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Sweep 22 Sep 2026 · 17:19Z Build v2.1.280 501 read Stable v2.1.267 Latest v2.1.280 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
Claude Code v2.1.259 ·

MCP connect: caching/rejecting the /v1/mcp_servers discover projection

MCP connections can cache a discovery projection to skip a round trip, discarding and re-probing it if the server rejects it.

TierUnder the hoodhow much it should matter to you
Useful3my rating, 1 to 5
Signal4worth watching, 1 to 5
AreaMCPwhat it touches
KindInternal Changesin v2.1.259,
Under the hood No documentation found

MCP connections can cache a discovery projection to skip a round trip, discarding and re-probing it if the server rejects it.

For claude.ai-proxy MCP connections, the client can now cache and adopt a "discover projection" from /v1/mcp_servers, skipping the server/discover round trip on connect. If the upstream later rejects a request built from that cached projection, the client discards it for that connector, re-probes server/discover on a fresh transport, and logs a tengu_mcp_listing_prior_rejected event.

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Names in the bundletengu_mcp_listing_prior_rejected

See this entry in the whole of v2.1.259 →

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