diff --git a/.gitea/workflows/ci.yml b/.gitea/workflows/ci.yml
index d3f2f8c9..d87bdacc 100644
--- a/.gitea/workflows/ci.yml
+++ b/.gitea/workflows/ci.yml
@@ -161,6 +161,12 @@ jobs:
       PLAYWRIGHT_SECRET_KEY: ci-playwright-secret-key
       PLAYWRIGHT_TEST_EMAIL: teamadmin@resolutionflow.example.com
       PLAYWRIGHT_TEST_PASSWORD: TestPass123!
+      # AI-touching endpoints (POST /ai-sessions, /chat, /respond, etc.) are
+      # gated by `_require_ai_enabled()`, which returns 503 when no provider
+      # key is set. Tests that exercise those flows stub the AI calls in the
+      # browser via `page.route`, so the backend never actually contacts
+      # Anthropic — but the gate still has to pass. A stub value is enough.
+      ANTHROPIC_API_KEY: ci-stub-key-not-used-by-tests
 
     steps:
       - uses: actions/checkout@v4