The Agent Utility Grid: Governed Machine-Payable Decision Intelligence for Autonomous AI Agents

Autonomous AI systems increasingly require external capabilities that are not economically or operationally sensible to bundle into a single model or runtime. Model Context Protocol (MCP) standardizes capability discovery and invocation, while x402 standardizes HTTP-native payment negotiation for machine actors. Those protocols solve important interoperability problems, but they do not by themselves determine how a paid tool should bound its claims, preserve the evidence supporting a decision, distinguish a payment challenge from realized revenue, or adapt its commercial surface without granting an autonomous controller open-ended economic authority. This preprint presents the Agent Utility Grid, a production architecture that combines native MCP discovery, x402 v2 payment gating, Base-mainnet USDC settlement, bounded technical decision products, SHA-256 evidence receipts, transaction-linked commercial accounting, and a constrained seller-side commercial controller. The paper describes this composition as a Governed Decision-Commerce Control Plane (GDCCP): an infrastructure layer in which discoverability, payment, execution, evidence, and commercial state remain coupled to one canonical authority path rather than diverging into independent trust surfaces. As of the 25 August 2026 evidence cutoff, the deployed service reports version 0.3.0, 16 implemented products, 11 active paid utilities, five demand-gated candidates, and a live controller whose most recently observed cycle completed over all 16 products with 32 observations, 16 decisions, and zero controller errors. The manuscript explicitly separates live endpoint evidence, repository-source evidence, operator-published release evidence, and proposed future work. It also states the receipt-system claim boundary: a matching SHA-256 digest establishes stored-evidence integrity, not independent truth or correctness. The central contribution is architectural rather than a priority claim. The paper does not claim invention of MCP, x402, stablecoin payments, paid MCP tools, agent marketplaces, or decision receipts as isolated primitives. It proposes a bounded seller-side systems pattern joining capability discovery, machine payment, evidence-bounded decision intelligence, receipt integrity, transaction-linked revenue admission, and constrained catalog adaptation. io.github.GabrielAllit1/salt19-agent-utility-grid