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fix(model): decode metadata-bearing input-required results affecting mrtr - #1097

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Jul 31, 2026
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fix(model): decode metadata-bearing input-required results affecting mrtr#1097
DaleSeo merged 2 commits into
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filintod:filintod/mrtr-meta-fix

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@filintod

@filintodfilintod commented Jul 30, 2026•
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The draft permits every Result, including InputRequiredResult, to carry
_meta and recommends that servers include
io.modelcontextprotocol/serverInfo on every response. It also requires
an InputRequiredResult to contain inputRequests or requestState so the
client knows what to provide or how to resume the request.

ServerResult uses untagged deserialization and attempts CallToolResult
before InputRequiredResult. Because CallToolResult accepts _meta and
defaults missing content to an empty list, it consumed valid
input_required results carrying metadata. Unknown inputRequests and
requestState fields were then discarded, leaving clients without the
information needed to continue.

Reject resultType input_required when deserializing CallToolResult so
Serde proceeds to the InputRequiredResult variant. Add regression
coverage proving that inputRequests, requestState, and serverInfo
metadata are preserved.

Spec:

Fixes#1098

Motivation and Context

Found while checking against the conformance tests and several of mrtr 2322 tests failed with missing inputRequests and/or requestState

A valid MRTR InputRequiredResult with result metadata can be misclassified as CallToolResult during untagged deserialization. The SDK then drops inputRequests and requestState, preventing clients from presenting the required elicitation or retrying with the server state.

How Has This Been Tested?

Re-run the conformance tests after building locally and tests passed

Breaking Changes

Types of changes

  • Bug fix (non-breaking change which fixes an issue)
  • New feature (non-breaking change which adds functionality)
  • Breaking change (fix or feature that would cause existing functionality to change)
  • Documentation update

Checklist

  • I have read the MCP Documentation
  • My code follows the repository's style guidelines
  • New and existing tests pass locally
  • I have added appropriate error handling
  • I have added or updated documentation as needed

Additional context

@filintod
fix(model): decode metadata-bearing input-required results
e8fe48f
 The draft permits every Result, including InputRequiredResult, to carry
_meta and recommends that servers include
io.modelcontextprotocol/serverInfo on every response. It also requires
an InputRequiredResult to contain inputRequests or requestState so the
client knows what to provide or how to resume the request.
ServerResult uses untagged deserialization and attempts CallToolResult
before InputRequiredResult. Because CallToolResult accepts _meta and
defaults missing content to an empty list, it consumed valid
input_required results carrying metadata. Unknown inputRequests and
requestState fields were then discarded, leaving clients without the
information needed to continue.
Reject resultType input_required when deserializing CallToolResult so
Serde proceeds to the InputRequiredResult variant. Add regression
coverage proving that inputRequests, requestState, and serverInfo
metadata are preserved.
Spec:
https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L137-L151https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L198-L224https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L541-L565
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@filintod
filintod requested a review from a team as a code ownerJuly 30, 2026 17:32
@github-actionsgithub-actionsBot added T-test Testing related changes T-core Core library changes labels Jul 30, 2026
@filintodfilintod changed the title fix(model): decode metadata-bearing input-required resultsfix(model): decode metadata-bearing input-required results affecting mrtrJul 30, 2026
DaleSeo
DaleSeo reviewed Jul 30, 2026
View reviewed changes
Comment threadcrates/rmcp/src/model.rs
@filintod
incorporate feedback - close gap in inputrequired not properly checki…
01dac4f
…ng that at least one of inputRequest or requestState is present
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@github-actionsgithub-actionsBot added the T-model Model/data structure changes label Jul 31, 2026
@filintod
filintod requested a review from DaleSeoJuly 31, 2026 03:37
@DaleSeo
DaleSeo merged commit 00bcf13 into modelcontextprotocol:mainJul 31, 2026
21 of 22 checks passed
@github-actionsgithub-actionsBot mentioned this pull request Jul 31, 2026
Merged
howardjohn pushed a commit to agentgateway/agentgateway that referenced this pull request Jul 31, 2026
@filintod
bump rmcp to 3.1.0 (#2788)
33d9d05
Bump to latest stable release
https://github.com/modelcontextprotocol/rust-sdk/releases/tag/rmcp-v3.1.0
```
Added
classify authorization-required errors (modelcontextprotocol/rust-sdk#1056)
add strict stateless protocol metadata validation (modelcontextprotocol/rust-sdk#1091)
SEP-2260 stream-based enforcement of client receive-side request association (modelcontextprotocol/rust-sdk#1055)
Fixed
(model) decode metadata-bearing input-required results affecting mrtr (modelcontextprotocol/rust-sdk#1097)
require metadata for modern HTTP requests (modelcontextprotocol/rust-sdk#1089)
honor supported_protocol_versions when negotiating initialize (modelcontextprotocol/rust-sdk#1093)
Other
document the ping utility with examples (modelcontextprotocol/rust-sdk#1106)
complete Tier 1 feature docs and finalize roadmap (modelcontextprotocol/rust-sdk#1101)
(conformance) meeting requirements for tier 1 (modelcontextprotocol/rust-sdk#1087)
```
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@SamMorrowDrumsSamMorrowDrums mentioned this pull request Jul 31, 2026
Closed
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InputRequiredResult metadata causes input and resume state to be dropped - mrtr requests sep 2322

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@filintod@DaleSeo
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fix(model): decode metadata-bearing input-required results affecting mrtr by filintod · Pull Request #1097 · modelcontextprotocol/rust-sdk · GitHub
Skip to content
fix(model): decode metadata-bearing input-required results affecting mrtr - #1097
Merged
DaleSeo merged 2 commits into
modelcontextprotocol:mainfrom 
filintod:filintod/mrtr-meta-fix
Jul 31, 2026
Merged
fix(model): decode metadata-bearing input-required results affecting mrtr#1097
DaleSeo merged 2 commits into
modelcontextprotocol:mainfrom 
filintod:filintod/mrtr-meta-fix
Conversation
@filintod
@filintodfilintod
commented
Jul 30, 2026•

edited

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Contributor
The draft permits every Result, including InputRequiredResult, to carry

_meta and recommends that servers include

io.modelcontextprotocol/serverInfo on every response. It also requires

an InputRequiredResult to contain inputRequests or requestState so the

client knows what to provide or how to resume the request.
ServerResult uses untagged deserialization and attempts CallToolResult

before InputRequiredResult. Because CallToolResult accepts _meta and

defaults missing content to an empty list, it consumed valid

input_required results carrying metadata. Unknown inputRequests and

requestState fields were then discarded, leaving clients without the

information needed to continue.
Reject resultType input_required when deserializing CallToolResult so

Serde proceeds to the InputRequiredResult variant. Add regression

coverage proving that inputRequests, requestState, and serverInfo

metadata are preserved.
Spec:
Fixes#1098
Motivation and Context
Found while checking against the conformance tests and several of mrtr 2322 tests failed with missing inputRequests and/or requestState
A valid MRTR InputRequiredResult with result metadata can be misclassified as CallToolResult during untagged deserialization. The SDK then drops inputRequests and requestState, preventing clients from presenting the required elicitation or retrying with the server state.
How Has This Been Tested?
Re-run the conformance tests after building locally and tests passed
Breaking Changes
Types of changes
  •  Bug fix (non-breaking change which fixes an issue)
  •  New feature (non-breaking change which adds functionality)
  •  Breaking change (fix or feature that would cause existing functionality to change)
  •  Documentation update
Checklist
  •  I have read the MCP Documentation
  •  My code follows the repository's style guidelines
  •  New and existing tests pass locally
  •  I have added appropriate error handling
  •  I have added or updated documentation as needed
Additional context
@filintod
fix(model): decode metadata-bearing input-required results
e8fe48f
 The draft permits every Result, including InputRequiredResult, to carry
_meta and recommends that servers include
io.modelcontextprotocol/serverInfo on every response. It also requires
an InputRequiredResult to contain inputRequests or requestState so the
client knows what to provide or how to resume the request.
ServerResult uses untagged deserialization and attempts CallToolResult
before InputRequiredResult. Because CallToolResult accepts _meta and
defaults missing content to an empty list, it consumed valid
input_required results carrying metadata. Unknown inputRequests and
requestState fields were then discarded, leaving clients without the
information needed to continue.
Reject resultType input_required when deserializing CallToolResult so
Serde proceeds to the InputRequiredResult variant. Add regression
coverage proving that inputRequests, requestState, and serverInfo
metadata are preserved.
Spec:
https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L137-L151https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L198-L224https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L541-L565
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@filintod
filintod
requested a review
from a team
as a code ownerJuly 30, 2026 17:32
@github-actionsgithub-actionsBot
added

T-test
Testing related changes
T-core
Core library changes
labels
Jul 30, 2026
@filintodfilintod
changed the title
fix(model): decode metadata-bearing input-required resultsfix(model): decode metadata-bearing input-required results affecting mrtrJul 30, 2026
DaleSeo
DaleSeo
reviewed
Jul 30, 2026
View reviewed changes
Comment threadcrates/rmcp/src/model.rs
@filintod
incorporate feedback - close gap in inputrequired not properly checki…
01dac4f
…ng that at least one of inputRequest or requestState is present
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@github-actionsgithub-actionsBot
added
the 
T-model
Model/data structure changes
label
Jul 31, 2026
@filintod
filintod
requested a review
from DaleSeoJuly 31, 2026 03:37
@DaleSeo
DaleSeo
merged commit 00bcf13
into
modelcontextprotocol:mainJul 31, 2026

21 of 22 checks passed

@github-actionsgithub-actionsBot
mentioned this pull request
Jul 31, 2026
 Merged

howardjohn pushed a commit
to agentgateway/agentgateway
that referenced
this pull request
Jul 31, 2026
@filintod
bump rmcp to 3.1.0 (#2788)
33d9d05
Bump to latest stable release
https://github.com/modelcontextprotocol/rust-sdk/releases/tag/rmcp-v3.1.0
```
Added
classify authorization-required errors (modelcontextprotocol/rust-sdk#1056)
add strict stateless protocol metadata validation (modelcontextprotocol/rust-sdk#1091)
SEP-2260 stream-based enforcement of client receive-side request association (modelcontextprotocol/rust-sdk#1055)
Fixed
(model) decode metadata-bearing input-required results affecting mrtr (modelcontextprotocol/rust-sdk#1097)
require metadata for modern HTTP requests (modelcontextprotocol/rust-sdk#1089)
honor supported_protocol_versions when negotiating initialize (modelcontextprotocol/rust-sdk#1093)
Other
document the ping utility with examples (modelcontextprotocol/rust-sdk#1106)
complete Tier 1 feature docs and finalize roadmap (modelcontextprotocol/rust-sdk#1101)
(conformance) meeting requirements for tier 1 (modelcontextprotocol/rust-sdk#1087)
```
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@SamMorrowDrumsSamMorrowDrums
mentioned this pull request
Jul 31, 2026

Closed

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InputRequiredResult metadata causes input and resume state to be dropped - mrtr requests sep 2322


2 participants

@filintod@DaleSeo

, 'i');
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fix(model): decode metadata-bearing input-required results affecting mrtr by filintod · Pull Request #1097 · modelcontextprotocol/rust-sdk · GitHub
Skip to content
fix(model): decode metadata-bearing input-required results affecting mrtr - #1097
Merged
DaleSeo merged 2 commits into
modelcontextprotocol:mainfrom 
filintod:filintod/mrtr-meta-fix
Jul 31, 2026
Merged
fix(model): decode metadata-bearing input-required results affecting mrtr#1097
DaleSeo merged 2 commits into
modelcontextprotocol:mainfrom 
filintod:filintod/mrtr-meta-fix
Conversation
@filintod
@filintodfilintod
commented
Jul 30, 2026•

edited

Loading

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Copy Markdown

Contributor
The draft permits every Result, including InputRequiredResult, to carry

_meta and recommends that servers include

io.modelcontextprotocol/serverInfo on every response. It also requires

an InputRequiredResult to contain inputRequests or requestState so the

client knows what to provide or how to resume the request.
ServerResult uses untagged deserialization and attempts CallToolResult

before InputRequiredResult. Because CallToolResult accepts _meta and

defaults missing content to an empty list, it consumed valid

input_required results carrying metadata. Unknown inputRequests and

requestState fields were then discarded, leaving clients without the

information needed to continue.
Reject resultType input_required when deserializing CallToolResult so

Serde proceeds to the InputRequiredResult variant. Add regression

coverage proving that inputRequests, requestState, and serverInfo

metadata are preserved.
Spec:
Fixes#1098
Motivation and Context
Found while checking against the conformance tests and several of mrtr 2322 tests failed with missing inputRequests and/or requestState
A valid MRTR InputRequiredResult with result metadata can be misclassified as CallToolResult during untagged deserialization. The SDK then drops inputRequests and requestState, preventing clients from presenting the required elicitation or retrying with the server state.
How Has This Been Tested?
Re-run the conformance tests after building locally and tests passed
Breaking Changes
Types of changes
  •  Bug fix (non-breaking change which fixes an issue)
  •  New feature (non-breaking change which adds functionality)
  •  Breaking change (fix or feature that would cause existing functionality to change)
  •  Documentation update
Checklist
  •  I have read the MCP Documentation
  •  My code follows the repository's style guidelines
  •  New and existing tests pass locally
  •  I have added appropriate error handling
  •  I have added or updated documentation as needed
Additional context
@filintod
fix(model): decode metadata-bearing input-required results
e8fe48f
 The draft permits every Result, including InputRequiredResult, to carry
_meta and recommends that servers include
io.modelcontextprotocol/serverInfo on every response. It also requires
an InputRequiredResult to contain inputRequests or requestState so the
client knows what to provide or how to resume the request.
ServerResult uses untagged deserialization and attempts CallToolResult
before InputRequiredResult. Because CallToolResult accepts _meta and
defaults missing content to an empty list, it consumed valid
input_required results carrying metadata. Unknown inputRequests and
requestState fields were then discarded, leaving clients without the
information needed to continue.
Reject resultType input_required when deserializing CallToolResult so
Serde proceeds to the InputRequiredResult variant. Add regression
coverage proving that inputRequests, requestState, and serverInfo
metadata are preserved.
Spec:
https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L137-L151https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L198-L224https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L541-L565
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@filintod
filintod
requested a review
from a team
as a code ownerJuly 30, 2026 17:32
@github-actionsgithub-actionsBot
added

T-test
Testing related changes
T-core
Core library changes
labels
Jul 30, 2026
@filintodfilintod
changed the title
fix(model): decode metadata-bearing input-required resultsfix(model): decode metadata-bearing input-required results affecting mrtrJul 30, 2026
DaleSeo
DaleSeo
reviewed
Jul 30, 2026
View reviewed changes
Comment threadcrates/rmcp/src/model.rs
@filintod
incorporate feedback - close gap in inputrequired not properly checki…
01dac4f
…ng that at least one of inputRequest or requestState is present
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@github-actionsgithub-actionsBot
added
the 
T-model
Model/data structure changes
label
Jul 31, 2026
@filintod
filintod
requested a review
from DaleSeoJuly 31, 2026 03:37
@DaleSeo
DaleSeo
merged commit 00bcf13
into
modelcontextprotocol:mainJul 31, 2026

21 of 22 checks passed

@github-actionsgithub-actionsBot
mentioned this pull request
Jul 31, 2026
 Merged

howardjohn pushed a commit
to agentgateway/agentgateway
that referenced
this pull request
Jul 31, 2026
@filintod
bump rmcp to 3.1.0 (#2788)
33d9d05
Bump to latest stable release
https://github.com/modelcontextprotocol/rust-sdk/releases/tag/rmcp-v3.1.0
```
Added
classify authorization-required errors (modelcontextprotocol/rust-sdk#1056)
add strict stateless protocol metadata validation (modelcontextprotocol/rust-sdk#1091)
SEP-2260 stream-based enforcement of client receive-side request association (modelcontextprotocol/rust-sdk#1055)
Fixed
(model) decode metadata-bearing input-required results affecting mrtr (modelcontextprotocol/rust-sdk#1097)
require metadata for modern HTTP requests (modelcontextprotocol/rust-sdk#1089)
honor supported_protocol_versions when negotiating initialize (modelcontextprotocol/rust-sdk#1093)
Other
document the ping utility with examples (modelcontextprotocol/rust-sdk#1106)
complete Tier 1 feature docs and finalize roadmap (modelcontextprotocol/rust-sdk#1101)
(conformance) meeting requirements for tier 1 (modelcontextprotocol/rust-sdk#1087)
```
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@SamMorrowDrumsSamMorrowDrums
mentioned this pull request
Jul 31, 2026

Closed

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InputRequiredResult metadata causes input and resume state to be dropped - mrtr requests sep 2322


2 participants

@filintod@DaleSeo

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fix(model): decode metadata-bearing input-required results affecting mrtr by filintod · Pull Request #1097 · modelcontextprotocol/rust-sdk · GitHub
Skip to content
fix(model): decode metadata-bearing input-required results affecting mrtr - #1097
Merged
DaleSeo merged 2 commits into
modelcontextprotocol:mainfrom 
filintod:filintod/mrtr-meta-fix
Jul 31, 2026
Merged
fix(model): decode metadata-bearing input-required results affecting mrtr#1097
DaleSeo merged 2 commits into
modelcontextprotocol:mainfrom 
filintod:filintod/mrtr-meta-fix
Conversation
@filintod
@filintodfilintod
commented
Jul 30, 2026•

edited

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Contributor
The draft permits every Result, including InputRequiredResult, to carry

_meta and recommends that servers include

io.modelcontextprotocol/serverInfo on every response. It also requires

an InputRequiredResult to contain inputRequests or requestState so the

client knows what to provide or how to resume the request.
ServerResult uses untagged deserialization and attempts CallToolResult

before InputRequiredResult. Because CallToolResult accepts _meta and

defaults missing content to an empty list, it consumed valid

input_required results carrying metadata. Unknown inputRequests and

requestState fields were then discarded, leaving clients without the

information needed to continue.
Reject resultType input_required when deserializing CallToolResult so

Serde proceeds to the InputRequiredResult variant. Add regression

coverage proving that inputRequests, requestState, and serverInfo

metadata are preserved.
Spec:
Fixes#1098
Motivation and Context
Found while checking against the conformance tests and several of mrtr 2322 tests failed with missing inputRequests and/or requestState
A valid MRTR InputRequiredResult with result metadata can be misclassified as CallToolResult during untagged deserialization. The SDK then drops inputRequests and requestState, preventing clients from presenting the required elicitation or retrying with the server state.
How Has This Been Tested?
Re-run the conformance tests after building locally and tests passed
Breaking Changes
Types of changes
  •  Bug fix (non-breaking change which fixes an issue)
  •  New feature (non-breaking change which adds functionality)
  •  Breaking change (fix or feature that would cause existing functionality to change)
  •  Documentation update
Checklist
  •  I have read the MCP Documentation
  •  My code follows the repository's style guidelines
  •  New and existing tests pass locally
  •  I have added appropriate error handling
  •  I have added or updated documentation as needed
Additional context
@filintod
fix(model): decode metadata-bearing input-required results
e8fe48f
 The draft permits every Result, including InputRequiredResult, to carry
_meta and recommends that servers include
io.modelcontextprotocol/serverInfo on every response. It also requires
an InputRequiredResult to contain inputRequests or requestState so the
client knows what to provide or how to resume the request.
ServerResult uses untagged deserialization and attempts CallToolResult
before InputRequiredResult. Because CallToolResult accepts _meta and
defaults missing content to an empty list, it consumed valid
input_required results carrying metadata. Unknown inputRequests and
requestState fields were then discarded, leaving clients without the
information needed to continue.
Reject resultType input_required when deserializing CallToolResult so
Serde proceeds to the InputRequiredResult variant. Add regression
coverage proving that inputRequests, requestState, and serverInfo
metadata are preserved.
Spec:
https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L137-L151https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L198-L224https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L541-L565
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@filintod
filintod
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as a code ownerJuly 30, 2026 17:32
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fix(model): decode metadata-bearing input-required resultsfix(model): decode metadata-bearing input-required results affecting mrtrJul 30, 2026
DaleSeo
DaleSeo
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Jul 30, 2026
View reviewed changes
Comment threadcrates/rmcp/src/model.rs
@filintod
incorporate feedback - close gap in inputrequired not properly checki…
01dac4f
…ng that at least one of inputRequest or requestState is present
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@github-actionsgithub-actionsBot
added
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T-model
Model/data structure changes
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@filintod
filintod
requested a review
from DaleSeoJuly 31, 2026 03:37
@DaleSeo
DaleSeo
merged commit 00bcf13
into
modelcontextprotocol:mainJul 31, 2026

21 of 22 checks passed

@github-actionsgithub-actionsBot
mentioned this pull request
Jul 31, 2026
 Merged

howardjohn pushed a commit
to agentgateway/agentgateway
that referenced
this pull request
Jul 31, 2026
@filintod
bump rmcp to 3.1.0 (#2788)
33d9d05
Bump to latest stable release
https://github.com/modelcontextprotocol/rust-sdk/releases/tag/rmcp-v3.1.0
```
Added
classify authorization-required errors (modelcontextprotocol/rust-sdk#1056)
add strict stateless protocol metadata validation (modelcontextprotocol/rust-sdk#1091)
SEP-2260 stream-based enforcement of client receive-side request association (modelcontextprotocol/rust-sdk#1055)
Fixed
(model) decode metadata-bearing input-required results affecting mrtr (modelcontextprotocol/rust-sdk#1097)
require metadata for modern HTTP requests (modelcontextprotocol/rust-sdk#1089)
honor supported_protocol_versions when negotiating initialize (modelcontextprotocol/rust-sdk#1093)
Other
document the ping utility with examples (modelcontextprotocol/rust-sdk#1106)
complete Tier 1 feature docs and finalize roadmap (modelcontextprotocol/rust-sdk#1101)
(conformance) meeting requirements for tier 1 (modelcontextprotocol/rust-sdk#1087)
```
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@SamMorrowDrumsSamMorrowDrums
mentioned this pull request
Jul 31, 2026

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InputRequiredResult metadata causes input and resume state to be dropped - mrtr requests sep 2322


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@filintod@DaleSeo

, 'i');
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// Strip utm_, fbclid, gclid, etc. from all links on page
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var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',
'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',
'ref', 'ref_src', 'source', 'medium', 'campaign'];
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try {
var u = new URL(url, window.location.origin);
var changed = false;
trackingParams.forEach(function(p) {
if (u.searchParams.has(p)) {
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return changed ? u.toString() : url;
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return url;
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}
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if (clean !== a.href) a.href = clean;
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mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1) {
if (node.tagName === 'A') cleanLinks();
node.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '
fix(model): decode metadata-bearing input-required results affecting mrtr by filintod · Pull Request #1097 · modelcontextprotocol/rust-sdk · GitHub
Skip to content
fix(model): decode metadata-bearing input-required results affecting mrtr - #1097
Merged
DaleSeo merged 2 commits into
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filintod:filintod/mrtr-meta-fix
Jul 31, 2026
Merged
fix(model): decode metadata-bearing input-required results affecting mrtr#1097
DaleSeo merged 2 commits into
modelcontextprotocol:mainfrom 
filintod:filintod/mrtr-meta-fix
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@filintod
@filintodfilintod
commented
Jul 30, 2026•

edited

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Contributor
The draft permits every Result, including InputRequiredResult, to carry

_meta and recommends that servers include

io.modelcontextprotocol/serverInfo on every response. It also requires

an InputRequiredResult to contain inputRequests or requestState so the

client knows what to provide or how to resume the request.
ServerResult uses untagged deserialization and attempts CallToolResult

before InputRequiredResult. Because CallToolResult accepts _meta and

defaults missing content to an empty list, it consumed valid

input_required results carrying metadata. Unknown inputRequests and

requestState fields were then discarded, leaving clients without the

information needed to continue.
Reject resultType input_required when deserializing CallToolResult so

Serde proceeds to the InputRequiredResult variant. Add regression

coverage proving that inputRequests, requestState, and serverInfo

metadata are preserved.
Spec:
Fixes#1098
Motivation and Context
Found while checking against the conformance tests and several of mrtr 2322 tests failed with missing inputRequests and/or requestState
A valid MRTR InputRequiredResult with result metadata can be misclassified as CallToolResult during untagged deserialization. The SDK then drops inputRequests and requestState, preventing clients from presenting the required elicitation or retrying with the server state.
How Has This Been Tested?
Re-run the conformance tests after building locally and tests passed
Breaking Changes
Types of changes
  •  Bug fix (non-breaking change which fixes an issue)
  •  New feature (non-breaking change which adds functionality)
  •  Breaking change (fix or feature that would cause existing functionality to change)
  •  Documentation update
Checklist
  •  I have read the MCP Documentation
  •  My code follows the repository's style guidelines
  •  New and existing tests pass locally
  •  I have added appropriate error handling
  •  I have added or updated documentation as needed
Additional context
@filintod
fix(model): decode metadata-bearing input-required results
e8fe48f
 The draft permits every Result, including InputRequiredResult, to carry
_meta and recommends that servers include
io.modelcontextprotocol/serverInfo on every response. It also requires
an InputRequiredResult to contain inputRequests or requestState so the
client knows what to provide or how to resume the request.
ServerResult uses untagged deserialization and attempts CallToolResult
before InputRequiredResult. Because CallToolResult accepts _meta and
defaults missing content to an empty list, it consumed valid
input_required results carrying metadata. Unknown inputRequests and
requestState fields were then discarded, leaving clients without the
information needed to continue.
Reject resultType input_required when deserializing CallToolResult so
Serde proceeds to the InputRequiredResult variant. Add regression
coverage proving that inputRequests, requestState, and serverInfo
metadata are preserved.
Spec:
https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L137-L151https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L198-L224https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L541-L565
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@filintod
filintod
requested a review
from a team
as a code ownerJuly 30, 2026 17:32
@github-actionsgithub-actionsBot
added

T-test
Testing related changes
T-core
Core library changes
labels
Jul 30, 2026
@filintodfilintod
changed the title
fix(model): decode metadata-bearing input-required resultsfix(model): decode metadata-bearing input-required results affecting mrtrJul 30, 2026
DaleSeo
DaleSeo
reviewed
Jul 30, 2026
View reviewed changes
Comment threadcrates/rmcp/src/model.rs
@filintod
incorporate feedback - close gap in inputrequired not properly checki…
01dac4f
…ng that at least one of inputRequest or requestState is present
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@github-actionsgithub-actionsBot
added
the 
T-model
Model/data structure changes
label
Jul 31, 2026
@filintod
filintod
requested a review
from DaleSeoJuly 31, 2026 03:37
@DaleSeo
DaleSeo
merged commit 00bcf13
into
modelcontextprotocol:mainJul 31, 2026

21 of 22 checks passed

@github-actionsgithub-actionsBot
mentioned this pull request
Jul 31, 2026
 Merged

howardjohn pushed a commit
to agentgateway/agentgateway
that referenced
this pull request
Jul 31, 2026
@filintod
bump rmcp to 3.1.0 (#2788)
33d9d05
Bump to latest stable release
https://github.com/modelcontextprotocol/rust-sdk/releases/tag/rmcp-v3.1.0
```
Added
classify authorization-required errors (modelcontextprotocol/rust-sdk#1056)
add strict stateless protocol metadata validation (modelcontextprotocol/rust-sdk#1091)
SEP-2260 stream-based enforcement of client receive-side request association (modelcontextprotocol/rust-sdk#1055)
Fixed
(model) decode metadata-bearing input-required results affecting mrtr (modelcontextprotocol/rust-sdk#1097)
require metadata for modern HTTP requests (modelcontextprotocol/rust-sdk#1089)
honor supported_protocol_versions when negotiating initialize (modelcontextprotocol/rust-sdk#1093)
Other
document the ping utility with examples (modelcontextprotocol/rust-sdk#1106)
complete Tier 1 feature docs and finalize roadmap (modelcontextprotocol/rust-sdk#1101)
(conformance) meeting requirements for tier 1 (modelcontextprotocol/rust-sdk#1087)
```
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@SamMorrowDrumsSamMorrowDrums
mentioned this pull request
Jul 31, 2026

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InputRequiredResult metadata causes input and resume state to be dropped - mrtr requests sep 2322


2 participants

@filintod@DaleSeo

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Auto-enable theater mode on YouTube
(function() {
function tryTheater() {
var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]');
if (btn && !btn.classList.contains('activated')) {
btn.click();
}
}
// Try immediately
tryTheater();
// Try after navigation (SPA)
var lastUrl = location.href;
setInterval(function() {
if (location.href !== lastUrl) {
lastUrl = location.href;
setTimeout(tryTheater, 500);
}
}, 1000);
// Also try on player load
var observer = new MutationObserver(tryTheater);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
fix(model): decode metadata-bearing input-required results affecting mrtr by filintod · Pull Request #1097 · modelcontextprotocol/rust-sdk · GitHub
Skip to content
fix(model): decode metadata-bearing input-required results affecting mrtr - #1097
Merged
DaleSeo merged 2 commits into
modelcontextprotocol:mainfrom 
filintod:filintod/mrtr-meta-fix
Jul 31, 2026
Merged
fix(model): decode metadata-bearing input-required results affecting mrtr#1097
DaleSeo merged 2 commits into
modelcontextprotocol:mainfrom 
filintod:filintod/mrtr-meta-fix
Conversation
@filintod
@filintodfilintod
commented
Jul 30, 2026•

edited

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Contributor
The draft permits every Result, including InputRequiredResult, to carry

_meta and recommends that servers include

io.modelcontextprotocol/serverInfo on every response. It also requires

an InputRequiredResult to contain inputRequests or requestState so the

client knows what to provide or how to resume the request.
ServerResult uses untagged deserialization and attempts CallToolResult

before InputRequiredResult. Because CallToolResult accepts _meta and

defaults missing content to an empty list, it consumed valid

input_required results carrying metadata. Unknown inputRequests and

requestState fields were then discarded, leaving clients without the

information needed to continue.
Reject resultType input_required when deserializing CallToolResult so

Serde proceeds to the InputRequiredResult variant. Add regression

coverage proving that inputRequests, requestState, and serverInfo

metadata are preserved.
Spec:
Fixes#1098
Motivation and Context
Found while checking against the conformance tests and several of mrtr 2322 tests failed with missing inputRequests and/or requestState
A valid MRTR InputRequiredResult with result metadata can be misclassified as CallToolResult during untagged deserialization. The SDK then drops inputRequests and requestState, preventing clients from presenting the required elicitation or retrying with the server state.
How Has This Been Tested?
Re-run the conformance tests after building locally and tests passed
Breaking Changes
Types of changes
  •  Bug fix (non-breaking change which fixes an issue)
  •  New feature (non-breaking change which adds functionality)
  •  Breaking change (fix or feature that would cause existing functionality to change)
  •  Documentation update
Checklist
  •  I have read the MCP Documentation
  •  My code follows the repository's style guidelines
  •  New and existing tests pass locally
  •  I have added appropriate error handling
  •  I have added or updated documentation as needed
Additional context
@filintod
fix(model): decode metadata-bearing input-required results
e8fe48f
 The draft permits every Result, including InputRequiredResult, to carry
_meta and recommends that servers include
io.modelcontextprotocol/serverInfo on every response. It also requires
an InputRequiredResult to contain inputRequests or requestState so the
client knows what to provide or how to resume the request.
ServerResult uses untagged deserialization and attempts CallToolResult
before InputRequiredResult. Because CallToolResult accepts _meta and
defaults missing content to an empty list, it consumed valid
input_required results carrying metadata. Unknown inputRequests and
requestState fields were then discarded, leaving clients without the
information needed to continue.
Reject resultType input_required when deserializing CallToolResult so
Serde proceeds to the InputRequiredResult variant. Add regression
coverage proving that inputRequests, requestState, and serverInfo
metadata are preserved.
Spec:
https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L137-L151https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L198-L224https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L541-L565
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@filintod
filintod
requested a review
from a team
as a code ownerJuly 30, 2026 17:32
@github-actionsgithub-actionsBot
added

T-test
Testing related changes
T-core
Core library changes
labels
Jul 30, 2026
@filintodfilintod
changed the title
fix(model): decode metadata-bearing input-required resultsfix(model): decode metadata-bearing input-required results affecting mrtrJul 30, 2026
DaleSeo
DaleSeo
reviewed
Jul 30, 2026
View reviewed changes
Comment threadcrates/rmcp/src/model.rs
@filintod
incorporate feedback - close gap in inputrequired not properly checki…
01dac4f
…ng that at least one of inputRequest or requestState is present
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@github-actionsgithub-actionsBot
added
the 
T-model
Model/data structure changes
label
Jul 31, 2026
@filintod
filintod
requested a review
from DaleSeoJuly 31, 2026 03:37
@DaleSeo
DaleSeo
merged commit 00bcf13
into
modelcontextprotocol:mainJul 31, 2026

21 of 22 checks passed

@github-actionsgithub-actionsBot
mentioned this pull request
Jul 31, 2026
 Merged

howardjohn pushed a commit
to agentgateway/agentgateway
that referenced
this pull request
Jul 31, 2026
@filintod
bump rmcp to 3.1.0 (#2788)
33d9d05
Bump to latest stable release
https://github.com/modelcontextprotocol/rust-sdk/releases/tag/rmcp-v3.1.0
```
Added
classify authorization-required errors (modelcontextprotocol/rust-sdk#1056)
add strict stateless protocol metadata validation (modelcontextprotocol/rust-sdk#1091)
SEP-2260 stream-based enforcement of client receive-side request association (modelcontextprotocol/rust-sdk#1055)
Fixed
(model) decode metadata-bearing input-required results affecting mrtr (modelcontextprotocol/rust-sdk#1097)
require metadata for modern HTTP requests (modelcontextprotocol/rust-sdk#1089)
honor supported_protocol_versions when negotiating initialize (modelcontextprotocol/rust-sdk#1093)
Other
document the ping utility with examples (modelcontextprotocol/rust-sdk#1106)
complete Tier 1 feature docs and finalize roadmap (modelcontextprotocol/rust-sdk#1101)
(conformance) meeting requirements for tier 1 (modelcontextprotocol/rust-sdk#1087)
```
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@SamMorrowDrumsSamMorrowDrums
mentioned this pull request
Jul 31, 2026

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InputRequiredResult metadata causes input and resume state to be dropped - mrtr requests sep 2322


2 participants

@filintod@DaleSeo

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Remove or un-stick sticky/fixed headers that block content
(function() {
function unstick() {
document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) {
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el.style.position = 'static';
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observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });
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}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
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})();
fix(model): decode metadata-bearing input-required results affecting mrtr by filintod · Pull Request #1097 · modelcontextprotocol/rust-sdk · GitHub
Skip to content
fix(model): decode metadata-bearing input-required results affecting mrtr - #1097
Merged
DaleSeo merged 2 commits into
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filintod:filintod/mrtr-meta-fix
Jul 31, 2026
Merged
fix(model): decode metadata-bearing input-required results affecting mrtr#1097
DaleSeo merged 2 commits into
modelcontextprotocol:mainfrom 
filintod:filintod/mrtr-meta-fix
Conversation
@filintod
@filintodfilintod
commented
Jul 30, 2026•

edited

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Contributor
The draft permits every Result, including InputRequiredResult, to carry

_meta and recommends that servers include

io.modelcontextprotocol/serverInfo on every response. It also requires

an InputRequiredResult to contain inputRequests or requestState so the

client knows what to provide or how to resume the request.
ServerResult uses untagged deserialization and attempts CallToolResult

before InputRequiredResult. Because CallToolResult accepts _meta and

defaults missing content to an empty list, it consumed valid

input_required results carrying metadata. Unknown inputRequests and

requestState fields were then discarded, leaving clients without the

information needed to continue.
Reject resultType input_required when deserializing CallToolResult so

Serde proceeds to the InputRequiredResult variant. Add regression

coverage proving that inputRequests, requestState, and serverInfo

metadata are preserved.
Spec:
Fixes#1098
Motivation and Context
Found while checking against the conformance tests and several of mrtr 2322 tests failed with missing inputRequests and/or requestState
A valid MRTR InputRequiredResult with result metadata can be misclassified as CallToolResult during untagged deserialization. The SDK then drops inputRequests and requestState, preventing clients from presenting the required elicitation or retrying with the server state.
How Has This Been Tested?
Re-run the conformance tests after building locally and tests passed
Breaking Changes
Types of changes
  •  Bug fix (non-breaking change which fixes an issue)
  •  New feature (non-breaking change which adds functionality)
  •  Breaking change (fix or feature that would cause existing functionality to change)
  •  Documentation update
Checklist
  •  I have read the MCP Documentation
  •  My code follows the repository's style guidelines
  •  New and existing tests pass locally
  •  I have added appropriate error handling
  •  I have added or updated documentation as needed
Additional context
@filintod
fix(model): decode metadata-bearing input-required results
e8fe48f
 The draft permits every Result, including InputRequiredResult, to carry
_meta and recommends that servers include
io.modelcontextprotocol/serverInfo on every response. It also requires
an InputRequiredResult to contain inputRequests or requestState so the
client knows what to provide or how to resume the request.
ServerResult uses untagged deserialization and attempts CallToolResult
before InputRequiredResult. Because CallToolResult accepts _meta and
defaults missing content to an empty list, it consumed valid
input_required results carrying metadata. Unknown inputRequests and
requestState fields were then discarded, leaving clients without the
information needed to continue.
Reject resultType input_required when deserializing CallToolResult so
Serde proceeds to the InputRequiredResult variant. Add regression
coverage proving that inputRequests, requestState, and serverInfo
metadata are preserved.
Spec:
https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L137-L151https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L198-L224https://github.com/modelcontextprotocol/modelcontextprotocol/blob/41d9e938e9a9edf23a69429be180cad172e00f4e/schema/draft/schema.ts#L541-L565
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@filintod
filintod
requested a review
from a team
as a code ownerJuly 30, 2026 17:32
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added

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Jul 30, 2026
@filintodfilintod
changed the title
fix(model): decode metadata-bearing input-required resultsfix(model): decode metadata-bearing input-required results affecting mrtrJul 30, 2026
DaleSeo
DaleSeo
reviewed
Jul 30, 2026
View reviewed changes
Comment threadcrates/rmcp/src/model.rs
@filintod
incorporate feedback - close gap in inputrequired not properly checki…
01dac4f
…ng that at least one of inputRequest or requestState is present
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@github-actionsgithub-actionsBot
added
the 
T-model
Model/data structure changes
label
Jul 31, 2026
@filintod
filintod
requested a review
from DaleSeoJuly 31, 2026 03:37
@DaleSeo
DaleSeo
merged commit 00bcf13
into
modelcontextprotocol:mainJul 31, 2026

21 of 22 checks passed

@github-actionsgithub-actionsBot
mentioned this pull request
Jul 31, 2026
 Merged

howardjohn pushed a commit
to agentgateway/agentgateway
that referenced
this pull request
Jul 31, 2026
@filintod
bump rmcp to 3.1.0 (#2788)
33d9d05
Bump to latest stable release
https://github.com/modelcontextprotocol/rust-sdk/releases/tag/rmcp-v3.1.0
```
Added
classify authorization-required errors (modelcontextprotocol/rust-sdk#1056)
add strict stateless protocol metadata validation (modelcontextprotocol/rust-sdk#1091)
SEP-2260 stream-based enforcement of client receive-side request association (modelcontextprotocol/rust-sdk#1055)
Fixed
(model) decode metadata-bearing input-required results affecting mrtr (modelcontextprotocol/rust-sdk#1097)
require metadata for modern HTTP requests (modelcontextprotocol/rust-sdk#1089)
honor supported_protocol_versions when negotiating initialize (modelcontextprotocol/rust-sdk#1093)
Other
document the ping utility with examples (modelcontextprotocol/rust-sdk#1106)
complete Tier 1 feature docs and finalize roadmap (modelcontextprotocol/rust-sdk#1101)
(conformance) meeting requirements for tier 1 (modelcontextprotocol/rust-sdk#1087)
```
Signed-off-by: Filinto Duran <1373693+filintod@users.noreply.github.com>
@SamMorrowDrumsSamMorrowDrums
mentioned this pull request
Jul 31, 2026

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@DaleSeoDaleSeoDaleSeo approved these changes

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InputRequiredResult metadata causes input and resume state to be dropped - mrtr requests sep 2322


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