1823aae891Co-authored-by: Matt <77928207+mattzcarey@users.noreply.github.com> Co-authored-by: Konstantin Konstantinov <KKonstantinov@users.noreply.github.com> Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
3 KiB
elicitation
Server requests user input. One factory, both protocol eras: elicitation works on both eras with different APIs — push-style on 2025, inputRequired on 2026; the protocol carries it differently but the user experience is the same.
| Mode | 2025-era (--legacy, push-style) |
2026-07-28 (multi-round-trip) |
|---|---|---|
form (register_user) |
await ctx.mcpReq.elicitInput({ mode: 'form', requestedSchema }) — the server pushes an elicitation/create request and awaits the answer in-line |
return inputRequired({ inputRequests: { form: inputRequired.elicit(...) } }) — the client collects the form and retries the same handler with the response attached |
url (link_account) |
await ctx.mcpReq.elicitInput({ mode: 'url', url, elicitationId }) + createElicitationCompletionNotifier(elicitationId) for the out-of-band notifications/elicitation/complete |
return inputRequired({ inputRequests: { auth: inputRequired.elicitUrl(...) } }) — no elicitationId / complete notification on this era |
url, throw (confirm_payment) |
throw new UrlElicitationRequiredError([...]) — the wire -32042; the client catches the typed error and reads .elicitations |
n/a — a throw on this era fails loudly with a steer to inputRequired.elicitUrl(...) |
plan_trip chains two form elicitations inside one tool call (destination → dates for that destination): two sequential ctx.mcpReq.elicitInput pushes on 2025, two inputRequired rounds with requestState carry-over on 2026. The register_user form schema includes an
enumNames field (display labels for the plan enum). For the secure requestState round-trip pattern see ../mrtr/.
Runs all four transport/era legs: server.ts inlines a sessionful NodeStreamableHTTPServerTransport arm for 2025 traffic (the same isLegacyRequest composition ../legacy-routing/ shows by hand), so push server→client requests reach the client over either transport.
pnpm --filter @mcp-examples/elicitation client # 2026-07-28 (inputRequired)
pnpm --filter @mcp-examples/elicitation client -- --legacy # 2025 (push-style)