env-always-inherited

A coding rule for setting up a process's environment, which is the collection of settings and paths passed to programs it starts. It requires the child environment to keep the parent process's PATH, the list of folders used to find commands.

In plain words
What is it for?
Use it when creating sessions or launching subprocesses, especially when adding extra tool directories to PATH.
Why use it?
Leaving out PATH can make subprocesses fail to find ordinary commands or cause code that expects PATH to crash.

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/beardfaceguy/daimonos/env-always-inherited
Clone the repo
git clone --depth 1 https://github.com/beardfaceguy/daimonos

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 262 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00000 $0.00262
Opus 5 $0.00000 $0.00131
Sonnet 5 $0.00000 $0.00052
Haiku 4.5 $0.00000 $0.00026

Measured 2d ago against content hash 9a5b66aa8420, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

env-always-inherited 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 2d 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.

.cursor/rules/env-always-inherited.mdc · 42 lines

What it actually says

Always Inherit Parent Environment

When building a session's environment map, always include the parent process PATH — even when no extra directories are appended.

What went wrong

build_initial_env() only inserted PATH into the env map when extra tool directories were found. If no extras existed, PATH was absent entirely. This caused downstream code that called .expect("PATH should be set") to panic, and meant subprocesses wouldn't inherit PATH at all.

Rule

  1. Always start with the parent PATH as the baseline.
  2. Prepend extras if they exist.
  3. The result should always be set in the env map (unless PATH is genuinely empty, which is pathological).
// BAD: conditional PATH
if !extra.is_empty() {
    env.insert("PATH".into(), new_path);
}

// GOOD: always inherit
let path_val = if !extra.is_empty() {
    format!("{}:{}", extra.join(":"), parent_path)
} else {
    parent_path
};
if !path_val.is_empty() {
    env.insert("PATH".into(), path_val);
}
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. 2d ago First seen · 42 lines · 0 tokens per session scan A 9a5b66aa8420

Subscribe to this mod's changes

env-always-inherited is a cursor rule published in the GitHub repository beardfaceguy/daimonos (2 stars, last pushed 2d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 262 tokens. 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.