# MCP Python SDK v1.27.2

- Product: MCP Python SDK (https://whatsnew.fyi/product/mcp-python-sdk)
- Vendor: Anthropic
- Date: 2026-05-29
- Version: v1.27.2
- Original notes: https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.27.2
- Permalink: https://whatsnew.fyi/product/mcp-python-sdk/releases/v1.27.2

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **added** — Add subject and claims to AccessToken
- **changed** — Bind transport sessions to the authenticated principal
- **changed** — Scope experimental tasks to the session that created them

##### What's Changed
* [v1.x] ci: deploy docs to py.sdk.modelcontextprotocol.io via Pages artifact by @maxisbey in https://github.com/modelcontextprotocol/python-sdk/pull/2635
* [v1.x] Add subject and claims to AccessToken by @maxisbey in https://github.com/modelcontextprotocol/python-sdk/pull/2690
* [v1.x] Bind transport sessions to the authenticated principal by @maxisbey in https://github.com/modelcontextprotocol/python-sdk/pull/2719
* [v1.x] Scope experimental tasks to the session that created them by @maxisbey in https://github.com/modelcontextprotocol/python-sdk/pull/2720


**Full Changelog**: https://github.com/modelcontextprotocol/python-sdk/compare/v1.27.1...v1.27.2