Characterizing Network Centralization and Observability in the Remote MCP Ecosystem
A measurement study of 179 remote MCP servers finds heavy infrastructure concentration (HHI 0.736) and a security-observability tradeoff in platform OAuth.
The paper introduces a three-tier observability framework (catalog metadata, passive compliance signals, live vulnerability analysis) applied to a stratified sample of 179 remote Model Context Protocol (MCP) endpoints from two public registries. The Herfindahl-Hirschman Index over ASN distribution is 0.736, well above the 0.25 high-concentration threshold, and 95% of commercial PaaS-hosted servers enforce gateway-level OAuth 2.1 with PKCE. Authentication correlates strongly with hosting platform choice rather than operator configuration, creating a security-observability tradeoff that constrains automated scanning for tool-poisoning vectors without prior credentials.
- HHI of 0.736 over ASN distribution shows heavy concentration in remote MCP hosting.
- 95% of commercial PaaS-hosted MCP servers enforce gateway-level OAuth 2.1 with PKCE.
- Authentication is strongly determined by hosting platform choice, not operator configuration.
- Platform-level security limits automated tool-poisoning scanning without prior credentials.
Full article189 words · extracted from arxiv.org · click to collapse
The Model Context Protocol (MCP) has emerged as the dominant interface for connecting autonomous agents to external data sources and execution environments. The ecosystem's transition from local process execution to remote Streamable HTTP deployments introduces unmeasured architectural and security constraints at scale. This paper presents a three-tier observability framework comprising catalog metadata (O_0), passive compliance signals (O_1), and live vulnerability analysis (O_2), applied to empirically characterize the public MCP server ecosystem. Evaluation of a stratified sample of 179 remote endpoints across two primary public registries reveals significant infrastructural consolidation. The Herfindahl-Hirschman Index (HHI) computed over the Autonomous System Number (ASN) distribution yields a value of 0.736, well above the 0.25 threshold for a highly concentrated market. Analysis further indicates that server authentication is strongly correlated with hosting platform choice rather than individual operator configuration, with 95\% of commercial PaaS-hosted servers enforcing gateway-level OAuth 2.1 with PKCE. The empirical results identify a Security-Observability Tradeoff observed in the current ecosystem: the platform-level authentication mechanisms that secure the majority of servers simultaneously limit automated vulnerability scanning capabilities, constraining the ability of AI gateway operators to assess tool-poisoning vectors without prior credential provisioning.
Text extracted automatically; images, tables and formatting may be missing. Original: https://arxiv.org/abs/2609.19100