Add function to generate database diagrams

.gitignore

@@ -5,6 +5,7 @@ tree.txt
 _ai-distrib/
 .mcpregistry*
 **/Playground.java
+**/dice.png
 
 # Created by https://www.toptal.com/developers/gitignore/api/java,eclipse,intellij+all,visualstudiocode,maven,gradle
 # Edit at https://www.toptal.com/developers/gitignore?templates=java,eclipse,intellij+all,visualstudiocode,maven,gradle

schemacrawler-ai-core/src/main/java/schemacrawler/tools/ai/functions/DiagramFunctionDefinition.java

@@ -0,0 +1,40 @@
+/*
+ * SchemaCrawler AI
+ * http://www.schemacrawler.com
+ * Copyright (c) 2000-2025, Sualeh Fatehi <sualeh@hotmail.com>.
+ * All rights reserved.
+ * SPDX-License-Identifier: CC-BY-NC-4.0
+ */
+
+package schemacrawler.tools.ai.functions;
+
+import schemacrawler.tools.ai.tools.base.AbstractFunctionDefinition;
+
+public final class DiagramFunctionDefinition
+    extends AbstractFunctionDefinition<DiagramFunctionParameters> {
+
+  @Override
+  public String getDescription() {
+    return """
+    Generates a database diagram in the specified format.
+    """
+        .stripIndent()
+        .replace("\n", " ")
+        .trim();
+  }
+
+  @Override
+  public Class<DiagramFunctionParameters> getParametersClass() {
+    return DiagramFunctionParameters.class;
+  }
+
+  @Override
+  public String getTitle() {
+    return "Generate database diagram";
+  }
+
+  @Override
+  public DiagramFunctionExecutor newExecutor() {
+    return new DiagramFunctionExecutor(getFunctionName());
+  }
+}

schemacrawler-ai-core/src/main/java/schemacrawler/tools/ai/functions/DiagramFunctionExecutor.java

@@ -0,0 +1,43 @@
+/*
+ * SchemaCrawler AI
+ * http://www.schemacrawler.com
+ * Copyright (c) 2000-2025, Sualeh Fatehi <sualeh@hotmail.com>.
+ * All rights reserved.
+ * SPDX-License-Identifier: CC-BY-NC-4.0
+ */
+
+package schemacrawler.tools.ai.functions;
+
+import schemacrawler.inclusionrule.InclusionRule;
+import schemacrawler.tools.ai.functions.DiagramFunctionParameters.DiagramType;
+import schemacrawler.tools.ai.tools.base.AbstractExecutableFunctionExecutor;
+import schemacrawler.tools.options.Config;
+import us.fatehi.utility.property.PropertyName;
+
+public final class DiagramFunctionExecutor
+    extends AbstractExecutableFunctionExecutor<DiagramFunctionParameters> {
+
+  protected DiagramFunctionExecutor(final PropertyName functionName) {
+    super(functionName);
+  }
+
+  @Override
+  protected String getCommand() {
+    return "script";
+  }
+
+  @Override
+  protected InclusionRule grepTablesInclusionRule() {
+    return makeInclusionRule(commandOptions.tableName());
+  }
+
+  @Override
+  protected Config createAdditionalConfig() {
+    final Config additionalConfig = super.createAdditionalConfig();
+
+    final DiagramType diagramType = commandOptions.diagramType();
+    additionalConfig.put("script-language", "python");
+    additionalConfig.put("script", diagramType.script());
+    return additionalConfig;
+  }
+}

schemacrawler-ai-core/src/main/java/schemacrawler/tools/ai/functions/DiagramFunctionParameters.java

@@ -0,0 +1,84 @@
+/*
+ * SchemaCrawler AI
+ * http://www.schemacrawler.com
+ * Copyright (c) 2000-2025, Sualeh Fatehi <sualeh@hotmail.com>.
+ * All rights reserved.
+ * SPDX-License-Identifier: CC-BY-NC-4.0
+ */
+
+package schemacrawler.tools.ai.functions;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonPropertyDescription;
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import schemacrawler.tools.ai.tools.FunctionParameters;
+import schemacrawler.tools.ai.tools.FunctionReturnType;
+import schemacrawler.tools.ai.tools.base.ParameterUtility;
+
+@JsonNaming(PropertyNamingStrategies.KebabCaseStrategy.class)
+public record DiagramFunctionParameters(
+    @JsonPropertyDescription(
+            """
+            Name of database table or view to describe.
+            May be specified as a regular expression, matching the fully qualified
+            table name (including the schema).
+            Use an empty string if all tables are requested.
+            If not specified, all tables will be returned, but the results
+            could be large.
+            """)
+        @JsonProperty(required = false)
+        String tableName,
+    @JsonPropertyDescription(
+            """
+            Indicates database schema diagram format - Graphviz, PlantUML, Mermaid
+            or DBML from dbdiagram.io.
+            """)
+        @JsonProperty(required = true)
+        DiagramType diagramType)
+    implements FunctionParameters {
+
+  public enum DiagramType {
+    PLANTUML("/scripts/plantuml.py", "https://editor.plantuml.com/"),
+    MERMAID("/scripts/mermaid.py", "https://mermaid.live/"),
+    DBML("/scripts/dbml.py", "https://dbdiagram.io/d"),
+    ;
+
+    private final String script;
+    private final String onlineEditorUrl;
+
+    private DiagramType(final String script, final String url) {
+      this.script = script;
+      onlineEditorUrl = url;
+    }
+
+    public String getOnlineEditorUrl() {
+      return onlineEditorUrl;
+    }
+
+    public String script() {
+      return script;
+    }
+  }
+
+  public DiagramFunctionParameters {
+    if (tableName == null || tableName.isBlank()) {
+      tableName = "";
+    }
+    if (diagramType == null) {
+      diagramType = DiagramType.PLANTUML;
+    }
+  }
+
+  @Override
+  public String toString() {
+    return ParameterUtility.parametersToString(this);
+  }
+
+  @JsonIgnore
+  @Override
+  public final FunctionReturnType getFunctionReturnType() {
+    return FunctionReturnType.TEXT;
+  }
+}

schemacrawler-ai-core/src/main/java/schemacrawler/tools/ai/tools/FunctionCallback.java

@@ -8,16 +8,16 @@
 
 package schemacrawler.tools.ai.tools;
 
-import static java.util.Objects.requireNonNull;
 import static schemacrawler.tools.ai.utility.JsonUtility.mapper;
-import static us.fatehi.utility.Utility.isBlank;
-
-import com.fasterxml.jackson.databind.JsonNode;
-import com.fasterxml.jackson.databind.node.ObjectNode;
 import java.sql.Connection;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import static java.util.Objects.requireNonNull;
+import static us.fatehi.utility.Utility.isBlank;
 import schemacrawler.schema.Catalog;
+import schemacrawler.schemacrawler.exceptions.InternalRuntimeException;
 import us.fatehi.utility.property.PropertyName;
 import us.fatehi.utility.string.StringFormat;
 
@@ -72,8 +72,12 @@ public FunctionReturn execute(final String argumentsString, final Connection con
           Level.INFO,
           e,
           new StringFormat(
-              "Exception executing: %s%n%s", toCallObject(argumentsString), e.getMessage()));
-      return new ExceptionFunctionReturn(e);
+              "Exception executing: <%s>%n%s", toCallObject(argumentsString), e.getMessage()));
+      if (e instanceof final RuntimeException runex) {
+        throw runex;
+      }
+      throw new InternalRuntimeException(
+          "Exception executing <%s>" + getFunctionName().getName(), e);
     }
   }
 

schemacrawler-ai-core/src/main/java/schemacrawler/tools/ai/tools/FunctionReturn.java

@@ -11,4 +11,7 @@
 import java.util.function.Supplier;
 
 public sealed interface FunctionReturn extends Supplier<String>
-    permits TextFunctionReturn, JsonFunctionReturn, ExceptionFunctionReturn {}
+    permits NoResultsFunctionReturn,
+        TextFunctionReturn,
+        JsonFunctionReturn,
+        ExceptionFunctionReturn {}

schemacrawler-ai-core/src/main/java/schemacrawler/tools/ai/tools/NoResultsFunctionReturn.java

@@ -0,0 +1,17 @@
+/*
+ * SchemaCrawler AI
+ * http://www.schemacrawler.com
+ * Copyright (c) 2000-2025, Sualeh Fatehi <sualeh@hotmail.com>.
+ * All rights reserved.
+ * SPDX-License-Identifier: CC-BY-NC-4.0
+ */
+
+package schemacrawler.tools.ai.tools;
+
+public record NoResultsFunctionReturn() implements FunctionReturn {
+
+  @Override
+  public String get() {
+    return "No results returned from tool call.";
+  }
+}

schemacrawler-ai-core/src/main/java/schemacrawler/tools/ai/tools/base/AbstractExecutableFunctionExecutor.java

@@ -11,7 +11,6 @@
 import static schemacrawler.tools.ai.utility.JsonUtility.mapper;
 
 import com.fasterxml.jackson.databind.JsonNode;
-import com.fasterxml.jackson.databind.node.ObjectNode;
 import java.io.StringWriter;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -25,6 +24,7 @@
 import schemacrawler.tools.ai.tools.FunctionReturn;
 import schemacrawler.tools.ai.tools.FunctionReturnType;
 import schemacrawler.tools.ai.tools.JsonFunctionReturn;
+import schemacrawler.tools.ai.tools.NoResultsFunctionReturn;
 import schemacrawler.tools.ai.tools.TextFunctionReturn;
 import schemacrawler.tools.command.text.schema.options.SchemaTextOptionsBuilder;
 import schemacrawler.tools.executable.SchemaCrawlerExecutable;
@@ -67,15 +67,7 @@ public final FunctionReturn call() {
     executable.execute();
 
     if (!hasResults()) {
-      switch (functionReturnType) {
-        case JSON:
-          final ObjectNode objectNode = mapper.createObjectNode();
-          objectNode.put("message", "No results");
-          return new JsonFunctionReturn(objectNode);
-        case TEXT:
-        default:
-          return new TextFunctionReturn("There were no matching results for your query.");
-      }
+      return new NoResultsFunctionReturn();
     }
 
     final String results = writer.toString();

schemacrawler-ai-core/src/main/java/schemacrawler/tools/ai/utility/ExceptionInfo.java

@@ -16,47 +16,27 @@
 
 @JsonNaming(PropertyNamingStrategies.KebabCaseStrategy.class)
 @JsonInclude(JsonInclude.Include.NON_EMPTY)
-@JsonPropertyOrder({"error-message", "error-type", "stack-trace"})
+@JsonPropertyOrder({"error-message", "error-type"})
 public class ExceptionInfo {
 
-  public static String getStackTraceHead(final Throwable ex, final int maxLines) {
-    final StringBuilder sb = new StringBuilder();
-    sb.append(ex.toString()).append("\n");
-
-    final StackTraceElement[] elements = ex.getStackTrace();
-    for (int i = 0; i < Math.min(maxLines, elements.length); i++) {
-      sb.append("\tat ").append(elements[i].toString()).append("\n");
-    }
-
-    return sb.toString();
-  }
-
   public final String type;
   public final String message;
-  public final String stackTrace;
 
   public ExceptionInfo(final Exception ex) {
     if (ex == null) {
       type = "";
       message = "An unknown error occurred";
-      stackTrace = "";
-      return;
+    } else {
+      type = ex.getClass().getName();
+      message = ex.getMessage();
     }
-    type = ex.getClass().getName();
-    message = ex.getMessage();
-    stackTrace = getStackTraceHead(ex, 8);
   }
 
   @JsonProperty("error-message")
   public String getMessage() {
     return message;
   }
 
-  @JsonProperty("stack-trace")
-  public String getStackTrace() {
-    return stackTrace;
-  }
-
   @JsonProperty("error-type")
   public String getType() {
     return type;

schemacrawler-ai-core/src/main/resources/META-INF/services/schemacrawler.tools.ai.tools.FunctionDefinition

@@ -1,5 +1,6 @@
 schemacrawler.tools.ai.functions.DescribeRoutinesFunctionDefinition
 schemacrawler.tools.ai.functions.DescribeTablesFunctionDefinition
+schemacrawler.tools.ai.functions.DiagramFunctionDefinition
 schemacrawler.tools.ai.functions.LintFunctionDefinition
 schemacrawler.tools.ai.functions.ListAcrossTablesFunctionDefinition
 schemacrawler.tools.ai.functions.ListFunctionDefinition

schemacrawler-ai-core/src/test/java/schemacrawler/tools/ai/tools/test/FunctionDefinitionRegistryTest.java

@@ -21,6 +21,7 @@
 import org.junit.jupiter.api.Test;
 import schemacrawler.tools.ai.functions.DescribeRoutinesFunctionDefinition;
 import schemacrawler.tools.ai.functions.DescribeTablesFunctionDefinition;
+import schemacrawler.tools.ai.functions.DiagramFunctionDefinition;
 import schemacrawler.tools.ai.functions.LintFunctionDefinition;
 import schemacrawler.tools.ai.functions.ListAcrossTablesFunctionDefinition;
 import schemacrawler.tools.ai.functions.ListFunctionDefinition;
@@ -32,7 +33,7 @@
 
 public class FunctionDefinitionRegistryTest {
 
-  private static final int NUM_FUNCTIONS = 7;
+  private static final int NUM_FUNCTIONS = 8;
 
   @Test
   public void name() {
@@ -60,6 +61,7 @@ public void registeredPlugins() {
             "lint",
             "list",
             "list-across-tables",
+            "diagram",
             "server-information",
             "table-sample"));
   }
@@ -80,6 +82,7 @@ public void testCommandPlugin() throws Exception {
             LintFunctionDefinition.class.getSimpleName(),
             ListFunctionDefinition.class.getSimpleName(),
             ListAcrossTablesFunctionDefinition.class.getSimpleName(),
+            DiagramFunctionDefinition.class.getSimpleName(),
             ServerInformationFunctionDefinition.class.getSimpleName(),
             TableSampleFunctionDefinition.class.getSimpleName()));
   }

schemacrawler-ai-mcpserver/src/main/java/schemacrawler/tools/ai/mcpserver/server/ToolHelper.java

@@ -10,6 +10,7 @@
 
 import static java.util.Objects.requireNonNull;
 import static schemacrawler.tools.ai.mcpserver.utility.LoggingUtility.log;
+import static schemacrawler.tools.ai.mcpserver.utility.LoggingUtility.logExceptionToClient;
 import static schemacrawler.tools.ai.utility.JsonUtility.mapper;
 
 import com.fasterxml.jackson.databind.JsonNode;
@@ -57,6 +58,10 @@ public CallToolResult apply(
         final Connection connection = ConnectionService.getConnection();
         functionReturn = functionCallback.execute(arguments, connection);
       } catch (final Exception e) {
+        logExceptionToClient(
+            exchange,
+            functionCallback.getFunctionName().getName() + ":\n" + request.arguments(),
+            e);
         functionReturn = new ExceptionFunctionReturn(e);
       }
       final List<Content> content = createContent(functionReturn);