Code Review

I found 3 issues that need attention:

Issue 1: Missing Migration Documentation

File: src/mcp/shared/context.py

This is a breaking change that requires migration documentation.

According to CLAUDE.md:

When making breaking changes, document them in docs/migration.md. Include:

• What changed
• Why it changed
• How to migrate existing code

This PR changes the type signatures of RequestContext and Context classes:

• RequestContext changed from Generic[SessionT, LifespanContextT, RequestT] to Generic[SessionT]
• Context changed from Generic[ServerSessionT, LifespanContextT, RequestT] to Generic[LifespanContextT, RequestT]

Users with type annotations for tool/prompt/resource handlers or client callbacks will need to update their code:

• Server side: Context[ServerSession, AppContext] → Context[AppContext]
• Client side: RequestContext[ClientSession, None] → RequestContext[ClientSession]

Please add a section to docs/migration.md documenting this breaking change.

Issue 2: Missing Docstring for Public API

File: src/mcp/server/context.py (line 16)

The new public API class ServerRequestContext is missing a docstring.

According to CLAUDE.md:

Public APIs must have docstrings

Similar classes in the codebase have docstrings:

• RequestContext: "Common context for handling incoming requests."
• Context: Has extensive docstring explaining usage

Please add a docstring to ServerRequestContext explaining its purpose and usage. See the class definition here:

Issue 3: Incorrect Type Signature

File: tests/client/test_list_roots_callback.py (line 36)

The type signature Context[ServerSession] is incorrect after the refactor.

The Context class changed from Generic[ServerSessionT, LifespanContextT, RequestT] to Generic[LifespanContextT, RequestT]. The ServerSessionT parameter was removed.

Current (incorrect):

async def test_list_roots(context: Context[ServerSession], message: str):

The problem: ServerSession is now being used as LifespanContextT (the first type parameter), but ServerSession is a session type, not a lifespan context type. Since this test has no lifespan context, it should be:

async def test_list_roots(context: Context[None], message: str):

See the incorrect line here: