What problem does it solve? Web applications often break business invariants under concurrent requests — one-time tokens get redeemed twice, balances go negative, approvals execute multiple times. This Skill provides a controlled, evidence-gated methodology to verify atomicity of duplicate submissions, one-time tokens, inventory/balance operations, and approval/revocation flows without causing real financial, inventory, or availability impact. ## Core Features & Use Cases - Controlled Concurrency Experiments: Runs low-volume concurrent replicas of the same self-owned operation via hunter_auto_race or Burp/HTTP2 single-packet gates, escalating gradually with full request logging. - Invariant-First Oracle Design: Requires writing explicit invariants (token consumed once, balance never negative, idempotent request IDs) and only accepts server-side persisted state or audit logs as proof — repeated 200s, async delays, and UI artifacts are rejected as false positives. - Strict Safety Gates: Enforces authorization and scope checks, self-owned test accounts and rollback-capable data, and hard stop conditions (real charges, resource exhaustion, third-party notifications, missing rollback). - Use Case: During an authorized assessment of a checkout flow, verify whether a coupon redemption endpoint atomically consumes a one-time token by firing a small concurrent burst against your own test order, then confirming via server-side state and audit logs before rolling back. ## Quick Start Ask the agent to verify whether the coupon redemption endpoint on my authorized test account is atomic under concurrent requests, using rollback-capable test data only.
