What problem does it solve? It explains how Archimedes actually charges copy-trading subscribers per pipeline step — an in-process 402-requirements → sign → verify → settle protocol over Circle Developer-Controlled Wallets — so engineers do not misread it as a public HTTP payment endpoint or mishandle the PAYMENTS_DRY_RUN safety switch. ## Core Features & Use Cases - Protocol walkthrough with line numbers: Traces the three-step charge flow (middleware.require, EIP-712 create_payment_header, verify/settle) through payments.py and service.py, including idempotency claims and 24h spend-cap reservations. - Dry-run and testnet posture: Documents where PAYMENTS_DRY_RUN gates every fund-moving method, why both money switches default to safe, and the Arc testnet-only configuration. - Custody and settlement model: Clarifies the custodial-interim DCW fee seam versus the non-custodial vault architecture, plus the three-stage settlement sweep in settlement.py. - Use Case: When modifying backend/archimedes/marketplace/payments.py, use this Skill to confirm that charge() never raises, that dry-run gating lives at call sites, and that circlekit is now imported in two files, not one. ## Quick Start Ask the AI to explain how Archimedes charges a copy-trading subscriber per tick and where PAYMENTS_DRY_RUN is enforced.
