feat: add elicitation callback support to MCP servers #2373

yamanahlawat · 2025-07-30T02:21:51Z

Step 1 of Support MCP elicitations both in client and server #2330

pydantic_ai_slim/pydantic_ai/mcp.py

tests/test_mcp_elicitation.py

pydantic_ai_slim/pydantic_ai/mcp.py

…tests

hyperlint-ai · 2025-07-31T17:39:25Z

PR Change Summary

Added support for elicitation callbacks in MCP servers, allowing user interaction during tool execution.

Introduced elicitation callback functionality for user input during tool execution.
Provided examples for setting up elicitation in MCP server and client.
Included practical use case for file deletion confirmation.

Modified Files

docs/mcp/client.md

How can I customize these reviews?

Check out the Hyperlint AI Reviewer docs for more information on how to customize the review.

If you just want to ignore it on this PR, you can add the hyperlint-ignore label to the PR. Future changes won't trigger a Hyperlint review.

Note specifically for link checks, we only check the first 30 links in a file and we cache the results for several hours (for instance, if you just added a page, you might experience this). Our recommendation is to add hyperlint-ignore to the PR to ignore the link check for this PR.

DouweM

@yamanahlawat The code and test looks good but the examples are wrong 😅

docs/mcp/client.md

DouweM

@yamanahlawat Still some issues with the examples, did you verify they actually work? They smell a bit AI generated to me with too little human oversight 😅 I realize this isn't the feature you were initially trying to implement, but unfortunately we can't get to that one until this feature it builds on is solid so I'd appreciate a bit more love for the examples here

docs/mcp/client.md

…rsion

yamanahlawat · 2025-08-02T09:52:15Z

@yamanahlawat Still some issues with the examples, did you verify they actually work? They smell a bit AI generated to me with too little human oversight 😅 I realize this isn't the feature you were initially trying to implement, but unfortunately we can't get to that one until this feature it builds on is solid so I'd appreciate a bit more love for the examples here

Guilty as charged. Thanks for the feedback. Here is my updated love for the docs, let me know if any other changes are required.

yamanahlawat · 2025-08-02T09:52:36Z

DouweM · 2025-08-06T16:41:54Z

@Kludex Can you please review this as our resident MCP expert? I'm thinking it would be more proper to add our own types instead of directly using those from mcp.

…elicitation-callback

Kludex · 2025-08-08T10:21:25Z

@Kludex Can you please review this as our resident MCP expert? I'm thinking it would be more proper to add our own types instead of directly using those from mcp.

I think it would be easier if we use their types.

yamanahlawat · 2025-08-11T07:38:00Z

@DouweM Can we merge this? or i'll add the server logic in this PR?

Kludex · 2025-08-08T10:21:41Z

docs/mcp/client.md

@@ -100,7 +100,7 @@ Will display as follows:
 [`MCPServerSSE`][pydantic_ai.mcp.MCPServerSSE] connects over HTTP using the [HTTP + Server Sent Events transport](https://spec.modelcontextprotocol.io/specification/2024-11-05/basic/transports/#http-with-sse) to a server.

 !!! note
-    [`MCPServerSSE`][pydantic_ai.mcp.MCPServerSSE] requires an MCP server to be running and accepting HTTP connections before running the agent. Running the server is not managed by Pydantic AI.


You need to revert those changes.

Kludex · 2025-08-11T08:54:27Z

tests/mcp_server.py

+
+
+@mcp.tool()
+async def use_elicitation(ctx: Context[ServerSessionT, LifespanContextT, RequestT], question: str) -> str:


This is not the correct type.

It's probably this:

Suggested change

async def use_elicitation(ctx: Context[ServerSessionT, LifespanContextT, RequestT], question: str) -> str:

async def use_elicitation(ctx: Context[ServerSession, None], question: str) -> str:

Kludex · 2025-08-11T08:55:09Z

pydantic_ai_slim/pydantic_ai/mcp.py

+__all__ = (
+    'MCPServer',
+    'MCPServerStdio',
+    'MCPServerHTTP',
+    'MCPServerSSE',
+    'MCPServerStreamableHTTP',
+)


Revert please.

Kludex · 2025-08-11T08:57:12Z

docs/mcp/client.md

+if __name__ == '__main__':
+    mcp.run(transport='stdio')
+```
+


We need something written here.

Kludex · 2025-08-11T08:57:33Z

docs/mcp/client.md

+### Supported Schema Types
+
+MCP elicitation supports string, number, boolean, and enum types with flat object structures only. These limitations ensure reliable cross-client compatibility. See [supported schema types](https://modelcontextprotocol.io/specification/2025-06-18/client/elicitation#supported-schema-types) for details.


Is this needed?

feat: add elicitation callback support to MCP servers

1416d6c

yamanahlawat mentioned this pull request Jul 30, 2025

Added MCP elicitation support for tool injection in mcp-run-python #2258

Open

yamanahlawat added 2 commits July 30, 2025 08:00

chore: update MCP dependency to v1.12.2

0a71a30

test: improve MCP elicitation test coverage and type safety

9e9693e

DouweM requested changes Jul 30, 2025

View reviewed changes

pydantic_ai_slim/pydantic_ai/mcp.py Outdated Show resolved Hide resolved

tests/test_mcp_elicitation.py Outdated Show resolved Hide resolved

pydantic_ai_slim/pydantic_ai/mcp.py Show resolved Hide resolved

DouweM self-assigned this Jul 30, 2025

DouweM added the awaiting author revision label Jul 30, 2025

refactor: remove allow_elicitation field and improve MCP elicitation …

d4cea64

…tests

refactor: updated client mcp docs example

bb22ba7

yamanahlawat requested a review from DouweM July 31, 2025 18:28

DouweM requested changes Aug 1, 2025

View reviewed changes

docs/mcp/client.md Outdated Show resolved Hide resolved

docs/mcp/client.md Outdated Show resolved Hide resolved

docs/mcp/client.md Outdated Show resolved Hide resolved

yamanahlawat added 2 commits August 1, 2025 22:15

refactor: updated mcp clients documentation

1294ca5

fix: mcp client docs import

dfb2c27

yamanahlawat requested a review from DouweM August 1, 2025 17:21

DouweM requested changes Aug 1, 2025

View reviewed changes

docs/mcp/client.md Outdated Show resolved Hide resolved

docs/mcp/client.md Outdated Show resolved Hide resolved

docs/mcp/client.md Outdated Show resolved Hide resolved

docs/mcp/client.md Outdated Show resolved Hide resolved

docs/mcp/client.md Outdated Show resolved Hide resolved

refactor: updated the mcp client docs example, chore - updated mcp ve…

5087505

…rsion

yamanahlawat requested a review from DouweM August 2, 2025 09:52

DouweM assigned Kludex Aug 6, 2025

Merge branch 'main' of github.com:pydantic/pydantic-ai into features/…

4f1af20

…elicitation-callback

Kludex reviewed Aug 11, 2025

View reviewed changes

docs/mcp/client.md

if __name__ == '__main__':

mcp.run(transport='stdio')

```

Copy link

Member

Kludex Aug 11, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

We need something written here.

Kludex reviewed Aug 11, 2025

View reviewed changes



		@mcp.tool()
		async def use_elicitation(ctx: Context[ServerSessionT, LifespanContextT, RequestT], question: str) -> str:

		### Supported Schema Types

		MCP elicitation supports string, number, boolean, and enum types with flat object structures only. These limitations ensure reliable cross-client compatibility. See [supported schema types](https://modelcontextprotocol.io/specification/2025-06-18/client/elicitation#supported-schema-types) for details.

feat: add elicitation callback support to MCP servers #2373

Are you sure you want to change the base?

feat: add elicitation callback support to MCP servers #2373

Uh oh!

Conversation

yamanahlawat commented Jul 30, 2025 • edited by DouweM Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

hyperlint-ai bot commented Jul 31, 2025

PR Change Summary

Uh oh!

DouweM left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

DouweM left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

yamanahlawat commented Aug 2, 2025

Uh oh!

yamanahlawat commented Aug 2, 2025

Uh oh!

DouweM commented Aug 6, 2025

Uh oh!

Kludex commented Aug 8, 2025

Uh oh!

yamanahlawat commented Aug 11, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Kludex Aug 8, 2025

Choose a reason for hiding this comment

Uh oh!

Kludex Aug 11, 2025

Choose a reason for hiding this comment

Uh oh!

Kludex Aug 11, 2025

Choose a reason for hiding this comment

Uh oh!

Kludex Aug 11, 2025

Choose a reason for hiding this comment

Uh oh!

Kludex Aug 11, 2025

Choose a reason for hiding this comment

Uh oh!

Uh oh!

yamanahlawat commented Jul 30, 2025 •

edited by DouweM

Loading

yamanahlawat commented Aug 11, 2025 •

edited

Loading