diff --git a/README.md b/README.md
index 7a4025f..11cab96 100644
--- a/README.md
+++ b/README.md
@@ -177,7 +177,7 @@ https://explorer.invariantlabs.ai/api/v1/gateway/{add-your-dataset-name-here}/op
 Set the API Key using the following format:
 
 ```text
-{your-llm-api-key}|invariant-auth: {your-invariant-api-key}
+{your-llm-api-key};invariant-auth={your-invariant-api-key}
 ```
 
 > **Note:** Do not include the curly braces `{}`.
@@ -209,8 +209,8 @@ Run `sweagent` with the following flag:
 Instead of setting your API Key normally, modify the environment variable as follows:
 
 ```bash
-export OPENAI_API_KEY={your-openai-api-key}|invariant-auth: {your-invariant-api-key}
-export ANTHROPIC_API_KEY={your-anthropic-api-key}|invariant-auth: {your-invariant-api-key}
+export OPENAI_API_KEY={your-openai-api-key};invariant-auth={your-invariant-api-key}
+export ANTHROPIC_API_KEY={your-anthropic-api-key};invariant-auth={your-invariant-api-key}
 ```
 
 > **Note:** Do not include the curly braces `{}`.
diff --git a/gateway/routes/anthropic.py b/gateway/routes/anthropic.py
index bb76fb3..45db6fb 100644
--- a/gateway/routes/anthropic.py
+++ b/gateway/routes/anthropic.py
@@ -66,12 +66,12 @@ async def anthropic_v1_messages_gateway(
     # In such cases, the Invariant API Key is passed as part of the
     # x-api-key header with the Anthropic API key.
     # The header in that case becomes:
-    # "x-api-key": "<Anthropic API Key>|invariant-auth: <Invariant API Key>"
+    # "x-api-key": "<Anthropic API Key>;invariant-auth=<Invariant API Key>"
     invariant_authorization = None
     if dataset_name:
         if request.headers.get(
             INVARIANT_AUTHORIZATION_HEADER
-        ) is None and "|invariant-auth:" not in request.headers.get(
+        ) is None and ";invariant-auth=" not in request.headers.get(
             ANTHROPIC_AUTHORIZATION_HEADER
         ):
             raise HTTPException(status_code=400, detail=MISSING_INVARIANT_AUTH_API_KEY)
@@ -81,7 +81,7 @@ async def anthropic_v1_messages_gateway(
             )
         else:
             header_value = request.headers.get(ANTHROPIC_AUTHORIZATION_HEADER)
-            api_keys = header_value.split("|invariant-auth: ")
+            api_keys = header_value.split(";invariant-auth=")
             invariant_authorization = f"Bearer {api_keys[1].strip()}"
             # Update the authorization header to pass the Anthropic API Key
             headers[ANTHROPIC_AUTHORIZATION_HEADER] = f"{api_keys[0].strip()}"
diff --git a/gateway/routes/open_ai.py b/gateway/routes/open_ai.py
index e04b154..0fd9d17 100644
--- a/gateway/routes/open_ai.py
+++ b/gateway/routes/open_ai.py
@@ -63,12 +63,12 @@ async def openai_chat_completions_gateway(
     # In such cases, the Invariant API Key is passed as part of the
     # authorization header with the OpenAI API key.
     # The header in that case becomes:
-    # "authorization": "<OpenAI API Key>|invariant-auth: <Invariant API Key>"
+    # "authorization": "<OpenAI API Key>;invariant-auth=<Invariant API Key>"
     invariant_authorization = None
     if dataset_name:
         if request.headers.get(
             INVARIANT_AUTHORIZATION_HEADER
-        ) is None and "|invariant-auth:" not in request.headers.get(
+        ) is None and ";invariant-auth=" not in request.headers.get(
             OPENAI_AUTHORIZATION_HEADER
         ):
             raise HTTPException(status_code=400, detail=MISSING_INVARIANT_AUTH_API_KEY)
@@ -79,7 +79,7 @@ async def openai_chat_completions_gateway(
             )
         else:
             header_value = request.headers.get(OPENAI_AUTHORIZATION_HEADER)
-            api_keys = header_value.split("|invariant-auth: ")
+            api_keys = header_value.split(";invariant-auth=")
             invariant_authorization = f"Bearer {api_keys[1].strip()}"
             # Update the authorization header to pass the OpenAI API Key to the OpenAI API
             headers[OPENAI_AUTHORIZATION_HEADER] = f"{api_keys[0].strip()}"
diff --git a/tests/anthropic/test_anthropic_header_with_invariant_key.py b/tests/anthropic/test_anthropic_header_with_invariant_key.py
index 2a73cc0..cbc512e 100644
--- a/tests/anthropic/test_anthropic_header_with_invariant_key.py
+++ b/tests/anthropic/test_anthropic_header_with_invariant_key.py
@@ -31,7 +31,7 @@ async def test_gateway_with_invariant_key_in_anthropic_key_header(
         os.environ,
         {
             "ANTHROPIC_API_KEY": anthropic_api_key
-            + "|invariant-auth: <not needed for test>"
+            + ";invariant-auth=<not needed for test>"
         },
     ):
         client = anthropic.Anthropic(
diff --git a/tests/open_ai/test_chat_without_tool_calls.py b/tests/open_ai/test_chat_without_tool_calls.py
index 6d52e21..b2b9200 100644
--- a/tests/open_ai/test_chat_without_tool_calls.py
+++ b/tests/open_ai/test_chat_without_tool_calls.py
@@ -183,7 +183,7 @@ async def test_chat_completion_with_invariant_key_in_openai_key_header(
     openai_api_key = os.getenv("OPENAI_API_KEY")
     with patch.dict(
         os.environ,
-        {"OPENAI_API_KEY": openai_api_key + "|invariant-auth: <not needed for test>"},
+        {"OPENAI_API_KEY": openai_api_key + ";invariant-auth=<not needed for test>"},
     ):
         client = OpenAI(
             http_client=Client(),