Add Cursor client attribution - #2
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Explain why Fly-Client-Interactive is sent as "false" and why it must not be removed: it is the instrumentation sentinel, so a missing or unparseable value classifies the request as uninstrumented and discards Fly-Client-Agent along with it. Both the removal and the "correction" to true are silent failures that zero out attribution. Add a plain-language attribution disclosure to the plugin README, which is what Marketplace users actually read. Bump both manifests to 0.2.0 so the header change is distributed.
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Summary
Fly-Client-Interactiveisfalseand must not be removed or "corrected"User impact
The Fly backend can distinguish calls initiated through the Cursor plugin without changing authentication, authorization, or tool behavior.
Header contract
Verified against
superfly/client-signals:Fly-Client-Agent: cursormatches the canonical tag inspec/markers.json, so it classifies asagent="cursor"rather than theotherfallback.Fly-Client-Interactive: falseis the instrumentation sentinel required byspec/request-metrics.md. Without it the request classifies as{"operator": "uninstrumented", "agent": "none"}and the agent header is discarded.falseis correct becauseInteractivemeans "stdout attached to a terminal," not "a human is present."Fly-Client-ParentandFly-Client-CIare omitted deliberately — the spec statesParentmust not affect classification, and false-valuedCIis omitted rather than sent.Testing
Verification still required before merge
Config validation only proves the JSON parses — it does not prove Cursor sends the headers. Cursor has a confirmed, unfixed bug where
headersinmcp.jsonare ignored when the server exposes RFC 9728 OAuth discovery, whichhttps://sprites.dev/.well-known/oauth-protected-resourcedoes. The reports center onAuthorization, so it is unclear whether unrelated headers are also stripped.This fails silently in both directions — no client warning, no server rejection, just permanently zero attributed traffic. Confirm end-to-end by installing this branch, invoking one MCP tool, and reading
fly_client_signals_requests_total:operator="agent", agent="cursor"— headers landed, good to merge.operator="uninstrumented", agent="none"— Cursor stripped them; this PR is a no-op and needs a client-side fix or server-side inference instead.Deployment
No backend deployment is required. The updated plugin configuration takes effect when the plugin update is distributed.