diff --git a/.env.example b/.env.example
index 79735fa..3894dca 100644
--- a/.env.example
+++ b/.env.example
@@ -25,7 +25,9 @@ PUBLIC_BASE_URL=https://mem0.your-domain.com
 
 # OAuth (Phase 2, leave blank for Phase 1)
 OAUTH_SIGNING_KEY=
-OAUTH_ALLOWED_REDIRECT_URIS=https://claude.ai/api/mcp/auth_callback,https://cowork.com/api/mcp/auth_callback
+# Comma-separated. A trailing * makes an entry a prefix match (e.g. ChatGPT
+# uses a per-connector callback path under https://chatgpt.com/connector/oauth/).
+OAUTH_ALLOWED_REDIRECT_URIS=https://claude.ai/api/mcp/auth_callback,https://cowork.com/api/mcp/auth_callback,https://chatgpt.com/connector/oauth/*
 
 # Misc
 LOG_LEVEL=INFO
diff --git a/app/config.py b/app/config.py
index 48f5b9d..dad4c5d 100644
--- a/app/config.py
+++ b/app/config.py
@@ -38,7 +38,8 @@ class Settings(BaseSettings):
     oauth_signing_key: str | None = None
     oauth_allowed_redirect_uris: str = (
         "https://claude.ai/api/mcp/auth_callback,"
-        "https://cowork.com/api/mcp/auth_callback"
+        "https://cowork.com/api/mcp/auth_callback,"
+        "https://chatgpt.com/connector/oauth/*"
     )
 
     # Misc
diff --git a/app/oauth.py b/app/oauth.py
index 2e7fb33..ad923b9 100644
--- a/app/oauth.py
+++ b/app/oauth.py
@@ -4,6 +4,7 @@
 import secrets
 import time
 from functools import lru_cache
+from urllib.parse import urlsplit
 
 import jwt
 import structlog
@@ -128,12 +129,38 @@ def jwks() -> dict:
     return _jwks()
 
 
+def _redirect_uri_allowed(uri: str, allowed: list[str]) -> bool:
+    # Exact match, or — for an allowlist entry ending in "*" — a path-prefix match
+    # under an exact scheme+host. The wildcard is enforced as host-locked here
+    # rather than via a raw startswith: it only extends the path of a concrete
+    # scheme://host/path/ prefix (e.g. ChatGPT's per-connector
+    # https://chatgpt.com/connector/oauth/*). Over-broad patterns that lack a
+    # concrete host or path (e.g. "*" or "https://chatgpt.com*") are ignored, so
+    # a misconfigured entry can't match lookalike hosts like chatgpt.com.evil.com.
+    for entry in allowed:
+        if not entry.endswith("*"):
+            if uri == entry:
+                return True
+            continue
+        prefix = urlsplit(entry[:-1])
+        if not (prefix.scheme and prefix.netloc and prefix.path):
+            continue
+        target = urlsplit(uri)
+        if (
+            target.scheme == prefix.scheme
+            and target.netloc == prefix.netloc
+            and target.path.startswith(prefix.path)
+        ):
+            return True
+    return False
+
+
 @router.post("/oauth/register")
 async def register(request: Request) -> JSONResponse:
     body = await request.json()
     redirect_uris = body.get("redirect_uris") or []
-    allowed = set(get_settings().allowed_redirect_uris_list)
-    rejected = [uri for uri in redirect_uris if uri not in allowed]
+    allowed = get_settings().allowed_redirect_uris_list
+    rejected = [uri for uri in redirect_uris if not _redirect_uri_allowed(uri, allowed)]
     if not redirect_uris or rejected:
         # Log the exact requested URIs and the active allowlist so a client whose
         # callback isn't allowed (the common cause of failed Claude.ai / Cowork
diff --git a/docs/USER_GUIDE.md b/docs/USER_GUIDE.md
index 3d5933f..2cae0a1 100644
--- a/docs/USER_GUIDE.md
+++ b/docs/USER_GUIDE.md
@@ -15,6 +15,7 @@ connect clients to it, and use it day to day. If you want to work on the code it
   - [Claude Code](#claude-code)
   - [Claude Desktop](#claude-desktop)
   - [Claude.ai web / Cowork (OAuth)](#claudeai-web--cowork-oauth)
+  - [ChatGPT (OAuth, Developer Mode)](#chatgpt-oauth-developer-mode)
   - [REST / curl / n8n](#rest--curl--n8n)
 - [REST API reference](#rest-api-reference)
 - [Backups and restore](#backups-and-restore)
@@ -99,7 +100,7 @@ runs, or set these in the CapRover app's **App Configs** panel for production.
 | `MEM0_API_KEY` | yes | — | Static bearer token protecting REST + MCP. Generate with `openssl rand -hex 32`. |
 | `PUBLIC_BASE_URL` | yes | — | Public URL, e.g. `https://mem0.your-domain.com`. Used in OAuth metadata. |
 | `OAUTH_SIGNING_KEY` | no | empty | PEM RSA private key. **Setting this enables Phase 2 OAuth.** Leave blank for Phase 1. |
-| `OAUTH_ALLOWED_REDIRECT_URIS` | no | claude.ai + cowork callbacks | Comma-separated allowlist for OAuth redirect URIs. |
+| `OAUTH_ALLOWED_REDIRECT_URIS` | no | claude.ai + cowork + chatgpt callbacks | Comma-separated allowlist for OAuth redirect URIs. An entry ending in `*` is a **path-prefix** match locked to an exact scheme + host — it must be a full `scheme://host/path/` prefix (e.g. `https://chatgpt.com/connector/oauth/*`). Host-only or bare wildcards (`https://chatgpt.com*`, `https://*`, `*`) are **ignored**, so a misconfigured entry can't match lookalike hosts like `chatgpt.com.evil.com`. |
 | `LOG_LEVEL` | no | `INFO` | Log level. |
 
 ### Phases
@@ -199,7 +200,25 @@ holder of that key can mint an access token to your memories. Treat `MEM0_API_KE
 credential — anyone with it has full access via either the bearer header or the OAuth flow.
 
 The server also only allows redirect URIs listed in `OAUTH_ALLOWED_REDIRECT_URIS`, which defaults to
-the official claude.ai and Cowork callback URLs.
+the official claude.ai, Cowork, and ChatGPT callbacks.
+
+### ChatGPT (OAuth, Developer Mode)
+
+Also **Phase 2**. In ChatGPT, enable **Developer Mode**, add a custom connector pointing at
+`https://mem0.your-domain.com/mcp`, and choose OAuth. On the consent screen enter your
+`MEM0_API_KEY` and authorize.
+
+ChatGPT's OAuth callback is a **per-connector** URL of the form
+`https://chatgpt.com/connector/oauth/<connector-id>` — the `<connector-id>` is unique to each
+connector you create. The default allowlist already covers these via the prefix entry
+`https://chatgpt.com/connector/oauth/*`, so you don't need to add the exact URL. If you've
+customized `OAUTH_ALLOWED_REDIRECT_URIS`, include that wildcard entry.
+
+A trailing `*` is a **path-prefix** match, not a free-form glob: it is locked to the exact
+scheme and host of the entry and only extends the path, so write the full
+`scheme://host/path/` prefix (keep the trailing `/`). An entry without a concrete host *and*
+path — `https://chatgpt.com*`, `https://*`, or a bare `*` — is ignored rather than honored, so
+a typo can't accidentally allow a lookalike host such as `chatgpt.com.evil.com`.
 
 ### REST / curl / n8n
 
diff --git a/tests/test_oauth.py b/tests/test_oauth.py
index 3259ea7..7fc680f 100644
--- a/tests/test_oauth.py
+++ b/tests/test_oauth.py
@@ -107,6 +107,45 @@ def test_dcr_rejects_disallowed_uri(oauth_client):
     assert resp.status_code == 400
 
 
+def test_dcr_allows_wildcard_prefix(oauth_client):
+    # The default allowlist includes https://chatgpt.com/connector/oauth/* so
+    # ChatGPT's per-connector callback (a unique path) registers without exact config.
+    resp = oauth_client.post(
+        "/oauth/register",
+        json={"redirect_uris": ["https://chatgpt.com/connector/oauth/eaQ3VyiNzLuI"]},
+    )
+    assert resp.status_code == 201
+
+
+def test_dcr_wildcard_is_host_locked(oauth_client):
+    # The trailing-* prefix must not allow a different host that merely contains
+    # the path, nor a lookalike host.
+    for bad in (
+        "https://evil.com/connector/oauth/x",
+        "https://chatgpt.com.evil.com/connector/oauth/x",
+    ):
+        resp = oauth_client.post("/oauth/register", json={"redirect_uris": [bad]})
+        assert resp.status_code == 400, bad
+
+
+def test_redirect_uri_allowed_enforces_scheme_host_path():
+    from app.oauth import _redirect_uri_allowed
+
+    allow = ["https://chatgpt.com/connector/oauth/*"]
+    assert _redirect_uri_allowed("https://chatgpt.com/connector/oauth/abc", allow)
+    # exact host, but different scheme or path → rejected
+    assert not _redirect_uri_allowed("http://chatgpt.com/connector/oauth/abc", allow)
+    assert not _redirect_uri_allowed("https://chatgpt.com/other/abc", allow)
+    # lookalike host → rejected
+    assert not _redirect_uri_allowed("https://chatgpt.com.evil.com/connector/oauth/x", allow)
+
+    # Over-broad patterns lacking a concrete host or path are ignored entirely,
+    # so a misconfigured allowlist can't open the door to arbitrary hosts.
+    for broad in (["*"], ["https://chatgpt.com*"], ["https://*"]):
+        assert not _redirect_uri_allowed("https://chatgpt.com.evil.com/x", broad)
+        assert not _redirect_uri_allowed("https://anything.example/x", broad)
+
+
 def test_dcr_registers_public_client(oauth_client):
     resp = oauth_client.post("/oauth/register", json={"redirect_uris": [ALLOWED_URI]})
     assert resp.status_code == 201