inspector/pr-screenshots

x-mcp-header Tools tooling (#1632) — proof screenshots

End-to-end verification of the SEP-2243 x-mcp-header Tools tooling against a real modern (2026-07-28) HTTP test server (test-servers/configs/xmcpheader-modern-http.json on port 3120), driven in a real browser through the web client's remote-proxy transport.

Connected with Protocol Era = Modern. invalid_header_tool is dropped from tools/list by the SDK (its x-mcp-header annotation is invalid), so the Inspector re-lists the raw list and surfaces it struck-through under an "Excluded (SEP-2243)" divider — showing why a tool vanished rather than silently omitting it.

Hovering the excluded tool shows the exact scan reason: the header name "Bad Header" contains a space, so it is not a valid RFC 9110 token.

get_weather's detail panel shows the "Mirrored request headers (SEP-2243)" section: its city argument mirrors to Mcp-Param-City, with the note that the SDK omits Mcp-Param-* on the browser transport.

Calling a tool the server no longer recognizes rejects with -32602 (SDK v2) instead of an isError result, and renders as an "Unknown Tool" error panel with a targeted hint (reproduced by swapping the sessionless server to one without echo while the cached list still showed it).

-32602 is the generic Invalid params code, so a known tool rejected for bad arguments throws the same code as an unknown tool. The panel disambiguates from the message: a -32602 that does not name an unknown tool renders under "Invalid Parameters" (with a schema hint) rather than "Unknown Tool". Triggered live via the trigger_invalid_params tool, which returns a real -32602 JSON-RPC error whose message is not about a missing tool.

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Tasks extension era fork (#1631) — proof screenshots

End-to-end verification of the Tasks era fork against two real test servers (test-servers/configs/tasks-modern-http.json on port 3222 and tasks-legacy-http.json on 3223), driven in a real browser through the web client's remote-proxy transport.

Modern era (2026-07-28, io.modelcontextprotocol/tasks extension)

Connected with Protocol Era = Modern (MCP 2026-07-28). The Tasks tab appears in the monitoring sidebar because the io.modelcontextprotocol/tasks extension was negotiated (it is empty until a task runs).

Connected with Protocol Era = Modern (MCP 2026-07-28). The Tasks tab is gated on the negotiated io.modelcontextprotocol/tasks extension (not capabilities.tasks). Running modern_task with Run as task on issues a tools/call that returns a CreateTaskResult (resultType: "task"), then polls tasks/get (no tasks/list); the completed task inlines its result (no blocking tasks/result) — shown both in the Results panel and the Tasks card.

modern_input_task moves to input_required: the tasks/get response's inputRequests map (visible in the task's Full Task Object) carries an embedded elicitation/create, surfaced through the same pending-request modal the MRTR path uses — note the accurate wording "your answer is submitted via a tasks/update request (SEP-2663), not a retry". Answering it sends tasks/update with the inputResponses, and the next poll completes the task:

Legacy era (2025-11-25, contrast — unchanged)

Connected with Protocol Era = Legacy. The Tasks tab is gated on capabilities.tasks; simple_task is taskSupport: "required" so Run as task is forced on. The legacy flow uses tasks/list to populate the list, tasks/get to poll, and the blocking tasks/result to fetch the payload ({ "message": "Task completed: no message", "taskId": … }). Note the legacy-only Logs tab (this server advertises logging), absent from the modern monitor set.

Notes

• SDK v2 removed all tasks support and era-gates the tasks/* spec methods out of the 2026-07-28 era on both the client (outbound) and server (inbound), and its codec rejects a resultType: "task" result outright. So the Inspector drives the extension itself: the task-creation frame is rewritten at the transport into a CallToolResult carrying the handle (the true resultType: "task" frame is still logged to the Protocol/Network tabs), and tasks/get / tasks/update / tasks/cancel ride a raw-wire request channel that carries the full modern envelope and is consumed by the transport before the SDK Client sees it. The test server serves tasks/* from an Express interceptor ahead of the SDK handler (the SDK's modern leg would answer them -32601).
• On modern, task creation is server-directed (SEP-2663): the client declares the extension once and any tool may return a task, so the Tools screen offers Run as task for every tool on a modern connection (rather than gating on the legacy per-tool taskSupport).