diff --git a/.github/workflows/feature-to-main.yml b/.github/workflows/feature-to-main.yml
index 54e7b37..7168ce9 100644
--- a/.github/workflows/feature-to-main.yml
+++ b/.github/workflows/feature-to-main.yml
@@ -90,7 +90,8 @@ jobs:
               \"schedule\": {\"type\": \"once\", \"at\": \"${FIRE_AT}\"},
               \"transport\": \"worker\",
               \"payload\": {
-                \"task\": \"verify-github-merge\",
+                \"task\": \"test-sdk\",
+                \"trigger\": \"post-merge\",
                 \"repo\": \"cueapi/cueapi-python\",
                 \"pr_number\": \"${{ github.event.pull_request.number }}\",
                 \"commit_sha\": \"${{ github.event.pull_request.head.sha }}\"
diff --git a/README.md b/README.md
index b9eec10..e6ef832 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,4 @@
+<!-- Pipeline validation: 2026-04-04 -->
 > **For AI agents:** This is the official Python SDK for CueAPI. Run `pip install cueapi-sdk`. Your API key is in `CUEAPI_API_KEY`. Create a client: `client = CueAPI(os.environ["CUEAPI_API_KEY"])`. Schedule a task: `client.cues.create(name="task-name", cron="0 9 * * *", callback="https://your-handler.com", payload={})`. For agents without a public URL: set `transport="worker"` and run `pip install cueapi-worker`, then define a handler with `@worker.handler("task-name")` returning `{"success": true}` or `{"success": false, "error": "reason"}`. List executions: `client.executions.list()`. Get one: `client.executions.get("exec_id")`. Do not retry on `AuthenticationError` or `CueLimitExceededError`. Wait `e.retry_after` seconds on `RateLimitError`.
 
 # cueapi-sdk
diff --git a/tests/test_client_init.py b/tests/test_client_init.py
new file mode 100644
index 0000000..f14aebc
--- /dev/null
+++ b/tests/test_client_init.py
@@ -0,0 +1,36 @@
+"""Tests for CueAPI client initialization and error handling."""
+
+import pytest
+
+from cueapi import CueAPI
+from cueapi.exceptions import AuthenticationError
+
+
+class TestClientInit:
+    def test_client_has_cues_resource(self):
+        """Client should have a cues attribute."""
+        client = CueAPI("test-key", base_url="https://example.com")
+        assert hasattr(client, "cues")
+        assert hasattr(client, "executions")
+        client.close()
+
+    def test_client_accepts_base_url(self):
+        """Client should accept a custom base_url."""
+        client = CueAPI("test-key", base_url="https://custom.example.com")
+        assert client._base_url == "https://custom.example.com"
+        client.close()
+
+    def test_client_close_is_idempotent(self):
+        """Calling close() multiple times should not raise."""
+        client = CueAPI("test-key", base_url="https://example.com")
+        client.close()
+        client.close()  # Should not raise
+
+
+class TestClientErrors:
+    def test_invalid_api_key_raises_auth_error(self):
+        """Using an invalid API key should raise AuthenticationError."""
+        client = CueAPI("invalid-key-that-does-not-exist", base_url="https://api-staging-e962.up.railway.app")
+        with pytest.raises((AuthenticationError, Exception)):
+            client.cues.list()
+        client.close()