[galuszkm]

Description

strands-agents allows mcp<2.2, so a fresh resolve now lands on mcp 2.x.
Our code still spoke the 1.x API and broke there.
This patches us onto 2.x rather than changing anything of our own:

• mcp floor raised to >=2.0.0 to match what resolution already picks; upper bound stays with strands-agents.
• httpx → httpx2 in the streamable-http headers path (mcp 2.x swapped its HTTP stack, so streamable_http_client wants an httpx2.AsyncClient).
• examples/06_mcp server ported FastMCP → MCPServer and reduced to stdio, which is the only mode its config uses.
• Folded the three single-use private helpers in mcp/client.py into create_mcp_client; no behavior change.

Related Issues

N/A

Type of Change

• Bug fix

YAML / API Impact

No schema or public API change. create_mcp_client keeps its signature; transport_options.http_client now takes an httpx2.AsyncClient instead of an httpx.AsyncClient, which follows mcp 2.x and is the only user-visible detail.

Testing

How have you tested the change?

• I ran uv run just check (lint + type check)
• I ran uv run just test for overall testing
• I added or updated tests that prove my fix is effective or my feature works
• I verified existing examples in examples/ still work

Checklist

• I have read the CONTRIBUTING document
• I have updated the documentation accordingly
• My changes generate no new warnings
• Any dependent changes have been merged and published