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Impact analysis example

What breaks when you change Prisma (packages/client)?

Real arc impact output on Prisma (packages/client) — same structure as the homepage demo. Know blast radius before you merge.

Project: Prisma (packages/client) · Score: 87.1/100 (Healthy architecture) · 166 modules · 390 edges

Engineering decision simulation

Validation procedure 01 · merge vs. hold before output

Before arc impact

You plan a change to a high fan-in module in Prisma (packages/client). Would you merge without knowing blast radius?

Typical answer: hold — need dependency context.

After arc impact

Structured output below: score, hotspots, corridors, and high-risk modules — same field schema as the homepage proof.

Decision: confirm hold, narrow change, or inspect paths first.

Published as part of the validation record. Run locally: arc impact <file-you-are-changing>

Architectural Risk Map

Where risk accumulates by control surface — drill down Surface → Substrate → Mechanism → Evidence.

See control surfaces →

Dependency evidence

Architecture visualization

Diagrams are generated from ArcSight analysis data. Dependency graph and risk map show key modules; subsystem view shows high-level structure.

Dependency graph
Dependency graph for this codebase
Subsystem architecture
Subsystem architecture for this codebase
Risk map
Risk map for this codebase

Architecture score & metrics

Score: 87.1/100 · Stability: 24/100 · Status: healthy · Confidence: 100%

  • Dependency cycles: 31
  • Duplicate authorities: 5

Modules to inspect

One row per module. Fan-in is direct dependents. Blast radius is downstream modules reachable from that file.

Fan-in, direct dependents
  • src/runtime/core/types/exported/JsApi16 dependents
  • src/runtime/core/errorRendering/base12 dependents
  • src/runtime/core/engines/common/Engine9 dependents
  • src/runtime/core/engines/common/types/Transaction8 dependents
  • src/runtime/core/types/exported/Utils7 dependents
  • src/runtime/core/types/exported/Public6 dependents
  • src/runtime/core/types/exported/TypedSql6 dependents
  • src/runtime/core/engines/common/types/Events5 dependents
Blast radius, downstream modules
  • src/runtime/core/engines/common/types/Transaction47 modules
  • src/runtime/core/engines/common/Engine45 modules
  • src/runtime/core/types/exported/Utils42 modules
  • src/runtime/core/types/exported/Public42 modules
  • src/runtime/core/types/exported/Result42 modules
  • src/runtime/core/errorRendering/base39 modules
  • src/runtime/core/types/exported/JsApi38 modules
  • src/runtime/core/types/exported/TypedSql37 modules
ModuleFan-inBlastRisk
src/runtime/core/engines/common/types/Transaction847MEDIUM
src/runtime/core/engines/common/Engine945MEDIUM
src/runtime/core/types/exported/Utils742CRITICAL
src/runtime/core/types/exported/Public642CRITICAL
src/runtime/core/types/exported/Result442CRITICAL
src/runtime/core/errorRendering/base1239CRITICAL
src/runtime/core/types/exported/JsApi1638CRITICAL
src/runtime/core/types/exported/TypedSql637CRITICAL
src/runtime/core/engines/common/types/Events5MEDIUM
src/runtime/core/engines/common/types/QueryEngine4MEDIUM
src/runtime/core/engines/common/types/RequestError2MEDIUM

Architectural gravity centers

  • src/runtime/core/errorRendering/base— concentrates too many responsibilities
  • src/runtime/core/errorRendering/base— shared utility hub
  • src/runtime/core/types/exported/JsApi— concentrates too many responsibilities
  • src/runtime/core/types/exported/JsApi— shared utility hub
  • src/runtime/core/engines— concentrates too many responsibilities

CLI workflow

Scan → Fix → Finish → Watch. Nothing else required.

  • arc scanFind issues
  • arc fixApply fixes
  • arc finishResolve remaining
  • arc watchKeep clean

More commands (explain, impact, guard…) →

Key takeaways

  • •Architecture score 87.1/100 indicates a healthy structure with room to reduce cycles and violations.
  • •Structural scan reports dependency cycles — inspect impact paths before refactors that cross module boundaries.
  • •High fan-in modules are change-risk zones; run arc explain <path> before refactoring.
  • •Run the full workflow (analyze, hotspots, explain, impact, snapshot, drift) in your repo for deterministic architecture insights.

Run ArcSight on your repo

Install the CLI and run analyze, then hotspots and explain for the same workflow.

npm install -g arcsight
arc analyze
Install ArcSight →

This case study is generated from ArcSight analysis data. View short analysis. View all analyses