Still OS Agent-Economy Measurement Standard

Silent-Drift Rate (SDR)

The share of observed MCP tool-surface changes that carried no change to the server's advertised version string. A high SDR means a client that pinned a version and approved a tool list can have what it exposes change underneath it without ever being asked to re-approve.

Current measured value: 78.3% of observed MCP tool-surface changes carried no version change.

Drift-Hazard Rate (DHR)

The cumulative probability, at a given horizon, that an audited MCP server's installed code has moved while the approval artifact an auditor would check still matches. The rating factor an AI-supply-chain underwriter prices on.

Current measured value: By 30 days, 9.16% of audited MCP servers have had their installed code move while the approval artifact still matches.

Counterparty Survival at 30 days (CS30)

The probability that a paid x402 service an agent could have started paying is still listed 30 days later, as a Kaplan-Meier survival estimate over a dated daily census. Its complement is the 30-day delisting incidence a dependent agent budgets failover against.

Current measured value: By 30 days, 74.56% of paid x402 services an agent could have started paying are no longer listed.

Operator Concentration (OC)

The gap between the x402 economy's listing count and its real operator count, measured by resolving listed resources to distinct payout wallets - the hardest-to-fake identity in the system - and reporting the share of operators running a single host and the top operators' share of all host-to-wallet links.

Current measured value: 34,391 listed x402 resources resolve to 3,268 hosts and 2,509 payout wallets; 84.5% of wallets run a single host and one collects for 296.