From 54222cc606c1cb673060287ffc454a4a35dbb64e Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Thu, 17 Sep 2026 00:07:06 +0000
Subject: [PATCH] ci: restrict GitHub Actions cache access with cache-mode

Set cache-mode to none at the workflow level, as none of the jobs
restores or saves a cache, and document the convention next to the
permissions rule.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AKZPpJJVhgvmm2GZbX3nxV
---
 .github/workflows/ci.yml              | 1 +
 .github/workflows/release.yml         | 1 +
 .github/workflows/update-material.yml | 1 +
 AGENTS.md                             | 3 +++
 4 files changed, 6 insertions(+)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2678470..83338cb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,6 +8,7 @@ on:
   workflow_dispatch:
 
 permissions: {}
+cache-mode: none
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 8ce614e..9174a97 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -9,6 +9,7 @@ on:
   workflow_dispatch:
 
 permissions: {}
+cache-mode: none
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.event_name == 'workflow_dispatch' && 'release' || github.ref }}
diff --git a/.github/workflows/update-material.yml b/.github/workflows/update-material.yml
index 064c045..4dcdeae 100644
--- a/.github/workflows/update-material.yml
+++ b/.github/workflows/update-material.yml
@@ -10,6 +10,7 @@ on:
   workflow_dispatch:
 
 permissions: {}
+cache-mode: none
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
diff --git a/AGENTS.md b/AGENTS.md
index 8cfecaa..900a97e 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -38,4 +38,7 @@ This repository publishes dev container features for use with the [Dev Container
   e.g. `uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0`.
 - Set workflow-level permissions to empty (`permissions: {}`) and grant
   the minimum required permissions per job.
+- Set workflow-level cache access to none (`cache-mode: none`) and grant
+  the minimum required mode per job: `read` when a job only restores
+  caches, `write` when it also saves ones later runs restore.
 - Set `persist-credentials: false` on `actions/checkout`.