MCP Dev Summit North America

MCP standardized how agents connect to tools and context, but enterprise deployments need control between the model and the data. Today, MCP lacks a standard way to apply these controls, leading to a fragmented landscape of bespoke sidecars and proxies that shifts the M×N integration problem from the data layer to the middleware layer.
This session is a Protocol-in-Depth walkthrough of SEP-1763 (Interceptors), which proposes a protocol-native framework to intercept, validate, and transform messages across the MCP lifecycle, elevating middleware to a first-class capability alongside core MCP concepts. We will cover the concrete protocol semantics implementers need to align on: capability negotiation, hook points and invocation models, deterministic ordering/composition, enforcement semantics, error handling and observability.
We motivate the proposal with Bloomberg’s production experience in adopting interceptors to build agents in a regulated financial environment, sharing lessons on what must be standardized for interoperability. To ground the design, we map the proposed semantics to AWS Bedrock AgentCore Gateway Interceptors and OpenAI Guardrails’ staged validation guidance.