diff --git a/app/image-tools/README.md b/app/image-tools/README.md
index 8aaf11c944..7b4a6a743c 100644
--- a/app/image-tools/README.md
+++ b/app/image-tools/README.md
@@ -13,8 +13,12 @@ A lightweight SPA + Vercel Functions app for uploading token/chain assets and op
     -   `APP_BASE_URL` — optional; default request origin. Only set if SPA and API are on different origins. For the
         public deployment, leave unset or set to `https://token-assets.yearn.fi`; do not point this at a Vercel alias.
     -   `REPO_OWNER` (default `yearn`), `REPO_NAME` (default `tokenAssets`).
-    -   `ALLOW_REPO_OVERRIDE` — set to `true` only if you intentionally want to target a non-yearn repo when deploying from a fork.
--   GitHub OAuth App callback must allow the current domain: `https://<domain>/api/auth/github/callback` (or `http://localhost:3000/...` for `vercel dev`).
+    -   `ALLOW_REPO_OVERRIDE` — set to `true` only if you intentionally want to target a non-yearn repo when deploying
+        from a fork.
+-   GitHub OAuth App callback must be configured to the deployed API callback URL:
+    `https://<api-domain>/api/auth/github/callback`. The client intentionally does not send a `redirect_uri`; GitHub
+    uses the callback URL registered on the OAuth App, and the API redirects back to `APP_BASE_URL` after exchanging the
+    code.
 
 ## Commands
 
diff --git a/app/image-tools/api/auth/github/callback.ts b/app/image-tools/api/auth/github/callback.ts
index 8515c32d77..152e82f408 100644
--- a/app/image-tools/api/auth/github/callback.ts
+++ b/app/image-tools/api/auth/github/callback.ts
@@ -5,7 +5,6 @@ export default async function (req: Request): Promise<Response> {
 		const url = new URL(req.url);
 		const code = url.searchParams.get('code');
 		const state = url.searchParams.get('state') || '';
-		const redirectUri = new URL('/api/auth/github/callback', url.origin).toString();
 		if (!code) {
 			return new Response(JSON.stringify({error: 'Missing code'}), {
 				status: 400,
@@ -28,8 +27,7 @@ export default async function (req: Request): Promise<Response> {
 			body: JSON.stringify({
 				client_id: clientId,
 				client_secret: clientSecret,
-				code,
-				redirect_uri: redirectUri
+				code
 			})
 		});
 		if (!tokenRes.ok) {
diff --git a/app/image-tools/src/components/GithubSignIn.tsx b/app/image-tools/src/components/GithubSignIn.tsx
index 8fd01ba64c..a93af3e5b3 100644
--- a/app/image-tools/src/components/GithubSignIn.tsx
+++ b/app/image-tools/src/components/GithubSignIn.tsx
@@ -6,12 +6,10 @@ import {
 	storeAuthState,
 	clearStoredAuth,
 	buildAuthorizeUrl,
-	getGithubCallbackUrl,
 	markAuthPending,
 	clearAuthPending,
 	readAuthPending
 } from '../lib/githubAuth';
-import {API_BASE_URL} from '../lib/api';
 
 function randomState(len = 20) {
 	const chars = 'abcdefghijklmnopqrstuvwxyz0123456789';
@@ -67,7 +65,7 @@ export const GithubSignIn: React.FC<Props> = ({token}) => {
 		storeAuthState(state);
 		markAuthPending();
 		setConnecting(true);
-		window.location.href = buildAuthorizeUrl(clientId, state, getGithubCallbackUrl(API_BASE_URL));
+		window.location.href = buildAuthorizeUrl(clientId, state);
 	};
 
 	const signOut = () => {
diff --git a/app/image-tools/src/lib/githubAuth.ts b/app/image-tools/src/lib/githubAuth.ts
index a537866edf..3ab7c726ab 100644
--- a/app/image-tools/src/lib/githubAuth.ts
+++ b/app/image-tools/src/lib/githubAuth.ts
@@ -3,16 +3,11 @@ export const AUTH_STATE_STORAGE_KEY = 'auth_state';
 export const AUTH_CHANGE_EVENT = 'github-auth-changed';
 export const AUTH_PENDING_STORAGE_KEY = 'github_oauth_pending';
 
-export function getGithubCallbackUrl(origin = window.location.origin) {
-	return new URL('/api/auth/github/callback', origin).toString();
-}
-
-export function buildAuthorizeUrl(clientId: string, state: string, redirectUri = getGithubCallbackUrl()) {
+export function buildAuthorizeUrl(clientId: string, state: string) {
 	const url = new URL('https://github.com/login/oauth/authorize');
 	url.searchParams.set('client_id', clientId);
 	url.searchParams.set('state', state);
 	url.searchParams.set('scope', 'public_repo');
-	url.searchParams.set('redirect_uri', redirectUri);
 	url.searchParams.set('prompt', 'select_account');
 	return url.toString();
 }