diff --git a/.gitignore b/.gitignore
index f7f8ce25..505b1ec7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,4 +7,5 @@ tmp-*
 chicken.*
 .vscode
 .idea
-e2e.*
\ No newline at end of file
+e2e.*
+.claude/.planning/
diff --git a/jest.json b/jest.json
index 6495a874..0a7d2614 100644
--- a/jest.json
+++ b/jest.json
@@ -6,7 +6,7 @@
     "**/*.spec.ts"
   ],
   "transform": {
-    "^.+\\.ts$": "ts-jest"
+    "^.+\\.ts$": ["ts-jest", { "tsconfig": "tsconfig-base.json", "isolatedModules": true }]
   },
   "transformIgnorePatterns": [
     "/node_modules/(?!(axios)/)"
diff --git a/packages/logging/src/otelProvider/internal-types.ts b/packages/logging/src/otelProvider/internal-types.ts
index 13bdeda9..489d8507 100644
--- a/packages/logging/src/otelProvider/internal-types.ts
+++ b/packages/logging/src/otelProvider/internal-types.ts
@@ -56,6 +56,7 @@ export interface EventAttributesException {
   type?: string;
   message?: string;
   stacktrace?: string;
+  cause?: EventAttributesException | string;
 }
 
 export enum OtelSeverity {
diff --git a/packages/logging/src/otelProvider/otelProvider.spec.ts b/packages/logging/src/otelProvider/otelProvider.spec.ts
index 082a4e74..f0481784 100644
--- a/packages/logging/src/otelProvider/otelProvider.spec.ts
+++ b/packages/logging/src/otelProvider/otelProvider.spec.ts
@@ -1,6 +1,6 @@
 import { OtelProviderError, otelProviderFactory } from "./otelProvider";
 import { DvelopLogEvent, DbRequest, HttpResponse, IncomingHttpRequest, OutgoingHttpRequest, DvelopLogLevel } from "../logger/log-event";
-import { OtelEvent, OtelSeverity } from "./internal-types";
+import { EventAttributesException, OtelEvent, OtelSeverity } from "./internal-types";
 import { DvelopContext, TraceContext } from "@dvelop-sdk/core";
 
 describe("otel provider", () => {
@@ -587,10 +587,11 @@ describe("otel provider", () => {
           appName: "test", transports: [async otelMessage => {
             const json: OtelEvent = JSON.parse(otelMessage);
             expect(json.attr).toBeDefined();
-            expect(json.attr.exception).toBeDefined();
-            expect(json.attr.exception.type).toEqual("Error");
-            expect(json.attr.exception.message).toEqual("some error");
-            expect(json.attr.exception.stacktrace).toBeDefined();
+            expect(json.attr?.exception).toBeDefined();
+            expect(json.attr?.exception?.type).toEqual("Error");
+            expect(json.attr?.exception?.message).toEqual("some error");
+            expect(json.attr?.exception?.stacktrace).toBeDefined();
+            expect(json.attr?.exception?.cause).toBeUndefined();
             done();
           }]
         });
@@ -603,6 +604,70 @@ describe("otel provider", () => {
       });
     });
 
+    test("should set exception cause when cause is an Error", () => {
+      return new Promise<void>(done => {
+        const provider = otelProviderFactory({
+          appName: "test", transports: [async otelMessage => {
+            const json: OtelEvent = JSON.parse(otelMessage);
+            expect(json.attr?.exception?.cause).toBeDefined();
+            expect((json.attr?.exception?.cause as EventAttributesException).type).toEqual("TypeError");
+            expect((json.attr?.exception?.cause as EventAttributesException).message).toEqual("root cause");
+            expect((json.attr?.exception?.cause as EventAttributesException).stacktrace).toBeDefined();
+            done();
+          }]
+        });
+
+        const cause = new TypeError("root cause");
+        const event: DvelopLogEvent = {
+          error: Object.assign(new Error("wrapper error"), { cause })
+        };
+
+        provider({}, event, "debug");
+      });
+    });
+
+    test("should set exception cause recursively for nested Error causes", () => {
+      return new Promise<void>(done => {
+        const provider = otelProviderFactory({
+          appName: "test", transports: [async otelMessage => {
+            const json: OtelEvent = JSON.parse(otelMessage);
+            const outerCause = json.attr?.exception?.cause as EventAttributesException;
+            expect(outerCause.message).toEqual("middle error");
+            expect(outerCause.cause).toBeDefined();
+            expect((outerCause.cause as EventAttributesException).message).toEqual("root cause");
+            done();
+          }]
+        });
+
+        const root = new Error("root cause");
+        const middle = Object.assign(new Error("middle error"), { cause: root });
+        const event: DvelopLogEvent = {
+          error: Object.assign(new Error("outer error"), { cause: middle })
+        };
+
+        provider({}, event, "debug");
+      });
+    });
+
+    test("should JSON-stringify exception cause when cause is not an Error", () => {
+      return new Promise<void>(done => {
+        const provider = otelProviderFactory({
+          appName: "test", transports: [async otelMessage => {
+            const json: OtelEvent = JSON.parse(otelMessage);
+            expect(typeof json.attr?.exception?.cause).toEqual("string");
+            expect(json.attr?.exception?.cause).toEqual(JSON.stringify({ code: 42 }));
+            done();
+          }]
+        });
+
+        const event: DvelopLogEvent = {
+          error: Object.assign(new Error("some error"), { cause: { code: 42 } })
+        };
+
+        provider({}, event, "debug");
+      });
+    });
+
   });
 
 });
diff --git a/packages/logging/src/otelProvider/otelProvider.ts b/packages/logging/src/otelProvider/otelProvider.ts
index 51ffdbb7..7fc2038a 100644
--- a/packages/logging/src/otelProvider/otelProvider.ts
+++ b/packages/logging/src/otelProvider/otelProvider.ts
@@ -9,7 +9,7 @@ import { LoggingError } from "../error";
 * @category Error
 */
 export class OtelProviderError extends LoggingError {
-   
+
   constructor(message: string, originalError?: Error) {
     super(message, originalError);
     Object.setPrototypeOf(this, OtelProviderError.prototype);
@@ -170,13 +170,18 @@ function mapDbAttribute(event: DvelopLogEvent): { db?: EventAttributesDb } {
 }
 
 function mapExceptionAttribute(event: DvelopLogEvent): { exception?: EventAttributesException } {
+  const mapErrorToAttributes = (error: Error): EventAttributesException => {
+    return {
+      message: error.message,
+      type: error.name,
+      stacktrace: error.stack,
+      cause: error.cause ? (error.cause instanceof Error ? mapErrorToAttributes(error.cause) : JSON.stringify(error.cause)) : undefined
+    };
+  };
+
   if (event.error) {
     return {
-      exception: {
-        message: event.error.message,
-        type: event.error.name,
-        stacktrace: event.error.stack
-      }
+      exception: mapErrorToAttributes(event.error)
     };
   } else {
     return {};