deepsec is a security scanner that uses coding agents to inspect existing codebases for vulnerabilities. Teams run it in their own infrastructure to review large repositories, with work distributed across machines when needed.
Borrowing it
Nothing to install: this file belongs to vercel-labs/deepsec. 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/vercel-labs/deepsec/main/CLAUDE.mdgit clone --depth 1 https://github.com/vercel-labs/deepsecWrote 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/vercel-labs/deepsec/claude-md)<a href="https://agentmods.dev/instructions/vercel-labs/deepsec/claude-md"><img src="https://agentmods.dev/badge/instructions/vercel-labs/deepsec/claude-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/vercel-labs/deepsec/claude-md"><img src="https://agentmods.dev/badge/instructions/vercel-labs/deepsec/claude-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 | $0.00481 | $0.00481 |
| Opus 5.5 | $0.00192 | $0.00192 |
| Sonnet 5.5 | $0.00096 | $0.00096 |
| Haiku 4.5 | $0.00048 | $0.00048 |
Grade A, and why
deepsec CLAUDE.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 25d 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
CLAUDE.md
Pointer file for Claude Code working in this repo. User-facing docs are in README.md; contributor docs in CONTRIBUTING.md. Read those first.
Repo shape
packages/
core/ Types, schemas, plugin contracts, config loader (defineConfig)
scanner/ Regex matchers + scanning engine
processor/ AI agent integration (Claude Agent SDK, Codex SDK), enrich, triage, revalidate
deepsec/ Publishable package: bundled CLI + the `deepsec/config` sub-export + the @vercel/sandbox executor
e2e/ End-to-end tests
Commands
pnpm install
pnpm test # all packages, including e2e
pnpm test:unit # excludes e2e
pnpm -r build # tsc across all workspaces (typecheck)
pnpm bundle # esbuild bundle for distribution
pnpm deepsec ... # the CLI (runs via tsx)
Writing
Always use the technical-writer skill
(.agents/skills/technical-writer/SKILL.md)
when you write or edit prose for this repo, including docs, READMEs, commit
messages, PR titles and descriptions, and issues.
Patterns to keep in mind
- Plugin contracts live in
packages/core/src/plugin.ts. Internals route throughgetRegistry()fromdeepsec/configrather than calling organization-specific code directly. - The CLI auto-loads
deepsec.config.{ts,mjs,js,cjs}from cwd upward (viapackages/deepsec/src/load-config.ts, jiti). - New matchers go in
packages/scanner/src/matchers/and register inmatchers/index.ts. Org-specific matchers belong in a separate plugin package, not in this tree. - The AI prompt template lives in
packages/processor/src/index.ts. It is intentionally generic. Don't add organization-specific context there; usedata/<projectId>/INFO.mdorconfig.json:promptAppend.
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.
- 25d ago Changed · +7 lines · +70 tokens per session 3c00a004d884
- 1mo ago First seen · 42 lines · 411 tokens per session scan A 3bf7fd9f4adb
deepsec CLAUDE.md is an instructions file published in the GitHub repository vercel-labs/deepsec (8,253 stars, last pushed 26d ago), licensed Apache-2.0. It adds 481 tokens to every session, about $0.0019 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 2026-08-30.
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).
deepseek-harness AGENTS.md
AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-stable apis and released session data, repository layout, commands and host sandbox failures.