Conformance: introduce @ConditionalOnScenario

- Useful for incoming auth scenarios in Conformance v2 / 2026-07-28 spec

Signed-off-by: Daniel Garnier-Moiroux <git@garnier.wf>

conformance-tests/client-spring-http-client/src/main/java/io/modelcontextprotocol/conformance/client/condition/ConditionalOnScenario.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2026-2026 the original author or authors.
+ */
+
+package io.modelcontextprotocol.conformance.client.condition;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import org.springframework.context.annotation.Conditional;
+
+/**
+ * Condition to include beans only when certain scenarios are active / inactive. Checks
+ * the value of the {@code MCP_CONFORMANCE_SCENARIO} environment variable and matches
+ * against {@link #included()} and {@link #excluded()}. Exactly one of these attributes
+ * must be defined.
+ * <p>
+ * Usage: <pre>
+ *
+ * &#64;Configuration
+ * &#64;ConditionalOnScenario(excluded =
+ *   {
+ *     "auth/pre-registration",
+ *     "auth/client-credentials-basic"
+ *   }
+ * )
+ * public class DefaultConfiguration {
+ *     // ...
+ * }
+ * </pre>
+ *
+ * @author Daniel Garnier-Moiroux
+ * @see OnScenarioCondition
+ */
+@Target({ ElementType.TYPE, ElementType.METHOD })
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+@Conditional(OnScenarioCondition.class)
+public @interface ConditionalOnScenario {
+
+	String[] included() default {};
+
+	String[] excluded() default {};
+
+}

conformance-tests/client-spring-http-client/src/main/java/io/modelcontextprotocol/conformance/client/condition/OnScenarioCondition.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2026-2026 the original author or authors.
+ */
+
+package io.modelcontextprotocol.conformance.client.condition;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+
+import org.jspecify.annotations.Nullable;
+
+import org.springframework.boot.autoconfigure.condition.ConditionMessage;
+import org.springframework.boot.autoconfigure.condition.ConditionOutcome;
+import org.springframework.boot.autoconfigure.condition.SpringBootCondition;
+import org.springframework.context.annotation.ConditionContext;
+import org.springframework.core.type.AnnotatedTypeMetadata;
+import org.springframework.util.Assert;
+
+/**
+ * Condition implementation for {@link ConditionalOnScenario}.
+ *
+ * @author Daniel Garnier-Moiroux
+ */
+class OnScenarioCondition extends SpringBootCondition {
+
+	private static final String ENV_VAR = "MCP_CONFORMANCE_SCENARIO";
+
+	@Override
+	public ConditionOutcome getMatchOutcome(ConditionContext context, AnnotatedTypeMetadata metadata) {
+		Map<String, @Nullable Object> attributes = metadata
+			.getAnnotationAttributes(ConditionalOnScenario.class.getName());
+		Assert.state(attributes != null, "'attributes' must not be null");
+
+		String[] included = (String[]) attributes.get("included");
+		String[] excluded = (String[]) attributes.get("excluded");
+
+		boolean hasIncluded = included != null && included.length > 0;
+		boolean hasExcluded = excluded != null && excluded.length > 0;
+
+		Assert.state(hasIncluded ^ hasExcluded,
+				"@ConditionalOnScenario must have exactly one of 'included' or 'excluded' defined");
+
+		String scenario = System.getenv(ENV_VAR);
+
+		if (hasIncluded) {
+			List<String> includedList = Arrays.asList(included);
+			boolean matches = scenario != null && includedList.contains(scenario);
+			ConditionMessage message = ConditionMessage.forCondition(ConditionalOnScenario.class)
+				.because("scenario '" + scenario + "' " + (matches ? "is" : "is not") + " in included list "
+						+ includedList);
+			return matches ? ConditionOutcome.match(message) : ConditionOutcome.noMatch(message);
+		}
+		else {
+			List<String> excludedList = Arrays.asList(excluded);
+			boolean matches = scenario == null || !excludedList.contains(scenario);
+			ConditionMessage message = ConditionMessage.forCondition(ConditionalOnScenario.class)
+				.because("scenario '" + scenario + "' " + (matches ? "is not" : "is") + " in excluded list "
+						+ excludedList);
+			return matches ? ConditionOutcome.match(message) : ConditionOutcome.noMatch(message);
+		}
+	}
+
+}

conformance-tests/client-spring-http-client/src/main/java/io/modelcontextprotocol/conformance/client/configuration/DefaultConfiguration.java

@@ -5,6 +5,7 @@
 package io.modelcontextprotocol.conformance.client.configuration;
 
 import io.modelcontextprotocol.client.transport.HttpClientStreamableHttpTransport;
+import io.modelcontextprotocol.conformance.client.condition.ConditionalOnScenario;
 import io.modelcontextprotocol.conformance.client.scenario.DefaultScenario;
 import org.springaicommunity.mcp.security.client.sync.config.McpClientOAuth2Configurer;
 import org.springaicommunity.mcp.security.client.sync.oauth2.http.client.OAuth2CimdHttpClientTransportCustomizer;
@@ -16,7 +17,6 @@ import org.springaicommunity.mcp.security.client.sync.oauth2.registration.cimd.M
 
 import org.springframework.ai.mcp.customizer.McpClientCustomizer;
 import org.springframework.beans.factory.annotation.Value;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnExpression;
 import org.springframework.boot.web.server.servlet.context.ServletWebServerApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -26,7 +26,7 @@ import org.springframework.security.oauth2.client.registration.ClientRegistratio
 import org.springframework.security.web.SecurityFilterChain;
 
 @Configuration
-@ConditionalOnExpression("#{environment['MCP_CONFORMANCE_SCENARIO'] != 'auth/pre-registration'}")
+@ConditionalOnScenario(excluded = { "auth/pre-registration", "auth/client-credentials-basic" })
 public class DefaultConfiguration {
 
 	private final String TEST_CLIENT_ID_URL = "https://conformance-test.local/client-metadata.json";

conformance-tests/client-spring-http-client/src/main/java/io/modelcontextprotocol/conformance/client/configuration/PreRegistrationConfiguration.java

@@ -4,12 +4,12 @@
 
 package io.modelcontextprotocol.conformance.client.configuration;
 
+import io.modelcontextprotocol.conformance.client.condition.ConditionalOnScenario;
 import io.modelcontextprotocol.conformance.client.scenario.PreRegistrationScenario;
 import org.springaicommunity.mcp.security.client.sync.config.McpClientOAuth2Configurer;
 import org.springaicommunity.mcp.security.client.sync.oauth2.metadata.McpMetadataDiscoveryService;
 import org.springaicommunity.mcp.security.client.sync.oauth2.registration.McpClientRegistrationRepository;
 
-import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.security.config.Customizer;
@@ -18,7 +18,7 @@ import org.springframework.security.oauth2.client.OAuth2AuthorizedClientService;
 import org.springframework.security.web.SecurityFilterChain;
 
 @Configuration
-@ConditionalOnProperty(name = "mcp.conformance.scenario", havingValue = "auth/pre-registration")
+@ConditionalOnScenario(included = { "auth/pre-registration", "auth/client-credentials-basic" })
 public class PreRegistrationConfiguration {
 
 	@Bean