Missing prompt-level _meta support in MCPServer.prompt() and Prompt model

[m3chanic]

Initial Checks

• I confirm that I'm using the newest release of my line (the latest 2.x, or the latest 1.x if I'm still on v1)
• I confirm that I searched for my issue in https://github.com/modelcontextprotocol/python-sdk/issues before opening this issue

Release line

2.x (current stable)

Description

Description

The 2026-07-28 specification defines the optional _meta field on the Prompt schema. While other decorators like @mcp.tool support meta and pass it down as _meta on serialization (e.g., in MCPServer.list_tools). The @mcp.prompt decorator and the high-level Prompt classes are missing support for meta.

Expected Behavior

Including meta on @mcp.prompt does not incur a type error and returns _meta for the prompt on list_prompts.

Example Code

from mcp.server.mcpserver import MCPServer

# ATTEMPTING TO USE METADATA ON PROMPTS
mcp = MCPServer("MetaTestServer")

# This currently raises a TypeError because meta is not a parameter in @mcp.prompt
@mcp.prompt(name="code_review",title="Code Review",
            description="Review code with specific metadata rules",
            meta={"strictness": "high"})
def review_code(code: str) -> str:
    return f"Review this: {code}"
   
# 2. EXPECTED BEHAVIOR
# If the decorator parameter was supported, list_prompts should return prompt with _meta:
# listed_prompts = await mcp.list_prompts()
# assert listed_prompts[0].meta == {"audience": "strictness": "high"}

Python & MCP Python SDK

- Python: 3.12+
- MCP Python SDK: 2.2.0

[siddharthgaur1]

I've opened #3479 for this. It was auto-closed because I'm not assigned here — the bot says it reopens on its own if a maintainer assigns me, so this is a request for that rather than anything needing action on the PR.

The wire type already supports it: on main, Prompt(name="x", _meta={"a": 1}).model_dump(by_alias=True) gives {'name': 'x', '_meta': {'a': 1}}. Only the high-level layer was missing it, so the change mirrors what @mcp.tool and @mcp.resource already do — a meta field on the high-level Prompt, a meta argument on Prompt.from_function and the decorator, and _meta=prompt.meta in list_prompts next to the existing _meta=info.meta in list_tools. Three source lines added, one changed.

Three tests next to the existing TestServerResourceMetadata, including your example verbatim; two of them fail on main with the TypeError from the issue. tests/server/mcpserver/: 633 passed, 1 skipped. ruff clean, and pyright on the changed files shows only the pre-existing asynccontextmanager deprecation at server.py:149.

I left get_prompt alone deliberately — it doesn't carry meta into the protocol response, mirroring read_resource, and this issue asks only about list_prompts. Happy to extend it if you'd rather have both.

Written with AI assistance (Claude Code); I reproduced the TypeError on main @ 9972c21 and read the tool/resource meta paths before mirroring them.