changelog

A project rule for keeping CHANGELOG.md, the file that records user-visible changes between software releases, up to date.

In plain words
What is it for?
Use it when changing JavaScript exports, function signatures, errors, defaults, or other library behavior, while skipping purely internal or tooling changes.
Why use it?
It prevents public API changes and behavior changes from being released without notes for users and developers.

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/simular-ai/simulang-js/changelog
Clone the repo
git clone --depth 1 https://github.com/simular-ai/simulang-js

Made for: Cursor.

Per session 421 This file is loaded in full into every session.
When invoked 421 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 $0.00421 $0.00421
Opus 5 $0.00211 $0.00211
Sonnet 5 $0.00084 $0.00084
Haiku 4.5 $0.00042 $0.00042

Measured 2d ago against content hash 8628106a2a8b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

changelog 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/changelog.mdc · 35 lines

What it actually says

Changelog maintenance

CHANGELOG.md is the release notes source for @simular-ai/simulang-js and the input that drives the semantic versioning bump on release (breaking → major, new API/behavior → minor, fixes only → patch). Keep it current whenever you change what consumers see.

Update the changelog when

  • Public exports change in index.d.ts, wrapped.d.ts, or wrapped.js (new, removed, or renamed symbols)
  • Method or function signatures, return types, or thrown errors change
  • Runtime semantics change (defaults, coordinate system, sync vs async, resource lifetime, platform quirks documented in JSDoc)
  • Breaking changes — mark clearly under Changed or Removed and call out migration steps

Add bullets under ## [Unreleased] using Keep a Changelog sections: Added, Changed, Deprecated, Removed, Fixed, Security.

Skip the changelog when

  • Changes are internal to Rust with no JS/API surface difference
  • CI, tooling, or dependency-only bumps with no behavior change
  • Tests, examples, or comments that only reflect existing behavior

On release

The version lifecycle script (scripts/stamp-changelog.mjs) renames [Unreleased] to the bumped version and date automatically — don't edit those headings by hand. Just make sure the [Unreleased] body accurately reflects what's about to ship before running npm version. See PUBLISH.md.

Style

  • Write for library consumers, not implementers — describe outcomes ("Instance.isRunning() polls process state") not file names
  • One concise bullet per user-visible change; group related API under one bullet when it ships together
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 · 35 lines · 421 tokens per session scan A 8628106a2a8b

Subscribe to this mod's changes

changelog is a cursor rule published in the GitHub repository simular-ai/simulang-js (2 stars, last pushed 5d ago), licensed MIT. It adds 421 tokens to every session, about $0.0021 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.