diff --git a/.github/workflows/build-wheel.yml b/.github/workflows/build-wheel.yml
index 390d6f88ae2..7fde2419e58 100644
--- a/.github/workflows/build-wheel.yml
+++ b/.github/workflows/build-wheel.yml
@@ -586,10 +586,14 @@ jobs:
 
           OLD_BRANCH=$(yq '.backport_branch' ci/versions.yml)
           OLD_BASENAME="cuda-bindings-python${PYTHON_VERSION_FORMATTED}-cuda*-${{ inputs.host-platform }}*"
-          LATEST_PRIOR_RUN_ID=$(./ci/tools/lookup-run-id --branch "${OLD_BRANCH}" NVIDIA/cuda-python "CI")
+          OLD_WHEEL_ARTIFACT_PATTERN="${OLD_BASENAME}[0-9a-f]"
+          LATEST_PRIOR_RUN_ID=$(./ci/tools/lookup-run-id \
+            --branch "${OLD_BRANCH}" \
+            --artifact "${OLD_WHEEL_ARTIFACT_PATTERN}" \
+            NVIDIA/cuda-python "CI")
           PREV_BINDINGS_DIR="cuda_bindings/dist-prev"
 
-          gh run download $LATEST_PRIOR_RUN_ID -p ${OLD_BASENAME} -R NVIDIA/cuda-python
+          gh run download "${LATEST_PRIOR_RUN_ID}" -p "${OLD_BASENAME}" -R NVIDIA/cuda-python
           rm -rf ${OLD_BASENAME}-tests  # exclude cython test artifacts
           ls -al $OLD_BASENAME
           mkdir -p "${PREV_BINDINGS_DIR}"
diff --git a/.github/workflows/test-wheel-linux.yml b/.github/workflows/test-wheel-linux.yml
index 8134a6844fd..2fd918e2859 100644
--- a/.github/workflows/test-wheel-linux.yml
+++ b/.github/workflows/test-wheel-linux.yml
@@ -219,9 +219,18 @@ jobs:
 
           OLD_BRANCH=${{ needs.compute-matrix.outputs.OLD_BRANCH }}
           OLD_BASENAME="cuda-bindings-python${PYTHON_VERSION_FORMATTED}-cuda*-${{ inputs.host-platform }}*"
-          LATEST_PRIOR_RUN_ID=$(./ci/tools/lookup-run-id --branch "${OLD_BRANCH}" NVIDIA/cuda-python "CI")
+          OLD_WHEEL_ARTIFACT_PATTERN="${OLD_BASENAME}[0-9a-f]"
+          LOOKUP_ARGS=(
+            --branch "${OLD_BRANCH}"
+            --artifact "${OLD_WHEEL_ARTIFACT_PATTERN}"
+          )
+          if ${{ inputs.test-python }}; then
+            LOOKUP_ARGS+=(--artifact cuda-python-wheel)
+          fi
+          LATEST_PRIOR_RUN_ID=$(./ci/tools/lookup-run-id \
+            "${LOOKUP_ARGS[@]}" NVIDIA/cuda-python "CI")
 
-          gh run download $LATEST_PRIOR_RUN_ID -p ${OLD_BASENAME} -R NVIDIA/cuda-python
+          gh run download "${LATEST_PRIOR_RUN_ID}" -p "${OLD_BASENAME}" -R NVIDIA/cuda-python
           rm -rf ${OLD_BASENAME}-tests  # exclude cython test artifacts
           ls -al $OLD_BASENAME
           mkdir -p "${{ env.CUDA_BINDINGS_ARTIFACTS_DIR }}"
@@ -229,7 +238,7 @@ jobs:
           rmdir $OLD_BASENAME
 
           if ${{ inputs.test-python }}; then
-            gh run download $LATEST_PRIOR_RUN_ID -p cuda-python-wheel -R NVIDIA/cuda-python
+            gh run download "${LATEST_PRIOR_RUN_ID}" -p cuda-python-wheel -R NVIDIA/cuda-python
             ls -al cuda-python-wheel
             mv cuda-python-wheel/*.whl .
             rmdir cuda-python-wheel
diff --git a/.github/workflows/test-wheel-windows.yml b/.github/workflows/test-wheel-windows.yml
index 04b290b1cd0..1af7c4b625b 100644
--- a/.github/workflows/test-wheel-windows.yml
+++ b/.github/workflows/test-wheel-windows.yml
@@ -199,9 +199,18 @@ jobs:
         run: |
           OLD_BRANCH=$(yq '.backport_branch' ci/versions.yml)
           OLD_BASENAME="cuda-bindings-python${PYTHON_VERSION_FORMATTED}-cuda*-${{ inputs.host-platform }}*"
-          LATEST_PRIOR_RUN_ID=$(./ci/tools/lookup-run-id --branch "${OLD_BRANCH}" NVIDIA/cuda-python "CI")
+          OLD_WHEEL_ARTIFACT_PATTERN="${OLD_BASENAME}[0-9a-f]"
+          LOOKUP_ARGS=(
+            --branch "${OLD_BRANCH}"
+            --artifact "${OLD_WHEEL_ARTIFACT_PATTERN}"
+          )
+          if ${{ inputs.test-python }}; then
+            LOOKUP_ARGS+=(--artifact cuda-python-wheel)
+          fi
+          LATEST_PRIOR_RUN_ID=$(./ci/tools/lookup-run-id \
+            "${LOOKUP_ARGS[@]}" NVIDIA/cuda-python "CI")
 
-          gh run download $LATEST_PRIOR_RUN_ID -p ${OLD_BASENAME} -R NVIDIA/cuda-python
+          gh run download "${LATEST_PRIOR_RUN_ID}" -p "${OLD_BASENAME}" -R NVIDIA/cuda-python
           rm -rf ${OLD_BASENAME}-tests  # exclude cython test artifacts
           ls -al $OLD_BASENAME
           mkdir -p "${{ env.CUDA_BINDINGS_ARTIFACTS_DIR }}"
@@ -209,7 +218,7 @@ jobs:
           rmdir $OLD_BASENAME
 
           if ${{ inputs.test-python }}; then
-            gh run download $LATEST_PRIOR_RUN_ID -p cuda-python-wheel -R NVIDIA/cuda-python
+            gh run download "${LATEST_PRIOR_RUN_ID}" -p cuda-python-wheel -R NVIDIA/cuda-python
             ls -al cuda-python-wheel
             mv cuda-python-wheel/*.whl .
             rmdir cuda-python-wheel
diff --git a/ci/tools/lookup-run-id b/ci/tools/lookup-run-id
index bd8ba413974..cc106c4e4f3 100755
--- a/ci/tools/lookup-run-id
+++ b/ci/tools/lookup-run-id
@@ -8,7 +8,7 @@
 #
 # Two modes:
 #   --tag <tag>      Find the successful CI run triggered by a tag push.
-#   --branch <branch> Find the latest successful CI run on a branch.
+#   --branch <branch> Find the latest qualifying successful CI run on a branch.
 #
 # Outputs the run ID on stdout.  All diagnostic messages go to stderr.
 # When --head-sha is passed, a second line with the run's head SHA is printed.
@@ -24,11 +24,14 @@ Usage:
 Options:
   --tag <tag>        Find run by git tag (requires local git repo with the tag)
   --branch <branch>  Find latest successful run on the given branch
+  --artifact <glob>  Require an unexpired artifact matching this shell glob
+                     (repeatable; branch mode only)
   --head-sha         Also print the run's head commit SHA (second line)
 
 Examples:
   $0 --tag v13.0.1 NVIDIA/cuda-python
   $0 --branch main NVIDIA/cuda-python
+  $0 --branch 12.9.x --artifact 'cuda-bindings-python313-*' NVIDIA/cuda-python
   $0 --branch main --head-sha NVIDIA/cuda-python "CI"
 EOF
     exit 1
@@ -38,15 +41,21 @@ EOF
 MODE=""
 REF=""
 HEAD_SHA_FLAG=0
+ARTIFACT_PATTERNS=()
 
 while [[ $# -gt 0 ]]; do
     case "${1}" in
         --tag)
+            [[ $# -ge 2 ]] || usage
             [[ -n "${MODE}" && "${MODE}" != "tag" ]] && { echo "Error: --tag and --branch are mutually exclusive" >&2; exit 1; }
             MODE="tag"; REF="${2}"; shift 2 ;;
         --branch)
+            [[ $# -ge 2 ]] || usage
             [[ -n "${MODE}" && "${MODE}" != "branch" ]] && { echo "Error: --tag and --branch are mutually exclusive" >&2; exit 1; }
             MODE="branch"; REF="${2}"; shift 2 ;;
+        --artifact)
+            [[ $# -ge 2 ]] || usage
+            ARTIFACT_PATTERNS+=("${2}"); shift 2 ;;
         --head-sha)
             HEAD_SHA_FLAG=1; shift ;;
         -h|--help)
@@ -69,6 +78,11 @@ WORKFLOW_NAME="${1:-CI}"
 
 if [[ -z "${REPOSITORY}" ]]; then usage; fi
 
+if [[ "${MODE}" != "branch" && ${#ARTIFACT_PATTERNS[@]} -gt 0 ]]; then
+    echo "Error: --artifact is only supported with --branch" >&2
+    exit 1
+fi
+
 # ── Prerequisite checks ──
 if [[ -z "${GH_TOKEN:-}" ]]; then
     echo "Error: GH_TOKEN environment variable is required" >&2
@@ -86,17 +100,79 @@ done
 if [[ "${MODE}" == "branch" ]]; then
     echo "Looking up latest successful '${WORKFLOW_NAME}' run on branch: ${REF}" >&2
 
-    RUN_ID=$(gh run list \
-        -b "${REF}" \
-        -L 1 \
-        -w "${WORKFLOW_NAME}" \
-        -s success \
-        -R "${REPOSITORY}" \
-        --json databaseId \
-        | jq -r '.[0].databaseId // empty')
+    RUN_DATA=$(gh run list \
+        --repo "${REPOSITORY}" \
+        --branch "${REF}" \
+        --workflow "${WORKFLOW_NAME}" \
+        --status completed \
+        --json databaseId,workflowName,status,conclusion,headSha,headBranch,createdAt,url \
+        --limit 100)
+
+    CANDIDATE_RUNS=$(echo "${RUN_DATA}" | jq -r \
+        --arg branch "${REF}" '
+        map(select(
+            .headBranch == $branch
+            and .conclusion == "success"
+        ))
+        | sort_by(.createdAt, .databaseId)
+        | reverse
+        | .[]
+        | [.databaseId, .headSha, .createdAt]
+        | @tsv
+    ')
+
+    if [[ -z "${CANDIDATE_RUNS}" ]]; then
+        echo "Error: No successful '${WORKFLOW_NAME}' run found on branch '${REF}'" >&2
+        exit 1
+    fi
+
+    if [[ ${#ARTIFACT_PATTERNS[@]} -gt 0 ]]; then
+        echo "Requiring unexpired artifacts matching:" >&2
+        printf '  - %s\n' "${ARTIFACT_PATTERNS[@]}" >&2
+    fi
+
+    RUN_ID=""
+    HEAD_SHA=""
+    while IFS= read -r candidate; do
+        IFS=$'\t' read -r candidate_id candidate_sha candidate_created_at <<< "${candidate}"
+
+        missing_patterns=()
+        if [[ ${#ARTIFACT_PATTERNS[@]} -gt 0 ]]; then
+            if ! ARTIFACT_NAMES=$(gh api --paginate \
+                "repos/${REPOSITORY}/actions/runs/${candidate_id}/artifacts?per_page=100" \
+                --jq '.artifacts[] | select(.expired == false) | .name'); then
+                echo "Error: Failed to list artifacts for run ${candidate_id}" >&2
+                exit 1
+            fi
+
+            for pattern in "${ARTIFACT_PATTERNS[@]}"; do
+                pattern_matched=0
+                while IFS= read -r artifact_name; do
+                    # The caller supplies a shell glob, so the RHS must remain unquoted.
+                    # shellcheck disable=SC2053
+                    if [[ -n "${artifact_name}" && "${artifact_name}" == ${pattern} ]]; then
+                        pattern_matched=1
+                        break
+                    fi
+                done <<< "${ARTIFACT_NAMES}"
+                if [[ ${pattern_matched} == 0 ]]; then
+                    missing_patterns+=("${pattern}")
+                fi
+            done
+        fi
+
+        if [[ ${#missing_patterns[@]} -gt 0 ]]; then
+            echo "Skipping run ${candidate_id} (${candidate_created_at}); missing unexpired artifact(s): ${missing_patterns[*]}" >&2
+            continue
+        fi
+
+        RUN_ID="${candidate_id}"
+        HEAD_SHA="${candidate_sha}"
+        break
+    done <<< "${CANDIDATE_RUNS}"
 
     if [[ -z "${RUN_ID}" ]]; then
-        echo "Error: No successful '${WORKFLOW_NAME}' run found on branch '${REF}'" >&2
+        echo "Error: No successful '${WORKFLOW_NAME}' run on branch '${REF}' has all required artifacts" >&2
         exit 1
     fi
 
@@ -104,10 +180,10 @@ if [[ "${MODE}" == "branch" ]]; then
     echo "${RUN_ID}"
 
     if [[ "${HEAD_SHA_FLAG}" == 1 ]]; then
-        HEAD_SHA=$(gh run view "${RUN_ID}" \
-            -R "${REPOSITORY}" \
-            --json headSha \
-            | jq -r '.headSha')
+        if [[ -z "${HEAD_SHA}" ]]; then
+            echo "Error: Run ${RUN_ID} has no head SHA" >&2
+            exit 1
+        fi
         echo "Head SHA: ${HEAD_SHA}" >&2
         echo "${HEAD_SHA}"
     fi
diff --git a/ci/tools/tests/test_lookup_run_id.py b/ci/tools/tests/test_lookup_run_id.py
new file mode 100644
index 00000000000..a61b2019a5c
--- /dev/null
+++ b/ci/tools/tests/test_lookup_run_id.py
@@ -0,0 +1,203 @@
+# SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+from __future__ import annotations
+
+import json
+import os
+import subprocess
+from pathlib import Path
+
+import pytest
+
+LOOKUP_RUN_ID = Path(__file__).parent.parent / "lookup-run-id"
+
+FAKE_GH = r"""#!/usr/bin/env python3
+import json
+import os
+import re
+import sys
+
+args = sys.argv[1:]
+if args[:2] == ["run", "list"]:
+    print(os.environ["FAKE_RUNS"])
+    raise SystemExit(0)
+
+if args[:1] == ["api"]:
+    if "--paginate" not in args or "--jq" not in args:
+        print("artifact lookup must be paginated and filtered", file=sys.stderr)
+        raise SystemExit(2)
+    match = re.search(r"/runs/(\d+)/artifacts", " ".join(args))
+    if match is None:
+        print("could not determine run ID", file=sys.stderr)
+        raise SystemExit(2)
+    artifacts_by_run = json.loads(os.environ["FAKE_ARTIFACTS"])
+    artifacts = artifacts_by_run.get(match.group(1))
+    if artifacts is None:
+        print("simulated artifact API failure", file=sys.stderr)
+        raise SystemExit(3)
+    for artifact in artifacts:
+        if not artifact.get("expired", False):
+            print(artifact["name"])
+    raise SystemExit(0)
+
+print(f"unexpected gh arguments: {args!r}", file=sys.stderr)
+raise SystemExit(2)
+"""
+
+
+def _run(run_id, created_at, *, branch="12.9.x", workflow="CI", conclusion="success"):
+    return {
+        "databaseId": run_id,
+        "workflowName": workflow,
+        "status": "completed",
+        "conclusion": conclusion,
+        "headSha": f"sha-{run_id}",
+        "headBranch": branch,
+        "createdAt": created_at,
+        "url": f"https://example.invalid/runs/{run_id}",
+    }
+
+
+@pytest.fixture
+def fake_gh(tmp_path):
+    fake_bin = tmp_path / "bin"
+    fake_bin.mkdir()
+    gh = fake_bin / "gh"
+    gh.write_text(FAKE_GH, encoding="utf-8")
+    gh.chmod(0o755)
+    return fake_bin
+
+
+def _lookup(fake_gh, runs, artifacts, *args, workflow="CI"):
+    env = os.environ.copy()
+    env.update(
+        {
+            "FAKE_ARTIFACTS": json.dumps(artifacts),
+            "FAKE_RUNS": json.dumps(runs),
+            "GH_TOKEN": "test-token",
+            "PATH": f"{fake_gh}{os.pathsep}{env['PATH']}",
+        }
+    )
+    return subprocess.run(  # noqa: S603 - invokes the repository script under test
+        [str(LOOKUP_RUN_ID), *args, "NVIDIA/cuda-python", workflow],
+        check=False,
+        capture_output=True,
+        env=env,
+        text=True,
+    )
+
+
+@pytest.mark.agent_authored(model="gpt-5.6")
+class TestBranchLookup:
+    def test_selects_newest_run_with_filename_workflow_selector(self, fake_gh):
+        runs = [
+            _run(100, "2026-08-10T12:00:00Z"),
+            _run(400, "2026-08-13T12:00:00Z", conclusion="failure"),
+            _run(300, "2026-08-12T12:00:00Z", branch="other"),
+            _run(200, "2026-08-11T12:00:00Z"),
+        ]
+
+        result = _lookup(
+            fake_gh,
+            runs,
+            {},
+            "--branch",
+            "12.9.x",
+            "--head-sha",
+            workflow="ci.yml",
+        )
+
+        assert result.returncode == 0, result.stderr
+        assert result.stdout.splitlines() == ["200", "sha-200"]
+
+    def test_falls_back_until_all_required_artifacts_are_unexpired(self, fake_gh):
+        bindings_pattern = "cuda-bindings-python315-cuda*-linux-64*[0-9a-f]"
+        runs = [
+            _run(300, "2026-08-13T12:00:00Z"),
+            _run(200, "2026-08-12T12:00:00Z"),
+            _run(100, "2026-08-11T12:00:00Z"),
+        ]
+        artifacts = {
+            "300": [
+                {
+                    "name": "cuda-bindings-python315-cuda12.9.1-linux-64-abc123",
+                    "expired": True,
+                },
+                {
+                    "name": "cuda-bindings-python315-cuda12.9.1-linux-64-abc123-tests",
+                    "expired": False,
+                },
+                {"name": "cuda-python-wheel", "expired": False},
+            ],
+            "200": [
+                {
+                    "name": "cuda-bindings-python315-cuda12.9.1-linux-64-def456",
+                    "expired": False,
+                }
+            ],
+            "100": [
+                {
+                    "name": "cuda-bindings-python315-cuda12.9.1-linux-64-fedcba",
+                    "expired": False,
+                },
+                {"name": "cuda-python-wheel", "expired": False},
+            ],
+        }
+
+        result = _lookup(
+            fake_gh,
+            runs,
+            artifacts,
+            "--branch",
+            "12.9.x",
+            "--artifact",
+            bindings_pattern,
+            "--artifact",
+            "cuda-python-wheel",
+        )
+
+        assert result.returncode == 0, result.stderr
+        assert result.stdout.strip() == "100"
+        assert "Skipping run 300" in result.stderr
+        assert "Skipping run 200" in result.stderr
+
+    def test_reports_when_no_successful_run_has_required_artifacts(self, fake_gh):
+        runs = [_run(100, "2026-08-11T12:00:00Z")]
+        artifacts = {
+            "100": [
+                {
+                    "name": "cuda-bindings-python315-cuda12.9.1-linux-64-fedcba",
+                    "expired": True,
+                }
+            ]
+        }
+
+        result = _lookup(
+            fake_gh,
+            runs,
+            artifacts,
+            "--branch",
+            "12.9.x",
+            "--artifact",
+            "cuda-bindings-python315-cuda*-linux-64*[0-9a-f]",
+        )
+
+        assert result.returncode == 1
+        assert "has all required artifacts" in result.stderr
+
+    def test_propagates_artifact_api_failures(self, fake_gh):
+        runs = [_run(100, "2026-08-11T12:00:00Z")]
+
+        result = _lookup(
+            fake_gh,
+            runs,
+            {},
+            "--branch",
+            "12.9.x",
+            "--artifact",
+            "cuda-bindings-*",
+        )
+
+        assert result.returncode == 1
+        assert "Failed to list artifacts for run 100" in result.stderr