Borrowing it
Nothing to install: this file belongs to gethelio/helio. 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/gethelio/helio/main/AGENTS.mdgit clone --depth 1 https://github.com/gethelio/helioWrote 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/gethelio/helio/agents-md)<a href="https://agentmods.dev/instructions/gethelio/helio/agents-md"><img src="https://agentmods.dev/badge/instructions/gethelio/helio/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/gethelio/helio/agents-md"><img src="https://agentmods.dev/badge/instructions/gethelio/helio/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 | $0.06311 | $0.06311 |
| Opus 5.5 | $0.02524 | $0.02524 |
| Sonnet 5.5 | $0.01262 | $0.01262 |
| Haiku 4.5 | $0.00631 | $0.00631 |
Grade A, and why
helio 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 24d 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 — 340 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Helio
Helio is an open-source MCP governance proxy. It sits between AI agents and external tools, applying policies, enforcing limits, requiring evidence, routing approvals, and recording an audit trail without modifying the agent or the tools.
GitHub org: gethelio · npm scope: @gethelio · PyPI: helio · Config file: helio.yaml
Architecture
Hybrid model: MCP proxy (core) + thin client SDKs (Python first, TypeScript planned).
Agent → Helio Proxy (policies, audit, limits, approvals) → Upstream MCP Server → External Tools
↑ optional sideband
Python SDK (evidence context, dependency annotations)
- The proxy intercepts
tools/callJSON-RPC methods. All other MCP methods pass through untouched. - The SDK communicates with the proxy via sideband HTTP. It NEVER makes governance decisions.
- SDK constraint: must stay under 500 lines per language. Governance logic belongs in the proxy.
Monorepo Structure
pnpm workspaces. Three packages:
packages/proxy/ → @gethelio/proxy (Node.js, Hono, TypeScript)
packages/dashboard/ → @gethelio/dashboard (React 19 + Vite + Tailwind CSS, internal workspace package bundled into proxy dist; not published)
packages/python-sdk/ → helio on PyPI (Python, <500 lines)
Supporting directories: examples/, docs/, docker/, scripts/, .github/
Tech Stack
- Runtime: Node.js 24+, TypeScript 5.x (strict mode), pnpm 11 workspaces
- HTTP: Hono (
@hono/node-server) - Validation: Zod v4 (single source of truth for helio.yaml schema)
- YAML: js-yaml
- Input matchers: custom dot-path (
$.field) conditions witheq/neq/gt/gte/lt/lte/contains/regexoperators — no JSONPath library - Globbing: picomatch (tool-name patterns); safe-regex2 (validates operator-supplied
regexconditions to reject catastrophic backtracking) - Database: better-sqlite3 (SQLite)
- File watching: chokidar
- CLI: Commander.js
- Dashboard: React 19, React Router 7, Vite, Tailwind CSS 4, Recharts 3
- Slack: @slack/web-api
- Testing: Vitest (JS), pytest (Python SDK)
- Linting: ESLint + Prettier
- Build: tsup (proxy), Vite (dashboard)
- CI: GitHub Actions; Husky pre-commit hooks (secret scan + lint/format/typecheck + docs-drift check)
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.
- 24d ago Changed · +1 lines · +103 tokens per session 8f988d347382
- 29d ago Changed · +67 tokens per session d0f440fc999e
- 1mo ago Changed · +1 lines · +184 tokens per session ce81622bb7d2
- 1mo ago Changed · +3 lines · +127 tokens per session 1d038ecddc0b
- 1mo ago Changed · +1 lines · +141 tokens per session 797c5dccb62d
- 1mo ago Changed · +1 lines · +163 tokens per session 2c0f36054e1b
- 1mo ago Changed · +45 tokens per session 6178686a8975
- 2mo ago First seen · 333 lines · 5,481 tokens per session scan A 0eeaa4716806
helio AGENTS.md is an instructions file published in the GitHub repository gethelio/helio (14 stars, last pushed 3d ago), licensed Apache-2.0. It adds 6,311 tokens to every session, about $0.0252 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).
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.