diff --git a/src/subscriptions/client.py b/src/subscriptions/client.py
index 4b33394..59be217 100644
--- a/src/subscriptions/client.py
+++ b/src/subscriptions/client.py
@@ -1,5 +1,4 @@
 import os
-from urllib.parse import parse_qsl, urlencode, urlsplit, urlunsplit
 
 import httpx
 
@@ -62,13 +61,6 @@ def update_customer(handle: str, data: dict) -> dict:
     return _call("PUT", f"/v1/customer/{handle}", json=data)
 
 
-def _with_query(url: str, **params: str) -> str:
-    parts = urlsplit(url)
-    query = dict(parse_qsl(parts.query))
-    query.update(params)
-    return urlunsplit(parts._replace(query=urlencode(query)))
-
-
 def create_subscription_session(
     plan_handle: str,
     handle: str,
@@ -78,9 +70,6 @@ def create_subscription_session(
     customer_handle: str | None = None,
     create_customer: dict | None = None,
 ) -> str:
-    # CreateSubscription (POST /v1/subscription) n'a pas de champs accept_url/
-    # cancel_url : ils doivent être ajoutés en query string sur le lien
-    # hosted_page_links.payment_info renvoyé, pas dans le body (cf. doc Frisbii).
     body: dict = {
         "plan": plan_handle,
         "signup_method": "link",
@@ -92,9 +81,21 @@ def create_subscription_session(
         body["create_customer"] = create_customer
     if no_trial:
         body["no_trial"] = True
-    data = _call("POST", "/v1/subscription", json=body)
-    payment_info = data["hosted_page_links"]["payment_info"]
-    return _with_query(payment_info, accept_url=accept_url, cancel_url=cancel_url)
+    _call("POST", "/v1/subscription", json=body)
+    # CreateSubscription (POST /v1/subscription) n'a pas de champs accept_url/
+    # cancel_url. La session de checkout dédiée (Checkout API), elle, les
+    # honore et redirige réellement le navigateur après succès/annulation.
+    data = _call(
+        "POST",
+        "/v1/session/subscription",
+        json={
+            "subscription": handle,
+            "accept_url": accept_url,
+            "cancel_url": cancel_url,
+        },
+        base_url=_checkout_url(),
+    )
+    return data["url"]
 
 
 def create_recurring_session(
diff --git a/tests/subscriptions/test_client.py b/tests/subscriptions/test_client.py
index 0d86150..347795a 100644
--- a/tests/subscriptions/test_client.py
+++ b/tests/subscriptions/test_client.py
@@ -26,14 +26,11 @@ def test_update_customer(fake_httpx):
 
 
 def test_create_subscription_session_with_customer_handle(fake_httpx):
+    fake_httpx["queue"].append(fake_httpx["Response"](200, {"handle": "abo-1-1"}))
     fake_httpx["queue"].append(
         fake_httpx["Response"](
             200,
-            {
-                "hosted_page_links": {
-                    "payment_info": "https://checkout.reepay.com/#/sub-1"
-                }
-            },
+            {"id": "cs_1", "url": "https://checkout.reepay.com/#/subscription/cs_1"},
         )
     )
     url = client.create_subscription_session(
@@ -43,33 +40,37 @@ def test_create_subscription_session_with_customer_handle(fake_httpx):
         "https://app/ko",
         customer_handle="colibre-1",
     )
-    assert url == (
-        "https://checkout.reepay.com/"
-        "?accept_url=https%3A%2F%2Fapp%2Fok&cancel_url=https%3A%2F%2Fapp%2Fko"
-        "#/sub-1"
+    assert url == "https://checkout.reepay.com/#/subscription/cs_1"
+
+    create_body = fake_httpx["calls"][0]["json"]
+    assert create_body["plan"] == "plan_simple"
+    assert create_body["handle"] == "abo-1-1"
+    assert create_body["customer"] == "colibre-1"
+    assert create_body["signup_method"] == "link"
+    assert "generate_handle" not in create_body
+    assert "prepare_subscription" not in create_body
+    # accept_url/cancel_url n'existent pas dans CreateSubscription : ils
+    # doivent passer par la session de checkout dédiée, pas ce body.
+    assert "accept_url" not in create_body
+    assert "cancel_url" not in create_body
+
+    session_call = fake_httpx["calls"][1]
+    assert (
+        session_call["url"]
+        == "https://checkout-api.frisbii.com/v1/session/subscription"
     )
-    body = fake_httpx["calls"][0]["json"]
-    assert body["plan"] == "plan_simple"
-    assert body["handle"] == "abo-1-1"
-    assert body["customer"] == "colibre-1"
-    assert body["signup_method"] == "link"
-    assert "generate_handle" not in body
-    assert "prepare_subscription" not in body
-    # accept_url/cancel_url ne sont pas des champs de CreateSubscription :
-    # Frisbii les ignore silencieusement s'ils sont dans le body.
-    assert "accept_url" not in body
-    assert "cancel_url" not in body
+    assert session_call["json"] == {
+        "subscription": "abo-1-1",
+        "accept_url": "https://app/ok",
+        "cancel_url": "https://app/ko",
+    }
 
 
 def test_create_subscription_session_no_trial(fake_httpx):
+    fake_httpx["queue"].append(fake_httpx["Response"](200, {"handle": "abo-1-2"}))
     fake_httpx["queue"].append(
         fake_httpx["Response"](
-            200,
-            {
-                "hosted_page_links": {
-                    "payment_info": "https://checkout.reepay.com/#/sub-2"
-                }
-            },
+            200, {"url": "https://checkout.reepay.com/#/subscription/cs_2"}
         )
     )
     client.create_subscription_session(