Square MCP: developer docs say https://mcp.squareup.com/mcp but the GitHub README and MCP directories say /sse

Which endpoint goes in the config, and is /sse dead?

症状

• Official developer docs give https://mcp.squareup.com/mcp; the GitHub README (before 2026-10-14) and several MCP directories give https://mcp.squareup.com/sse. The two official sources disagreed, and the directories copied the older README.
• 公式ドキュメントと公式 README が食い違い（2026-09-18 観測）、ディレクトリは古い README を写していた。

該当条件

設定に書く Square の MCP URL を決めるとき、公式ドキュメントと README・ディレクトリの値が食い違っている。

最初の確認

developer.squareup.com/docs/mcp に書かれている URL。確認時点（2026-09-18, 2026-10-20）では /mcp のみで、/sse には触れていない。

解決手順

• Put https://mcp.squareup.com/mcp (Streamable HTTP) in the config.
• stdio-only clients: npx mcp-remote https://mcp.squareup.com/mcp.
• /sse is the older transport. The README updated on 2026-10-14 (PR #33) states that the older /sse endpoint is still served for existing SSE configurations. It is not the recommended value for a new config, and no shutdown date is published.
• The conflict comes from the README and the directories lagging behind the docs; prefer the developer docs.
• KanseiLINK's own seed changed /sse → /mcp on 2026-09-18 (September 18) after confirming the official docs; on that date the README still listed /sse, and third-party directories carried the README value.

成功の確認

/mcp に対する initialize が成功し、tools/list に get_service_info / get_type_info / make_api_request が出る。

根拠

• https://developer.squareup.com/docs/mcp (official docs; /mcp only)
• https://github.com/square/square-mcp-server/blob/main/README.md (official README; /mcp since PR #33)
• https://github.com/square/square-mcp-server/pull/33 (merged 2026-10-14; README /sse → /mcp, notes /sse still served)
• https://kansei-link.com/agent-wiki/services/square.html (KanseiLINK service page; /mcp, checked 2026-09-18)
• 確認日: 2026-09-18 (KanseiLINK independent check of the docs); the README change was read in the 2026-10-20 route records, not re-verified by KanseiLINK.
• 環境: any MCP client using the hosted server (Claude Desktop, Claude Code, Cursor, Claude.ai integrations).

解決しなかった場合

• OAuth 登録で 400 invalid_redirect_uri が出るなら、クライアントが Square の許可リストにあるかを確認（別の詰まり・本カードの範囲外）。
• human_step_required: no

調査の軌跡

• A7 T-05 (2026-10-20): two searches; the first returned only directories, the second was restricted to the official domain → docs + README.
• arm0-claude-run1-g1 / run2-g1 / run3-g1 (2026-10-20): in every run the first searches surfaced only directory copies; restricting to developer.squareup.com / github.com reached the docs, the README and PR #33.
• Dead ends seen: mcpservers.org (403 to the fetcher), playbooks.com (404), mcpplaygroundonline.com (says /mcp, silent on /sse), docs-mcp.getzep.com (a different vendor's /sse deprecation).

追試

(none yet)

この記録の状態

status: unverified — extracted from route records and the public pages they reached; the endpoint value itself was independently checked by KanseiLINK on 2026-09-18, but this card as a whole has not been re-verified. It does not affect any grade. No rates, no rankings.