What it is
Two telemetry events were allowlisted, one for rejected MCP tool listings and one comparing served model catalogs.
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.259.
Presence across releases
0The miner has never read a build containing this name. It is here because a changelog entry of ours names it, which is evidence that it existed and not evidence of which releases carried it. The inventory starts at v2.1.138 and everything older than that was never mined.
First cited
1The earliest release whose published evidence quoted tengu_mcp_listing_prior_rejected was v2.1.259, 2 Sep 2026. That is the oldest release this project wrote about it, so it is a floor on the name's age and not the release that introduced it. It is not a presence reading: which builds carried the name is the table above.
Gate readings
0No release here has a gate table behind it for this flag. Most published releases have none at all: the readings exist only for versions the pipeline captured flag state on.
Names beside it
Every feature flag in the inventory starting tengu_mcp, up to twelve of them.
tengu_mcp_auto_backgroundNo description from anybody. v2.1.212
tengu_mcp_cgroupOn Linux you can force MCP servers into their own memory cgroup with an environment variable. never mined
tengu_mcp_claudeai_eligibility_gateNo description from anybody. v2.1.212
tengu_mcp_claudeai_proxy_401MCP proxy 401 telemetry now sanitizes the error code before logging it never mined
tengu_mcp_cli_command_executedNo description from anybody. never mined
tengu_mcp_connect_timeout_retryMCP connect timeouts now respect the global timeout and get retried instead of failing. v2.1.227
tengu_mcp_degradedMCP events are forwarded for logging with identifying fields stripped, and skipped entirely if analytics are off. never mined
tengu_mcp_deleteMCP CLI commands now hash server names in telemetry instead of sending them raw. never mined
tengu_mcp_directory_bffNo description from anybody. v2.1.138
tengu_mcp_directory_visibilityNo description from anybody. v2.1.138
tengu_mcp_discover_projection_priorA new gate resolves MCP discovery projection to legacy-only, all or off, and defaults to off. v2.1.259
tengu_mcp_discovery_cacheThe /mcp view now counts cached servers separately so you can tell them from live connections. v2.1.221
Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the feature flag does. All feature flags.