Skip to content

As of 1.8.0, does the SDK fully support the 2025-03-26 MCP spec? #677

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom
Closed
lcfyi-stripe opened this issue May 9, 2025 · 0 comments
Closed

As of 1.8.0, does the SDK fully support the 2025-03-26 MCP spec? #677

lcfyi-stripe opened this issue May 9, 2025 · 0 comments

Comments

@lcfyi-stripe
Copy link

Version 1.8.0 brings in support for 2025-03-26's Streamable HTTP transport, but it doesn't seem to have 2025-03-26 listed as a supported version.

On initialization, the server's response is validated here:

python-sdk/src/mcp/client/session.py

Lines 145 to 149 in ed25167

if result.protocolVersion not in SUPPORTED_PROTOCOL_VERSIONS:
raise RuntimeError(
"Unsupported protocol version from the server: "
f"{result.protocolVersion}"
)

Where SUPPORTED_PROTOCOL_VERSION is defined here:

python-sdk/src/mcp/shared/version.py

Line 3 in ed25167

SUPPORTED_PROTOCOL_VERSIONS: tuple[int, str] = (1, LATEST_PROTOCOL_VERSION)

And, finally, LATEST_PROTOCOL_VERSION is here:

python-sdk/src/mcp/types.py

Line 32 in ed25167

LATEST_PROTOCOL_VERSION = "2024-11-05"

Which means that the SDK supports (1, 2024-11-05).

I haven't done a full diff of the changes in 2025-03-26 to determine if they're supported in the SDK, but the version negotiation phase of the spec means that this SDK will be unable to communicate with any server that only supports 2025-03-26.

Is this expected?
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
None yet
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
2 participants
@ihrpr @lcfyi-stripe