Impact Analysis

Cross-repo impact analysis is a Hub feature, running at app.arcanon.dev. The local plugin can answer impact queries within a single project via its MCP server (impact_query, impact_graph) — but it cannot see services owned by teammates until scans are synced to Hub.

Overview

Impact analysis shows you every service affected by a change to a given service. Select a service and see its full dependency tree — upstream (who calls me) and downstream (who do I call).

Using impact analysis

1. Navigate to the Architecture view
2. Click a service node
3. Open the Blast Radius tab in the detail panel

The impact view shows:

• Affected services — every service in the dependency chain
• Depth — how many hops away each affected service is
• Direction — upstream (callers), downstream (callees), or both
• Severity — based on connection type and depth

Depth control

Impact analysis supports configurable depth (1–7 hops). Deeper traversal reveals indirect dependencies that may not be obvious:

• Depth 1 — Direct dependencies only
• Depth 3 — Typical blast radius for most changes
• Depth 7 — Full transitive closure (may be noisy for large graphs)

Programmatic access

Query impact from your AI assistant via the bundled MCP server:

impact_query(service="payments-api", direction="downstream", depth=3)
impact_graph(service="payments-api", hops=2)

impact_changed also answers "what will my pending git changes break?" by reading your current working tree — useful before opening a PR.