Borrowing it
Nothing to install: this file belongs to tontoko/fast-playwright-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/tontoko/fast-playwright-mcp/main/.github/copilot-instructions.mdgit clone --depth 1 https://github.com/tontoko/fast-playwright-mcpWrote 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/instructions/tontoko/fast-playwright-mcp/copilot-instructions)<a href="https://agentmods.dev/instructions/tontoko/fast-playwright-mcp/copilot-instructions"><img src="https://agentmods.dev/badge/instructions/tontoko/fast-playwright-mcp/copilot-instructions.svg" alt="Measured on agentmods" 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 | $0.00338 | $0.00338 |
| Opus 5 | $0.00169 | $0.00169 |
| Sonnet 5 | $0.00068 | $0.00068 |
| Haiku 4.5 | $0.00034 | $0.00034 |
Grade A, and why
fast-playwright-mcp copilot-instructions.md 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 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.
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.
What it actually says
Fast Playwright MCP - GitHub Copilot Instructions
Project Context
This is the Fast Playwright MCP Server project - a TypeScript/JavaScript automation tool using Playwright for browser automation via MCP (Model Context Protocol).
Key Principles
- Use Biome (via Ultracite) for consistent formatting and linting
- Follow existing patterns in the codebase
- Prioritize type safety and error handling
- Write comprehensive tests
Coding Guidelines
TypeScript Best Practices
- Use strict type definitions
- Prefer
import typefor types - Use
constassertions where appropriate - Avoid
anytype - use proper typing
Error Handling
- Always handle errors appropriately
- Use proper error types and messages
- Log errors for debugging
- Don't swallow exceptions
Testing
- Write comprehensive tests for new features
- Use Playwright's built-in test utilities
- Mock external dependencies appropriately
- Test both success and error paths
MCP Protocol
- Follow MCP specification for tool definitions
- Provide clear tool descriptions and parameters
- Handle MCP transport properly
- Return structured responses
Project Structure
/src/- Main source code/tests/- Test files/benchmark/- Performance benchmarking/extension/- Browser extension code
Commands
npm run build- Build TypeScriptnpm test- Run Playwright testsnpm run lint-fix- Format and fix codenpm run benchmark- Run performance tests
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 · 52 lines · 338 tokens per session scan A c0abd2e5b02c
fast-playwright-mcp copilot-instructions.md is an instructions file published in the GitHub repository tontoko/fast-playwright-mcp (40 stars, last pushed 19d ago), licensed Apache-2.0. It adds 338 tokens to every session, about $0.0017 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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