claude-codex-settings is a collection of configurations and reusable extensions for Claude Code, OpenAI Codex, Cursor, and related coding tools. Developers use its skills, commands, hooks, agents, plugins, and MCP servers to shape coding-agent workflows and connect alternative model APIs. The catalogue entries are components of this collection that can be installed into supported coding tools.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add fcakyon/claude-codex-settings --skill sandbox-stablegit clone --depth 1 https://github.com/fcakyon/claude-codex-settingsWrote 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.
[](https://agentmods.dev/skills/fcakyon/claude-codex-settings/sandbox-stable)<a href="https://agentmods.dev/skills/fcakyon/claude-codex-settings/sandbox-stable"><img src="https://agentmods.dev/badge/skills/fcakyon/claude-codex-settings/sandbox-stable/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.
<a href="https://agentmods.dev/skills/fcakyon/claude-codex-settings/sandbox-stable"><img src="https://agentmods.dev/badge/skills/fcakyon/claude-codex-settings/sandbox-stable.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00039 | $0.02144 |
| Opus 5.5 | $0.00016 | $0.00858 |
| Sonnet 5.5 | $0.00008 | $0.00429 |
| Haiku 4.5 | $0.00004 | $0.00214 |
Grade A, and why
sandbox-stable 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 17d 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.
This is a copy
100% identical to sandbox-stable — 1 line differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 112 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Sandbox SDK — stable package
Isolated Linux environments on Cloudflare Containers, driven from Workers.
Prefer the main Sandbox docs and installed stable types over memory. This skill is a gate, a contract, and a retrieval map—not a full manual.
This line is the current stable default npm package. The main Sandbox documentation describes it. Existing apps can stay here and keep shipping.
We recommend new projects on @cloudflare/sandbox@next with sandbox-next. When you can, plan a move with sandbox-migrate-to-next so you are ready when 1.0 becomes the stable release. Do not force that port unless the user asks.
1. Gate — confirm the package line
Before writing code, inspect the app:
| Check | Must match |
|---|---|
| npm dependency | Default @cloudflare/sandbox (not @next / preview tags) |
| Container image | Matching stable image (not cloudflare/sandbox:next) |
| If you find… | Action |
|---|---|
@cloudflare/sandbox@next or a next image |
Stop. Load sandbox-next. |
User wants to port to 1.0 / @next |
Stop. Load sandbox-migrate-to-next. Do not half-apply preview APIs on a stable package. |
| Only cleaning deprecated stable APIs | Stay here; use the 2026 deprecation guide. That is not a move to @next. |
Never mix a stable Worker package with an @next container image (or the reverse).
Skills install: Agent setup · cloudflare/skills
2. Contract — non-negotiables
await sandbox.exec(command)takes a command string and resolves when the command finishes, with bufferedstdout/stderr/exitCode(and related fields).- Long-running and streaming work use the stable command APIs (
startProcess,execStream, and related helpers)—not the@nextsingle-handle model. Open the Commands docs; do not invent@nextoutput()handles on stable. - Sessions can preserve working directory and environment across commands (default session /
enableDefaultSession,createSession). See Sessions docs when state must carry across calls. - Interactive browser terminals often use
sandbox.terminal(request)and session/xterm helpers on stable—not previewcreateTerminalunless the package is@next. - Prefer RPC transport when using tunnels or large/binary streaming. HTTP/WebSocket transports are deprecated (cleanup guide below).
- Files, mounts, ports, tunnels, backups, lifecycle, and interpreter: use main docs for signatures; trust installed stable types.
- Non-secret config in sandbox env; live credentials in the Worker. Use outbound handlers when processes call external APIs.
- Production preview hostnames need wildcard DNS on a custom domain when using those URL patterns.
- Do not apply
@nextargv/process.output()APIs while the dependency is still stable. - Self-deployed bridge stays on the stable package and image. Bridge
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.
- 17d ago Changed a4e8b36aeca7
- 1mo ago First seen · 112 lines · 39 tokens per session scan A 2993335e7057
sandbox-stable is a skill published in the GitHub repository fcakyon/claude-codex-settings (1,181 stars, last pushed yesterday), licensed Apache-2.0. It adds 39 tokens to every session and 2,144 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to sandbox-stable, differing in 1 line, and is treated as a copy.
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