Blast Radius

Blast radius

Review the requested change beyond its immediate callers. Produce supported risks, cleared concerns, and executable evidence for the critical assumptions. Requires repository reading and search; execution is needed for runtime proof.

1. Anchor the change. Identify the requested diff or proposed behavior, its base revision, and any working-tree edits included. Read surrounding code and tests until you can describe the behavioral change, including implicit changes to defaults, ordering, ownership, or error handling.
2. Trace hidden contracts. Follow relevant consumers across serialization, storage, language boundaries, feature flags, and lifecycle timing. Inspect the actual pinned dependency source and local patches when behavior depends on a library. Caller search alone does not establish coverage. Name the important paths you inspected and any unavailable consumers.
3. Name the safety assumptions. Identify the few facts on which the change's safety depends. For each, describe a concrete failure if it is false. Keep plausible, consequential risks; resolve speculative concerns by reading or running the relevant path rather than padding the report.
4. Challenge those assumptions. Use the cheapest meaningful executable check that calls the real implementation. Where useful, contrast the base and changed revisions against the same expected behavior. Confirm failures are caused by the suspected behavior, not setup. Run in an isolated scratch location when a probe mutates state; retain its commands, result, and evidence path. A source argument is still useful when execution is unavailable, but label it unproven at runtime. Code changes require an implementation request.
5. Deliver the assessment. Explain the change, each critical assumption and its evidence, confirmed risks with file/line references and failure conditions, concerns checked and cleared, and the smallest remaining pre-merge check. Distinguish source-supported, executed, and observed-in-app evidence. Report missing coverage explicitly; a clean local probe does not prove all consumers safe.

For a broad review, use independent reviewers only when available and authorized. Verify their findings against the actual code and evidence. A single agent can complete this workflow; repeated passes are not independent review.