diff --git a/docs/tasks/streams.mdx b/docs/tasks/streams.mdx
index 52b607d88..3045e8901 100644
--- a/docs/tasks/streams.mdx
+++ b/docs/tasks/streams.mdx
@@ -676,6 +676,7 @@ Examples:
 - ✅ `\u2009https://api.trigger.dev/custom-prefix/\u2009` (thin-space wrapper trimmed)
 - ✅ `\u2008https://api.trigger.dev/custom-prefix/\u2008` (punctuation-space wrapper trimmed)
 - ✅ `\u2006https://api.trigger.dev/custom-prefix/\u2006` (six-per-em-space wrapper trimmed)
+- ✅ `\u2003https://api.trigger.dev/custom-prefix/\u2003` (em-space wrapper trimmed)
 - ✅ `\u205Fhttps://api.trigger.dev/custom-prefix/\u205F` (medium-mathematical-space wrapper trimmed)
 - ✅ `\u3000https://api.trigger.dev/custom-prefix/\u3000` (ideographic-space wrapper trimmed)
 - ✅ `\uFEFFhttps://api.trigger.dev/custom-prefix/\uFEFF` (BOM wrapper trimmed)
@@ -713,6 +714,7 @@ Examples:
 - ❌ `https://api.trigger.dev/\u2009internal`
 - ❌ `https://api.trigger.dev/\u2008internal`
 - ❌ `https://api.trigger.dev/\u2006internal`
+- ❌ `https://api.trigger.dev/\u2003internal`
 - ❌ `https://api.trigger.dev/\u202Finternal`
 - ❌ `https://api.trigger.dev/\u205Finternal`
 - ❌ `https://api.trigger.dev/\u180Einternal`
diff --git a/packages/ai/README.md b/packages/ai/README.md
index 477f38e81..772139871 100644
--- a/packages/ai/README.md
+++ b/packages/ai/README.md
@@ -183,6 +183,7 @@ Examples:
 - ✅ `\u2009https://api.trigger.dev/custom-prefix/\u2009` (thin-space wrapper trimmed)
 - ✅ `\u2008https://api.trigger.dev/custom-prefix/\u2008` (punctuation-space wrapper trimmed)
 - ✅ `\u2006https://api.trigger.dev/custom-prefix/\u2006` (six-per-em-space wrapper trimmed)
+- ✅ `\u2003https://api.trigger.dev/custom-prefix/\u2003` (em-space wrapper trimmed)
 - ✅ `\u205Fhttps://api.trigger.dev/custom-prefix/\u205F` (medium-mathematical-space wrapper trimmed)
 - ✅ `\u3000https://api.trigger.dev/custom-prefix/\u3000` (ideographic-space wrapper trimmed)
 - ✅ `\uFEFFhttps://api.trigger.dev/custom-prefix/\uFEFF` (BOM wrapper trimmed)
@@ -220,6 +221,7 @@ Examples:
 - ❌ `https://api.trigger.dev/\u2009internal` (internal thin-space characters)
 - ❌ `https://api.trigger.dev/\u2008internal` (internal punctuation-space characters)
 - ❌ `https://api.trigger.dev/\u2006internal` (internal six-per-em-space characters)
+- ❌ `https://api.trigger.dev/\u2003internal` (internal em-space characters)
 - ❌ `https://api.trigger.dev/\u202Finternal` (internal narrow no-break space characters)
 - ❌ `https://api.trigger.dev/\u205Finternal` (internal medium-mathematical-space characters)
 - ❌ `https://api.trigger.dev/\u180Einternal` (internal mongolian-vowel-separator characters)
diff --git a/packages/ai/src/chatTransport.test.ts b/packages/ai/src/chatTransport.test.ts
index b158f687c..50bc5f568 100644
--- a/packages/ai/src/chatTransport.test.ts
+++ b/packages/ai/src/chatTransport.test.ts
@@ -1005,6 +1005,17 @@ describe("TriggerChatTransport", function () {
     }).toThrowError("baseURL must not contain internal whitespace characters");
   });
 
+  it("throws when baseURL contains internal em-space characters", function () {
+    expect(function () {
+      new TriggerChatTransport({
+        task: "chat-task",
+        accessToken: "pk_trigger",
+        baseURL: "https://api.trigger.dev/\u2003internal",
+        stream: "chat-stream",
+      });
+    }).toThrowError("baseURL must not contain internal whitespace characters");
+  });
+
   it("throws when baseURL contains internal mongolian-vowel-separator characters", function () {
     expect(function () {
       new TriggerChatTransport({
@@ -1566,6 +1577,17 @@ describe("TriggerChatTransport", function () {
     }).not.toThrow();
   });
 
+  it("accepts em-space wrapped baseURL values", function () {
+    expect(function () {
+      new TriggerChatTransport({
+        task: "chat-task",
+        accessToken: "pk_trigger",
+        baseURL: "\u2003https://api.trigger.dev/custom-prefix/\u2003",
+        stream: "chat-stream",
+      });
+    }).not.toThrow();
+  });
+
   it("accepts ideographic-space wrapped baseURL values", function () {
     expect(function () {
       new TriggerChatTransport({
@@ -4230,6 +4252,17 @@ describe("TriggerChatTransport", function () {
     }).toThrowError("baseURL must not contain internal whitespace characters");
   });
 
+  it("throws from factory when baseURL contains internal em-space characters", function () {
+    expect(function () {
+      createTriggerChatTransport({
+        task: "chat-task",
+        accessToken: "pk_trigger",
+        baseURL: "https://api.trigger.dev/\u2003internal",
+        stream: "chat-stream",
+      });
+    }).toThrowError("baseURL must not contain internal whitespace characters");
+  });
+
   it("throws from factory when baseURL contains internal mongolian-vowel-separator characters", function () {
     expect(function () {
       createTriggerChatTransport({
@@ -4780,6 +4813,17 @@ describe("TriggerChatTransport", function () {
     }).not.toThrow();
   });
 
+  it("accepts em-space wrapped baseURL values from factory", function () {
+    expect(function () {
+      createTriggerChatTransport({
+        task: "chat-task",
+        accessToken: "pk_trigger",
+        baseURL: "\u2003https://api.trigger.dev/custom-prefix/\u2003",
+        stream: "chat-stream",
+      });
+    }).not.toThrow();
+  });
+
   it("accepts ideographic-space wrapped baseURL values from factory", function () {
     expect(function () {
       createTriggerChatTransport({