feat: add streaming methods for elicitation and sampling by LucaButBoring · Pull Request #1210 · modelcontextprotocol/typescript-sdk

LucaButBoring · 2025-12-01T23:34:15Z

Following #1041, this adds streaming methods for elicitation and sampling to simplify usage with Tasks.

Motivation and Context

Introduces a consistent way to use Tasks with elicitation and sampling just like we have with tool calls.

How Has This Been Tested?

New unit tests and example tool.

Breaking Changes

N/A

Types of changes

Bug fix (non-breaking change which fixes an issue)
New feature (non-breaking change which adds functionality)
Breaking change (fix or feature that would cause existing functionality to change)
Documentation update

Checklist

I have read the MCP Documentation
My code follows the repository's style guidelines
New and existing tests pass locally
I have added appropriate error handling
I have added or updated documentation as needed

Additional context

pkg-pr-new · 2025-12-01T23:35:02Z

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commit: 79904ec

LucaButBoring · 2025-12-02T00:20:51Z

Doing some manual testing on this, converted back to draft temporarily

LucaButBoring · 2025-12-02T00:39:14Z

Validated with new example tool.

…ript-sdk into feat/elicitation-sampling-streaming

changeset-bot · 2025-12-22T21:48:41Z

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Latest commit: 79904ec

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…ript-sdk into LucaButBoring-feat/elicitation-sampling-streaming # Conflicts: # examples/client/src/simpleStreamableHttp.ts

cliffhall · 2026-02-07T16:53:31Z

@LucaButBoring could you resolve the conflicts on this PR? Hoping to get it merged soon.

…ript-sdk into feat/elicitation-sampling-streaming

- Replace schema-based setRequestHandler with string methods - Update context API from extra.taskStore to extra.task?.store - Add CreateTaskResult to ResultTypeMap for elicitation/create sampling/createMessage

LucaButBoring · 2026-02-08T02:07:34Z

@cliffhall updated 👍

KKonstantinov · 2026-02-08T20:41:07Z

packages/server/src/experimental/tasks/server.ts

+        type ServerWithCapabilities = {
+            getClientCapabilities(): { elicitation?: { form?: boolean; url?: boolean } } | undefined;
+        };
+        const clientCapabilities = (this._server as unknown as ServerWithCapabilities).getClientCapabilities();


Hi, could we achieve this without the as unknown? It's something we're actively trying to avoid. Is there something not matching on the ClientCapabilities.elicitation that we need to fix here? (them not being a boolean but an object | undefined)? Would rather fix that than have a proprietary casting here, basically forfeiting the type system fully for it

The checks bellow would pass even if elicitation.form or elicitation.url were objects and not boolean, so is that really needed

Oh, I think that was due to other type inference failures around _server at the time this was originally written which are no longer applicable, I'm doing a scrub for this again.

FWIW the hard casts are needed around getTask and getTaskResult still either way, and that won't be addressed until #1449 is merged.

Alright, updated - this cast and the similar ones in sampling are no longer needed and have been removed.

LucaButBoring force-pushed the feat/elicitation-sampling-streaming branch 3 times, most recently from f8755d8 to 7520307 Compare December 1, 2025 23:52

feat: add streaming methods for elicitation and createMessage

4ed61b6

LucaButBoring force-pushed the feat/elicitation-sampling-streaming branch from 7520307 to 4ed61b6 Compare December 1, 2025 23:58

LucaButBoring marked this pull request as ready for review December 2, 2025 00:04

LucaButBoring requested a review from a team as a code owner December 2, 2025 00:04

LucaButBoring marked this pull request as draft December 2, 2025 00:20

chore: add elicitRequestStream example for validation

d41bcf8

LucaButBoring marked this pull request as ready for review December 2, 2025 00:39

LucaButBoring and others added 4 commits December 2, 2025 09:41

Merge branch 'main' of https://github.com/modelcontextprotocol/typesc…

26ebf24

…ript-sdk into feat/elicitation-sampling-streaming

Merge branch 'main' into feat/elicitation-sampling-streaming

2a2709a

Merge branch 'main' of https://github.com/modelcontextprotocol/typesc…

ca06490

…ript-sdk into feat/elicitation-sampling-streaming

Merge branch 'main' of https://github.com/modelcontextprotocol/typesc…

771f101

…ript-sdk into feat/elicitation-sampling-streaming

LucaButBoring force-pushed the feat/elicitation-sampling-streaming branch from ba50e0a to 771f101 Compare December 8, 2025 23:21

felixweinberger self-requested a review December 9, 2025 14:53

Merge branch 'main' of https://github.com/modelcontextprotocol/typesc…

01f864b

…ript-sdk into feat/elicitation-sampling-streaming

LucaButBoring added 3 commits December 22, 2025 14:56

chore: update elicitation/sampling streaming for v2

9943196

Merge branch 'main' of https://github.com/modelcontextprotocol/typesc…

f123dae

…ript-sdk into LucaButBoring-feat/elicitation-sampling-streaming # Conflicts: # examples/client/src/simpleStreamableHttp.ts

chore: fix lint errors

7c3e35d

cliffhall mentioned this pull request Feb 7, 2026

Manage display of "Run as Task" checkbox on Tools Tab modelcontextprotocol/inspector#1072

Open

15 tasks

cliffhall requested a review from KKonstantinov February 7, 2026 16:52

LucaButBoring added 3 commits February 7, 2026 17:02

Merge branch 'main' of https://github.com/modelcontextprotocol/typesc…

1fbb82c

…ript-sdk into feat/elicitation-sampling-streaming

fix: migrate handlers to string-based API after merge

d8d7686

- Replace schema-based setRequestHandler with string methods - Update context API from extra.taskStore to extra.task?.store - Add CreateTaskResult to ResultTypeMap for elicitation/create sampling/createMessage

fix(examples): update task context API in server example

e928f94

fix: lint import sorting and type imports

72f986e

KKonstantinov reviewed Feb 8, 2026

View reviewed changes

LucaButBoring added 2 commits February 8, 2026 13:55

chore: remove unneeded typecasts in elicitation/sampling streaming

56a28db

chore: rerun ci

79904ec

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feat: add streaming methods for elicitation and sampling#1210

feat: add streaming methods for elicitation and sampling#1210
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