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 fanfan-de/anybox --skill sandbox-sdkgit clone --depth 1 https://github.com/fanfan-de/anyboxWrote 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/fanfan-de/anybox/sandbox-sdk)<a href="https://agentmods.dev/skills/fanfan-de/anybox/sandbox-sdk"><img src="https://agentmods.dev/badge/skills/fanfan-de/anybox/sandbox-sdk/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/fanfan-de/anybox/sandbox-sdk"><img src="https://agentmods.dev/badge/skills/fanfan-de/anybox/sandbox-sdk.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 | $0.00066 | $0.01341 |
| Opus 5 | $0.00033 | $0.00671 |
| Sonnet 5 | $0.00013 | $0.00268 |
| Haiku 4.5 | $0.00007 | $0.00134 |
Grade C, and why
sandbox-sdk scanned grade C with 1 finding 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 6d 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.
Recursive force deletehighDestructive command
rm -rf with a variable or a broad path is one typo away from removing the wrong tree.
RUN apt-get update && apt-get install -y ffmpeg && rm -rf /var/lib/apt/lists/* Copies of this mod
2 near-identical copies found in the catalogue:
- sandbox-sdk — 100% identical, 0 lines differ
- sandbox-sdk — 100% identical, 10 lines differ
How it starts
The opening of the file, as written. The whole thing — 178 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Cloudflare Sandbox SDK
Build secure, isolated code execution environments on Cloudflare Workers.
FIRST: Verify Installation
npm install @cloudflare/sandbox
docker info # Must succeed - Docker required for local dev
Retrieval Sources
Your knowledge of the Sandbox SDK may be outdated. Prefer retrieval over pre-training for any Sandbox SDK task.
| Resource | URL |
|---|---|
| Docs | https://developers.cloudflare.com/sandbox/ |
| API Reference | https://developers.cloudflare.com/sandbox/api/ |
| Examples | https://github.com/cloudflare/sandbox-sdk/tree/main/examples |
| Get Started | https://developers.cloudflare.com/sandbox/get-started/ |
When implementing features, fetch the relevant doc page or example first.
Required Configuration
wrangler.jsonc (exact - do not modify structure):
{
"containers": [{
"class_name": "Sandbox",
"image": "./Dockerfile",
"instance_type": "lite",
"max_instances": 1
}],
"durable_objects": {
"bindings": [{ "class_name": "Sandbox", "name": "Sandbox" }]
},
"migrations": [{ "new_sqlite_classes": ["Sandbox"], "tag": "v1" }]
}
Worker entry - must re-export Sandbox class:
import { getSandbox } from '@cloudflare/sandbox';
export { Sandbox } from '@cloudflare/sandbox'; // Required export
Quick Reference
| Task | Method |
|---|---|
| Get sandbox | getSandbox(env.Sandbox, 'user-123') |
| Run command | await sandbox.exec('python script.py') |
| Run code (interpreter) | await sandbox.runCode(code, { language: 'python' }) |
| Write file | await sandbox.writeFile('/workspace/app.py', content) |
| Read file | await sandbox.readFile('/workspace/app.py') |
| Create directory | await sandbox.mkdir('/workspace/src', { recursive: true }) |
| List files | await sandbox.listFiles('/workspace') |
| Expose port | await sandbox.exposePort(8080) |
| Destroy | await sandbox.destroy() |
Core Patterns
Execute Commands
What ships with it
3 files 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.
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.
- 6d ago First seen · 178 lines · 66 tokens per session scan C 0f3501e65109
sandbox-sdk is a skill published in the GitHub repository fanfan-de/anybox (57 stars, last pushed 27d ago), licensed MIT. It adds 66 tokens to every session and 1,341 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it C with 1 finding (recursive force delete). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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