System Prompts Leaks is a collection of captured system instructions used to guide AI chatbots and coding agents before they receive user messages. It serves researchers and developers studying how different AI assistants are directed.
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 asgeirtj/system_prompts_leaks --skill claude-in-chromegit clone --depth 1 https://github.com/asgeirtj/system_prompts_leaksWrote 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/asgeirtj/system_prompts_leaks/claude-in-chrome)<a href="https://agentmods.dev/skills/asgeirtj/system_prompts_leaks/claude-in-chrome"><img src="https://agentmods.dev/badge/skills/asgeirtj/system_prompts_leaks/claude-in-chrome/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/asgeirtj/system_prompts_leaks/claude-in-chrome"><img src="https://agentmods.dev/badge/skills/asgeirtj/system_prompts_leaks/claude-in-chrome.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Snyk warn
- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Excessive Agency · line 50 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 | $0.00057 | $0.00983 |
| Opus 5 | $0.00028 | $0.00491 |
| Sonnet 5 | $0.00011 | $0.00197 |
| Haiku 4.5 | $0.00006 | $0.00098 |
Grade A, and why
claude-in-chrome 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 13d 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- claude-in-chrome — 91% identical, 5 lines differ
How it starts
The opening of the file, as written. The whole thing — 61 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Claude in Chrome browser automation
You have access to browser automation tools (mcp__claude-in-chrome__*) for interacting with web pages in Chrome. Follow these guidelines for effective browser automation.
Loading deferred tools
If the mcp__claude-in-chrome__* tools are deferred (must be loaded via ToolSearch before use), load every tool you expect to need in ONE ToolSearch call — the select query accepts a comma-separated list — never one call per tool. Start with the core set:
ToolSearch with query "select:mcp__claude-in-chrome__tabs_context_mcp,mcp__claude-in-chrome__navigate,mcp__claude-in-chrome__computer,mcp__claude-in-chrome__read_page,mcp__claude-in-chrome__tabs_create_mcp,mcp__claude-in-chrome__tabs_close_mcp"
Add task-specific tools to the same call when the task obviously needs them: read_console_messages / read_network_requests for debugging, form_input for forms, gif_creator for recordings, javascript_tool for page scripting.
GIF recording
When performing multi-step browser interactions that the user may want to review or share, use mcp__claude-in-chrome__gif_creator to record them.
You must ALWAYS:
- Capture extra frames before and after taking actions to ensure smooth playback
- Name the file meaningfully to help the user identify it later (e.g., "login_process.gif")
Console log debugging
You can use mcp__claude-in-chrome__read_console_messages to read console output. Console output may be verbose. If you are looking for specific log entries, use the 'pattern' parameter with a regex-compatible pattern. This filters results efficiently and avoids overwhelming output. For example, use pattern: "[MyApp]" to filter for application-specific logs rather than reading all console output.
Alerts and dialogs
IMPORTANT: Do not trigger JavaScript alerts, confirms, prompts, or browser modal dialogs through your actions. These browser dialogs block all further browser events and will prevent the extension from receiving any subsequent commands. Instead, when possible, use console.log for debugging and then use the mcp__claude-in-chrome__read_console_messages tool to read those log messages. If a page has dialog-triggering elements:
- Avoid clicking buttons or links that may trigger alerts (e.g., "Delete" buttons with confirmation dialogs)
- If you must interact with such elements, warn the user first that this may interrupt the session
- Use mcp__claude-in-chrome__javascript_tool to check for and dismiss any existing dialogs before proceeding
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.
- 13d ago First seen · 61 lines · 57 tokens per session scan A 7e1daafcd1dd
claude-in-chrome is a skill published in the GitHub repository asgeirtj/system_prompts_leaks (64,893 stars, last pushed 2d ago), licensed CC0-1.0. It adds 57 tokens to every session and 983 once invoked, about $0.0003 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.
Other skills, from other repositories
har-derived-api-client
Record a site's XHR into a HAR, derive an HTTP client.
scrapling
Scrape sites with stealth browsing and Cloudflare bypass.
page-agent
Embed an in-page natural-language GUI copilot in web apps.
dogfood
Exploratory QA of web apps: find bugs, evidence, reports.
blocked-page-recovery
Use when a fetch fails: 403/429, paywall, WAF, bot wall.
parallel-cli
Agent-native web search, deep research, and enrichment.