On July 28, the Model Context Protocol (MCP) received its most substantial update to date. MCP 2026-07-28 deprecates the initialize handshake and session headers entirely. Protocol versions and capabilities now transmit on every request, a new server/discover method replaces handshake-time discovery, and three HTTP headers (MCP-Protocol-Version, Mcp-Method, Mcp-Name) allow infrastructure components to route and manage MCP traffic without opening the request body.
The specification has evolved into enterprise-grade architecture, explicitly incorporating gateways into its design.
The Brutor AI Gateway, which is the enforcement engine of the Brutor AI Control Plane, supports the new specification as of today. Below is an overview of its implementation and scope.
Dual-era compatibility
To prevent operational disruptions during protocol transitions, the gateway was updated using a dual-era serving model sanctioned by the 2026-07-28 specification:
- All existing clients and servers continue to function without modification. The legacy handshake process (initialize, Mcp-Session-Id, notifications/initialized) remains fully supported. MCP servers currently utilizing sticky sessions will continue to do so.
- Stateless clients function automatically. The plane’s internal MCP components (Virtual MCP, Agent Skills, Web Search) operate on a dual-era model: they respond to server/discover, accept per-request _meta, and append current cache metadata, while concurrently handling legacy handshakes on the same endpoints. Each response matches the dialect of the incoming request, allowing 2024-era and 2026-07-28 clients to query the same server without conflict. (These servers display a dual protocol badge in the Admin UI.)
- Upstream servers maintain native dialects. During capability discovery, the gateway attempts server/discover first and falls back to initialize, following the specification’s era-detection workflow, before logging each server’s negotiated protocol version and dialect. Consequently, stateless 2026-07-28 servers and legacy handshake servers can coexist within a single catalog.
Routing headers and security verification
The Mcp-Method and Mcp-Name headers allow load balancers and gateways to route MCP traffic without parsing JSON payloads. However, this introduces potential spoofing risks if a caller presents a benign tool name in the header while executing a restricted action in the payload.
Brutor addresses this vulnerability across all traffic and dialects by default: the gateway parses the payload for policy enforcement and auditing. Any request containing routing headers that contradict its payload is immediately rejected (HTTP 400, JSON-RPC -32020). Legacy clients that do not transmit these headers are unaffected; only mismatched requests fail validation.
This aligns with our approach: as new protocol features are introduced, the governance layer ensures they are secure and verified by default.
Roadmap: governed elicitation
The specification replaces server-initiated SSE requests with multi round-trip requests. When a server requires user input during execution, it returns an input_required response, prompting the client to re-issue the call with the required parameters. Because elicitation now uses standard request/response cycles, the gateway can inspect, govern, and audit user inputs. This functionality will be introduced in an upcoming release alongside the official Tasks extension for long-running agent workflows.
Configuration requirements
No configuration changes are required. Legacy behaviors remain fully intact, and stateless clients are processed automatically. Dialect discovery, dual-era serving, and header verification are enabled by default.
| Feature | Status |
|---|---|
| Legacy handshake clients and servers | Supported, unchanged, indefinitely |
| Header/body consistency enforcement | Enabled for all traffic |
| Per-server dialect discovery and recording | Enabled |
| Stateless serving (server/discover, _meta, cache metadata) | Active by default (dual-era, no configuration required) |
| Multi round-trip (governed elicitation), Tasks extension | In development |
Detailed technical specifications are available in the MCP reference documentation at docs.brutor.ai.
The Brutor AI Gateway serves as the enforcement engine for the Brutor AI Control Plane, providing routing, security, and governance for LLMs, MCP servers, and autonomous agents. Learn more here.
