amendment-history

amendment-history is a skill for Claude Code from anthropics/claude-for-legal. It costs 84 tokens per session (2,517 once invoked), scanned A, original, Apache-2.0.

A workflow for comparing a base contract with all later amendments, which are documents that change parts of an agreement. It can summarize the contract's history or trace one clause to the wording that currently controls.

In plain words
What is it for?
Use it to review amendment history, find the current wording of a provision such as indemnity, or summarize changes across contract versions.
Why use it?
It removes the need to manually compare several versions to find the latest terms. It helps distinguish old language from the changes that now apply.

Skill for Claude Code ✓ vendor

Written for Claude Code: argument-hint in frontmatter. Also seen: reads .claude/ paths; mentions CLAUDE.md.

Part of the commercial-legal plugin — 9 skills, 3 agents shipped together

Good fit Use it to review amendment history, find the current wording of a provision such as indemnity, or summarize changes across contract versions.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/anthropics/claude-for-legal/amendment-history
About the project

Claude for Legal is a collection of AI agents, skills, and data connectors for legal work such as commercial, privacy, employment, litigation, regulatory, and intellectual-property matters. Lawyers and legal teams use it through Claude Cowork, Claude Code, or the Claude Managed Agents API, with attorney review required for every output. The catalogue entries are its workflow plugins, skills, agents, and connectors.

anthropics/claude-for-legal · 9,433 stars · on GitHub

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.

Any agent
npx skills add anthropics/claude-for-legal --skill amendment-history
Clone the repo
git clone --depth 1 https://github.com/anthropics/claude-for-legal

Made for: Claude Code.

Or install commercial-legal, the plugin that ships this one along with the rest of its 9 skills, 3 agents.

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 amendment-history

README.md
[![agentmods](https://agentmods.dev/badge/skills/anthropics/claude-for-legal/amendment-history/github.svg)](https://agentmods.dev/skills/anthropics/claude-for-legal/amendment-history)
Your own site
<a href="https://agentmods.dev/skills/anthropics/claude-for-legal/amendment-history"><img src="https://agentmods.dev/badge/skills/anthropics/claude-for-legal/amendment-history/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 amendment-history

Your own site · 80×15
<a href="https://agentmods.dev/skills/anthropics/claude-for-legal/amendment-history"><img src="https://agentmods.dev/badge/skills/anthropics/claude-for-legal/amendment-history.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 84 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,517 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. Third-party audits
  • Socket pass 13 May 2026
  • Snyk pass 13 May 2026
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 2 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Rogue Agent · line 56
    Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.
    Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
  • medium Excessive Agency · line 120
    Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.
    Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
How audits are shown
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 $0.00084 $0.02517
Opus 5 $0.00042 $0.01259
Sonnet 5 $0.00017 $0.00503
Haiku 4.5 $0.00008 $0.00252

Measured 13d ago against content hash 99ab56dec5bd, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

amendment-history 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 13d 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:

commercial-legal/skills/amendment-history/SKILL.md · 299 lines

How it starts

The opening of the file, as written. The whole thing — 299 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/amendment-history

Loads a base agreement and all amendments, then either summarizes what changed over time or traces a specific provision to its current controlling language.

Instructions

  1. Get the documents: From file upload, [CLM ID (coming soon)], or [repository link (coming soon)]. Accept multiple files in one invocation. If none provided, ask.

  2. Detect the mode by parsing the request per the mode detection rules below. If a provision name is clearly stated, go straight to Mode 2. If no provision is mentioned, run Mode 1. Ask only if genuinely ambiguous.

  3. Run the workflow below. Follow it fully.

  4. Offer follow-ups after output:

    • "Want me to trace another provision?"
    • "Want a full playbook review of the current agreement as amended?" (routes to vendor-agreement-review)
    • "Want a stakeholder summary of the key changes?" (routes to stakeholder-summary)

Examples

/commercial-legal:amendment-history acme-msa.pdf amendment-1.pdf amendment-2.pdf
/commercial-legal:amendment-history --provision indemnity
/commercial-legal:amendment-history
[paste agreement and amendment text]

Matter context

Matter context. Check ## Matter workspaces in the practice-level CLAUDE.md. If Enabled is (the default for in-house users), skip the rest of this paragraph — skills use practice-level context and the matter machinery is invisible. If enabled and there is no active matter, ask: "Which matter is this for? Run /commercial-legal:matter-workspace switch <slug> or say practice-level." Load the active matter's matter.md for matter-specific context and overrides. Write outputs to the matter folder at ~/.claude/plugins/config/claude-for-legal/commercial-legal/matters/<matter-slug>/. Never read another matter's files unless Cross-matter context is on.


Purpose

Contracts accumulate amendments. By the third amendment, nobody remembers what the original said or which version of a clause controls. This skill reads the base agreement and all amendments in chronological order and either summarizes what changed across the whole contract or traces a specific provision through every version to find the current controlling language.

Read the full file on GitHub · 299 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. 13d ago First seen · 299 lines · 84 tokens per session scan A 99ab56dec5bd

Subscribe to this mod's changes

amendment-history is a skill published in the GitHub repository anthropics/claude-for-legal (9,433 stars, last pushed 22d ago), licensed Apache-2.0. It adds 84 tokens to every session and 2,517 once invoked, about $0.0004 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 2026-08-30.

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