README.md

Migrating from 1.5.378 to 2.0.x

Version 2.0 introduces a major architectural change from pre-generated code files to runtime source generation and more efficient memory use, with several major breaking changes requiring changes to your applications.

This folder includes all of the 1.5.378 → 2.0 migration content as a set of focused sub-documents so you can read only the parts that affect your application. Start with the Migration sub-doc index below to find the sub-doc that matches the symptom you are seeing.

Automate the migration. Add the OPCFoundation.NetStandard.Opc.Ua.MigrationAnalyzer analyzer package to your projects to receive analyzer warnings and one-click fixes for many of the patterns in these sub-docs. Rule IDs UA0001 – UA0020 map directly to the type-safety patterns described in types.md.

Pro TIP. Point your favorite coding agent at the opcua-v20-migration skill, which knows when to load each sub-doc and runs the codefixer for you.

Migration sub-doc index

Find the row that matches the error / API surface you are dealing with and read only the listed sub-doc. The agent skill uses the same table; loading a single sub-doc keeps the context window small.

When you hit…	Read
CS0029 / CS1503 / CS0266 on NodeId, Variant, DataValue, ExtensionObject, QualifiedName, LocalizedText, ArrayOf<T> / MatrixOf<T>, ByteString, StatusCode, XmlElement, EnumValue; [Obsolete] warnings on built-in type APIs (analyzer UA0001–UA0020)	types.md
Loggers (Utils.LogX, Utils.Trace), removed static logger helpers (Utils.SetLogger / Utils.SetLogLevel), telemetry context, constructor ITelemetryContext parameter changes, OLD-vs-NEW snippets, fluent DI registration (AddOpcUa().AddLogging().AddMetrics()), breaking-changes inventory, migration utilities	telemetry.md
OPCFoundation.NetStandard.Opc.Ua.* package upgrade, TFM changes, Newtonsoft removal	packages.md
Source-generated *Collection shims, NodeManager generator, default of boolean properties, project structure	source-generation.md
IEncodeableFactoryBuilder, IType, JSON / XML / binary encoders, EncodeableFactory.GlobalFactory, IJsonEncodeable, ComplexTypes namespace move	encoders.md
CustomNodeManager, NodeState clone / read / write helpers, OnAfterCreate(CancellationToken), INodeManager3, INodeCache.InvalidateNode, generics on BaseVariableState / BaseVariableTypeState, predefined-node processing	node-states.md
IUserIdentityTokenHandler, IClientIdentityProvider, IUserTokenAuthenticator, IAccessTokenProvider, ITokenIssuer, IIdentityClaims, caller-supplied secrets, secret store	identity.md
CertificateValidator, ref-counted Certificate wrapper, CertificateManager, ICertificateProvider, obsoleted X509Certificate2 direct-exposure APIs	certificates.md
ApplicationConfiguration changes, Data-Contract serializer removal, ParseExtension / UpdateExtension signature, session / browser state persistence	configuration.md
Session → ManagedSession, V2 subscription engine, GDS-client Task → ValueTask modernisation, removed obsolete GDS APIs, durable subscriptions, PubSub, reverse-connect	sessions-subscriptions.md
UaPubSubApplication.Create*, IUaPubSubConnection, UaPubSubConfigurator, IUaPublisher, AMQP transport, JsonEncodingMode.Reversible/NonReversible, PubSub JSON encoder changes, DataSetFieldContentMask RawData / timestamp behaviour	pubsub.md
AlarmConditionState state-transition behaviour, auto-emitted GeneralModelChangeEvent, ModelChangeAggregator, INodeCache.InvalidateNode triggered by model change	alarms-model-change.md
DateTime.UtcNow, Timer, deterministic time in tests; System.TimeProvider adoption	timeprovider.md
ITransportListener.Open / Close removed, using var listener = … no longer compiles, custom ITransportListenerFactory / ITransportListenerCertificateRotation implementers need the new async method names	transport-listener-async.md

All sub-documents

• telemetry.md — Telemetry and Logging
• packages.md — Package, Target Framework, and Dependency Changes
• source-generation.md — Source Generation
• types.md — Improved Type Safety
• encoders.md — Encoders and Complex Types
• node-states.md — Node States and INodeCache
• identity.md — Identity, Token Handlers, and Secrets
• certificates.md — Certificates and ICertificateProvider
• configuration.md — Configuration and State Persistence
• sessions-subscriptions.md — Sessions, GDS Client, and Subscriptions
• pubsub.md — PubSub (Part 14): breaking API, transport, JSON, and field-encoding changes
• alarms-model-change.md — Alarms and Address-Space Model Changes
• timeprovider.md — Time and Timer Abstraction (TimeProvider)
• transport-listener-async.md — Async ITransportListener API (issue #3923)

See also

• Migration Guide landing page — index across all versions, including the small 1.05.377 → 1.05.378 and 1.04 → 1.05 legacy notes.
• What's New in 2.0 — narrative tour of the 2.0 changes, grouped by theme and layer.
• Profiles — facet / profile coverage of the 2.0 release.