diff --git a/AGENTS.md b/AGENTS.md
index daf0f491702b..3d5436a02a85 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -1 +1,17 @@
 - This is the only AGENTS.md, there are no recursive AGENTS.md
+- When you are working on a bug, first create a standalone file that
+  reproduces the bug and verify it fails in the expected way.  Use this to
+  test if your changes work.  Once the change is passing, find an appropriate
+  test file to add the test to and make sure to follow local conventions on
+  the test file.
+- If you are running the real test suite, DO NOT run the entire test suite.
+  Instead run only a single test case, e.g., 'python test/test_torch.py TestTorch.test_dir'
+- Do NOT run setup.py, you do not have a working build environment
+- Do NOT run pre-commit, it is not setup
+- To run lint, run 'lintrunner -a' (which will autoapply changes)
+- Do NOT attempt to install dependencies, you do not have Internet access
+- When you are ready to make a PR, do exactly these steps:
+  - git stash -u
+  - git reset --hard $(cat /tmp/orig_work.txt) # NB: reset to the LOCAL branch, do NOT fetch
+  - git stash pop
+  - Resolve conflicts if necessary
diff --git a/codex_setup.sh b/codex_setup.sh
new file mode 100755
index 000000000000..f169a7b1f693
--- /dev/null
+++ b/codex_setup.sh
@@ -0,0 +1,18 @@
+set -ex
+uv venv
+source .venv/bin/activate
+uv pip install -r requirements.txt
+uv pip install numpy
+lintrunner init
+NIGHTLY_PATCH=$(curl -s https://github.com/pytorch/pytorch/commit/nightly.patch | head -n20)
+COMMIT=$(grep -oE '[0-9a-f]{40}' <<< "$NIGHTLY_PATCH" | head -1)
+COMMIT_DATE=$(echo "$NIGHTLY_PATCH" | grep '^Date:' | sed -E 's/Date: .*, ([0-9]+) ([A-Za-z]+) ([0-9]+) .*/\3 \2 \1/' | awk 'BEGIN{split("Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec", months, " "); for(i=1;i<=12;i++) month[months[i]]=sprintf("%02d",i)} {print $1 month[$2] sprintf("%02d",$3)}')
+VERSION_STRING="2.9.0.dev${COMMIT_DATE}+cpu"
+git rev-parse HEAD > /tmp/orig_work.txt
+cp AGENTS.md /tmp
+git reset --hard $COMMIT
+cp /tmp/AGENTS.md .
+curl https://patch-diff.githubusercontent.com/raw/pytorch/pytorch/pull/159965.diff | patch -p1
+USE_NIGHTLY=$VERSION_STRING python setup.py develop
+git commit -asm "Agents patch"
+echo "source $PWD/.venv/bin/activate" >> ~/.bashrc