aether-mcp

Development rules for AETHER_02, a Rust MCP server for administering Linux systems through tools. They define safety requirements, build checks, and the available administration areas.

In plain words
What is it for?
Use them when developing AETHER_02 tools for processes, files, packages, services, networking, users, security, hardware, or system automation.
Why use it?
They keep standard output available for MCP communication, require safeguards for destructive or sensitive operations, and enforce validation and code-quality checks. This lowers the chance of unsafe system changes or broken releases.

Cursor rule for Cursor

Install

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.

agentmods
npx agentmods add rules/foursecondfivefour/aether-linux-mcp-server/aether-mcp
Clone the repo
git clone --depth 1 https://github.com/foursecondfivefour/aether-linux-mcp-server

Made for: Cursor.

Per session 262 This file is loaded in full into every session.
When invoked 262 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00262 $0.00262
Opus 5 $0.00131 $0.00131
Sonnet 5 $0.00052 $0.00052
Haiku 4.5 $0.00026 $0.00026

Measured yesterday against content hash 95998ef06ac8, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

aether-mcp 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 yesterday.

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.

.cursor/rules/aether-mcp.mdc · 32 lines

What it actually says

AETHER_02 Cursor Rules

AETHER_02 is a Rust MCP server for Linux administration over stdio. Keep stdout reserved for MCP JSON-RPC. All logs, diagnostics, and audit messages must go to stderr.

Safety

  • Do not use shell interpolation (bash -c, sh -c, system()) for tool actions.
  • Use direct syscalls via nix/libc or std::process::Command with explicit argv.
  • Require force: true for destructive changes.
  • Require .env feature gates for kernel, mount, partition, ptrace, BPF, namespace, or token/capability operations.
  • Canonicalize paths and validate parameters at the tool boundary.

Build Checks

Run before submitting changes:

cargo fmt --check
cargo clippy -- -D warnings
cargo test
cargo build --release

Tool Map

process_control, file_system, package_manager, system_config, service_manager, gui_automation, system_info, network_manager, user_management, security_audit, hardware_control, system_automation.

Changes

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.

  1. yesterday First seen · 32 lines · 262 tokens per session scan A 95998ef06ac8

Subscribe to this mod's changes

aether-mcp is a cursor rule published in the GitHub repository foursecondfivefour/aether-linux-mcp-server (0 stars, last pushed 2mo ago), licensed MIT. It adds 262 tokens to every session, about $0.0013 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 2026-08-31.