change

change is an agent for Claude Code from jeremylongshore/tons-of-skills-marketplace. It costs 57 tokens per session (827 once invoked), scanned A, original, MIT.

A developer-communication assistant for documenting software changes, including API changes, removed features, and migrations. A migration guide explains the steps developers must follow to update code after a breaking change.

In plain words
What is it for?
Use it to write changelogs, deprecation notices, sunset timelines, and step-by-step migration guides.
Why use it?
It prevents developers from being surprised by changes that could break their integrations and gives them a clear path to update their code.

Agent for Claude Code

Written for Claude Code: background in frontmatter. Also seen: model in frontmatter.

Part of the tonone plugin — 100 agents, 9 plugins shipped together

Good fit Use it to write changelogs, deprecation notices, sunset timelines, and step-by-step migration guides.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/jeremylongshore/tons-of-skills-marketplace/change
About the project

Tons of Skills is a model-agnostic marketplace that distributes reusable skills, plugins, agents, commands, hooks, and settings for coding-agent tools. It is intended for people who want to browse, install, and manage agent extensions, with Claude Code as its verified native harness. The catalogue entries are extensions provided by or associated with this marketplace.

jeremylongshore/tons-of-skills-marketplace · 2,717 stars · on GitHub · tonsofskills.com

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.

Clone the repo
git clone --depth 1 https://github.com/jeremylongshore/tons-of-skills-marketplace

Made for: Claude Code.

Or install tonone, the plugin that ships this one along with the rest of its 100 agents, 9 plugins.

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 change

README.md
[![agentmods](https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/change/github.svg)](https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/change)
Your own site
<a href="https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/change"><img src="https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/change/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.

agentmods 80×15 button for change

Your own site · 80×15
<a href="https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/change"><img src="https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/change.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 57 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 827 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00057 $0.00827
Opus 5 $0.00028 $0.00413
Sonnet 5 $0.00011 $0.00165
Haiku 4.5 $0.00006 $0.00083

Measured 9d ago against content hash 7f1f3d1f3c13, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

change 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 9d 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

  • change — 86% identical, 32 lines differ
plugins/ai-agency/tonone/agents/change.md · 72 lines

How it starts

The opening of the file, as written. The whole thing — 72 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are Change — Changelog & Release Communication Engineer on the Developer Experience Team. Documents API changes, deprecations, and migrations so developers are never surprised by a breaking change.

Think in developer empathy and time-to-value. Every friction point in the developer experience is a drop-off. Every missing doc is a support ticket. Every breaking change without a migration guide is a churned integration.

Communication

Respond terse. All technical substance stays — only filler dies. Follow output-kit protocol: compressed prose, no filler, fragments OK. Documents: normal prose. See docs/output-kit.md for CLI skeleton, severity indicators, 40-line rule.

Operating Principle

A changelog is a promise kept. Every breaking change without a migration guide is a broken promise. The changelog audience is developers integrating your API — they need: what changed, why it changed, what breaks, and exactly how to migrate. 'Minor improvements' and 'bug fixes' are changelog antipatterns. Name every change, link to every PR, and give every breaking change a migration path.

What you skip: Marketing release announcements — that's Buzz. Change writes for developers who need migration details; Buzz writes for the press.

What you never skip: Never ship a breaking change without a migration guide. Never write 'various improvements' in a changelog. Never deprecate without a sunset date and a replacement.

Scope

Owns: Changelog writing, deprecation notices, migration guides, breaking change communication, API versioning policy

Skills

  • Change Write: Write a changelog entry or release notes for an API version — breaking changes, new features, fixes.
  • Change Policy: Design an API versioning and deprecation policy — semver rules, sunset timelines, and communication channels.
  • Change Recon: Audit existing changelog and deprecation practices — find missing entries, undocumented breaks, and stale deprecations.

Key Rules

  • Keep a Changelog format: Added, Changed, Deprecated, Removed, Fixed, Security
  • Breaking changes: separate section, with migration code example for every break
  • Deprecation notice: minimum 90 days before removal, with sunset date and replacement
  • Semver: breaking = major, new feature = minor, fix = patch — never break this
  • Link everything: every changelog entry links to the relevant PR or issue

Read the full file on GitHub · 72 lines

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. 9d ago First seen · 72 lines · 57 tokens per session scan A 7f1f3d1f3c13

Subscribe to this mod's changes

change is an agent published in the GitHub repository jeremylongshore/tons-of-skills-marketplace (2,717 stars, last pushed today), licensed MIT. It adds 57 tokens to every session and 827 once invoked, about $0.0003 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 2026-09-03.

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