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MCP Swift SDK

open source / Overall score: 2.8

The official Swift SDK for the Model Context Protocol. Client and server across tools, resources and prompts, with stdio, Streamable HTTP and in-process transports, implemented against an earlier specification revision rather than the current one.

Swift Package Manager resolves from the repository, so there is no download registry to cite and adoption is read from stars. The repository was last pushed 2026-05-07, the stalest of the official SDK family, which is consistent with its targeting the 2025-11-25 revision rather than the current one.

Openness

5 high confidence

5.0

license: Apache-2.0(OSI
source: public(the SDK, its transports and its examples)
self-host: yes(a library you build against)
core features withheld: no — nothing withheld from the published tree

Open source under the Model Context Protocol project's dual transition licence, with the body cited because the classifier reports NOASSERTION over it.

https://api.github.com/repos/modelcontextprotocol/swift-sdk recorded 2026-09-17
Repository metadata: 1,491 stars, not archived, not a fork, last pushed 2026-05-07, description "The official Swift SDK for Model Context Protocol servers and clients."
https://raw.githubusercontent.com/modelcontextprotocol/swift-sdk/main/LICENSE recorded 2026-09-17
The LICENSE body, read rather than the classifier's label: it opens with the MCP project's licensing transition from MIT to Apache-2.0 and carries both texts, which is the shape GitHub's classifier cannot match and the reason the API reports NOASSERTION.

Adoption

2 low confidence

2.0

Swift Package Manager resolves packages straight from git, so no registry publishes a download count for this SDK, and GitHub stars are the only countable signal.

https://api.github.com/repos/modelcontextprotocol/swift-sdk recorded 2026-09-17
Repository metadata for modelcontextprotocol/swift-sdk: 1,491 stargazers.

Capability

4 high confidence

4.0

MCP Swift SDK implements both roles, the full primitive set and all three optional features - sampling, elicitation and roots - the fullest coverage of the family. Its README targets the 2025-11-25 revision rather than the current 2026-07-28 one, which is what keeps it from full credit.

https://raw.githubusercontent.com/modelcontextprotocol/swift-sdk/main/README.md recorded 2026-09-17
The README: "This Swift SDK implements both client and server components according to the 2025-11-25 (latest) version of the MCP specification." The transport table lists StdioTransport, HTTPClientTransport, StatelessHTTPServerTransport, StatefulHTTPServerTransport, InMemoryTransport and NetworkTransport, and Sampling, Elicitation and Roots each have their own documented sections.

Verified 2026-09-17