The Model Context Protocol working group published the 1.1 spec update this week. The headline change is streamable HTTP transport — a new connection mode that allows MCP servers to handle tool calls over standard HTTP request/response cycles instead of requiring a persistent SSE connection. This matters for serverless environments where long-lived connections are expensive or impossible.
AGNT's existing /mcp/sse endpoint continues to work unchanged under MCP 1.1. The spec is backward-compatible: clients that speak 1.0 SSE connect and operate exactly as before. The new streamable HTTP transport is additive — it does not replace SSE, it provides an alternative for environments that prefer stateless request/response patterns.
We are adding the streamable HTTP transport to AGNT's backend in the next release. The implementation is straightforward — the same tool handlers (search_venues, list_venues, confirm_booking) serve both transports. The routing layer inspects the client's declared transport preference during capability negotiation and dispatches accordingly.
The other notable 1.1 addition is tool annotations — optional metadata on each tool declaration that hints at side effects, idempotency, and estimated latency. AGNT's search_venues is annotated as read-only and idempotent. confirm_booking is annotated as write with side effects. These annotations help MCP clients make smarter decisions about retry behavior and caching without hardcoding per-tool logic.
For existing AGNT MCP integrations: no action required. Your current setup continues working. When the streamable HTTP transport ships, you will have the option to switch — useful if you are running in Lambda, Cloudflare Workers, or any environment where SSE connections are constrained.