npx skills add ...
npx skills add anthropics/claude-for-legal --skill amendment-history
npx skills add anthropics/claude-for-legal --skill amendment-history
Trace how a contract has changed across its base agreement and all amendments — either a summary of all changes over time, or a provision trace for a specific clause. Use when the user says "what changed in this contract over time", "show me the amendment history", "where's the latest [clause]", "how has [provision] evolved", or uploads multiple versions of an agreement.
Loads a base agreement and all amendments, then either summarizes what changed over time or traces a specific provision to its current controlling language.
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.
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.
Run the workflow below. Follow it fully.
Offer follow-ups after output:
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.
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.
Parse the user's request to determine which mode to run. Do not ask which mode unless the request is genuinely ambiguous.
Mode 1 — Summary (no specific provision mentioned) Trigger phrases: "what changed", "amendment history", "show me changes over time", "summarize amendments", "what does this contract look like now"
Mode 2 — Provision trace (specific clause or topic named) Trigger phrases: "where's the [clause]", "latest [provision]", "how did [term] change", "find the indemnity", "what does it say now about [topic]"
Common provision mappings:
If the term is ambiguous and maps to more than one provision, list the candidates and ask which one:
"I found [N] provisions related to [term] — [list them]. Which one?"
If the overall request is ambiguous between modes, ask one question:
"Summary of all changes across the contract, or trace a specific provision — like indemnity, liability, or termination?"
Accept documents from any of these sources:
[CLM integration coming soon] (if connected): Search by counterparty name or agreement title. Pull the base agreement and all amendments. Record metadata typically includes execution dates — use these to establish chronological order.
[Document repository integration coming soon] (if connected): Search by counterparty name or filename. Look for files matching patterns like "Amendment", "Addendum", "Amendment No. 1", "First Amendment", or numbered suffixes. Pull all matches and sort by file date or filename numbering.
Direct upload: User provides files directly. In most cases the ordering is self-explanatory from document titles (e.g., "Amendment No. 1", "Second Amendment", "Addendum A") or dates visible in the filename or document header — proceed without asking.
Only ask the user to confirm ordering if:
If ordering was inferred rather than confirmed, note confidence at the top of the output only where uncertain:
"Order inferred from document titles — one item I was less certain about: [specific document]. Confirm if this affects your review."
Ordering rules:
This skill reads the base agreement and amendments — often privileged or confidential in their own right, and typically used for privileged analysis. The output inherits the source's privilege and confidentiality status. Prepend the work-product header from ~/.claude/plugins/config/claude-for-legal/commercial-legal/CLAUDE.md ## Outputs to every output below, distribute only within the privilege circle, and store it where privileged materials live. Strip the header before any external delivery.
Read each document in chronological order. For each, extract:
Build a working index before producing output. Use it internally to drive the output — do not show it to the user.
Every finding must include an inline section reference so the reader can verify against the source document without searching:
"Termination for convenience (§12.3): Added. Customer may terminate on 90 days written notice with no fee after the initial term."
If a provision spans multiple sections or the section number changed across amendments, cite all references: "Indemnification (§9.1 base; §9.1 restated in Amendment 5)"
Show only what changed. Do not list amendments where the provision was untouched — skip them entirely.
If the provision was never amended after the base agreement:
"This provision has not been modified by any amendment. Original language controls. §[X.X], base agreement, [date]."
End with the next-steps decision tree per CLAUDE.md ## Outputs. Customize the options to what this skill just produced — the five default branches (draft the X, escalate, get more facts, watch and wait, something else) are a starting point, not a lock-in. The tree is the output; the lawyer picks.
~/.claude/plugins/config/claude-for-legal/commercial-legal/CLAUDE.md — that is the
vendor-agreement-review skill's job. This skill is purely historical.# Provision Trace: [Provision name]
## [Counterparty] — [Agreement type]
---
### Original — [Base agreement date], §[X.X]
> "[exact quote]"
*Plain English:* [one sentence]
---
### Amendment [N] — [date], §[X.X]
**Was:**
> "[exact quote of prior language]"
**Now:**
> "[exact quote of replacement language]"
*What changed:* [one sentence — practical effect on the parties]
---
[Only subsequent amendments that touched this provision appear here.
All others are omitted.]
---
## Current controlling language
**§[X.X] — [source document, date]**
> "[exact quote]"
*Plain English:* [one sentence]
---
## Watch items
[Flags, inconsistencies, open questions — with section references.
Common items to check: whether the provision is subject to or carved
out of the liability cap; whether the section number shifted across
amendments; whether the amendment language conflicts with another
provision.]