Module proxy 

MCP Streamable HTTP reverse proxy.

Implements the Streamable HTTP transport (MCP spec 2025-11-25) as a reverse proxy that intercepts tool calls, evaluates policies, and forwards allowed requests to an upstream MCP server.

Re-exports

pub use call_chain::PrivilegeEscalationCheck;

pub use discovery::handle_transport_discovery;

pub use websocket::handle_ws_upgrade;

pub use websocket::WebSocketConfig;

Modules

call_chain

Session tracking, call chain management, and privilege escalation detection.

discovery

Transport discovery and negotiation endpoint.

gateway

MCP Gateway Router — multi-backend tool routing with health tracking (Phase 20).

origin

CSRF and DNS rebinding origin validation.

smart_fallback

Smart cross-transport fallback chain orchestrator (Phase 29).

trace_propagation

Trace context propagation for distributed tracing (Phase 28).

transport_health

Per-transport circuit breaker for cross-transport fallback (Phase 29).

websocket

WebSocket transport for MCP JSON-RPC messages (SEP-1288).

Structs

McpQueryParams

Query parameters for POST /mcp.

ProxyState

Shared state for the HTTP proxy handlers.

TrustedProxyContext

Per-request trust signal for forwarded-header handling.

Constants

X_UPSTREAM_AGENTS

OWASP ASI08: Header for tracking upstream agents in multi-hop MCP scenarios. Contains a JSON-encoded array of CallChainEntry objects from previous hops. This header is added by Vellaveto when forwarding requests downstream and read when receiving requests from upstream.

Functions

handle_mcp_delete

DELETE /mcp handler — session termination (MCP spec).

handle_mcp_get

GET /mcp handler for SSE stream initiation/resumption.

handle_mcp_post

Main POST /mcp handler.

handle_protected_resource_metadata

GET /.well-known/oauth-protected-resource handler (RFC 9728).

Type Aliases

HmacSha256

HMAC-SHA256 type alias for call chain signing (FIND-015).