feat: ENABLE_OAUTH_TOKEN_EXCHANGE

backend/open_webui/env.py

@@ -523,6 +523,12 @@ OAUTH_SESSION_TOKEN_ENCRYPTION_KEY = os.environ.get(
     "OAUTH_SESSION_TOKEN_ENCRYPTION_KEY", WEBUI_SECRET_KEY
 )
 
+# Token Exchange Configuration
+# Allows external apps to exchange OAuth tokens for OpenWebUI tokens
+ENABLE_OAUTH_TOKEN_EXCHANGE = (
+    os.environ.get("ENABLE_OAUTH_TOKEN_EXCHANGE", "False").lower() == "true"
+)
+
 ####################################
 # SCIM Configuration
 ####################################

backend/open_webui/routers/auths.py

@@ -37,6 +37,8 @@ from open_webui.env import (
     WEBUI_AUTH_COOKIE_SECURE,
     WEBUI_AUTH_SIGNOUT_REDIRECT_URL,
     ENABLE_INITIAL_ADMIN_SIGNUP,
+    ENABLE_OAUTH_TOKEN_EXCHANGE,
+    AIOHTTP_CLIENT_SESSION_SSL,
 )
 from fastapi import APIRouter, Depends, HTTPException, Request, status
 from fastapi.responses import RedirectResponse, Response, JSONResponse
@@ -45,6 +47,8 @@ from open_webui.config import (
     ENABLE_OAUTH_SIGNUP,
     ENABLE_LDAP,
     ENABLE_PASSWORD_AUTH,
+    OAUTH_PROVIDERS,
+    OAUTH_MERGE_ACCOUNTS_BY_EMAIL,
 )
 from pydantic import BaseModel
 
@@ -87,6 +91,39 @@ signin_rate_limiter = RateLimiter(
     redis_client=get_redis_client(), limit=5 * 3, window=60 * 3
 )
 
+
+def create_session_response(request: Request, user, db) -> dict:
+    """
+    Create JWT token and build session response for a user.
+    Shared helper for signin, signup, ldap_auth, add_user, and token_exchange endpoints.
+    """
+    expires_delta = parse_duration(request.app.state.config.JWT_EXPIRES_IN)
+    expires_at = None
+    if expires_delta:
+        expires_at = int(time.time()) + int(expires_delta.total_seconds())
+
+    token = create_token(
+        data={"id": user.id},
+        expires_delta=expires_delta,
+    )
+
+    user_permissions = get_permissions(
+        user.id, request.app.state.config.USER_PERMISSIONS, db=db
+    )
+
+    return {
+        "token": token,
+        "token_type": "Bearer",
+        "expires_at": expires_at,
+        "id": user.id,
+        "email": user.email,
+        "name": user.name,
+        "role": user.role,
+        "profile_image_url": user.profile_image_url,
+        "permissions": user_permissions,
+    }
+
+
 ############################
 # GetSessionUser
 ############################
@@ -1287,3 +1324,108 @@ async def get_api_key(
         }
     else:
         raise HTTPException(404, detail=ERROR_MESSAGES.API_KEY_NOT_FOUND)
+
+
+############################
+# Token Exchange
+############################
+
+
+class TokenExchangeForm(BaseModel):
+    token: str  # OAuth access token from external provider
+
+
+@router.post("/oauth/{provider}/token/exchange", response_model=SessionUserResponse)
+async def token_exchange(
+    request: Request,
+    response: Response,
+    provider: str,
+    form_data: TokenExchangeForm,
+    db: Session = Depends(get_session),
+):
+    """
+    Exchange an external OAuth provider token for an OpenWebUI JWT.
+    This endpoint is disabled by default. Set ENABLE_OAUTH_TOKEN_EXCHANGE=True to enable.
+    """
+    if not ENABLE_OAUTH_TOKEN_EXCHANGE:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Token exchange is disabled",
+        )
+
+    provider = provider.lower()
+
+    # Check if provider is configured
+    if provider not in OAUTH_PROVIDERS:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Provider '{provider}' is not configured",
+        )
+    # Get the OAuth client for this provider
+    oauth_manager = request.app.state.oauth_manager
+    client = oauth_manager.get_client(provider)
+    if not client:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"OAuth client for '{provider}' not found",
+        )
+
+    # Validate the token by calling the userinfo endpoint
+    try:
+        token_data = {"access_token": form_data.token, "token_type": "Bearer"}
+        user_data = await client.userinfo(token=token_data)
+
+        if not user_data:
+            raise HTTPException(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                detail="Invalid token or unable to fetch user info",
+            )
+    except Exception as e:
+        log.warning(f"Token exchange failed for provider {provider}: {e}")
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Invalid token or unable to validate with provider",
+        )
+
+    # Extract user information from the token claims
+    email_claim = request.app.state.config.OAUTH_EMAIL_CLAIM
+    username_claim = request.app.state.config.OAUTH_USERNAME_CLAIM
+
+    # Get sub claim
+    sub = user_data.get(
+        request.app.state.config.OAUTH_SUB_CLAIM
+        or OAUTH_PROVIDERS[provider].get("sub_claim", "sub")
+    )
+    if not sub:
+        log.warning(f"Token exchange failed: sub claim missing from user data")
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Token missing required 'sub' claim",
+        )
+
+    email = user_data.get(email_claim, "")
+    if not email:
+        log.warning(f"Token exchange failed: email claim missing from user data")
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Token missing required email claim",
+        )
+    email = email.lower()
+
+    # Try to find the user by OAuth sub
+    user = Users.get_user_by_oauth_sub(provider, sub, db=db)
+
+    if not user and OAUTH_MERGE_ACCOUNTS_BY_EMAIL.value:
+        # Try to find by email if merge is enabled
+        user = Users.get_user_by_email(email, db=db)
+        if user:
+            # Link the OAuth sub to this user
+            Users.update_user_oauth_by_id(user.id, provider, sub, db=db)
+
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="User not found. Please sign in via the web interface first.",
+        )
+
+    return create_session_response(request, user, db)