# MCP specification: 2025-03-26 revision published

> The Model Context Protocol published a new dated spec revision, 2025-03-26. The release note enumerates no changes and states that SDKs adopt new revisions at their own pace, with version negotiation covering the period where both revisions are live.

| | |
|---|---|
| **Tool** | MCP specification |
| **Version** | 2025-03-26 |
| **Kind** | spec_revision |
| **Published** | 2025-03-26 |
| **Observed** | 2026-08-11 |
| **Significance** | 5/5 |
| **Breaking** | no |
| **Categories** | api-change, docs |

## What changed


- New dated spec revision `2025-03-26` cut.
- Release note contains no list of changes.
- SDKs adopt on their own timelines; the prior revision remains in use for an undetermined period.
- Clients and servers negotiate versions for backwards and forwards compatibility.


## Sources

- [github_release](https://github.com/modelcontextprotocol/modelcontextprotocol/releases/tag/2025-03-26) — 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/2025-03-26
Entity: https://changelogs.info/mcp-spec
Event ID: `evt_2025-03-26_mcp-spec_2025-03-26`
Licence: event synthesis © changelogs.info, CC BY 4.0. Linked sources belong to their vendors.