MCP spec 2026-07-28

Your MCP server is on a 12-month deprecation clock

The 2026-07-28 MCP specification ships breaking changes under a formal deprecation policy with a twelve-month minimum window. Every MCP server built on an earlier spec version now carries a migration obligation: new transport semantics, new authorization requirements, and client expectations that did not exist when it was written. You can rebuild it yourself, again, every time the spec moves. Or you can make it megamcp's problem permanently.

Migrate to megamcp See pricing

What changed

Four reasons your old server is now legacy

The 2026-07-28 revision was not a version bump. It restructured how MCP servers speak, authenticate, and confirm.

The stateless core replaced the session model

No initialize handshake, no session IDs. Every request is self-describing: protocol version in the MCP-Protocol-Version header, routing via Mcp-Method and Mcp-Name headers, capabilities in metadata, with server/discover as an optional capabilities call. Servers built around the old handshake and session lifecycle need structural rework, not a patch.

Authorization was hardened, and DCR is on the way out

Dynamic Client Registration is deprecated in favor of Client ID Metadata Documents (CIMD). RFC 9207 issuer validation is required and credentials are bound to their issuer. If your server's auth story was written before this spec, it is now legacy.

MRTR made human confirmation a protocol feature

Multi Round-Trip Requests let a tool pause with input_required, show the human a preview, and resume with their response. Clients increasingly expect it for write actions. Servers without it feel unsafe by comparison, because they are.

Legacy transports and features are deprecated

HTTP+SSE transport, Roots, Sampling, and protocol-level Logging are deprecated. The window to move off them is formal and finite.

The offer

Rebuild it once, as a maintained connector

Migration is not a port of your code. It is a promotion to infrastructure someone else maintains.

We re-express your server as a mapping

Your existing MCP server becomes a declarative mapping on our hardened Universal Adapter Engine. Same tools your team already uses, now running on the 2026-07-28 stateless core, with a compatibility mode that accepts recent earlier protocol versions while your clients roll forward.

You inherit the whole safety stack

MRTR confirm-mode writes, field constraints, scope-minimal auth, activity logging with redaction, and one-click pause. Things a hand-rolled server almost never has.

This is the last migration you do

Future spec revisions ship as engine-level upgrades that cover every connector at once. When the next breaking release lands, you read a changelog entry instead of scheduling an engineering project.

Migration offer

First month waived

Migrate an existing MCP server onto an annual plan and the first month is on us. Complex servers that resist automatic re-expression route to our done-for-you team at customconnectors.ai, so the migration path never dead-ends.

Start your migration

Stop maintaining protocol plumbing

Tell us what your server connects to. We will tell you the migration verdict before you pay anything.

Get your migration verdict