Borrowing it
Nothing to install: this file belongs to BashaarJavaid/MCP-Sentinel. 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/BashaarJavaid/MCP-Sentinel/main/AGENTS.mdgit clone --depth 1 https://github.com/BashaarJavaid/MCP-SentinelWrote 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/bashaarjavaid/mcp-sentinel/agents-md)<a href="https://agentmods.dev/instructions/bashaarjavaid/mcp-sentinel/agents-md"><img src="https://agentmods.dev/badge/instructions/bashaarjavaid/mcp-sentinel/agents-md/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/instructions/bashaarjavaid/mcp-sentinel/agents-md"><img src="https://agentmods.dev/badge/instructions/bashaarjavaid/mcp-sentinel/agents-md.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 | $0.02929 | $0.02929 |
| Opus 5.5 | $0.01172 | $0.01172 |
| Sonnet 5.5 | $0.00586 | $0.00586 |
| Haiku 4.5 | $0.00293 | $0.00293 |
Grade A, and why
MCP-Sentinel AGENTS.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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 212 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md
Project
PortunusMCP Sentinel — a build-time static/dynamic security scanner for MCP (Model Context Protocol) servers, mapped to the OWASP Agentic Top 10, shipped as a CLI tool and a GitHub Action that outputs SARIF.
Sentinel is one of three components of the PortunusMCP family:
- PortunusMCP Gateway — runtime zero-trust enforcement gateway (separate repo, out of scope here).
- PortunusMCP Sentinel (this repo) — build-time scanner.
- PortunusMCP Identity — short-lived credential broker (separate repo, out of scope here).
Sentinel helps maintainers and small teams catch MCP server security regressions before release, with actionable source findings and reproducible evidence for supported runtime checks. It combines static source/manifest analysis and adversarial probes against sandboxed targets. A completed scan is not proof that a server is safe; OWASP mappings classify findings, not coverage of all ten categories. Start with supported Python server maintainers and expand according to measured detection gaps and pilot demand.
The historical build context lives in mcp-sentinel-buildplan.md; active contracts and status live in ARCHITECTURE.md and ROADMAP.md. Read the historical brief first for project context, then use the active documents as authority.
Where things live
mcp-sentinel-buildplan.md— historical build brief and original scope. Read this first for context; defer to Architecture and Roadmap for current contracts.README.md— public quickstart, install, supported scope, and usage examples.src/sentinel/static/rules/— one file per detection rule; each rule is independently testable and tagged with its OWASP Agentic Top 10 category (src/sentinel/owasp_mapping.pyholds the canonical rule-id → category map).src/sentinel/dynamic/— the sandbox launcher (sandbox.py) and adversarial prober (prober.py).src/sentinel/report/—sarif.py(SARIF 2.1.0 writer) andconsole.py(human-readable terminal report).tests/fixtures/vulnerable_server/andtests/fixtures/clean_server/— the reference sample servers every rule is tested against.tests/evals/andartifacts/— existing review truth sets and retained evidence; Phase 20 adds independent vulnerable/fixed cases and held-out evaluation. Fixture success and code coverage are not detection accuracy.action.yml— the GitHub Action wrapper around the CLI.
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.
- 1mo ago Changed · -2,557 lines · -37,722 tokens per session 1927e30dc6bb
- 1mo ago Changed · +2,500 lines · +36,730 tokens per session 9c49ce965a23
- 1mo ago Changed · +12 lines · +159 tokens per session f406bd278975
- 1mo ago Changed · +102 lines · +1,324 tokens per session 61ab64b9157f
- 1mo ago Changed · +11 lines · +212 tokens per session fbff9bde6111
- 1mo ago First seen · 144 lines · 2,226 tokens per session scan A d2ffc301f13c
MCP-Sentinel AGENTS.md is an instructions file published in the GitHub repository BashaarJavaid/MCP-Sentinel (8 stars, last pushed today), licensed MIT. It adds 2,929 tokens to every session, about $0.0117 per session on Opus 5.5. 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 2026-08-31.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
vscode model-prompts.instructions.md
Model-specific prompt authoring and registry guidelines.