Blast Radius

Analyze the structural impact of current code changes using the knowledge graph.

Prerequisites

• Graph must be built first: run /graph-build if .code-graph/graph.db doesn't exist
• Requires Python 3.10+ with tree-sitter, tree-sitter-language-pack, networkx

Steps

1. Check graph exists — Verify .code-graph/graph.db exists. If not, suggest /graph-build.

2. Run blast-radius analysis via Bash:

   python .claude/scripts/code_graph blast-radius --json
   

3. Parse JSON output and present:

   • Changed files: List of modified files (auto-detected from git)
   • Changed nodes: Functions/classes directly modified
   • Impacted nodes: Functions/classes affected within 2 hops (callers, dependents, tests)
   • Impacted files: Additional files that may need attention
   • Truncation: If results were truncated, note total vs shown

4. Risk assessment based on blast radius size:

   • Low risk: <5 impacted nodes, changes well-contained
   • Medium risk: 5-20 impacted nodes, review callers carefully
   • High risk: >20 impacted nodes, consider splitting PR

5. Recommendations:

   • Flag untested changed functions
   • Suggest files to prioritize in review
   • Warn about inheritance/implementation relationship changes

Trace for Deep Impact Analysis

For impact beyond direct callers/importers, use the trace command to follow the full chain through implicit connections:

python .claude/scripts/code_graph trace <changed-file> --direction downstream --depth 3 --json

# File-level overview first (10-30x less noise), then drill into functions:
python .claude/scripts/code_graph trace <changed-file> --direction downstream --node-mode file --json

This reveals downstream impact through MESSAGE_BUS edges (cross-service event consumers), TRIGGERS_EVENT (entity event handlers), and other implicit relationships that blast-radius may not surface directly.

Additional Queries

For deeper investigation, run via Bash:

• python ... query callers_of <function> --json — who calls this function?
• python ... query tests_for <function> --json — what tests cover this?
• python ... query inheritors_of <class> --json — what inherits from this?
• python ... query importers_of <file> --json — who imports this file?