diff --git a/src/main/java/it/cnr/isti/workflow/manager/executions/bias/BiasImpactJudge.java b/src/main/java/it/cnr/isti/workflow/manager/executions/bias/BiasImpactJudge.java
index 4d4cb11..10afd7c 100644
--- a/src/main/java/it/cnr/isti/workflow/manager/executions/bias/BiasImpactJudge.java
+++ b/src/main/java/it/cnr/isti/workflow/manager/executions/bias/BiasImpactJudge.java
@@ -30,6 +30,7 @@ import it.cnr.isti.workflow.manager.flows.model.bias.BlockBiasAnnotation;
 import it.cnr.isti.workflow.manager.flows.validation.ValidationErrorCode;
 import it.cnr.isti.workflow.manager.llms.LLMCredentialResolver;
 import it.cnr.isti.workflow.manager.llms.LLMDescriptor;
+import it.cnr.isti.workflow.manager.llms.ProviderCredential;
 import it.cnr.isti.workflow.manager.llms.providers.LLMProvider;
 import tools.jackson.databind.JsonNode;
 
@@ -79,7 +80,7 @@ public class BiasImpactJudge {
     public BiasJudgeSummary evaluate(BiasImpactReport comparison, LLMDescriptor descriptor, ExecutionObject baseline,
             ExecutionObject biased) {
         LLMProvider provider = resolveProvider(descriptor.provider());
-        String authorization = resolveAuthorization(provider, baseline);
+        ProviderCredential authorization = resolveAuthorization(provider, baseline);
         String interventions = describeInterventions(biased, comparison.annotationIds());
 
         List<BiasJudgeTarget> targets = BiasJudgeTarget.collect(comparison);
@@ -117,7 +118,7 @@ public class BiasImpactJudge {
                 errors, verdicts);
     }
 
-    private BiasJudgeVerdict judgeTarget(LLMProvider provider, LLMDescriptor descriptor, String authorization,
+    private BiasJudgeVerdict judgeTarget(LLMProvider provider, LLMDescriptor descriptor, ProviderCredential authorization,
             String interventions, BiasJudgeTarget target, List<String> errors) {
         String prompt = pairPrompt(interventions, target);
         try {
@@ -150,7 +151,7 @@ public class BiasImpactJudge {
      * this, where the answer is the real one - and the extractor below pulls the object out of
      * whatever prose it arrives wrapped in.
      */
-    private String askForJson(LLMProvider provider, LLMDescriptor descriptor, String authorization, String prompt) {
+    private String askForJson(LLMProvider provider, LLMDescriptor descriptor, ProviderCredential authorization, String prompt) {
         String json = null;
         try {
             json = provider.generateJson(descriptor.model(), prompt, authorization, descriptor.parameters());
@@ -183,7 +184,7 @@ public class BiasImpactJudge {
      * per-pair verdicts in code, so that re-reading a report cannot show a different headline than
      * the pairs it is made of.
      */
-    private String narrate(LLMProvider provider, LLMDescriptor descriptor, String authorization, String interventions,
+    private String narrate(LLMProvider provider, LLMDescriptor descriptor, ProviderCredential authorization, String interventions,
             BiasImpactReport comparison, Map<String, BiasJudgeVerdict> verdicts, BiasJudgeImpactLevel impact,
             BiasJudgeAttribution attribution, List<String> errors) {
         String prompt = """
@@ -504,7 +505,7 @@ public class BiasImpactJudge {
      * run is reached the same way as the models that produced it, and the internal provider - the
      * one a local install has - needs no credential at all.
      */
-    private String resolveAuthorization(LLMProvider provider, ExecutionObject baseline) {
+    private ProviderCredential resolveAuthorization(LLMProvider provider, ExecutionObject baseline) {
         try {
             return credentialResolver.resolve(provider, baseline.getProvidedAuthorizations(),
                     baseline.getContext().getResolvedExecutionVariables());
diff --git a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/ChatInteractionExecutor.java b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/ChatInteractionExecutor.java
index ea829f7..565a7da 100644
--- a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/ChatInteractionExecutor.java
+++ b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/ChatInteractionExecutor.java
@@ -29,6 +29,7 @@ import it.cnr.isti.workflow.manager.llms.ChatMessage;
 import it.cnr.isti.workflow.manager.llms.LLMDescriptor;
 import it.cnr.isti.workflow.manager.llms.LLMDescriptorInputBinding;
 import it.cnr.isti.workflow.manager.llms.LLMCredentialResolver;
+import it.cnr.isti.workflow.manager.llms.ProviderCredential;
 import it.cnr.isti.workflow.manager.llms.providers.LLMProvider;
 
 @Component
@@ -65,7 +66,7 @@ public class ChatInteractionExecutor implements BlockExecutor<ChatInteractionBlo
 
         LLMDescriptor chatDescriptor = LLMDescriptorInputBinding.resolve(configuration.getLlmDescriptor(), inputs, executionVariables);
         LLMProvider chatProvider = SimulatedChatSupport.resolveProvider(llmProviders, chatDescriptor.provider());
-        String chatAuthorization = SimulatedChatSupport.resolveAuthorization(credentialResolver, chatProvider, authorizations,
+        ProviderCredential chatCredential = SimulatedChatSupport.resolveAuthorization(credentialResolver, chatProvider, authorizations,
                 executionVariables);
         if (eventLogger != null) {
             eventLogger.info(ExecutionEventType.LLM_REQUEST,
@@ -74,7 +75,7 @@ public class ChatInteractionExecutor implements BlockExecutor<ChatInteractionBlo
         }
 
         LLMProvider simulatorProvider = SimulatedChatSupport.resolveProvider(llmProviders, simulatorDescriptor.provider());
-        String simulatorAuthorization = SimulatedChatSupport.resolveAuthorization(credentialResolver, simulatorProvider,
+        ProviderCredential simulatorCredential = SimulatedChatSupport.resolveAuthorization(credentialResolver, simulatorProvider,
                 authorizations, executionVariables);
 
         String resolvedGoal = ExecutionTemplateResolver.resolve(configuration.getGoalDescription(), inputs, executionVariables);
@@ -82,7 +83,7 @@ public class ChatInteractionExecutor implements BlockExecutor<ChatInteractionBlo
 
         for (int turn = 1; turn <= MAX_SIMULATED_INTERACTIONS; turn++) {
             String simulatedMessage = SimulatedChatSupport.generateSimulatorMessage(simulatorProvider, simulatorDescriptor,
-                    simulatorAuthorization, resolvedGoal, inputs, history, turn, MAX_SIMULATED_INTERACTIONS, "ChatInteraction");
+                    simulatorCredential, resolvedGoal, inputs, history, turn, MAX_SIMULATED_INTERACTIONS, "ChatInteraction");
             history.add(SimulatedChatSupport.formatConversationLine(ChatMessage.Role.USER.name(), simulatedMessage));
 
             List<ChatMessage> messages = history.stream().map(this::parseHistoryLine).collect(Collectors.toList());
@@ -91,12 +92,12 @@ public class ChatInteractionExecutor implements BlockExecutor<ChatInteractionBlo
                 messages.addFirst(new ChatMessage(ChatMessage.Role.SYSTEM, experimentalDirective));
             }
             String assistantResponse = chatProvider.chat(chatDescriptor.model(), List.copyOf(messages),
-                    chatAuthorization, chatDescriptor.parameters());
+                    chatCredential, chatDescriptor.parameters());
             history.add(SimulatedChatSupport.formatConversationLine(ChatMessage.Role.ASSISTANT.name(), assistantResponse));
         }
 
         String finalResponse = SimulatedChatSupport.generateSimulatorFinalResponse(simulatorProvider, simulatorDescriptor,
-                simulatorAuthorization, resolvedGoal, inputs, history, "ChatInteraction");
+                simulatorCredential, resolvedGoal, inputs, history, "ChatInteraction");
         return buildResult(configuration, finalResponse, List.copyOf(history));
     }
 
@@ -124,7 +125,7 @@ public class ChatInteractionExecutor implements BlockExecutor<ChatInteractionBlo
                     "Calling chat model " + llmDescriptor.model(),
                     Map.of("provider", llmDescriptor.provider(), "model", llmDescriptor.model()));
         }
-        String authorization = SimulatedChatSupport.resolveAuthorization(credentialResolver, llmProvider, authorizations,
+        ProviderCredential credential = SimulatedChatSupport.resolveAuthorization(credentialResolver, llmProvider, authorizations,
                 executionVariables);
 
         if (interaction.containsKey(ChatInteractionBlockFactory.INTERACTION_FIELD)) {
@@ -142,7 +143,7 @@ public class ChatInteractionExecutor implements BlockExecutor<ChatInteractionBlo
                     .collect(Collectors.toList());
             messages.add(new ChatMessage(ChatMessage.Role.USER, resolvedMessage));
 
-            String assistantResponse = llmProvider.chat(llmDescriptor.model(), List.copyOf(messages), authorization,
+            String assistantResponse = llmProvider.chat(llmDescriptor.model(), List.copyOf(messages), credential,
                     llmDescriptor.parameters());
 
             List<String> updatedHistory = new ArrayList<>(history);
diff --git a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/ConditionalExecutor.java b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/ConditionalExecutor.java
index db6c325..8ffa4de 100644
--- a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/ConditionalExecutor.java
+++ b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/ConditionalExecutor.java
@@ -27,6 +27,7 @@ import it.cnr.isti.workflow.manager.executions.bias.runtime.BiasRuntimeSupport;
 import it.cnr.isti.workflow.manager.llms.LLMDescriptor;
 import it.cnr.isti.workflow.manager.llms.LLMDescriptorInputBinding;
 import it.cnr.isti.workflow.manager.llms.LLMCredentialResolver;
+import it.cnr.isti.workflow.manager.llms.ProviderCredential;
 import it.cnr.isti.workflow.manager.llms.providers.LLMProvider;
 
 @Component
@@ -84,12 +85,12 @@ public class ConditionalExecutor implements BlockExecutor<ConditionalBlockType>
             ExecutionEventLogger eventLogger) {
         LLMDescriptor llmDescriptor = LLMDescriptorInputBinding.resolve(config.getLlmDescriptor(), inputValues, executionVariables);
         LLMProvider llmProvider = SimulatedChatSupport.resolveProvider(llmProviders, llmDescriptor.provider());
-        String authorization = credentialResolver.resolve(llmProvider, authorizations, executionVariables);
+        ProviderCredential credential = credentialResolver.resolve(llmProvider, authorizations, executionVariables);
 
         String prompt = buildLlmPrompt(config, inputValues, executionVariables);
         ModelParameterReporting.reportUnsupported(llmProvider, llmDescriptor.parameters(), llmDescriptor.model(),
                 eventLogger);
-        String response = llmProvider.generate(llmDescriptor.model(), prompt, authorization,
+        String response = llmProvider.generate(llmDescriptor.model(), prompt, credential,
                 llmDescriptor.parameters());
         try {
             return parseBooleanResponse(response);
diff --git a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/HumanDecisionExecutor.java b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/HumanDecisionExecutor.java
index c9ddd21..83fcc23 100644
--- a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/HumanDecisionExecutor.java
+++ b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/HumanDecisionExecutor.java
@@ -26,6 +26,7 @@ import it.cnr.isti.workflow.manager.executions.steps.Input;
 import it.cnr.isti.workflow.manager.executions.bias.runtime.BiasRuntimeSupport;
 import it.cnr.isti.workflow.manager.llms.LLMDescriptor;
 import it.cnr.isti.workflow.manager.llms.LLMCredentialResolver;
+import it.cnr.isti.workflow.manager.llms.ProviderCredential;
 import it.cnr.isti.workflow.manager.llms.providers.LLMProvider;
 
 @Component
@@ -64,7 +65,7 @@ public class HumanDecisionExecutor implements BlockExecutor<HumanDecisionBlockTy
         if (llmProvider == null) {
             throw new IllegalArgumentException("Provider not found: " + simulatorDescriptor.provider());
         }
-        String authorization = credentialResolver.resolve(llmProvider, authorizations, executionVariables);
+        ProviderCredential credential = credentialResolver.resolve(llmProvider, authorizations, executionVariables);
 
         String context = inputs.stream()
                 .map(input -> "%s= %s".formatted(input.getDescriptor().getName(), input.getValue()))
@@ -87,7 +88,7 @@ public class HumanDecisionExecutor implements BlockExecutor<HumanDecisionBlockTy
 
         ModelParameterReporting.reportUnsupported(llmProvider, simulatorDescriptor.parameters(),
                 simulatorDescriptor.model(), eventLogger);
-        String response = llmProvider.generate(simulatorDescriptor.model(), prompt, authorization,
+        String response = llmProvider.generate(simulatorDescriptor.model(), prompt, credential,
                 simulatorDescriptor.parameters());
         if (!StringUtils.hasText(response)) {
             throw new IllegalArgumentException("Simulated HumanDecision produced an empty response");
diff --git a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/HumanInteractionExecutor.java b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/HumanInteractionExecutor.java
index fe26a4f..5743e23 100644
--- a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/HumanInteractionExecutor.java
+++ b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/HumanInteractionExecutor.java
@@ -21,6 +21,7 @@ import it.cnr.isti.workflow.manager.executions.steps.Input;
 import it.cnr.isti.workflow.manager.executions.bias.runtime.BiasRuntimeSupport;
 import it.cnr.isti.workflow.manager.llms.LLMDescriptor;
 import it.cnr.isti.workflow.manager.llms.LLMCredentialResolver;
+import it.cnr.isti.workflow.manager.llms.ProviderCredential;
 import it.cnr.isti.workflow.manager.llms.providers.LLMProvider;
 
 @Component
@@ -68,11 +69,11 @@ public class HumanInteractionExecutor implements BlockExecutor<HumanInteractionB
         if (llmProvider == null) {
             throw new IllegalArgumentException("Provider not found: " + llmDescriptor.provider());
         }
-        String authorization = credentialResolver.resolve(llmProvider, authorizations, executionVariables);
+        ProviderCredential credential = credentialResolver.resolve(llmProvider, authorizations, executionVariables);
 
         ModelParameterReporting.reportUnsupported(llmProvider, llmDescriptor.parameters(), llmDescriptor.model(),
                 eventLogger);
-        String response = llmProvider.generate(llmDescriptor.model(), prompt, authorization,
+        String response = llmProvider.generate(llmDescriptor.model(), prompt, credential,
                 llmDescriptor.parameters());
 
         return Map.of("output", response);
diff --git a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/LLMExecutor.java b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/LLMExecutor.java
index 24a6601..10fbd0a 100644
--- a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/LLMExecutor.java
+++ b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/LLMExecutor.java
@@ -26,6 +26,7 @@ import it.cnr.isti.workflow.manager.executions.bias.runtime.BiasRuntimeSupport;
 import it.cnr.isti.workflow.manager.llms.LLMDescriptor;
 import it.cnr.isti.workflow.manager.llms.LLMDescriptorInputBinding;
 import it.cnr.isti.workflow.manager.llms.LLMCredentialResolver;
+import it.cnr.isti.workflow.manager.llms.ProviderCredential;
 import it.cnr.isti.workflow.manager.llms.providers.LLMProvider;
 import it.cnr.isti.workflow.manager.skills.SkillPromptService;
 
@@ -77,11 +78,11 @@ public class LLMExecutor implements BlockExecutor<LLMBlockType> {
         if (llmProvider == null) {
             throw new IllegalArgumentException("Provider not found: " + llmDescriptor.provider());
         }
-        String authorization = credentialResolver.resolve(llmProvider, authorizations, executionVariables);
+        ProviderCredential credential = credentialResolver.resolve(llmProvider, authorizations, executionVariables);
 
         ModelParameterReporting.reportUnsupported(llmProvider, llmDescriptor.parameters(), llmDescriptor.model(),
                 eventLogger);
-        String response = llmProvider.generate(llmDescriptor.model(), prompt, authorization,
+        String response = llmProvider.generate(llmDescriptor.model(), prompt, credential,
                 llmDescriptor.parameters());
 
         if (eventLogger != null) {
diff --git a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/MCPAgentChatExecutor.java b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/MCPAgentChatExecutor.java
index 8037176..75a2a9d 100644
--- a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/MCPAgentChatExecutor.java
+++ b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/MCPAgentChatExecutor.java
@@ -28,6 +28,7 @@ import it.cnr.isti.workflow.manager.executions.bias.runtime.BiasRuntimeSupport;
 import it.cnr.isti.workflow.manager.llms.ConfigurableInputBinding;
 import it.cnr.isti.workflow.manager.llms.LLMDescriptor;
 import it.cnr.isti.workflow.manager.llms.LLMCredentialResolver;
+import it.cnr.isti.workflow.manager.llms.ProviderCredential;
 import it.cnr.isti.workflow.manager.llms.providers.LLMProvider;
 import it.cnr.isti.workflow.manager.mcp.MCPAgentService;
 import it.cnr.isti.workflow.manager.mcp.MCPSharedSessionRegistry;
@@ -74,7 +75,7 @@ public class MCPAgentChatExecutor implements BlockExecutor<MCPAgentChatBlockType
             throw new IllegalArgumentException("Missing simulation descriptor for MCPAgentChat execution");
         }
         LLMProvider simulatorProvider = SimulatedChatSupport.resolveProvider(llmProviders, simulatorDescriptor.provider());
-        String simulatorAuthorization = SimulatedChatSupport.resolveAuthorization(credentialResolver, simulatorProvider,
+        ProviderCredential simulatorCredential = SimulatedChatSupport.resolveAuthorization(credentialResolver, simulatorProvider,
                 authorizations, executionVariables);
         String resolvedGoal = ExecutionTemplateResolver.resolve(configuration.getGoalDescription(), inputs, executionVariables);
         resolvedGoal = BiasRuntimeSupport.decoratePrompt(resolvedGoal, executionVariables);
@@ -92,7 +93,7 @@ public class MCPAgentChatExecutor implements BlockExecutor<MCPAgentChatBlockType
         try {
             for (int turn = 1; turn <= MAX_SIMULATED_INTERACTIONS; turn++) {
                 String simulatedMessage = SimulatedChatSupport.generateSimulatorMessage(simulatorProvider, simulatorDescriptor,
-                        simulatorAuthorization, resolvedGoal, inputs, history, turn, MAX_SIMULATED_INTERACTIONS, "MCPAgentChat");
+                        simulatorCredential, resolvedGoal, inputs, history, turn, MAX_SIMULATED_INTERACTIONS, "MCPAgentChat");
                 history.add(SimulatedChatSupport.formatConversationLine("USER", simulatedMessage));
 
                 String assistantResponse = mcpAgentService.querySession(sessionId, simulatedMessage);
@@ -100,7 +101,7 @@ public class MCPAgentChatExecutor implements BlockExecutor<MCPAgentChatBlockType
             }
 
             String finalResponse = SimulatedChatSupport.generateSimulatorFinalResponse(simulatorProvider, simulatorDescriptor,
-                    simulatorAuthorization, resolvedGoal, inputs, history, "MCPAgentChat");
+                    simulatorCredential, resolvedGoal, inputs, history, "MCPAgentChat");
             return buildResult(configuration, finalResponse, List.copyOf(history), null);
         } finally {
             if (!managedSharedSession) {
diff --git a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/SimulatedChatSupport.java b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/SimulatedChatSupport.java
index eab7dd7..aeb3714 100644
--- a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/SimulatedChatSupport.java
+++ b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/SimulatedChatSupport.java
@@ -14,6 +14,7 @@ import it.cnr.isti.workflow.manager.executions.ExecutionTemplateResolver;
 import it.cnr.isti.workflow.manager.executions.steps.Input;
 import it.cnr.isti.workflow.manager.llms.LLMCredentialResolver;
 import it.cnr.isti.workflow.manager.llms.LLMDescriptor;
+import it.cnr.isti.workflow.manager.llms.ProviderCredential;
 import it.cnr.isti.workflow.manager.llms.providers.LLMProvider;
 
 final class SimulatedChatSupport {
@@ -32,7 +33,7 @@ final class SimulatedChatSupport {
                 .orElseThrow(() -> new IllegalArgumentException("Provider not found: " + providerName));
     }
 
-    static String resolveAuthorization(LLMCredentialResolver credentialResolver, LLMProvider provider,
+    static ProviderCredential resolveAuthorization(LLMCredentialResolver credentialResolver, LLMProvider provider,
             Map<String, Object> authorizations, Map<String, Object> executionVariables) {
         return credentialResolver.resolve(provider, authorizations, executionVariables);
     }
@@ -72,7 +73,7 @@ final class SimulatedChatSupport {
     }
 
     static String generateSimulatorMessage(LLMProvider simulatorProvider, LLMDescriptor simulatorDescriptor,
-            String simulatorAuthorization, String goalDescription, List<Input> inputs, List<String> history, int turn,
+            ProviderCredential simulatorCredential, String goalDescription, List<Input> inputs, List<String> history, int turn,
             int maxTurns, String blockLabel) {
         String prompt = """
                 ###SIMULATED_CHAT_MESSAGE###
@@ -89,7 +90,7 @@ final class SimulatedChatSupport {
 
                 Return only the next user message for the conversation.
                 """.formatted(goalDescription, turn, maxTurns, formatInputs(inputs), formatHistory(history));
-        String response = simulatorProvider.generate(simulatorDescriptor.model(), prompt, simulatorAuthorization,
+        String response = simulatorProvider.generate(simulatorDescriptor.model(), prompt, simulatorCredential,
                 simulatorDescriptor.parameters());
         if (!StringUtils.hasText(response)) {
             throw new IllegalArgumentException("Simulated " + blockLabel + " produced an empty message");
@@ -98,7 +99,7 @@ final class SimulatedChatSupport {
     }
 
     static String generateSimulatorFinalResponse(LLMProvider simulatorProvider, LLMDescriptor simulatorDescriptor,
-            String simulatorAuthorization, String goalDescription, List<Input> inputs, List<String> history, String blockLabel) {
+            ProviderCredential simulatorCredential, String goalDescription, List<Input> inputs, List<String> history, String blockLabel) {
         String prompt = """
                 ###SIMULATED_CHAT_FINAL###
                 Goal:
@@ -112,7 +113,7 @@ final class SimulatedChatSupport {
 
                 Return only the final response value that the simulated user would submit.
                 """.formatted(goalDescription, formatInputs(inputs), formatHistory(history));
-        String response = simulatorProvider.generate(simulatorDescriptor.model(), prompt, simulatorAuthorization,
+        String response = simulatorProvider.generate(simulatorDescriptor.model(), prompt, simulatorCredential,
                 simulatorDescriptor.parameters());
         if (!StringUtils.hasText(response)) {
             throw new IllegalArgumentException("Simulated " + blockLabel + " produced an empty final response");
diff --git a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/SwitchExecutor.java b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/SwitchExecutor.java
index 934be2a..4b9723f 100644
--- a/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/SwitchExecutor.java
+++ b/src/main/java/it/cnr/isti/workflow/manager/executions/executors/blocks/SwitchExecutor.java
@@ -33,6 +33,7 @@ import it.cnr.isti.workflow.manager.ios.IOType;
 import it.cnr.isti.workflow.manager.llms.LLMDescriptor;
 import it.cnr.isti.workflow.manager.llms.LLMDescriptorInputBinding;
 import it.cnr.isti.workflow.manager.llms.LLMCredentialResolver;
+import it.cnr.isti.workflow.manager.llms.ProviderCredential;
 import it.cnr.isti.workflow.manager.llms.providers.LLMProvider;
 
 @Component
@@ -112,12 +113,12 @@ public class SwitchExecutor implements BlockExecutor<SwitchBlockType> {
             ExecutionEventLogger eventLogger) {
         LLMDescriptor llmDescriptor = LLMDescriptorInputBinding.resolve(config.getLlmDescriptor(), inputValues, executionVariables);
         LLMProvider llmProvider = SimulatedChatSupport.resolveProvider(llmProviders, llmDescriptor.provider());
-        String authorization = credentialResolver.resolve(llmProvider, authorizations, executionVariables);
+        ProviderCredential credential = credentialResolver.resolve(llmProvider, authorizations, executionVariables);
 
         String prompt = buildLlmPrompt(config, inputValues, executionVariables, allowedOutputs);
         ModelParameterReporting.reportUnsupported(llmProvider, llmDescriptor.parameters(), llmDescriptor.model(),
                 eventLogger);
-        String response = llmProvider.generate(llmDescriptor.model(), prompt, authorization,
+        String response = llmProvider.generate(llmDescriptor.model(), prompt, credential,
                 llmDescriptor.parameters());
         return parseSelectedOutput(response, allowedOutputs);
     }
diff --git a/src/main/java/it/cnr/isti/workflow/manager/llms/LLMCredentialResolver.java b/src/main/java/it/cnr/isti/workflow/manager/llms/LLMCredentialResolver.java
index be9046a..c3f4a85 100644
--- a/src/main/java/it/cnr/isti/workflow/manager/llms/LLMCredentialResolver.java
+++ b/src/main/java/it/cnr/isti/workflow/manager/llms/LLMCredentialResolver.java
@@ -23,7 +23,13 @@ public class LLMCredentialResolver {
         this.userSecretService = userSecretService;
     }
 
-    public String resolve(LLMProvider provider, Map<String, Object> authorizations,
+    /**
+     * Returns a {@link ProviderCredential}, carrying the endpoint alongside the secret value for a
+     * provider whose {@code requiresEndpoint()} is true. Not yet called from every executor: see
+     * {@code docs/llm-providers-openai-remote-ollama-plan-2026-09-17.md} step 11 for which call
+     * sites still resolve through the plain secret value only, and why.
+     */
+    public ProviderCredential resolve(LLMProvider provider, Map<String, Object> authorizations,
             Map<String, Object> executionVariables) {
         if (!provider.requiresAuthorization()) {
             return null;
@@ -38,7 +44,7 @@ public class LLMCredentialResolver {
             throw new IllegalArgumentException(
                     "A user-owned execution is required to resolve credential for provider: " + provider.getName());
         }
-        return userSecretService.resolveValue(owner, credentialId.trim(), provider.getName());
+        return userSecretService.resolveCredential(owner, credentialId.trim(), provider.getName());
     }
 
     private String asText(Object value) {
diff --git a/src/test/java/it/cnr/isti/workflow/manager/llms/LLMCredentialResolverTest.java b/src/test/java/it/cnr/isti/workflow/manager/llms/LLMCredentialResolverTest.java
new file mode 100644
index 0000000..2cf8ca2
--- /dev/null
+++ b/src/test/java/it/cnr/isti/workflow/manager/llms/LLMCredentialResolverTest.java
@@ -0,0 +1,110 @@
+// SPDX-FileCopyrightText: 2025-2026 Lucio Lelii <lucio.lelii@isti.cnr.it> - ISTI-CNR
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// Attribution term under AGPL-3.0 section 7(b): see LICENSE-ADDENDUM.
+
+package it.cnr.isti.workflow.manager.llms;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.util.List;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+
+import it.cnr.isti.workflow.manager.executions.ExecutionRuntimeContextSupport;
+import it.cnr.isti.workflow.manager.llms.providers.LLMProvider;
+import it.cnr.isti.workflow.manager.vault.UserSecretService;
+
+/**
+ * Not previously covered on its own - only ever exercised indirectly through a full execution.
+ * This pins the branching {@code resolve} itself does (no authorization required, no credential
+ * id, no owner) before it becomes even harder to isolate from what calls it.
+ */
+class LLMCredentialResolverTest {
+
+    private final UserSecretService userSecretService = mock(UserSecretService.class);
+    private final LLMCredentialResolver resolver = new LLMCredentialResolver(userSecretService);
+
+    private LLMProvider provider(boolean requiresAuthorization) {
+        return new LLMProvider() {
+            @Override
+            public String getName() {
+                return "Test";
+            }
+
+            @Override
+            public List<String> getRegisteredModels() {
+                return List.of();
+            }
+
+            @Override
+            public String generate(String model, String prompt) {
+                throw new UnsupportedOperationException();
+            }
+
+            @Override
+            public boolean requiresAuthorization() {
+                return requiresAuthorization;
+            }
+        };
+    }
+
+    @Test
+    void returnsNullWithoutTouchingTheVaultWhenTheProviderNeedsNoAuthorization() {
+        ProviderCredential result = resolver.resolve(provider(false), Map.of(), Map.of());
+
+        assertNull(result);
+        verify(userSecretService, never()).resolveCredential(any(), any(), any());
+    }
+
+    @Test
+    void throwsWhenTheAuthorizationsMapHasNoEntryForTheProvidersKey() {
+        LLMProvider provider = provider(true);
+
+        assertThrows(IllegalArgumentException.class,
+                () -> resolver.resolve(provider, Map.of(), Map.of(ExecutionRuntimeContextSupport.EXECUTION_OWNER, "alice")));
+    }
+
+    @Test
+    void throwsWhenTheCredentialIdIsBlank() {
+        LLMProvider provider = provider(true);
+        Map<String, Object> authorizations = Map.of(provider.authorizationKey(), "   ");
+
+        assertThrows(IllegalArgumentException.class,
+                () -> resolver.resolve(provider, authorizations,
+                        Map.of(ExecutionRuntimeContextSupport.EXECUTION_OWNER, "alice")));
+    }
+
+    @Test
+    void throwsWhenThereIsNoOwnedExecutionContext() {
+        LLMProvider provider = provider(true);
+        Map<String, Object> authorizations = Map.of(provider.authorizationKey(), "secret-1");
+
+        assertThrows(IllegalArgumentException.class, () -> resolver.resolve(provider, authorizations, Map.of()));
+    }
+
+    @Test
+    void resolvesThroughUserSecretServiceAndReturnsItsCredentialAsIs() {
+        LLMProvider provider = provider(true);
+        Map<String, Object> authorizations = Map.of(provider.authorizationKey(), "  secret-1  ");
+        Map<String, Object> executionVariables = Map.of(ExecutionRuntimeContextSupport.EXECUTION_OWNER, "alice");
+        ProviderCredential expected = new ProviderCredential("api-key", "https://gateway.example.com");
+        when(userSecretService.resolveCredential("alice", "secret-1", "Test")).thenReturn(expected);
+
+        ProviderCredential result = resolver.resolve(provider, authorizations, executionVariables);
+
+        assertEquals(expected, result);
+        // The id is trimmed before being used - a pasted value with surrounding whitespace must
+        // still resolve.
+        verify(userSecretService).resolveCredential(eq("alice"), eq("secret-1"), eq("Test"));
+    }
+
+}