diff --git a/README.md b/README.md
index 8e86273..c924f96 100644
--- a/README.md
+++ b/README.md
@@ -520,6 +520,8 @@ The server is designed for horizontal scaling using Redis as the backbone:
 - **Automatic Cleanup**: No explicit cleanup required
 
 #### Redis Key Structure
+
+##### MCP Session Keys
 ```
 session:{sessionId}:owner                    # Session ownership
 mcp:shttp:toserver:{sessionId}              # Client→Server messages
@@ -527,6 +529,17 @@ mcp:shttp:toclient:{sessionId}:{requestId}  # Server→Client responses
 mcp:control:{sessionId}                     # Control messages
 ```
 
+##### OAuth/Auth Keys
+```
+auth:client:{clientId}                      # OAuth client registrations
+auth:pending:{authCode}                     # Pending authorizations
+auth:installation:{accessToken}             # Active MCP installations
+auth:exch:{authCode}                        # Token exchanges
+auth:refresh:{refreshToken}                 # Refresh tokens
+```
+
+Note: The `auth:` prefix ensures complete namespace isolation between auth and MCP functions in both integrated and separate modes.
+
 ### Transport Methods
 
 #### Streamable HTTP (Recommended)
diff --git a/docs/user-id-system.md b/docs/user-id-system.md
index eb4daff..917b41c 100644
--- a/docs/user-id-system.md
+++ b/docs/user-id-system.md
@@ -127,6 +127,7 @@ Redis stores session ownership information using a structured key system.
 
 ### Redis Key Structure
 
+#### MCP Session Keys (MCP Server)
 ```
 session:{sessionId}:owner → userId                    # Session ownership
 mcp:shttp:toserver:{sessionId} → [pub/sub channel]   # Client→Server messages (also indicates liveness)
@@ -134,6 +135,17 @@ mcp:shttp:toclient:{sessionId}:{requestId} → [pub/sub channel] # Server→Clie
 mcp:control:{sessionId}   → [pub/sub channel]        # Control messages
 ```
 
+#### Auth Keys (Auth Server)
+```
+auth:client:{clientId} → client registration          # OAuth client registrations
+auth:pending:{authCode} → pending authorization       # Pending auth (10 min TTL)
+auth:installation:{accessToken} → MCP installation    # Active sessions (7 days TTL)
+auth:exch:{authCode} → token exchange                 # Token exchange (10 min TTL)
+auth:refresh:{refreshToken} → access token            # Refresh tokens (7 days TTL)
+```
+
+Note: The `auth:` prefix ensures complete isolation from MCP session keys, allowing both integrated and separate modes to work consistently.
+
 ### Redis Operations
 
 | Operation | Key Pattern | Value | Purpose |
diff --git a/shared/redis-auth.ts b/shared/redis-auth.ts
index 7539c10..fc4d636 100644
--- a/shared/redis-auth.ts
+++ b/shared/redis-auth.ts
@@ -7,13 +7,14 @@ import { logger } from "../src/utils/logger.js";
 
 /**
  * Redis key prefixes for different data types
+ * All auth-related keys use "auth:" prefix to avoid collision with MCP session keys
  */
 export const REDIS_KEY_PREFIXES = {
-  CLIENT_REGISTRATION: "client:",
-  PENDING_AUTHORIZATION: "pending:",
-  MCP_AUTHORIZATION: "mcp:",
-  TOKEN_EXCHANGE: "exch:",
-  REFRESH_TOKEN: "refresh:",
+  CLIENT_REGISTRATION: "auth:client:",
+  PENDING_AUTHORIZATION: "auth:pending:",
+  MCP_AUTHORIZATION: "auth:installation:",  // Changed from "mcp:" to avoid collision
+  TOKEN_EXCHANGE: "auth:exch:",
+  REFRESH_TOKEN: "auth:refresh:",
 } as const;
 
 /**
diff --git a/src/services/auth.test.ts b/src/services/auth.test.ts
index 6a761bd..4964031 100644
--- a/src/services/auth.test.ts
+++ b/src/services/auth.test.ts
@@ -124,8 +124,8 @@ describe("auth utils", () => {
       // instead of using exchangeToken which changes the value
       await saveTokenExchange(authCode, tokenExchange);
       
-      // Get the key used by saveTokenExchange
-      const key = "exch:" + crypto.createHash("sha256").update(authCode).digest("hex");
+      // Get the key used by saveTokenExchange (now with auth: prefix)
+      const key = "auth:exch:" + crypto.createHash("sha256").update(authCode).digest("hex");
       
       // Get the encrypted data
       const encryptedData = await mockRedis.get(key);
@@ -266,8 +266,8 @@ describe("auth utils", () => {
 
       await revokeMcpInstallation(accessToken);
       
-      // Should have called getDel with the correct key
-      expect(getDel).toHaveBeenCalledWith(expect.stringContaining("mcp:"));
+      // Should have called getDel with the correct key (now auth:installation:)
+      expect(getDel).toHaveBeenCalledWith(expect.stringContaining("auth:installation:"));
       
     });