedulejobroute value missing its own trailing separator silently produces the wrong request resource (CR-UC4-02); because both values are snapshotted into properties in the constructor, a long-lived (Singleton) UC4Client never observes an Environment API change until process restart (CR-UC4-05).

Related documentation

• Index
• Overview
• Architecture
• Dependencies
• Operations and processes
• Business rules
• API reference

Note: Statements marked with * were inferred from code structure, naming conventions, or contextual evidence where direct confirmation was not available in source artifacts. Statements marked with ** could not be confirmed; treat as unknown until verified.

Sources

• src/SAIF.NetCore.Clients.UC4/SAIF.NetCore.Clients.UC4/SAIF.NetCore.Clients.UC4/Services/UC4Client.cs
• src/SAIF.NetCore.Clients.UC4/SAIF.NetCore.Clients.UC4/SAIF.NetCore.Clients.UC4/Constants.cs
• src/SAIF.NetCore.EnvironmentClient/SAIF.NetCore.EnvironmentClient/SAIF.NetCore.EnvironmentClient/BaseEnvironmentClient.cs — declares HasSetting/GetSettingValue and the Environment API section/host resolution behavior UC4 relies on.
• src/SAIF.NetCore.EnvironmentClient/SAIF.NetCore.EnvironmentClient/SAIF.NetCore.EnvironmentClient/SecureEnvironmentClient.cs — declares the secure-client construction requirement referenced by the COREAPIENABLED row.
• src/SAIF.NetCore.HttpClients/SAIF.NetCore.HttpClients/SAIF.NetCore.HttpClients/HttpJsonClient/HttpJsonClient.cs — declares SetClientInfo, the behavior IHttpJsonClient registration backs.
• src/SAIF.NetCore.ServiceContracts/SAIF.NetCore.ServiceContracts/SAIF.NetCore.ServiceContracts/HttpClientOptions.cs — declares the retry/delay defaults referenced in the transitive configuration table.
• src/SAIF.NetCore.ServiceExtensions/SAIF.NetCore.ServiceExtensions/SAIF.NetCore.ServiceExtensions/IServiceCollectionExtensions.cs — registers IEnvironmentClient and IHttpJsonClient for consuming applications.