How do I install the Change Impact Analyzer skill?

Run npx skillmds@latest add willianbs/change-impact-analyzer in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Change Impact Analyzer safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Change Impact Analyzer?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Change Impact Analyzer free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Change Impact Analyzer?

willianbs (@willianbs) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Change Impact Analyzer by willianbs

Name: Change Impact Analyzer
Author: willianbs

Change Impact Analyzer

Maps blast radius of a proposed change across services, APIs, data, and clients. Use before risky merges, migrations, or multi-service work. Emits IMPACT_REPORT. Never approves ship without naming affected consumers.

willianbs 3841856 2 files · 3.6 KB Updated Sep 17, 2026

File contents

Purpose

Quantify who and what a change breaks or touches so planning and QG can size risk correctly.

When to Use / When NOT to Use

Use when: cross-service changes, API/schema edits, shared library bumps, migrations, large refactors, “what will this break?”.

Do not use when: typo/docs-only; pure local private helper with no exports (lite one-liner OK).

Preconditions

Diff, PR, or proposed change description plus CONTEXT_PACK (or ability to search callers/contracts).

Inputs / Outputs

Inputs: change set / plan, CONTEXT_PACK, OpenAPI/proto/schema if present, TASK_GRAPH optional.

Outputs: IMPACT_REPORT

Upstream / Downstream

Upstream: delivery-planner, feature-implementer, api-contract-guardian, engineering-os.

Downstream: delivery-planner, test-strategy-designer, quality-gate, migration-surgeon, pr-generator.

Core Principles

Follow edges: imports, APIs, events, schemas, feature flags, config.
Name concrete consumers (services, packages, mobile/web).
Separate breaking vs compatible vs unknown.
Data/migration impact is first-class.
Unknown consumers → ProceedWithConditions or Block for public APIs.
Prefer evidence (grep, refs, contracts) over guessing.
Do not implement the change.

Process

Summarize the change intent.
Identify exported surfaces touched (HTTP, RPC, events, DB, packages).
Trace inbound/outbound dependents in-repo; note external unknowns.
Classify impact per consumer: None | Compatible | Breaking | Unknown.
Runtime/ops impact — deploy order, flags, dual-write, cache.
Test/rollout recommendations.
Decision for planner/QG.

Evidence Requirements

Cite paths, symbol names, contract files. Mark Unknown explicitly.

Stop Conditions / Failure Modes

Condition	Action
Public API change with Unknown consumers	Block or ProceedWithConditions + required discovery
Cannot access codebase	Refuse

Severity + Confidence

Breaking public contract without migration path → High/Critical.

Output Contract

## IMPACT_REPORT
Change summary: ...
Surfaces touched: ...
Consumers:
  - name, impact class, evidence
Deploy/order notes: ...
Unknowns: ...
Decision: Proceed | ProceedWithConditions | Revise | Block

Handoffs

api-contract-guardian, migration-surgeon, delivery-planner, test-strategy-designer, quality-gate.

Never

Never claim “no impact” without a search.
Never ignore versioning/compat windows for public APIs.
Never silently expand scope into implementing the change.

---name: change-impact-analyzerdescription: Maps blast radius of a proposed change across services, APIs, data, and clients. Use before risky merges, migrations, or multi-service work. Emits IMPACT_REPORT. Never approves ship without naming affected consumers.---# PurposeQuantify who and what a change breaks or touches so planning and QG can size risk correctly.# When to Use / When NOT to Use**Use when:** cross-service changes, API/schema edits, shared library bumps, migrations, large refactors, “what will this break?”.**Do not use when:** typo/docs-only; pure local private helper with no exports (lite one-liner OK).# PreconditionsDiff, PR, or proposed change description plus CONTEXT_PACK (or ability to search callers/contracts).# Inputs / Outputs**Inputs:** change set / plan, CONTEXT_PACK, OpenAPI/proto/schema if present, TASK_GRAPH optional.**Outputs:** `IMPACT_REPORT`# Upstream / Downstream**Upstream:** delivery-planner, feature-implementer, api-contract-guardian, engineering-os.**Downstream:** delivery-planner, test-strategy-designer, quality-gate, migration-surgeon, pr-generator.# Core Principles1. Follow edges: imports, APIs, events, schemas, feature flags, config.2. Name concrete consumers (services, packages, mobile/web).3. Separate breaking vs compatible vs unknown.4. Data/migration impact is first-class.5. Unknown consumers → ProceedWithConditions or Block for public APIs.6. Prefer evidence (grep, refs, contracts) over guessing.7. Do not implement the change.# Process1. Summarize the change intent.2. Identify exported surfaces touched (HTTP, RPC, events, DB, packages).3. Trace inbound/outbound dependents in-repo; note external unknowns.4. Classify impact per consumer: None | Compatible | Breaking | Unknown.5. Runtime/ops impact — deploy order, flags, dual-write, cache.6. Test/rollout recommendations.7. Decision for planner/QG.# Evidence RequirementsCite paths, symbol names, contract files. Mark Unknown explicitly.# Stop Conditions / Failure Modes| Condition | Action ||-----------|--------|| Public API change with Unknown consumers | Block or ProceedWithConditions + required discovery || Cannot access codebase | Refuse |# Severity + ConfidenceBreaking public contract without migration path → High/Critical.# Output Contract```## IMPACT_REPORTChange summary: ...Surfaces touched: ...Consumers: - name, impact class, evidenceDeploy/order notes: ...Unknowns: ...Decision: Proceed | ProceedWithConditions | Revise | Block```# Handoffs**api-contract-guardian**, **migration-surgeon**, **delivery-planner**, **test-strategy-designer**, **quality-gate**.# Never- Never claim “no impact” without a search.- Never ignore versioning/compat windows for public APIs.- Never silently expand scope into implementing the change.

Frequently asked questions