bex-security: Skill for Claude Code

.claude/skills/merge-upstream-main/SKILL.md

merge-upstream-main is a skill for Claude Code, Codex from bex-co/bex-security. It costs 44 tokens per session (828 once invoked), scanned A, original, Apache-2.0.

A procedure for bringing changes from the public openai/codex-security repository into a fork's main branch. A fork is a separate copy of a repository that can receive upstream changes.

In plain words
What is it for?
Use it to inspect the repository, merge upstream main into the fork's main branch, resolve conflicts when appropriate, and push the result.
Why use it?
It provides a defined way to sync the fork while protecting local work and avoiding rewritten Git history.

Skill for Claude CodeCodex

Written for Claude Code and Codex: installed under .claude/, but also agents/openai.yaml present. Also seen: mentions AGENTS.md; mentions Codex.

This is bex-co/bex-security's own configuration. It tells Claude Code and Codex how to work on bex-security itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything bex-security configures →

Reuse

Borrowing it

Nothing to install: this file belongs to bex-co/bex-security. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/bex-co/bex-security/main/.claude/skills/merge-upstream-main/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/bex-co/bex-security

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for merge-upstream-main

README.md
[![agentmods](https://agentmods.dev/badge/skills/bex-co/bex-security/merge-upstream-main/github.svg)](https://agentmods.dev/skills/bex-co/bex-security/merge-upstream-main)
Your own site
<a href="https://agentmods.dev/skills/bex-co/bex-security/merge-upstream-main"><img src="https://agentmods.dev/badge/skills/bex-co/bex-security/merge-upstream-main/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for merge-upstream-main

Your own site · 80×15
<a href="https://agentmods.dev/skills/bex-co/bex-security/merge-upstream-main"><img src="https://agentmods.dev/badge/skills/bex-co/bex-security/merge-upstream-main.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 828 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00044 $0.00828
Opus 5 $0.00022 $0.00414
Sonnet 5 $0.00009 $0.00166
Haiku 4.5 $0.00004 $0.00083

Measured 9d ago against content hash 2cfd0362f27d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

merge-upstream-main scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/merge-upstream-main/SKILL.md · 72 lines

How it starts

The opening of the file, as written. The whole thing — 72 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Merge Upstream Main

Sync this fork from https://github.com/openai/codex-security.git with a Git merge. Do not rebase or rewrite main.

Inspect The Repository

  1. Confirm the current repository, branch, worktree, and remotes with git rev-parse --show-toplevel, git branch --show-current, git status --short --branch, and git remote -v.
  2. Continue only on main with a clean worktree, including no untracked files. Do not switch branches, stash changes, or discard work automatically. Report the state and ask the user how to proceed when either condition is not met.
  3. Read the applicable AGENTS.md instructions before resolving conflicts or running checks.

Identify The Remotes

  • The canonical upstream is the remote whose normalized GitHub repository is openai/codex-security. Reuse an existing matching remote. If none exists, add it as upstream with the canonical URL above when that remote name is available. If upstream already points elsewhere, stop and ask rather than rewriting it.
  • The fork remote is the remote tracked by local main, when that remote is not the canonical repository; otherwise prefer a noncanonical origin, then the sole remaining noncanonical remote.
  • Never select the canonical repository as the fork remote. If no fork remote exists, or multiple candidates make the destination ambiguous, stop and ask the user to identify or configure the fork remote. Do not guess a repository URL or rewrite an existing remote.

Show the selected upstream and fork remote names and URLs before fetching. This guards against pushing the fork merge to the canonical repository.

Use task-specific upstream_remote and fork_remote shell variables for the selected remote names, and quote their expansions in commands.

Merge And Verify

  1. Fetch both selected remotes with git fetch "$upstream_remote" and git fetch "$fork_remote".
  2. Fast-forward local main to the fork's remote-tracking main with git merge --ff-only "$fork_remote/main". If local and fork main have diverged, stop and report the commits on each side instead of choosing a history strategy.
  3. Merge upstream with git merge --no-edit "$upstream_remote/main". A fast-forward is acceptable when the fork has no unique commits.
  4. If conflicts occur, inspect each one and reconcile the fork's behavior with the upstream change. Do not resolve all conflicts with a blanket ours or theirs strategy. Continue the merge only after the result is coherent.
  5. Run the repository checks relevant to the merged or conflict-resolved files. A clean, conflict-free upstream merge does not require inventing new tests.
  6. Push local main with git push "$fork_remote" main:main without force.
  7. Fetch both remotes again, then verify:
    • git merge-base --is-ancestor "$upstream_remote/main" main succeeds.
    • git rev-list --left-right --count "$fork_remote/main...main" reports 0 0.
    • git status --short --branch is clean.

Read the full file on GitHub · 72 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 72 lines · 44 tokens per session scan A 2cfd0362f27d

Subscribe to this mod's changes

merge-upstream-main is a skill published in the GitHub repository bex-co/bex-security (44 stars, last pushed 2d ago), licensed Apache-2.0. It adds 44 tokens to every session and 828 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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