# MCP specification: 2025-06-18 revision published

> The Model Context Protocol published a new dated spec revision, 2025-06-18. The release note itself lists no changes — it points to a separate changelog page — and warns that SDKs will move to this revision on their own schedules, so clients and servers will be running mixed spec versions and relying on the protocol's version negotiation for compatibility.

| | |
|---|---|
| **Tool** | MCP specification |
| **Version** | 2025-06-18 |
| **Kind** | spec_revision |
| **Published** | 2025-06-18 |
| **Observed** | 2026-08-11 |
| **Significance** | 5/5 |
| **Breaking** | no |
| **Categories** | api-change, docs |

## What changed


- New dated spec revision `2025-06-18` cut.
- Concrete changes are not in the release note; they live in the linked `2025-06-18` changelog on modelcontextprotocol.io.
- SDK adoption is explicitly staggered — the prior revision stays in use indefinitely.
- Cross-version interop is handled by the spec's client/server version negotiation (backwards and forwards compatible).


## Sources

- [github_release](https://github.com/modelcontextprotocol/modelcontextprotocol/releases/tag/2025-06-18) — retrieved 2026-08-11

## Community

_No curated reactions recorded. Facts and community takes are kept in separate layers
and never blended._

---
Canonical: https://changelogs.info/mcp-spec/2025-06-18
Entity: https://changelogs.info/mcp-spec
Event ID: `evt_2025-06-18_mcp-spec_2025-06-18`
Licence: event synthesis © changelogs.info, CC BY 4.0. Linked sources belong to their vendors.