Hacktoberfest 2026: the issues maintainers tagged for October, open and beginner-friendly. Browse Hacktoberfest issues

AbstractClientTransport.checkState builds a broken error message

Open Beginner friendly
#1,083 1 comment 0 reactions 0 assignees View on GitHub

Maintainers usually reply within 1 day

@mvanhorn is already working on this.

Since Oct 20, 2026.

  • #1132 by @mvanhorn — open

Assessment

Difficulty
2/5
Estimated time
1-3 hours
Newbie friendliness
72/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Active
Tech stack
kotlin

Research direction

Start by locating AbstractClientTransport.checkState and read the surrounding transport API, then review issue #1038 because the payload leaves fixing the call versus removing the protected method open. Done means the exception text uses the actual state and the ABI/API decision is consistent with that review.

Written by the indexing model from the issue text.

Description

api bug P3

AbstractClientTransport.checkState calls check(actualState == expected) { lazyMessage }. That returns the lambda itself instead of lazyMessage(actualState), so the exception text is a function's toString(). Nothing in the SDK calls the method, but it is protected API in the ABI dump, so subclasses can.

Expected: fix the call, or remove the method while the public API is being reviewed (#1038).

Dominant language
Kotlin
Stars
1.5k
Forks
261
Avg merge
2d 9h
Merged PRs (30d)
36

Getting set up

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from modelcontextprotocol/kotlin-sdk

All issues in modelcontextprotocol/kotlin-sdk

Similar issues

More Kotlin issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.