Pipeline context reference

Properties

Every behavior receives IPipelineContext:

Property	Type	Description
correlationId	string	Immutable ID fixed before the behavior chain starts
tenantId	string | undefined	Current tenant when the pipeline started; write-once
request	TRequest	The command / query / event instance
requestType	Type<TRequest>	Class constructor (e.g. CreateUserCommand)
requestName	string	Class name string (e.g. "CreateUserCommand")
handlerType	Type	Handler class constructor
handlerName	string	Handler class name (e.g. "CreateUserHandler")
requestKind	'command' | 'query' | 'event' | 'unknown'	Auto-detected from @nestjs/cqrs metadata
startedAt	Date	UTC timestamp of pipeline start
response	TResponse | undefined	Set after next() returns; undefined before handler runs
items	Map<string | symbol, unknown>	Shared bag for inter-behavior communication

Using items for Inter-Behavior Communication

// AuthBehavior — runs before other behaviors
@Injectable()
export class AuthBehavior implements IPipelineBehavior {
  async handle(context: IPipelineContext, next: NextDelegate): Promise<any> {
    const userId = await this.authService.getCurrentUserId();
    context.items.set('currentUserId', userId);  // ← store data
    return next();
  }
}

// AuditBehavior — runs after AuthBehavior in the chain
@Injectable()
export class AuditBehavior implements IPipelineBehavior {
  async handle(context: IPipelineContext, next: NextDelegate): Promise<any> {
    const result = await next();
    const userId = context.items.get('currentUserId');  // ← read data
    await this.auditService.log({
      action: context.requestName,
      userId,
      correlationId: context.correlationId,
    });
    return result;
  }
}

Behavior Options

Pass per-handler options with the [Behavior, { ... }] tuple form and read them with getBehaviorOptions():

// Handler declaration
@CommandHandler(CreateUserCommand)
@UsePipeline(
  [AuditBehavior, { action: 'user.create', severity: 'high' }],
  [LoggingBehavior, { metricLogLevel: 'verbose', requestResponseLogLevel: 'log' }],
)
export class CreateUserHandler implements ICommandHandler<CreateUserCommand> {
  /* ... */
}

// Inside AuditBehavior
async handle(context: IPipelineContext, next: NextDelegate): Promise<any> {
  const opts = context.getBehaviorOptions<AuditOptions>(AuditBehavior);
  // opts → { action: 'user.create', severity: 'high' }
  // ...
}

Options can also be set at the global level:

PipelineModule.forRoot({
  globalBehaviors: {
    scope: 'all',
    before: [
      [LoggingBehavior, { metricLogLevel: 'log', requestResponseLogLevel: 'debug' }],
    ],
    after: [
      [TraceBehavior, { tracerName: 'my-service' }],
    ],
  },
})

When the same behavior has options at both global and handler level, the handler entry replaces its whole options record while the behavior retains its global chain position. The core does not shallow-merge individual properties inside those two records.