chore(deps): bump kotlin from 2.4.10 to 2.4.20 in /samples/simple-streamable-server (#996)

Bumps `kotlin` from 2.4.10 to 2.4.20.
Updates `org.jetbrains.kotlin.jvm` from 2.4.10 to 2.4.20
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a
href="https://github.com/JetBrains/kotlin/releases">org.jetbrains.kotlin.jvm's
releases</a>.</em></p>
<blockquote>
<h2>Kotlin 2.4.20</h2>
<h2>Changelog</h2>
<h3>Analysis API</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86546"><code>KT-86546</code></a>
Check suspicious when over ConeKotlinType in
ConeTypeCompatibilityChecker</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85418"><code>KT-85418</code></a>
Implement an API for accessing deserialized file annotations in Analysis
API</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-74448"><code>KT-74448</code></a>
K2. False positive MISSING_DEPENDENCY_SUPERCLASS in LinkedListTest.kt,
kotlinx.coroutines</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85856"><code>KT-85856</code></a>
containingSymbol of constructor property differs for local and non-local
classes</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-65417"><code>KT-65417</code></a>
K2 IDE: KTOR false positive expect-actual matching error on enum class
because of implicit clone() in non-JVM source sets</li>
</ul>
<h3>Analysis API. Code Compilation</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-76457"><code>KT-76457</code></a>
K2 IDE / KMP Debugger: KISEWA “Cannot compile a common source without a
JVM counterpart” on evaluating inline fun from common module inside
jvm</li>
</ul>
<h3>Analysis API. FIR</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-70552"><code>KT-70552</code></a>
No expects for actual</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-69727"><code>KT-69727</code></a>
K2 IDE. Wrong error in the editor on calling <code>clone</code> function
of actual enum instance in non-jvm platform</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-69726"><code>KT-69726</code></a>
FP errors on declaring <code>fun clone()</code> in actual enum in
not-jvm source-set</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86014"><code>KT-86014</code></a>
Types are broken after remove parameter through change signature</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86363"><code>KT-86363</code></a>
KotlinIllegalArgumentExceptionWithAttachments: No dangling modifier
found on companion blocks</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86147"><code>KT-86147</code></a>
Drop <code>kotlin.parallel.resolve.under.global.lock</code> registry
key</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85543"><code>KT-85543</code></a>
Avoid lazy resolve for the contracts phase if no constracts might be
resolved</li>
</ul>
<h3>Analysis API. Infrastructure</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-84914"><code>KT-84914</code></a>
Do not publish analysis-api-test-framework</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86986"><code>KT-86986</code></a>
<code>kotlin-compiler-common-for-ide</code> bundles unrelated Analysis
API modules</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86186"><code>KT-86186</code></a>
Analysis API: Codebase tests run twice in some analysis modules — pick a
single JUnit runner and migrate</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85360"><code>KT-85360</code></a>
Drop kotlin-compiler-testdata-for-ide artifact</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85585"><code>KT-85585</code></a>
Simplify the dependencies graph for the Analysis API modules</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85381"><code>KT-85381</code></a>
Remove tests for the FE10 implementation</li>
</ul>
<h3>Analysis API. Light Classes</h3>
<h4>New Features</h4>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-84645"><code>KT-84645</code></a>
Support resolving to companion block members &amp; extensions from Java
(light classes)</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-80775"><code>KT-80775</code></a>
Support PsiClass#getRecordComponents in light classes</li>
</ul>
<h4>Fixes</h4>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-57537"><code>KT-57537</code></a>
SLC: propagate default parameter value from (<code>@JvmOverloads</code>)
<code>expect</code> declarations to <code>actual</code>
declarations</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85040"><code>KT-85040</code></a>
[Analysis API] Improve Java / Kotlin interop in KMP projects</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-87301"><code>KT-87301</code></a>
SymbolLightAccessorMethod#isValid returns false for delegated
properties</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-87171"><code>KT-87171</code></a>
SLC: non-mapped Kotlin collection supertype is dropped from supertype
list</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-87250"><code>KT-87250</code></a>
JvmExposeBoxed: light classes shouldn't be autogenerated for private
declarations</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-70428"><code>KT-70428</code></a>
AA: good code is red when a Java class extends a Kotlin class
implementing MutableList by delegation</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-63568"><code>KT-63568</code></a>
Symbol Light Classes:
KtAnnotationApplicationWithArgumentsInfo.normalizedArguments() may work
incorrectly when psi is not set</li>
</ul>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a
href="https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md">org.jetbrains.kotlin.jvm's
changelog</a>.</em></p>
<blockquote>
<h2>2.4.20</h2>
<h3>Analysis API</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86546"><code>KT-86546</code></a>
Check suspicious when over ConeKotlinType in
ConeTypeCompatibilityChecker</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85418"><code>KT-85418</code></a>
Implement an API for accessing deserialized file annotations in Analysis
API</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-74448"><code>KT-74448</code></a>
K2. False positive MISSING_DEPENDENCY_SUPERCLASS in LinkedListTest.kt,
kotlinx.coroutines</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85856"><code>KT-85856</code></a>
containingSymbol of constructor property differs for local and non-local
classes</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-65417"><code>KT-65417</code></a>
K2 IDE: KTOR false positive expect-actual matching error on enum class
because of implicit clone() in non-JVM source sets</li>
</ul>
<h3>Analysis API. Code Compilation</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-76457"><code>KT-76457</code></a>
K2 IDE / KMP Debugger: KISEWA “Cannot compile a common source without a
JVM counterpart” on evaluating inline fun from common module inside
jvm</li>
</ul>
<h3>Analysis API. FIR</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-70552"><code>KT-70552</code></a>
No expects for actual</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-69727"><code>KT-69727</code></a>
K2 IDE. Wrong error in the editor on calling <code>clone</code> function
of actual enum instance in non-jvm platform</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-69726"><code>KT-69726</code></a>
FP errors on declaring <code>fun clone()</code> in actual enum in
not-jvm source-set</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86014"><code>KT-86014</code></a>
Types are broken after remove parameter through change signature</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86363"><code>KT-86363</code></a>
KotlinIllegalArgumentExceptionWithAttachments: No dangling modifier
found on companion blocks</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86147"><code>KT-86147</code></a>
Drop <code>kotlin.parallel.resolve.under.global.lock</code> registry
key</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85543"><code>KT-85543</code></a>
Avoid lazy resolve for the contracts phase if no constracts might be
resolved</li>
</ul>
<h3>Analysis API. Infrastructure</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-84914"><code>KT-84914</code></a>
Do not publish analysis-api-test-framework</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86986"><code>KT-86986</code></a>
<code>kotlin-compiler-common-for-ide</code> bundles unrelated Analysis
API modules</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86186"><code>KT-86186</code></a>
Analysis API: Codebase tests run twice in some analysis modules — pick a
single JUnit runner and migrate</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85360"><code>KT-85360</code></a>
Drop kotlin-compiler-testdata-for-ide artifact</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85585"><code>KT-85585</code></a>
Simplify the dependencies graph for the Analysis API modules</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85381"><code>KT-85381</code></a>
Remove tests for the FE10 implementation</li>
</ul>
<h3>Analysis API. Light Classes</h3>
<h4>New Features</h4>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-84645"><code>KT-84645</code></a>
Support resolving to companion block members &amp; extensions from Java
(light classes)</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-80775"><code>KT-80775</code></a>
Support PsiClass#getRecordComponents in light classes</li>
</ul>
<h4>Fixes</h4>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-57537"><code>KT-57537</code></a>
SLC: propagate default parameter value from (<code>@JvmOverloads</code>)
<code>expect</code> declarations to <code>actual</code>
declarations</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85040"><code>KT-85040</code></a>
[Analysis API] Improve Java / Kotlin interop in KMP projects</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-87301"><code>KT-87301</code></a>
SymbolLightAccessorMethod#isValid returns false for delegated
properties</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-87171"><code>KT-87171</code></a>
SLC: non-mapped Kotlin collection supertype is dropped from supertype
list</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-87250"><code>KT-87250</code></a>
JvmExposeBoxed: light classes shouldn't be autogenerated for private
declarations</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-70428"><code>KT-70428</code></a>
AA: good code is red when a Java class extends a Kotlin class
implementing MutableList by delegation</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-63568"><code>KT-63568</code></a>
Symbol Light Classes:
KtAnnotationApplicationWithArgumentsInfo.normalizedArguments() may work
incorrectly when psi is not set</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-36740"><code>KT-36740</code></a>
MPP: False-positive incompatible types in .java when using expect-class
returned by non-expect member from common when actual is actual
typealias</li>
</ul>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a
href="890ac1d94f"><code>890ac1d</code></a>
Add Changelog for 2.4.20-RC3</li>
<li><a
href="8860aed4ae"><code>8860aed</code></a>
🍒 [FIR] Fix suspend conversion when expected type is nullable (<a
href="https://redirect.github.com/JetBrains/kotlin/issues/7769">#7769</a>)</li>
<li><a
href="ab5bcd9428"><code>ab5bcd9</code></a>
Edit ChangeLog for 2.4.20-RC2</li>
<li><a
href="9464edc097"><code>9464edc</code></a>
Add ChangeLog for 2.4.20-RC2</li>
<li><a
href="0261e43b78"><code>0261e43</code></a>
Cherry-pick &quot;Fix <code>asBodyAndResultVar</code> call in
`visitInlinedLambdaInComposable...</li>
<li><a
href="0763513670"><code>0763513</code></a>
[box-tests] Workaround for klib compatibility tests (<a
href="https://redirect.github.com/JetBrains/kotlin/issues/7626">#7626</a>)</li>
<li><a
href="045aec6647"><code>045aec6</code></a>
[Wasm] Append scripts from webpack.config.d in the end of the file (<a
href="https://redirect.github.com/JetBrains/kotlin/issues/7615">#7615</a>)</li>
<li><a
href="cd7173bf0b"><code>cd7173b</code></a>
🍒 [2.4.20] [K/JS] Keep associated obj annotation only if getInstance
survives...</li>
<li><a
href="d36a2ffbcc"><code>d36a2ff</code></a>
CastsOptimizationPass: break aliases cycles (<a
href="https://redirect.github.com/JetBrains/kotlin/issues/7578">#7578</a>)</li>
<li><a
href="8664983b34"><code>8664983</code></a>
[CLI] Restore custom IC search scope creation</li>
<li>Additional commits viewable in <a
href="https://github.com/JetBrains/kotlin/compare/v2.4.10...v2.4.20">compare
view</a></li>
</ul>
</details>
<br />

Updates `org.jetbrains.kotlin.plugin.serialization` from 2.4.10 to
2.4.20
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a
href="https://github.com/JetBrains/kotlin/releases">org.jetbrains.kotlin.plugin.serialization's
releases</a>.</em></p>
<blockquote>
<h2>Kotlin 2.4.20</h2>
<h2>Changelog</h2>
<h3>Analysis API</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86546"><code>KT-86546</code></a>
Check suspicious when over ConeKotlinType in
ConeTypeCompatibilityChecker</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85418"><code>KT-85418</code></a>
Implement an API for accessing deserialized file annotations in Analysis
API</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-74448"><code>KT-74448</code></a>
K2. False positive MISSING_DEPENDENCY_SUPERCLASS in LinkedListTest.kt,
kotlinx.coroutines</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85856"><code>KT-85856</code></a>
containingSymbol of constructor property differs for local and non-local
classes</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-65417"><code>KT-65417</code></a>
K2 IDE: KTOR false positive expect-actual matching error on enum class
because of implicit clone() in non-JVM source sets</li>
</ul>
<h3>Analysis API. Code Compilation</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-76457"><code>KT-76457</code></a>
K2 IDE / KMP Debugger: KISEWA “Cannot compile a common source without a
JVM counterpart” on evaluating inline fun from common module inside
jvm</li>
</ul>
<h3>Analysis API. FIR</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-70552"><code>KT-70552</code></a>
No expects for actual</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-69727"><code>KT-69727</code></a>
K2 IDE. Wrong error in the editor on calling <code>clone</code> function
of actual enum instance in non-jvm platform</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-69726"><code>KT-69726</code></a>
FP errors on declaring <code>fun clone()</code> in actual enum in
not-jvm source-set</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86014"><code>KT-86014</code></a>
Types are broken after remove parameter through change signature</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86363"><code>KT-86363</code></a>
KotlinIllegalArgumentExceptionWithAttachments: No dangling modifier
found on companion blocks</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86147"><code>KT-86147</code></a>
Drop <code>kotlin.parallel.resolve.under.global.lock</code> registry
key</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85543"><code>KT-85543</code></a>
Avoid lazy resolve for the contracts phase if no constracts might be
resolved</li>
</ul>
<h3>Analysis API. Infrastructure</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-84914"><code>KT-84914</code></a>
Do not publish analysis-api-test-framework</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86986"><code>KT-86986</code></a>
<code>kotlin-compiler-common-for-ide</code> bundles unrelated Analysis
API modules</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86186"><code>KT-86186</code></a>
Analysis API: Codebase tests run twice in some analysis modules — pick a
single JUnit runner and migrate</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85360"><code>KT-85360</code></a>
Drop kotlin-compiler-testdata-for-ide artifact</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85585"><code>KT-85585</code></a>
Simplify the dependencies graph for the Analysis API modules</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85381"><code>KT-85381</code></a>
Remove tests for the FE10 implementation</li>
</ul>
<h3>Analysis API. Light Classes</h3>
<h4>New Features</h4>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-84645"><code>KT-84645</code></a>
Support resolving to companion block members &amp; extensions from Java
(light classes)</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-80775"><code>KT-80775</code></a>
Support PsiClass#getRecordComponents in light classes</li>
</ul>
<h4>Fixes</h4>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-57537"><code>KT-57537</code></a>
SLC: propagate default parameter value from (<code>@JvmOverloads</code>)
<code>expect</code> declarations to <code>actual</code>
declarations</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85040"><code>KT-85040</code></a>
[Analysis API] Improve Java / Kotlin interop in KMP projects</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-87301"><code>KT-87301</code></a>
SymbolLightAccessorMethod#isValid returns false for delegated
properties</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-87171"><code>KT-87171</code></a>
SLC: non-mapped Kotlin collection supertype is dropped from supertype
list</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-87250"><code>KT-87250</code></a>
JvmExposeBoxed: light classes shouldn't be autogenerated for private
declarations</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-70428"><code>KT-70428</code></a>
AA: good code is red when a Java class extends a Kotlin class
implementing MutableList by delegation</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-63568"><code>KT-63568</code></a>
Symbol Light Classes:
KtAnnotationApplicationWithArgumentsInfo.normalizedArguments() may work
incorrectly when psi is not set</li>
</ul>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a
href="https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md">org.jetbrains.kotlin.plugin.serialization's
changelog</a>.</em></p>
<blockquote>
<h2>2.4.20</h2>
<h3>Analysis API</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86546"><code>KT-86546</code></a>
Check suspicious when over ConeKotlinType in
ConeTypeCompatibilityChecker</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85418"><code>KT-85418</code></a>
Implement an API for accessing deserialized file annotations in Analysis
API</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-74448"><code>KT-74448</code></a>
K2. False positive MISSING_DEPENDENCY_SUPERCLASS in LinkedListTest.kt,
kotlinx.coroutines</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85856"><code>KT-85856</code></a>
containingSymbol of constructor property differs for local and non-local
classes</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-65417"><code>KT-65417</code></a>
K2 IDE: KTOR false positive expect-actual matching error on enum class
because of implicit clone() in non-JVM source sets</li>
</ul>
<h3>Analysis API. Code Compilation</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-76457"><code>KT-76457</code></a>
K2 IDE / KMP Debugger: KISEWA “Cannot compile a common source without a
JVM counterpart” on evaluating inline fun from common module inside
jvm</li>
</ul>
<h3>Analysis API. FIR</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-70552"><code>KT-70552</code></a>
No expects for actual</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-69727"><code>KT-69727</code></a>
K2 IDE. Wrong error in the editor on calling <code>clone</code> function
of actual enum instance in non-jvm platform</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-69726"><code>KT-69726</code></a>
FP errors on declaring <code>fun clone()</code> in actual enum in
not-jvm source-set</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86014"><code>KT-86014</code></a>
Types are broken after remove parameter through change signature</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86363"><code>KT-86363</code></a>
KotlinIllegalArgumentExceptionWithAttachments: No dangling modifier
found on companion blocks</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86147"><code>KT-86147</code></a>
Drop <code>kotlin.parallel.resolve.under.global.lock</code> registry
key</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85543"><code>KT-85543</code></a>
Avoid lazy resolve for the contracts phase if no constracts might be
resolved</li>
</ul>
<h3>Analysis API. Infrastructure</h3>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-84914"><code>KT-84914</code></a>
Do not publish analysis-api-test-framework</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86986"><code>KT-86986</code></a>
<code>kotlin-compiler-common-for-ide</code> bundles unrelated Analysis
API modules</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-86186"><code>KT-86186</code></a>
Analysis API: Codebase tests run twice in some analysis modules — pick a
single JUnit runner and migrate</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85360"><code>KT-85360</code></a>
Drop kotlin-compiler-testdata-for-ide artifact</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85585"><code>KT-85585</code></a>
Simplify the dependencies graph for the Analysis API modules</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85381"><code>KT-85381</code></a>
Remove tests for the FE10 implementation</li>
</ul>
<h3>Analysis API. Light Classes</h3>
<h4>New Features</h4>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-84645"><code>KT-84645</code></a>
Support resolving to companion block members &amp; extensions from Java
(light classes)</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-80775"><code>KT-80775</code></a>
Support PsiClass#getRecordComponents in light classes</li>
</ul>
<h4>Fixes</h4>
<ul>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-57537"><code>KT-57537</code></a>
SLC: propagate default parameter value from (<code>@JvmOverloads</code>)
<code>expect</code> declarations to <code>actual</code>
declarations</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-85040"><code>KT-85040</code></a>
[Analysis API] Improve Java / Kotlin interop in KMP projects</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-87301"><code>KT-87301</code></a>
SymbolLightAccessorMethod#isValid returns false for delegated
properties</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-87171"><code>KT-87171</code></a>
SLC: non-mapped Kotlin collection supertype is dropped from supertype
list</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-87250"><code>KT-87250</code></a>
JvmExposeBoxed: light classes shouldn't be autogenerated for private
declarations</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-70428"><code>KT-70428</code></a>
AA: good code is red when a Java class extends a Kotlin class
implementing MutableList by delegation</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-63568"><code>KT-63568</code></a>
Symbol Light Classes:
KtAnnotationApplicationWithArgumentsInfo.normalizedArguments() may work
incorrectly when psi is not set</li>
<li><a
href="https://youtrack.jetbrains.com/issue/KT-36740"><code>KT-36740</code></a>
MPP: False-positive incompatible types in .java when using expect-class
returned by non-expect member from common when actual is actual
typealias</li>
</ul>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a
href="890ac1d94f"><code>890ac1d</code></a>
Add Changelog for 2.4.20-RC3</li>
<li><a
href="8860aed4ae"><code>8860aed</code></a>
🍒 [FIR] Fix suspend conversion when expected type is nullable (<a
href="https://redirect.github.com/JetBrains/kotlin/issues/7769">#7769</a>)</li>
<li><a
href="ab5bcd9428"><code>ab5bcd9</code></a>
Edit ChangeLog for 2.4.20-RC2</li>
<li><a
href="9464edc097"><code>9464edc</code></a>
Add ChangeLog for 2.4.20-RC2</li>
<li><a
href="0261e43b78"><code>0261e43</code></a>
Cherry-pick &quot;Fix <code>asBodyAndResultVar</code> call in
`visitInlinedLambdaInComposable...</li>
<li><a
href="0763513670"><code>0763513</code></a>
[box-tests] Workaround for klib compatibility tests (<a
href="https://redirect.github.com/JetBrains/kotlin/issues/7626">#7626</a>)</li>
<li><a
href="045aec6647"><code>045aec6</code></a>
[Wasm] Append scripts from webpack.config.d in the end of the file (<a
href="https://redirect.github.com/JetBrains/kotlin/issues/7615">#7615</a>)</li>
<li><a
href="cd7173bf0b"><code>cd7173b</code></a>
🍒 [2.4.20] [K/JS] Keep associated obj annotation only if getInstance
survives...</li>
<li><a
href="d36a2ffbcc"><code>d36a2ff</code></a>
CastsOptimizationPass: break aliases cycles (<a
href="https://redirect.github.com/JetBrains/kotlin/issues/7578">#7578</a>)</li>
<li><a
href="8664983b34"><code>8664983</code></a>
[CLI] Restore custom IC search scope creation</li>
<li>Additional commits viewable in <a
href="https://github.com/JetBrains/kotlin/compare/v2.4.10...v2.4.20">compare
view</a></li>
</ul>
</details>
<br />

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/apidocs.yaml

@@ -27,14 +27,14 @@ jobs:
       - uses: actions/checkout@v7
 
       - name: Set up JDK ${{ env.JAVA_VERSION }}
-        uses: actions/setup-java@v5
+        uses: actions/setup-java@v6
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.JAVA_DISTRIBUTION }}
           cache: gradle
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v6
+        uses: gradle/actions/setup-gradle@v6.3.0
 
       - name: Generate Dokka Site
         run: |-

.github/workflows/automations.yml

@@ -27,7 +27,7 @@ jobs:
     name: Mark/unmark stale PRs and issues
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/stale@v10
+    - uses: actions/stale@v11
       with:
         debug-only: ${{ env.DRY_RUN }}
         exempt-draft-pr: true
@@ -66,7 +66,7 @@ jobs:
     name: Close stale PRs and issues
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/stale@v10
+    - uses: actions/stale@v11
       with:
         debug-only: ${{ env.DRY_RUN }}
         only-labels: 'stale'

.github/workflows/build.yml

@@ -46,14 +46,14 @@ jobs:
       - uses: actions/checkout@v7
 
       - name: Set up JDK ${{ env.JAVA_VERSION }}
-        uses: actions/setup-java@v5
+        uses: actions/setup-java@v6
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.JAVA_DISTRIBUTION }}
 
       - name: Set up Node.js
         if: matrix.os == 'ubuntu-latest'
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@v7
         with:
           node-version: '22' # increase only after https://github.com/nodejs/node/issues/56645 will be fixed
 
@@ -63,7 +63,7 @@ jobs:
         run: npm ci
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v6
+        uses: gradle/actions/setup-gradle@v6.3.0
         with:
           validate-wrappers: true
           add-job-summary: 'always'
@@ -129,13 +129,13 @@ jobs:
       - uses: actions/checkout@v7
 
       - name: Set up JDK ${{ env.JAVA_VERSION }}
-        uses: actions/setup-java@v5
+        uses: actions/setup-java@v6
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.JAVA_DISTRIBUTION }}
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v6
+        uses: gradle/actions/setup-gradle@v6.3.0
         with:
           validate-wrappers: true
           add-job-summary: 'always'
@@ -171,13 +171,13 @@ jobs:
       - uses: actions/checkout@v7
 
       - name: Set up JDK ${{ env.JAVA_VERSION }}
-        uses: actions/setup-java@v5
+        uses: actions/setup-java@v6
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.JAVA_DISTRIBUTION }}
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v6
+        uses: gradle/actions/setup-gradle@v6.3.0
         with:
           add-job-summary: 'always'
           cache-read-only: true

.github/workflows/codeql.yml

@@ -28,19 +28,19 @@ jobs:
         uses: actions/checkout@v7
 
       - name: Set up JDK ${{ env.JAVA_VERSION }}
-        uses: actions/setup-java@v5
+        uses: actions/setup-java@v6
         with:
           distribution: ${{ env.JAVA_DISTRIBUTION }}
           java-version: ${{ env.JAVA_VERSION }}
 
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@v4
+        uses: github/codeql-action/init@v4.38.0
         with:
           languages: java-kotlin
           build-mode: manual
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v6
+        uses: gradle/actions/setup-gradle@v6.3.0
         with:
           validate-wrappers: true
           cache-read-only: true
@@ -52,6 +52,6 @@ jobs:
             --no-daemon --rerun-tasks --stacktrace
 
       - name: Analyze
-        uses: github/codeql-action/analyze@v4
+        uses: github/codeql-action/analyze@v4.38.0
         with:
           category: '/language:java-kotlin'

.github/workflows/conformance.yml

@@ -28,13 +28,13 @@ jobs:
       - uses: actions/checkout@v7
 
       - name: Set up JDK
-        uses: actions/setup-java@v5
+        uses: actions/setup-java@v6
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.JAVA_DISTRIBUTION }}
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v6
+        uses: gradle/actions/setup-gradle@v6.3.0
         with:
           cache-read-only: ${{ github.ref != 'refs/heads/main' }}
 
@@ -79,13 +79,13 @@ jobs:
       - uses: actions/checkout@v7
 
       - name: Set up JDK
-        uses: actions/setup-java@v5
+        uses: actions/setup-java@v6
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.JAVA_DISTRIBUTION }}
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v6
+        uses: gradle/actions/setup-gradle@v6.3.0
         with:
           cache-read-only: ${{ github.ref != 'refs/heads/main' }}
 
@@ -110,13 +110,13 @@ jobs:
       - uses: actions/checkout@v7
 
       - name: Set up JDK
-        uses: actions/setup-java@v5
+        uses: actions/setup-java@v6
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.JAVA_DISTRIBUTION }}
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v6
+        uses: gradle/actions/setup-gradle@v6.3.0
         with:
           cache-read-only: ${{ github.ref != 'refs/heads/main' }}
 
@@ -149,13 +149,13 @@ jobs:
       - uses: actions/checkout@v7
 
       - name: Set up JDK
-        uses: actions/setup-java@v5
+        uses: actions/setup-java@v6
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.JAVA_DISTRIBUTION }}
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v6
+        uses: gradle/actions/setup-gradle@v6.3.0
         with:
           cache-read-only: ${{ github.ref != 'refs/heads/main' }}
 

.github/workflows/gradle-publish.yml

@@ -19,18 +19,18 @@ jobs:
     steps:
       - uses: actions/checkout@v7
       - name: Set up JDK 21
-        uses: actions/setup-java@v5
+        uses: actions/setup-java@v6
         with:
           java-version: '21'
           distribution: 'temurin'
 
       - name: Set up Node.js
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@v7
         with:
           node-version: '22' # increase only after https://github.com/nodejs/node/issues/56645 will be fixed
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v6
+        uses: gradle/actions/setup-gradle@v6.3.0
 
       - name: Check
         run: ./gradlew check --no-configuration-cache

.github/workflows/samples.yml

@@ -39,13 +39,13 @@ jobs:
       - uses: actions/checkout@v7
 
       - name: Set up JDK ${{ env.JAVA_VERSION }}
-        uses: actions/setup-java@v5
+        uses: actions/setup-java@v6
         with:
           java-version: ${{ env.JAVA_VERSION }}
           distribution: ${{ env.JAVA_DISTRIBUTION }}
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v6
+        uses: gradle/actions/setup-gradle@v6.3.0
         with:
           validate-wrappers: true
           add-job-summary: 'always'

README.md

@@ -729,7 +729,7 @@ val client = Client(
 )
 
 client.setRequestHandler<CreateMessageRequest>(Method.Defined.SamplingCreateMessage) { request, _ ->
-    val content = request.messages.lastOrNull()?.content
+    val content = request.messages.lastOrNull()?.content?.firstOrNull()
     val prompt = if (content is TextContent) content.text else "your topic"
     CreateMessageResult(
         model = "gpt-4o-mini",

config/detekt/detekt.yml

@@ -416,7 +416,6 @@ potential-bugs:
   Deprecation:
     active: false
     aliases: ['DEPRECATION']
-    excludeImportStatements: false
   DontDowncastCollectionTypes:
     active: false
   DoubleMutabilityForCollection:

gradle.properties

@@ -8,4 +8,4 @@ kotlin.daemon.jvmargs=-Xmx4G
 kotlin.native.ignoreDisabledTargets=true
 
 group=io.modelcontextprotocol
-version=0.14.0
+version=0.15.0

gradle/libs.versions.toml

@@ -1,28 +1,28 @@
 [versions]
 # plugins version
 atomicfu = "0.33.0"
-binaryCompatibilityValidatorPlugin = "0.18.1"
-detekt = "2.0.0-alpha.3"
+binaryCompatibilityValidatorPlugin = "0.18.2"
+detekt = "2.0.0-alpha.6"
 dokka = "2.2.0"
-kotlin = "2.3.21"
-kover = "0.9.8"
+kotlin = "2.4.10"
+kover = "0.9.9"
 ktlint = "14.2.0"
 knit = "0.5.1"
 mavenPublish = "0.37.0"
-netty = "4.2.15.Final"
+netty = "4.2.18.Final"
 
 # libraries version
 awaitility = "4.3.0"
-collections-immutable = "0.5.0"
+collections-immutable = "0.5.2"
 coroutines = "1.11.0"
-kotest = "6.2.1"
+kotest = "6.2.5"
 kotlinx-io = "0.9.1"
-ktor = "3.4.3"
+ktor = "3.5.2"
 logging = "8.0.4"
 mockk = "1.14.11"
 serialization = "1.11.0"
-slf4j = "2.0.18"
-logback = "1.5.37"
+slf4j = "2.0.19"
+logback = "1.6.3"
 junit = "5.14.4"
 
 [libraries]

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-9.6.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.7.1-bin.zip
 networkTimeout=10000
 retries=0
 retryBackOffMs=500

integration-test/src/commonTest/kotlin/io/modelcontextprotocol/kotlin/sdk/client/ClientTest.kt

@@ -24,6 +24,7 @@ import io.modelcontextprotocol.kotlin.sdk.types.InitializeRequest
 import io.modelcontextprotocol.kotlin.sdk.types.InitializeResult
 import io.modelcontextprotocol.kotlin.sdk.types.IntegerSchema
 import io.modelcontextprotocol.kotlin.sdk.types.JSONRPCMessage
+import io.modelcontextprotocol.kotlin.sdk.types.JSONRPCNotification
 import io.modelcontextprotocol.kotlin.sdk.types.JSONRPCRequest
 import io.modelcontextprotocol.kotlin.sdk.types.JSONRPCResponse
 import io.modelcontextprotocol.kotlin.sdk.types.LATEST_PROTOCOL_VERSION
@@ -52,6 +53,7 @@ import io.modelcontextprotocol.kotlin.sdk.types.UntitledSingleSelectEnumSchema
 import io.modelcontextprotocol.kotlin.sdk.types.UrlElicitationRequiredException
 import kotlinx.coroutines.CompletableDeferred
 import kotlinx.coroutines.TimeoutCancellationException
+import kotlinx.coroutines.awaitCancellation
 import kotlinx.coroutines.cancel
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.joinAll
@@ -71,6 +73,7 @@ import kotlin.test.assertIs
 import kotlin.test.assertNull
 import kotlin.test.assertTrue
 import kotlin.test.fail
+import kotlin.time.Duration.Companion.seconds
 
 class ClientTest {
     @Test
@@ -543,6 +546,15 @@ class ClientTest {
 
         val serverSession = serverSessionResult.await()
 
+        // Register the tap after createSession so it chains onto the session's subscription instead
+        // of pre-empting the handshake.
+        val cancelledOnWire = CompletableDeferred<Unit>()
+        serverTransport.onMessage { message ->
+            if (message is JSONRPCNotification && message.method == Method.Defined.NotificationsCancelled.value) {
+                cancelledOnWire.complete(Unit)
+            }
+        }
+
         serverSession.setRequestHandler<ListResourcesRequest>(Method.Defined.ResourcesList) { _, _ ->
             // Simulate delay
             def.complete(Unit)
@@ -568,6 +580,7 @@ class ClientTest {
         def.await()
         runCatching { job.cancel("Cancelled by test") }
         defCancel.await()
+        cancelledOnWire.await()
         defTimeOut.await()
     }
 
@@ -606,17 +619,9 @@ class ClientTest {
 
         val serverSession = serverSessionResult.await()
         serverSession.setRequestHandler<ListResourcesRequest>(Method.Defined.ResourcesList) { _, _ ->
-            // Simulate a delayed response
-            // Wait ~100ms unless canceled
-            try {
-                withTimeout(100L) {
-                    // Just delay here, if timeout is 0 on the client side, this won't return in time
-                    delay(100)
-                }
-            } catch (_: Exception) {
-                // If aborted, just rethrow or return early
-            }
-            ListResourcesResult(resources = emptyList())
+            // Never respond: the handler runs on a real dispatcher while the 1 ms timeout runs on the
+            // virtual test clock, so a real-time delay could race it. Parking keeps the test deterministic.
+            awaitCancellation()
         }
 
         // Request with 1 msec timeout should fail immediately
@@ -895,8 +900,8 @@ class ClientTest {
             ),
         )
 
-        // Track notifications
-        var rootListChangedNotificationReceived = false
+        // The handler runs on Dispatchers.Default after concurrent dispatch is enabled; await the deferred.
+        val rootListChangedReceived = CompletableDeferred<Unit>()
 
         val serverSessionResult = CompletableDeferred<ServerSession>()
 
@@ -915,16 +920,13 @@ class ClientTest {
         serverSession.setNotificationHandler<RootsListChangedNotification>(
             Method.Defined.NotificationsRootsListChanged,
         ) {
-            rootListChangedNotificationReceived = true
+            rootListChangedReceived.complete(Unit)
             CompletableDeferred(Unit)
         }
 
         client.sendRootsListChanged()
 
-        assertTrue(
-            rootListChangedNotificationReceived,
-            "Notification should be sent when sendRootsListChanged is called",
-        )
+        withTimeout(5.seconds) { rootListChangedReceived.await() }
     }
 
     @Test
@@ -1122,6 +1124,103 @@ class ClientTest {
         assertEquals(elicitationResultContent, result.content)
     }
 
+    @Test
+    fun `should reject accepted elicitation content that does not match requested schema`() = runTest {
+        val requestedSchema = ElicitRequestParams.RequestedSchema(
+            properties = mapOf("name" to StringSchema()),
+            required = listOf("name"),
+        )
+        val (client, serverSession) = setupElicitationPair {
+            ElicitResult(action = ElicitResult.Action.Accept, content = buildJsonObject { put("name", 42) })
+        }
+
+        val exception = assertFailsWith<McpException> {
+            serverSession.createElicitation(message = "mismatch", requestedSchema = requestedSchema)
+        }
+        assertTrue(
+            exception.message.orEmpty()
+                .startsWith("Elicitation response content does not match requested schema: "),
+            "Unexpected message: ${exception.message}",
+        )
+        assertTrue("'name' must be string" in exception.message.orEmpty(), "Unexpected message: ${exception.message}")
+
+        client.close()
+    }
+
+    @Test
+    fun `should reject accepted elicitation without content when schema has required properties`() = runTest {
+        val requestedSchema = ElicitRequestParams.RequestedSchema(
+            properties = mapOf("name" to StringSchema()),
+            required = listOf("name"),
+        )
+        val (client, serverSession) = setupElicitationPair {
+            ElicitResult(action = ElicitResult.Action.Accept, content = null)
+        }
+
+        val exception = assertFailsWith<McpException> {
+            serverSession.createElicitation(message = "no content", requestedSchema = requestedSchema)
+        }
+        assertTrue(
+            "must have required property 'name'" in exception.message.orEmpty(),
+            "Unexpected message: ${exception.message}",
+        )
+
+        client.close()
+    }
+
+    @Test
+    fun `should accept elicitation without content when schema has no required properties`() = runTest {
+        val requestedSchema = ElicitRequestParams.RequestedSchema(
+            properties = mapOf("name" to StringSchema()),
+        )
+        val (client, serverSession) = setupElicitationPair {
+            ElicitResult(action = ElicitResult.Action.Accept, content = null)
+        }
+
+        val result = serverSession.createElicitation(message = "no required", requestedSchema = requestedSchema)
+
+        assertEquals(ElicitResult.Action.Accept, result.action)
+        assertNull(result.content)
+
+        client.close()
+    }
+
+    @Test
+    fun `should pass through declined elicitation without validation`() = runTest {
+        val requestedSchema = ElicitRequestParams.RequestedSchema(
+            properties = mapOf("name" to StringSchema()),
+            required = listOf("name"),
+        )
+        val (client, serverSession) = setupElicitationPair {
+            ElicitResult(action = ElicitResult.Action.Decline)
+        }
+
+        val result = serverSession.createElicitation(message = "decline", requestedSchema = requestedSchema)
+
+        assertEquals(ElicitResult.Action.Decline, result.action)
+        assertNull(result.content)
+
+        client.close()
+    }
+
+    @Test
+    fun `should pass through cancelled elicitation without validation`() = runTest {
+        val requestedSchema = ElicitRequestParams.RequestedSchema(
+            properties = mapOf("name" to StringSchema()),
+            required = listOf("name"),
+        )
+        val (client, serverSession) = setupElicitationPair {
+            ElicitResult(action = ElicitResult.Action.Cancel)
+        }
+
+        val result = serverSession.createElicitation(message = "cancel", requestedSchema = requestedSchema)
+
+        assertEquals(ElicitResult.Action.Cancel, result.action)
+        assertNull(result.content)
+
+        client.close()
+    }
+
     @Test
     fun `should apply elicitation defaults for missing fields in empty content`() = runTest {
         val schema = defaultsTestSchema()

integration-test/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/integration/ProtocolConcurrencyIntegrationTest.kt

@@ -0,0 +1,306 @@
+package io.modelcontextprotocol.kotlin.sdk.integration
+
+import io.kotest.matchers.shouldBe
+import io.modelcontextprotocol.kotlin.sdk.ExperimentalMcpApi
+import io.modelcontextprotocol.kotlin.sdk.client.Client
+import io.modelcontextprotocol.kotlin.sdk.client.ClientOptions
+import io.modelcontextprotocol.kotlin.sdk.server.Server
+import io.modelcontextprotocol.kotlin.sdk.server.ServerOptions
+import io.modelcontextprotocol.kotlin.sdk.server.ServerSession
+import io.modelcontextprotocol.kotlin.sdk.shared.InMemoryTransport
+import io.modelcontextprotocol.kotlin.sdk.shared.currentRequestHandlerExtra
+import io.modelcontextprotocol.kotlin.sdk.testing.ChannelTransport
+import io.modelcontextprotocol.kotlin.sdk.types.CallToolRequest
+import io.modelcontextprotocol.kotlin.sdk.types.CallToolRequestParams
+import io.modelcontextprotocol.kotlin.sdk.types.CallToolResult
+import io.modelcontextprotocol.kotlin.sdk.types.ClientCapabilities
+import io.modelcontextprotocol.kotlin.sdk.types.CreateMessageRequest
+import io.modelcontextprotocol.kotlin.sdk.types.CreateMessageRequestParams
+import io.modelcontextprotocol.kotlin.sdk.types.CreateMessageResult
+import io.modelcontextprotocol.kotlin.sdk.types.Implementation
+import io.modelcontextprotocol.kotlin.sdk.types.InitializeRequest
+import io.modelcontextprotocol.kotlin.sdk.types.InitializeRequestParams
+import io.modelcontextprotocol.kotlin.sdk.types.InitializedNotification
+import io.modelcontextprotocol.kotlin.sdk.types.JSONRPCError
+import io.modelcontextprotocol.kotlin.sdk.types.JSONRPCMessage
+import io.modelcontextprotocol.kotlin.sdk.types.JSONRPCResponse
+import io.modelcontextprotocol.kotlin.sdk.types.LATEST_PROTOCOL_VERSION
+import io.modelcontextprotocol.kotlin.sdk.types.ListRootsRequest
+import io.modelcontextprotocol.kotlin.sdk.types.ListRootsResult
+import io.modelcontextprotocol.kotlin.sdk.types.ListToolsRequest
+import io.modelcontextprotocol.kotlin.sdk.types.ListToolsResult
+import io.modelcontextprotocol.kotlin.sdk.types.Method
+import io.modelcontextprotocol.kotlin.sdk.types.RequestId
+import io.modelcontextprotocol.kotlin.sdk.types.Role
+import io.modelcontextprotocol.kotlin.sdk.types.SamplingMessage
+import io.modelcontextprotocol.kotlin.sdk.types.ServerCapabilities
+import io.modelcontextprotocol.kotlin.sdk.types.TextContent
+import io.modelcontextprotocol.kotlin.sdk.types.toJSON
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.withTimeout
+import java.util.concurrent.ConcurrentHashMap
+import java.util.concurrent.CopyOnWriteArrayList
+import java.util.concurrent.atomic.AtomicReference
+import kotlin.coroutines.cancellation.CancellationException
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.time.Duration.Companion.seconds
+
+/**
+ * End-to-end tests for concurrent inbound dispatch enabled after the MCP handshake.
+ *
+ * Handlers run on a real [kotlinx.coroutines.Dispatchers.Default], so these use [runBlocking] with
+ * explicit [withTimeout] guards. A virtual test clock would false-fire timeouts against cross-thread
+ * real dispatchers.
+ */
+@OptIn(ExperimentalMcpApi::class)
+class ProtocolConcurrencyIntegrationTest {
+
+    private fun rootsClient(): Client = Client(
+        clientInfo = Implementation(name = "test client", version = "1.0"),
+        options = ClientOptions(
+            capabilities = ClientCapabilities(roots = ClientCapabilities.Roots(listChanged = null)),
+        ),
+    )
+
+    private fun toolsServer(): Server = Server(
+        serverInfo = Implementation(name = "test server", version = "1.0"),
+        options = ServerOptions(
+            capabilities = ServerCapabilities(tools = ServerCapabilities.Tools(listChanged = null)),
+        ),
+    )
+
+    // ChannelTransport delivers inbound messages as soon as its read loop starts, which is before
+    // start() marks it operational. Creating the session first keeps the client's initialize from
+    // landing on a transport that would reject the session's response.
+    private suspend fun connect(
+        client: Client,
+        clientTransport: ChannelTransport,
+        server: Server,
+        serverTransport: ChannelTransport,
+    ): ServerSession {
+        val serverSession = server.createSession(serverTransport)
+        client.connect(clientTransport)
+        return serverSession
+    }
+
+    // The motivating deadlock over real serial read loops: a server tool handler makes a
+    // server-to-client request (roots/list) while still handling the client's tools/call.
+    @Test
+    fun `server tool handler can call roots list mid-handling without deadlock`() = runBlocking {
+        val client = rootsClient()
+        val server = toolsServer()
+        val (clientTransport, serverTransport) = ChannelTransport.createLinkedPair()
+
+        val serverSession = connect(client, clientTransport, server, serverTransport)
+
+        // Register the tools/call handler directly on the session so it can call back to the client
+        // mid-handling. Before concurrent dispatch this would deadlock: the server read loop is
+        // blocked by the tool handler and can never deliver the roots/list response.
+        serverSession.setRequestHandler<CallToolRequest>(Method.Defined.ToolsCall) { _, _ ->
+            val roots = serverSession.request<ListRootsResult>(ListRootsRequest())
+            CallToolResult(content = listOf(TextContent(text = "roots=${roots.roots.size}")))
+        }
+
+        val result = withTimeout(10.seconds) {
+            client.callTool(CallToolRequest(CallToolRequestParams("needs-roots")))
+        }
+        val text = (result as CallToolResult).content.filterIsInstance<TextContent>().single().text
+        text shouldBe "roots=0"
+
+        client.close()
+        server.close()
+    }
+
+    // Client-side mirror: a client sampling handler makes a client-to-server request (tools/list)
+    // while still handling the server's sampling/createMessage.
+    @Test
+    fun `client sampling handler can call the server mid-handling without deadlock`() = runBlocking {
+        val client = Client(
+            clientInfo = Implementation(name = "test client", version = "1.0"),
+            options = ClientOptions(
+                capabilities = ClientCapabilities(sampling = ClientCapabilities.Sampling()),
+            ),
+        )
+        val server = toolsServer()
+        val (clientTransport, serverTransport) = ChannelTransport.createLinkedPair()
+
+        client.setRequestHandler<CreateMessageRequest>(Method.Defined.SamplingCreateMessage) { _, _ ->
+            val tools = client.request<ListToolsResult>(ListToolsRequest())
+            CreateMessageResult(
+                role = Role.Assistant,
+                content = TextContent(text = "tools=${tools.tools.size}"),
+                model = "test-model",
+            )
+        }
+
+        val serverSession = connect(client, clientTransport, server, serverTransport)
+
+        val result = withTimeout(10.seconds) {
+            serverSession.request<CreateMessageResult>(
+                CreateMessageRequest(
+                    CreateMessageRequestParams(
+                        maxTokens = 100,
+                        messages = listOf(SamplingMessage(role = Role.User, content = TextContent(text = "hi"))),
+                    ),
+                ),
+            )
+        }
+        val text = result.content.filterIsInstance<TextContent>().single().text
+        text shouldBe "tools=0"
+
+        client.close()
+        server.close()
+    }
+
+    // Nested-cancel cascade: cancelling the client's tools/call must reach the server tool handler
+    // over the wire and cascade into its nested roots/list request, cancelling the parked
+    // client-side roots handler. No tools/call response is ever sent.
+    @Test
+    fun `cancelling a tool call cascades into its nested roots list request`() = runBlocking {
+        val client = rootsClient()
+        val server = toolsServer()
+        val (clientTransport, serverTransport) = ChannelTransport.createLinkedPair()
+
+        val capturedToolCallId = AtomicReference<RequestId?>(null)
+        val toolHandlerCancelled = CompletableDeferred<CancellationException>()
+        val rootsHandlerEntered = CompletableDeferred<Unit>()
+        val rootsHandlerCancelled = CompletableDeferred<CancellationException>()
+        val parkForever = CompletableDeferred<ListRootsResult>()
+        val unexpectedToolCallResponse = CompletableDeferred<Unit>()
+
+        // Tap the server->client direction (client transport inbound) to prove no tools/call
+        // response is ever delivered once the call is cancelled.
+        clientTransport.onMessage { message ->
+            if (message is JSONRPCResponse && message.id == capturedToolCallId.get()) {
+                unexpectedToolCallResponse.complete(Unit)
+            }
+        }
+
+        val serverSession = connect(client, clientTransport, server, serverTransport)
+
+        // Client roots handler parks until cancelled and records the cancellation.
+        client.setRequestHandler<ListRootsRequest>(Method.Defined.RootsList) { _, _ ->
+            rootsHandlerEntered.complete(Unit)
+            try {
+                parkForever.await()
+            } catch (e: CancellationException) {
+                rootsHandlerCancelled.complete(e)
+                throw e
+            }
+        }
+
+        // Tool handler makes a nested server->client request and records its own cancellation.
+        serverSession.setRequestHandler<CallToolRequest>(Method.Defined.ToolsCall) { _, _ ->
+            val extra = currentRequestHandlerExtra()!!
+            capturedToolCallId.set(extra.requestId)
+            try {
+                extra.sendRequest<ListRootsResult>(ListRootsRequest())
+            } catch (e: CancellationException) {
+                toolHandlerCancelled.complete(e)
+                throw e
+            }
+            CallToolResult(content = listOf(TextContent(text = "unreachable")))
+        }
+
+        val call = launch { client.callTool(CallToolRequest(CallToolRequestParams("nested"))) }
+
+        withTimeout(10.seconds) { rootsHandlerEntered.await() }
+        call.cancel(CancellationException("user aborted"))
+
+        withTimeout(10.seconds) { toolHandlerCancelled.await() }
+        withTimeout(10.seconds) { rootsHandlerCancelled.await() }
+
+        // The server suppresses the response for a cancelled request, so none is ever sent.
+        assertFalse(
+            unexpectedToolCallResponse.isCompleted,
+            "no tools/call response should be delivered after the call was cancelled",
+        )
+
+        client.close()
+        server.close()
+    }
+
+    // Init gate plus context element in a high-level handler: initialize and tools/list are
+    // pipelined before notifications/initialized and answered serially in order. After the
+    // handshake a high-level addTool handler can observe currentRequestHandlerExtra().
+    @Test
+    fun `pipelined initialize and tools list are processed serially then context element is available`(): Unit =
+        runBlocking {
+            val server = toolsServer()
+            server.addTool(name = "ctx-tool", description = "returns its request id") {
+                val extra = currentRequestHandlerExtra()
+                checkNotNull(extra) { "currentRequestHandlerExtra() must be non-null inside a tool handler" }
+                CallToolResult(content = listOf(TextContent(text = extra.requestId.asText())))
+            }
+
+            val (clientTransport, serverTransport) = InMemoryTransport.createLinkedPair()
+
+            val arrivalOrder = CopyOnWriteArrayList<RequestId>()
+            val pending = ConcurrentHashMap<RequestId, CompletableDeferred<JSONRPCMessage>>()
+            clientTransport.onMessage { message ->
+                val id = when (message) {
+                    is JSONRPCResponse -> message.id
+                    is JSONRPCError -> message.id
+                    else -> null
+                }
+                if (id != null) {
+                    arrivalOrder.add(id)
+                    pending[id]?.complete(message)
+                }
+            }
+
+            // Drive the client side manually over the raw transport.
+            server.createSession(serverTransport)
+
+            val initRequest = InitializeRequest(
+                InitializeRequestParams(
+                    protocolVersion = LATEST_PROTOCOL_VERSION,
+                    capabilities = ClientCapabilities(),
+                    clientInfo = Implementation(name = "raw-client", version = "1.0"),
+                ),
+            ).toJSON()
+            val toolsListRequest = ListToolsRequest().toJSON()
+
+            val initAnswered = pending.expect(initRequest.id)
+            val toolsListAnswered = pending.expect(toolsListRequest.id)
+
+            // Pipelined before notifications/initialized: both handled in the serial dispatch phase.
+            clientTransport.send(initRequest)
+            clientTransport.send(toolsListRequest)
+
+            withTimeout(10.seconds) { initAnswered.await() }
+            withTimeout(10.seconds) { toolsListAnswered.await() }
+
+            // Deterministic serial ordering: initialize answered before tools/list.
+            assertEquals(
+                listOf(initRequest.id, toolsListRequest.id),
+                arrivalOrder.toList(),
+                "pipelined requests must be answered in arrival order",
+            )
+
+            // Complete the handshake, then call the high-level tool.
+            clientTransport.send(InitializedNotification().toJSON())
+
+            val toolCallRequest = CallToolRequest(CallToolRequestParams("ctx-tool")).toJSON()
+            val toolCallAnswered = pending.expect(toolCallRequest.id)
+            clientTransport.send(toolCallRequest)
+
+            val toolCallResponse = withTimeout(10.seconds) { toolCallAnswered.await() } as JSONRPCResponse
+            val text = (toolCallResponse.result as CallToolResult).content.filterIsInstance<TextContent>().single().text
+            // The handler echoed its request id, proving currentRequestHandlerExtra() was available.
+            text shouldBe toolCallRequest.id.asText()
+        }
+
+    private fun ConcurrentHashMap<RequestId, CompletableDeferred<JSONRPCMessage>>.expect(
+        id: RequestId,
+    ): CompletableDeferred<JSONRPCMessage> = CompletableDeferred<JSONRPCMessage>().also { put(id, it) }
+
+    private fun RequestId.asText(): String = when (this) {
+        is RequestId.StringId -> value
+        is RequestId.NumberId -> value.toString()
+    }
+}

integration-test/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/integration/kotlin/AbstractPromptIntegrationTest.kt

@@ -698,8 +698,8 @@ abstract class AbstractPromptIntegrationTest : KotlinTestBase() {
 
         val expectedMessage = "Prompt not found: non-existent-prompt"
 
-        withClue("Exception code should be INTERNAL_ERROR: -32603") {
-            exception.code shouldBe -32603
+        withClue("Exception code should be INVALID_PARAMS: ${RPCError.ErrorCode.INVALID_PARAMS}") {
+            exception.code shouldBe RPCError.ErrorCode.INVALID_PARAMS
         }
         withClue("Unexpected error message for non-existent prompt") {
             exception.message shouldBe expectedMessage

integration-test/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/integration/kotlin/AbstractResourceIntegrationTest.kt

@@ -77,23 +77,6 @@ abstract class AbstractResourceIntegrationTest : KotlinTestBase() {
             )
         }
 
-        server.addResource(
-            uri = testResourceUri,
-            name = testResourceName,
-            description = testResourceDescription,
-            mimeType = "text/plain",
-        ) { request ->
-            ReadResourceResult(
-                contents = listOf(
-                    TextResourceContents(
-                        text = testResourceContent,
-                        uri = request.params.uri,
-                        mimeType = "text/plain",
-                    ),
-                ),
-            )
-        }
-
         server.addResource(
             uri = binaryResourceUri,
             name = binaryResourceName,

integration-test/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/integration/streamablehttp/AbstractStreamableHttpIntegrationTest.kt

@@ -3,6 +3,7 @@ package io.modelcontextprotocol.kotlin.sdk.integration.streamablehttp
 import io.ktor.server.cio.CIOApplicationEngine
 import io.ktor.server.engine.EmbeddedServer
 import io.ktor.server.engine.embeddedServer
+import io.ktor.server.sse.Heartbeat
 import io.modelcontextprotocol.kotlin.sdk.server.Server
 import io.modelcontextprotocol.kotlin.sdk.server.ServerOptions
 import io.modelcontextprotocol.kotlin.sdk.server.mcpStreamableHttp
@@ -17,7 +18,10 @@ import io.ktor.server.cio.CIO as ServerCIO
 
 open class AbstractStreamableHttpIntegrationTest {
 
-    suspend fun initTestServer(name: String? = null): StreamableHttpTestServer {
+    suspend fun initTestServer(
+        name: String? = null,
+        sseHeartbeatConfig: (Heartbeat.() -> Unit)? = null,
+    ): StreamableHttpTestServer {
         val mcpServer = Server(
             Implementation(name = name ?: DEFAULT_SERVER_NAME, version = VERSION),
             ServerOptions(
@@ -52,7 +56,7 @@ open class AbstractStreamableHttpIntegrationTest {
             host = URL,
             port = PORT,
         ) {
-            mcpStreamableHttp { mcpServer }
+            mcpStreamableHttp(sseHeartbeatConfig = sseHeartbeatConfig) { mcpServer }
         }
 
         return StreamableHttpTestServer(

integration-test/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/integration/streamablehttp/StreamableHttpHeartbeatIntegrationTest.kt

@@ -0,0 +1,174 @@
+package io.modelcontextprotocol.kotlin.sdk.integration.streamablehttp
+
+import io.kotest.matchers.shouldBe
+import io.ktor.client.HttpClient
+import io.ktor.client.plugins.sse.SSE
+import io.ktor.client.request.header
+import io.ktor.client.request.post
+import io.ktor.client.request.prepareGet
+import io.ktor.client.request.setBody
+import io.ktor.client.statement.bodyAsChannel
+import io.ktor.http.ContentType
+import io.ktor.http.HttpHeaders
+import io.ktor.http.HttpStatusCode
+import io.ktor.http.contentType
+import io.ktor.sse.ServerSentEvent
+import io.ktor.utils.io.ByteReadChannel
+import io.ktor.utils.io.readUTF8Line
+import io.modelcontextprotocol.kotlin.sdk.types.ClientCapabilities
+import io.modelcontextprotocol.kotlin.sdk.types.Implementation
+import io.modelcontextprotocol.kotlin.sdk.types.InitializeRequest
+import io.modelcontextprotocol.kotlin.sdk.types.InitializeRequestParams
+import io.modelcontextprotocol.kotlin.sdk.types.JSONRPCRequest
+import io.modelcontextprotocol.kotlin.sdk.types.LATEST_PROTOCOL_VERSION
+import io.modelcontextprotocol.kotlin.sdk.types.toJSON
+import io.modelcontextprotocol.kotlin.test.utils.actualPort
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.withTimeoutOrNull
+import kotlinx.serialization.json.Json
+import kotlin.test.Test
+import kotlin.test.assertNotNull
+import kotlin.time.Duration.Companion.milliseconds
+import io.ktor.client.engine.cio.CIO as ClientCIO
+
+private const val SESSION_ID_HEADER = "mcp-session-id"
+private const val PROTOCOL_VERSION_HEADER = "mcp-protocol-version"
+private const val DEFAULT_HEARTBEAT_LINE = ": heartbeat"
+private const val CUSTOM_HEARTBEAT_LINE = ": mcp-heartbeat"
+
+class StreamableHttpHeartbeatIntegrationTest : AbstractStreamableHttpIntegrationTest() {
+
+    @Test
+    fun `GET SSE stream emits configured heartbeat`(): Unit = runBlocking(Dispatchers.IO) {
+        var server: StreamableHttpTestServer? = null
+        var httpClient: HttpClient? = null
+
+        try {
+            server = initTestServer("heartbeat-test") {
+                period = 50.milliseconds
+                event = ServerSentEvent(comments = "mcp-heartbeat")
+            }
+            val mcpUrl = "http://$URL:${server.ktorServer.actualPort()}/mcp"
+            httpClient = HttpClient(ClientCIO) { install(SSE) }
+            val sessionId = initializeSession(httpClient, mcpUrl)
+
+            httpClient.prepareGet(mcpUrl) {
+                addSseHeaders(sessionId)
+            }.execute { response ->
+                response.status shouldBe HttpStatusCode.OK
+                response.headers[SESSION_ID_HEADER] shouldBe sessionId
+
+                response.bodyAsChannel().readLineMatching(CUSTOM_HEARTBEAT_LINE) shouldBe CUSTOM_HEARTBEAT_LINE
+            }
+        } finally {
+            httpClient?.close()
+            server?.ktorServer?.stopSuspend(1000, 2000)
+        }
+    }
+
+    @Test
+    fun `GET SSE stream does not emit heartbeat by default`(): Unit = runBlocking(Dispatchers.IO) {
+        var server: StreamableHttpTestServer? = null
+        var httpClient: HttpClient? = null
+
+        try {
+            server = initTestServer("no-heartbeat-test")
+            val mcpUrl = "http://$URL:${server.ktorServer.actualPort()}/mcp"
+            httpClient = HttpClient(ClientCIO) { install(SSE) }
+            val sessionId = initializeSession(httpClient, mcpUrl)
+
+            httpClient.prepareGet(mcpUrl) {
+                addSseHeaders(sessionId)
+            }.execute { response ->
+                response.status shouldBe HttpStatusCode.OK
+                response.headers[SESSION_ID_HEADER] shouldBe sessionId
+
+                response.bodyAsChannel().readLineMatching(timeoutMillis = 150) { line ->
+                    line.isHeartbeatSseLine()
+                } shouldBe null
+            }
+        } finally {
+            httpClient?.close()
+            server?.ktorServer?.stopSuspend(1000, 2000)
+        }
+    }
+
+    @Test
+    fun `GET SSE stream emits configured heartbeat repeatedly`(): Unit = runBlocking(Dispatchers.IO) {
+        var server: StreamableHttpTestServer? = null
+        var httpClient: HttpClient? = null
+
+        try {
+            server = initTestServer("repeating-heartbeat-test") {
+                period = 50.milliseconds
+                event = ServerSentEvent(comments = "mcp-heartbeat")
+            }
+            val mcpUrl = "http://$URL:${server.ktorServer.actualPort()}/mcp"
+            httpClient = HttpClient(ClientCIO) { install(SSE) }
+            val sessionId = initializeSession(httpClient, mcpUrl)
+
+            httpClient.prepareGet(mcpUrl) {
+                addSseHeaders(sessionId)
+            }.execute { response ->
+                response.status shouldBe HttpStatusCode.OK
+                response.headers[SESSION_ID_HEADER] shouldBe sessionId
+
+                val channel = response.bodyAsChannel()
+                channel.readLineMatching(CUSTOM_HEARTBEAT_LINE) shouldBe CUSTOM_HEARTBEAT_LINE
+                channel.readLineMatching(CUSTOM_HEARTBEAT_LINE) shouldBe CUSTOM_HEARTBEAT_LINE
+            }
+        } finally {
+            httpClient?.close()
+            server?.ktorServer?.stopSuspend(1000, 2000)
+        }
+    }
+
+    private suspend fun initializeSession(client: HttpClient, mcpUrl: String): String {
+        val response = client.post(mcpUrl) {
+            contentType(ContentType.Application.Json)
+            header(
+                HttpHeaders.Accept,
+                "${ContentType.Application.Json}, ${ContentType.Text.EventStream}",
+            )
+            setBody(Json.encodeToString(buildInitPayload()))
+        }
+
+        response.status shouldBe HttpStatusCode.OK
+        return assertNotNull(response.headers[SESSION_ID_HEADER])
+    }
+
+    private fun buildInitPayload(): JSONRPCRequest = InitializeRequest(
+        InitializeRequestParams(
+            protocolVersion = LATEST_PROTOCOL_VERSION,
+            capabilities = ClientCapabilities(),
+            clientInfo = Implementation(name = "heartbeat-test-client", version = "1.0.0"),
+        ),
+    ).toJSON()
+
+    private fun io.ktor.client.request.HttpRequestBuilder.addSseHeaders(sessionId: String) {
+        header(HttpHeaders.Accept, ContentType.Text.EventStream.toString())
+        header(SESSION_ID_HEADER, sessionId)
+        header(PROTOCOL_VERSION_HEADER, LATEST_PROTOCOL_VERSION)
+    }
+
+    private suspend fun ByteReadChannel.readLineMatching(expectedLine: String, timeoutMillis: Long = 2_000): String? =
+        readLineMatching(timeoutMillis) { line -> line == expectedLine }
+
+    private suspend fun ByteReadChannel.readLineMatching(
+        timeoutMillis: Long = 2_000,
+        matches: (String) -> Boolean,
+    ): String? = withTimeoutOrNull(timeoutMillis.milliseconds) {
+        var line = readUTF8Line()
+        while (line != null) {
+            if (matches(line)) return@withTimeoutOrNull line
+            line = readUTF8Line()
+        }
+        null
+    }
+
+    private fun String.isHeartbeatSseLine(): Boolean = this == DEFAULT_HEARTBEAT_LINE ||
+        this == CUSTOM_HEARTBEAT_LINE ||
+        (startsWith(":") && contains("heartbeat", ignoreCase = true)) ||
+        (startsWith("event:") && contains("heartbeat", ignoreCase = true))
+}

integration-test/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/server/ClientConnectionLoggingTest.kt

@@ -1,5 +1,7 @@
 package io.modelcontextprotocol.kotlin.sdk.server
 
+import io.kotest.assertions.nondeterministic.continually
+import io.kotest.assertions.nondeterministic.eventually
 import io.kotest.matchers.collections.shouldBeEmpty
 import io.kotest.matchers.collections.shouldHaveSize
 import io.kotest.matchers.shouldBe
@@ -17,6 +19,9 @@ import kotlinx.serialization.json.JsonPrimitive
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.params.ParameterizedTest
 import org.junit.jupiter.params.provider.EnumSource
+import java.util.concurrent.CopyOnWriteArrayList
+import kotlin.time.Duration.Companion.milliseconds
+import kotlin.time.Duration.Companion.seconds
 
 class ClientConnectionLoggingTest : AbstractServerFeaturesTest() {
 
@@ -56,7 +61,7 @@ class ClientConnectionLoggingTest : AbstractServerFeaturesTest() {
     @ParameterizedTest
     @EnumSource(LoggingLevel::class)
     fun `notification should filter logging messages below level`(minLevel: LoggingLevel): Unit = runBlocking {
-        val receivedMessages = mutableListOf<LoggingMessageNotification>()
+        val receivedMessages = CopyOnWriteArrayList<LoggingMessageNotification>()
         client.setNotificationHandler<LoggingMessageNotification>(Method.Defined.NotificationsMessage) {
             receivedMessages.add(it)
             CompletableDeferred(Unit)
@@ -79,8 +84,10 @@ class ClientConnectionLoggingTest : AbstractServerFeaturesTest() {
 
         client.callTool(CallToolRequest(CallToolRequestParams("test-notification-filtered")))
 
+        // Handlers dispatch on Dispatchers.Default after the handshake, so await the expected count
+        // before asserting order.
         val expectedLevels = LoggingLevel.entries.filter { it >= minLevel }
-        receivedMessages shouldHaveSize expectedLevels.size
+        eventually(5.seconds) { receivedMessages shouldHaveSize expectedLevels.size }
         receivedMessages.map { it.params.level } shouldBe expectedLevels
     }
 
@@ -115,7 +122,7 @@ class ClientConnectionLoggingTest : AbstractServerFeaturesTest() {
     @ParameterizedTest
     @EnumSource(LoggingLevel::class)
     fun `sendLoggingMessage should filter messages below level`(minLevel: LoggingLevel): Unit = runBlocking {
-        val receivedMessages = mutableListOf<LoggingMessageNotification>()
+        val receivedMessages = CopyOnWriteArrayList<LoggingMessageNotification>()
         client.setNotificationHandler<LoggingMessageNotification>(Method.Defined.NotificationsMessage) {
             receivedMessages.add(it)
             CompletableDeferred(Unit)
@@ -138,14 +145,16 @@ class ClientConnectionLoggingTest : AbstractServerFeaturesTest() {
 
         client.callTool(CallToolRequest(CallToolRequestParams("test-logging-level")))
 
+        // Handlers dispatch on Dispatchers.Default after the handshake, so await the expected count
+        // before asserting order.
         val expectedLevels = LoggingLevel.entries.filter { it >= minLevel }
-        receivedMessages shouldHaveSize expectedLevels.size
+        eventually(5.seconds) { receivedMessages shouldHaveSize expectedLevels.size }
         receivedMessages.map { it.params.level } shouldBe expectedLevels
     }
 
     @Test
     fun `sendLoggingMessage should send no messages when level is set to highest`(): Unit = runBlocking {
-        val receivedMessages = mutableListOf<LoggingMessageNotification>()
+        val receivedMessages = CopyOnWriteArrayList<LoggingMessageNotification>()
         client.setNotificationHandler<LoggingMessageNotification>(Method.Defined.NotificationsMessage) {
             receivedMessages.add(it)
             CompletableDeferred(Unit)
@@ -167,6 +176,7 @@ class ClientConnectionLoggingTest : AbstractServerFeaturesTest() {
         }
 
         client.callTool(CallToolRequest(CallToolRequestParams("test-logging-highest")))
-        receivedMessages.shouldBeEmpty()
+        // Handlers dispatch asynchronously, so hold for a window to confirm nothing ever arrives.
+        continually(500.milliseconds) { receivedMessages.shouldBeEmpty() }
     }
 }