diff --git a/tests/e2e/claude_code/_pr_gate_unit_tests/__init__.py b/tests/e2e/claude_code/_pr_gate_unit_tests/__init__.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/e2e/claude_code/_pr_gate_unit_tests/test_pr_gate_version_resolver.py b/tests/e2e/claude_code/_pr_gate_unit_tests/test_pr_gate_version_resolver.py
new file mode 100644
index 00000000000..0ed7e2bf083
--- /dev/null
+++ b/tests/e2e/claude_code/_pr_gate_unit_tests/test_pr_gate_version_resolver.py
@@ -0,0 +1,60 @@
+"""Unit tests for the Claude Code PR-gate version resolver.
+
+Markerless harness tests: they feed the resolver a hand-built packument and a
+fixed clock, so they run without a proxy, never reach the npm registry, and
+carry no `e2e` marker.
+"""
+
+from __future__ import annotations
+
+from datetime import datetime, timezone
+from typing import Final, Mapping
+
+import pytest
+
+from claude_code.pr_gate_version_resolver import NoEligibleVersionError, resolve_pr_gate_version
+
+NOW: Final = datetime(2026, 4, 25, 12, 0, tzinfo=timezone.utc)
+INSIDE_THE_2_1_88_WINDOW: Final = datetime(2026, 4, 3, 12, 0, tzinfo=timezone.utc)
+
+
+def _packument(times: Mapping[str, str], unpublished: frozenset[str] = frozenset()) -> dict[str, object]:
+    return {
+        "name": "@anthropic-ai/claude-code",
+        "time": {"created": "2024-01-01T00:00:00.000Z", "modified": "2026-04-25T00:00:00.000Z", **times},
+        "versions": {version: {"version": version} for version in times if version not in unpublished},
+    }
+
+
+def test_skips_a_version_npm_has_unpublished() -> None:
+    metadata: Final = _packument(
+        {
+            "2.1.87": "2026-03-28T20:00:00.000Z",
+            "2.1.88": "2026-03-30T22:36:48.424Z",
+            "2.1.89": "2026-03-31T23:32:40.000Z",
+        },
+        unpublished=frozenset({"2.1.88"}),
+    )
+    assert resolve_pr_gate_version(metadata=metadata, as_of=INSIDE_THE_2_1_88_WINDOW) == "2.1.87"
+
+
+def test_raises_when_the_only_old_enough_version_is_unpublished() -> None:
+    metadata: Final = _packument(
+        {"2.1.88": "2026-03-30T22:36:48.424Z", "2.1.89": "2026-03-31T23:32:40.000Z"},
+        unpublished=frozenset({"2.1.88"}),
+    )
+    with pytest.raises(NoEligibleVersionError):
+        resolve_pr_gate_version(metadata=metadata, as_of=INSIDE_THE_2_1_88_WINDOW)
+
+
+def test_picks_the_newest_published_version_at_least_min_age_old() -> None:
+    metadata: Final = _packument(
+        {
+            "2.1.118": "2026-04-15T10:00:00.000Z",
+            "2.1.119": "2026-04-21T10:00:00.000Z",
+            "2.2.0-rc.1": "2026-04-22T10:00:00.000Z",
+            "2.1.120": "2026-04-23T10:00:00.000Z",
+            "2.1.121": "2026-04-25T11:00:00.000Z",
+        }
+    )
+    assert resolve_pr_gate_version(metadata=metadata, as_of=NOW) == "2.1.119"
diff --git a/tests/e2e/claude_code/pr_gate_version_resolver.py b/tests/e2e/claude_code/pr_gate_version_resolver.py
index 82e12a2bf15..756dafb7d73 100644
--- a/tests/e2e/claude_code/pr_gate_version_resolver.py
+++ b/tests/e2e/claude_code/pr_gate_version_resolver.py
@@ -80,7 +80,9 @@ def resolve_pr_gate_version(
 
     "Newest" means newest by **publish time**, not semver string order —
     if a patch lands on an older major after a newer release, the
-    patched line is the eligible one.
+    patched line is the eligible one. A version npm has unpublished keeps
+    its ``time`` entry but drops out of ``versions``, so only versions
+    still present in ``versions`` are candidates.
 
     Args:
         metadata: Pre-fetched npm packument (skips the HTTP call). Useful
@@ -101,6 +103,7 @@ def resolve_pr_gate_version(
         metadata = fetch(package_name)
 
     times = metadata.get("time") or {}
+    versions = metadata.get("versions") or {}
     if as_of is None:
         as_of = datetime.now(timezone.utc)
     cutoff = as_of - min_age
@@ -109,6 +112,8 @@ def resolve_pr_gate_version(
     for version, raw_ts in times.items():
         if version in _TIME_META_KEYS:
             continue
+        if version not in versions:
+            continue
         if not isinstance(raw_ts, str):
             continue
         if "-" in version: