secrets-env-only

secrets-env-only is a cursor rule for Cursor from AlphaBitCore/nexus-gateway. It costs 0 tokens per session (393 once invoked), scanned A, original, Apache-2.0.

A coding rule that keeps real secrets, such as passwords, tokens, and encryption keys, in environment variables instead of committed YAML files. An environment variable is a value supplied to a program when it runs.

In plain words
What is it for?
Use it when adding authentication settings, database credentials, encryption keys, or other secret configuration to a service.
Why use it?
It reduces the chance of credentials being stored in source control and makes shared secrets easier to check across services.

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/alphabitcore/nexus-gateway/secrets-env-only
Clone the repo
git clone --depth 1 https://github.com/AlphaBitCore/nexus-gateway

Made for: Cursor.

Wrote 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.

agentmods badge for secrets-env-only

README.md
[![agentmods](https://agentmods.dev/badge/rules/alphabitcore/nexus-gateway/secrets-env-only.svg)](https://agentmods.dev/rules/alphabitcore/nexus-gateway/secrets-env-only)
Your own site
<a href="https://agentmods.dev/rules/alphabitcore/nexus-gateway/secrets-env-only"><img src="https://agentmods.dev/badge/rules/alphabitcore/nexus-gateway/secrets-env-only.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 393 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 $0.00393
Opus 5 $0.00000 $0.00197
Sonnet 5 $0.00000 $0.00079
Haiku 4.5 $0.00000 $0.00039

Measured 4d ago against content hash 7ea196741471, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

secrets-env-only 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 4d 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/secrets-env-only.mdc · 44 lines

What it actually says

Secrets are env-only — never YAML (binding)

No secret field may appear in any YAML committed to the repo. Secrets ride env variables, documented in .env.example at repo root, read at runtime via os.Getenv / bootenv.

Forbidden in committed YAML

  • Auth tokens.
  • HMAC keys.
  • Credential-encryption keys / passphrases / salts.
  • Internal-service tokens.
  • DB passwords.
  • Any field named secret / password / token / key carrying a real value.

Allowed in committed YAML

  • Service shape (ports, timeouts, feature flags, log levels, allowlists).
  • Non-secret tunings.
  • Empty/placeholder fields that get overridden by env at boot — but every such field has a corresponding env var in .env.example.

Cross-service shared secrets

When two services share a secret (e.g., inter-service HMAC), tag both env-var lines in .env.example with [MUST MATCH]. Drift between consumers is the most common source of inter-service 403s.

Adding a new secret YAML field

Forbidden by default. Requires explicit user approval in chat with a stated reason (real reason — "it's easier" is not valid).

Operational detail

  • Local: repo-root .env loaded via bootenv.
  • Prod: systemd EnvironmentFile= or K8s Secret.
  • Full operational rules: docs/developers/workflow/local-dev-debugging.md "Environment variables" — that section carries the same binding force as this file.

Skipping this rule requires explicit user approval in chat.

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. 4d ago First seen · 44 lines · 0 tokens per session scan A 7ea196741471

Subscribe to this mod's changes

secrets-env-only is a cursor rule published in the GitHub repository AlphaBitCore/nexus-gateway (22 stars, last pushed 8d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 393 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 2026-08-30.