# Description
Adds `MinimalClient`, a compact console OPC UA application demonstrating
the unified dependency-injection surface, secure endpoint discovery,
managed sessions, fluent V2 subscriptions, and Alarms & Conditions
support.
## Changes
- Adds `ConfigureApplication(options => ...)` to build and validate one
shared `ApplicationConfiguration` for combined client/server hosts.
- Extends `OpcUaClientOptions` so the existing `AddClient(options =>
...)` callback accepts application identity, PKI, and
certificate-validation settings like `AddServer(...)`.
- Composes root `ConfigureApplication(...)` values with client defaults
in either registration order; shared values take precedence and client
values fill gaps.
- Keeps server samples on their established `AddServer(...)`
configuration pattern.
- Adds `MinimalClient` as a .NET 10 Native AOT console application using
top-level statements and `HostApplicationBuilder`.
- Discovers a `SignAndEncrypt` / `Basic256Sha256` endpoint by default;
`--insecure` and `--auto-accept` are explicit opt-ins with warnings.
- Demonstrates fluent `AddSubscription(...)`,
`TryAddMonitoredItem(...)`, and `AlarmClientFactory` usage.
- Adds targeted configuration, client, and combined client/server tests.
## Example
```csharp
builder.Services
.AddOpcUa()
.AddClient(options =>
{
options.ApplicationName = "MinimalClient";
options.ApplicationUri = "urn:localhost:OPCFoundation:MinimalClient";
options.ProductUri = "uri:opcfoundation.org:MinimalClient";
options.Session = new ManagedSessionOptions
{
SessionName = "MinimalClient",
SessionTimeout = TimeSpan.FromSeconds(60)
};
})
.AddDiscoveryAndConnect(options =>
{
options.DiscoveryUrl = discoveryUrl;
options.SecurityMode = MessageSecurityMode.SignAndEncrypt;
options.SecurityPolicyUri = SecurityPolicies.Basic256Sha256;
})
.AddSubscriptions()
.AddAlarms();
```
## Related Issues
_If there is no issue yet, open one and link it here._
## Checklist
- [ ] I have signed the
[CLA](https://opcfoundation.org/license/cla/ContributorLicenseAgreementv1.0.pdf)
and read the
[CONTRIBUTING](https://github.com/OPCFoundation/UA-.NETStandard/blob/master/CONTRIBUTING.md)
doc.
- [x] I have added tests that prove my fix is effective or that my
feature works and increased code coverage.
- [x] I have added all necessary documentation.
- [x] I have verified that my changes do not introduce new build or
analyzer warnings.
- [ ] I ran all tests locally using the `UA.slnx` solution against at
least .NET Framework and .NET 10.
- [ ] I fixed all failing and flaky tests in the CI pipelines and all
CodeQL warnings.
- [x] I have addressed all PR feedback received.
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: romanett <romanett98@gmail.com>
Co-authored-by: Marc Schier <marcschier@hotmail.com>
Copilot