fix: resolve the server 406 error in API calls - #203

Merged
4t145 merged 1 commit into
modelcontextprotocol:mainfrom
A-afflatus:main
May 21, 2025
Merged

fix: resolve the server 406 error in API calls#203
4t145 merged 1 commit into
modelcontextprotocol:mainfrom
A-afflatus:main

Conversation

@A-afflatus

@A-afflatusA-afflatus commented May 20, 2025•
edited
Loading

Copy link
Copy Markdown
Contributor

Motivation and Context

  • ​​Problem​​: When using the typescript-sdk's StreamableHttp server (from src/examples/server/simpleStreamableHttp.ts), requests from rust-sdk clients would return 406 errors, making the service unusable for these clients.
    ​​- Root Cause​​: The server's Accept header validation was too strict, rejecting valid requests from certain SDK implementations.
    ​​- Solution​​: By merging and properly handling Accept headers, we maintain compatibility across different SDK implementations while preserving the expected behavior.

How Has This Been Tested?

  • Modified the typescript-sdk and verified using the rust-sdk client example (examples/clients/src/streamable_http.rs)
  • Confirmed that:
    • 406 errors no longer occur for valid requests
    • Standard JSON requests (Accept: application/json) continue to work as expected
    • The service remains stable with different Accept header variations

Breaking Changes

No 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

issue:

image

after repair:

image

@4t145

4t145 commented May 20, 2025

Copy link
Copy Markdown
Contributor

Thanks a lot! Could you fix the clippy and fmt failure?

cargo clippy --fix --all-targets --all-features
cargo +nightly fmt --all

@A-afflatusA-afflatus changed the title fix: resolve the server 406 error in API calls (406 is an HTTP "Not A…fix: resolve the server 406 error in API callsMay 21, 2025
@A-afflatus

A-afflatus commented May 21, 2025

Copy link
Copy Markdown
ContributorAuthor

@4t145 done

@4t145
4t145 merged commit 8222e18 into modelcontextprotocol:mainMay 21, 2025
@github-actionsgithub-actionsBot mentioned this pull request Jul 2, 2025
Merged
takumi-earth pushed a commit to earthlings-dev/rmcp that referenced this pull request Jan 27, 2026
@A-afflatus
fix: resolve the server 406 error in API calls (modelcontextprotocol#203
ccc258c
)
Sign up for freeto join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

1 more reviewer
@4t1454t1454t145 approved these changes
Reviewers whose approvals may not affect merge requirements

Assignees

No one assigned

Labels

None yet

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

2 participants

@A-afflatus@4t145
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

Skip to content
fix: resolve the server 406 error in API calls - #203
Merged
4t145 merged 1 commit into
modelcontextprotocol:mainfrom 
A-afflatus:main
May 21, 2025
Merged
fix: resolve the server 406 error in API calls#203
4t145 merged 1 commit into
modelcontextprotocol:mainfrom 
A-afflatus:main
Conversation
@A-afflatus
@A-afflatusA-afflatus
commented
May 20, 2025•

edited

Loading

Copy link


Copy Markdown

Contributor
Motivation and Context
  • ​​Problem​​: When using the typescript-sdk's StreamableHttp server (from src/examples/server/simpleStreamableHttp.ts), requests from rust-sdk clients would return 406 errors, making the service unusable for these clients.
    
​​- Root Cause​​: The server's Accept header validation was too strict, rejecting valid requests from certain SDK implementations.
    
​​- Solution​​: By merging and properly handling Accept headers, we maintain compatibility across different SDK implementations while preserving the expected behavior.
How Has This Been Tested?
  • Modified the typescript-sdk and verified using the rust-sdk client example (examples/clients/src/streamable_http.rs)
  • Confirmed that:

    • 406 errors no longer occur for valid requests
    • Standard JSON requests (Accept: application/json) continue to work as expected
    • The service remains stable with different Accept header variations
Breaking Changes
No 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
issue:
image
after repair:
image
@4t145
4t145
commented
May 20, 2025

Copy link


Copy Markdown

Contributor
Thanks a lot! Could you fix the clippy and fmt failure?
cargo clippy --fix --all-targets --all-features
cargo +nightly fmt --all
@A-afflatusA-afflatus
changed the title
fix: resolve the server 406 error in API calls (406 is an HTTP "Not A…fix: resolve the server 406 error in API callsMay 21, 2025
@A-afflatus
A-afflatus
commented
May 21, 2025

Copy link


Copy Markdown

ContributorAuthor
@4t145 done
@4t145
4t145
merged commit 8222e18
into
modelcontextprotocol:mainMay 21, 2025
@github-actionsgithub-actionsBot
mentioned this pull request
Jul 2, 2025
 Merged

takumi-earth pushed a commit
to earthlings-dev/rmcp
that referenced
this pull request
Jan 27, 2026
@A-afflatus
fix: resolve the server 406 error in API calls (modelcontextprotocol#203
ccc258c
)
Sign up for freeto join this conversation on GitHub.
Already have an account?
Sign in to comment

Reviewers


1 more reviewer

@4t1454t1454t145 approved these changes
Reviewers whose approvals may not affect merge requirements

Assignees


No one assigned


Labels


None yet


Projects


None yet


Milestone


No milestone


Development

Successfully merging this pull request may close these issues.

2 participants

@A-afflatus@4t145

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
fix: resolve the server 406 error in API calls - #203
Merged
4t145 merged 1 commit into
modelcontextprotocol:mainfrom 
A-afflatus:main
May 21, 2025
Merged
fix: resolve the server 406 error in API calls#203
4t145 merged 1 commit into
modelcontextprotocol:mainfrom 
A-afflatus:main
Conversation
@A-afflatus
@A-afflatusA-afflatus
commented
May 20, 2025•

edited

Loading

Copy link


Copy Markdown

Contributor
Motivation and Context
  • ​​Problem​​: When using the typescript-sdk's StreamableHttp server (from src/examples/server/simpleStreamableHttp.ts), requests from rust-sdk clients would return 406 errors, making the service unusable for these clients.
    
​​- Root Cause​​: The server's Accept header validation was too strict, rejecting valid requests from certain SDK implementations.
    
​​- Solution​​: By merging and properly handling Accept headers, we maintain compatibility across different SDK implementations while preserving the expected behavior.
How Has This Been Tested?
  • Modified the typescript-sdk and verified using the rust-sdk client example (examples/clients/src/streamable_http.rs)
  • Confirmed that:

    • 406 errors no longer occur for valid requests
    • Standard JSON requests (Accept: application/json) continue to work as expected
    • The service remains stable with different Accept header variations
Breaking Changes
No 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
issue:
image
after repair:
image
@4t145
4t145
commented
May 20, 2025

Copy link


Copy Markdown

Contributor
Thanks a lot! Could you fix the clippy and fmt failure?
cargo clippy --fix --all-targets --all-features
cargo +nightly fmt --all
@A-afflatusA-afflatus
changed the title
fix: resolve the server 406 error in API calls (406 is an HTTP "Not A…fix: resolve the server 406 error in API callsMay 21, 2025
@A-afflatus
A-afflatus
commented
May 21, 2025

Copy link


Copy Markdown

ContributorAuthor
@4t145 done
@4t145
4t145
merged commit 8222e18
into
modelcontextprotocol:mainMay 21, 2025
@github-actionsgithub-actionsBot
mentioned this pull request
Jul 2, 2025
 Merged

takumi-earth pushed a commit
to earthlings-dev/rmcp
that referenced
this pull request
Jan 27, 2026
@A-afflatus
fix: resolve the server 406 error in API calls (modelcontextprotocol#203
ccc258c
)
Sign up for freeto join this conversation on GitHub.
Already have an account?
Sign in to comment

Reviewers


1 more reviewer

@4t1454t1454t145 approved these changes
Reviewers whose approvals may not affect merge requirements

Assignees


No one assigned


Labels


None yet


Projects


None yet


Milestone


No milestone


Development

Successfully merging this pull request may close these issues.

2 participants

@A-afflatus@4t145

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
fix: resolve the server 406 error in API calls - #203
Merged
4t145 merged 1 commit into
modelcontextprotocol:mainfrom 
A-afflatus:main
May 21, 2025
Merged
fix: resolve the server 406 error in API calls#203
4t145 merged 1 commit into
modelcontextprotocol:mainfrom 
A-afflatus:main
Conversation
@A-afflatus
@A-afflatusA-afflatus
commented
May 20, 2025•

edited

Loading

Copy link


Copy Markdown

Contributor
Motivation and Context
  • ​​Problem​​: When using the typescript-sdk's StreamableHttp server (from src/examples/server/simpleStreamableHttp.ts), requests from rust-sdk clients would return 406 errors, making the service unusable for these clients.
    
​​- Root Cause​​: The server's Accept header validation was too strict, rejecting valid requests from certain SDK implementations.
    
​​- Solution​​: By merging and properly handling Accept headers, we maintain compatibility across different SDK implementations while preserving the expected behavior.
How Has This Been Tested?
  • Modified the typescript-sdk and verified using the rust-sdk client example (examples/clients/src/streamable_http.rs)
  • Confirmed that:

    • 406 errors no longer occur for valid requests
    • Standard JSON requests (Accept: application/json) continue to work as expected
    • The service remains stable with different Accept header variations
Breaking Changes
No 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
issue:
image
after repair:
image
@4t145
4t145
commented
May 20, 2025

Copy link


Copy Markdown

Contributor
Thanks a lot! Could you fix the clippy and fmt failure?
cargo clippy --fix --all-targets --all-features
cargo +nightly fmt --all
@A-afflatusA-afflatus
changed the title
fix: resolve the server 406 error in API calls (406 is an HTTP "Not A…fix: resolve the server 406 error in API callsMay 21, 2025
@A-afflatus
A-afflatus
commented
May 21, 2025

Copy link


Copy Markdown

ContributorAuthor
@4t145 done
@4t145
4t145
merged commit 8222e18
into
modelcontextprotocol:mainMay 21, 2025
@github-actionsgithub-actionsBot
mentioned this pull request
Jul 2, 2025
 Merged

takumi-earth pushed a commit
to earthlings-dev/rmcp
that referenced
this pull request
Jan 27, 2026
@A-afflatus
fix: resolve the server 406 error in API calls (modelcontextprotocol#203
ccc258c
)
Sign up for freeto join this conversation on GitHub.
Already have an account?
Sign in to comment

Reviewers


1 more reviewer

@4t1454t1454t145 approved these changes
Reviewers whose approvals may not affect merge requirements

Assignees


No one assigned


Labels


None yet


Projects


None yet


Milestone


No milestone


Development

Successfully merging this pull request may close these issues.

2 participants

@A-afflatus@4t145

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
fix: resolve the server 406 error in API calls - #203
Merged
4t145 merged 1 commit into
modelcontextprotocol:mainfrom 
A-afflatus:main
May 21, 2025
Merged
fix: resolve the server 406 error in API calls#203
4t145 merged 1 commit into
modelcontextprotocol:mainfrom 
A-afflatus:main
Conversation
@A-afflatus
@A-afflatusA-afflatus
commented
May 20, 2025•

edited

Loading

Copy link


Copy Markdown

Contributor
Motivation and Context
  • ​​Problem​​: When using the typescript-sdk's StreamableHttp server (from src/examples/server/simpleStreamableHttp.ts), requests from rust-sdk clients would return 406 errors, making the service unusable for these clients.
    
​​- Root Cause​​: The server's Accept header validation was too strict, rejecting valid requests from certain SDK implementations.
    
​​- Solution​​: By merging and properly handling Accept headers, we maintain compatibility across different SDK implementations while preserving the expected behavior.
How Has This Been Tested?
  • Modified the typescript-sdk and verified using the rust-sdk client example (examples/clients/src/streamable_http.rs)
  • Confirmed that:

    • 406 errors no longer occur for valid requests
    • Standard JSON requests (Accept: application/json) continue to work as expected
    • The service remains stable with different Accept header variations
Breaking Changes
No 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
issue:
image
after repair:
image
@4t145
4t145
commented
May 20, 2025

Copy link


Copy Markdown

Contributor
Thanks a lot! Could you fix the clippy and fmt failure?
cargo clippy --fix --all-targets --all-features
cargo +nightly fmt --all
@A-afflatusA-afflatus
changed the title
fix: resolve the server 406 error in API calls (406 is an HTTP "Not A…fix: resolve the server 406 error in API callsMay 21, 2025
@A-afflatus
A-afflatus
commented
May 21, 2025

Copy link


Copy Markdown

ContributorAuthor
@4t145 done
@4t145
4t145
merged commit 8222e18
into
modelcontextprotocol:mainMay 21, 2025
@github-actionsgithub-actionsBot
mentioned this pull request
Jul 2, 2025
 Merged

takumi-earth pushed a commit
to earthlings-dev/rmcp
that referenced
this pull request
Jan 27, 2026
@A-afflatus
fix: resolve the server 406 error in API calls (modelcontextprotocol#203
ccc258c
)
Sign up for freeto join this conversation on GitHub.
Already have an account?
Sign in to comment

Reviewers


1 more reviewer

@4t1454t1454t145 approved these changes
Reviewers whose approvals may not affect merge requirements

Assignees


No one assigned


Labels


None yet


Projects


None yet


Milestone


No milestone


Development

Successfully merging this pull request may close these issues.

2 participants

@A-afflatus@4t145

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
fix: resolve the server 406 error in API calls - #203
Merged
4t145 merged 1 commit into
modelcontextprotocol:mainfrom 
A-afflatus:main
May 21, 2025
Merged
fix: resolve the server 406 error in API calls#203
4t145 merged 1 commit into
modelcontextprotocol:mainfrom 
A-afflatus:main
Conversation
@A-afflatus
@A-afflatusA-afflatus
commented
May 20, 2025•

edited

Loading

Copy link


Copy Markdown

Contributor
Motivation and Context
  • ​​Problem​​: When using the typescript-sdk's StreamableHttp server (from src/examples/server/simpleStreamableHttp.ts), requests from rust-sdk clients would return 406 errors, making the service unusable for these clients.
    
​​- Root Cause​​: The server's Accept header validation was too strict, rejecting valid requests from certain SDK implementations.
    
​​- Solution​​: By merging and properly handling Accept headers, we maintain compatibility across different SDK implementations while preserving the expected behavior.
How Has This Been Tested?
  • Modified the typescript-sdk and verified using the rust-sdk client example (examples/clients/src/streamable_http.rs)
  • Confirmed that:

    • 406 errors no longer occur for valid requests
    • Standard JSON requests (Accept: application/json) continue to work as expected
    • The service remains stable with different Accept header variations
Breaking Changes
No 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
issue:
image
after repair:
image
@4t145
4t145
commented
May 20, 2025

Copy link


Copy Markdown

Contributor
Thanks a lot! Could you fix the clippy and fmt failure?
cargo clippy --fix --all-targets --all-features
cargo +nightly fmt --all
@A-afflatusA-afflatus
changed the title
fix: resolve the server 406 error in API calls (406 is an HTTP "Not A…fix: resolve the server 406 error in API callsMay 21, 2025
@A-afflatus
A-afflatus
commented
May 21, 2025

Copy link


Copy Markdown

ContributorAuthor
@4t145 done
@4t145
4t145
merged commit 8222e18
into
modelcontextprotocol:mainMay 21, 2025
@github-actionsgithub-actionsBot
mentioned this pull request
Jul 2, 2025
 Merged

takumi-earth pushed a commit
to earthlings-dev/rmcp
that referenced
this pull request
Jan 27, 2026
@A-afflatus
fix: resolve the server 406 error in API calls (modelcontextprotocol#203
ccc258c
)
Sign up for freeto join this conversation on GitHub.
Already have an account?
Sign in to comment

Reviewers


1 more reviewer

@4t1454t1454t145 approved these changes
Reviewers whose approvals may not affect merge requirements

Assignees


No one assigned


Labels


None yet


Projects


None yet


Milestone


No milestone


Development

Successfully merging this pull request may close these issues.

2 participants

@A-afflatus@4t145

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
fix: resolve the server 406 error in API calls - #203
Merged
4t145 merged 1 commit into
modelcontextprotocol:mainfrom 
A-afflatus:main
May 21, 2025
Merged
fix: resolve the server 406 error in API calls#203
4t145 merged 1 commit into
modelcontextprotocol:mainfrom 
A-afflatus:main
Conversation
@A-afflatus
@A-afflatusA-afflatus
commented
May 20, 2025•

edited

Loading

Copy link


Copy Markdown

Contributor
Motivation and Context
  • ​​Problem​​: When using the typescript-sdk's StreamableHttp server (from src/examples/server/simpleStreamableHttp.ts), requests from rust-sdk clients would return 406 errors, making the service unusable for these clients.
    
​​- Root Cause​​: The server's Accept header validation was too strict, rejecting valid requests from certain SDK implementations.
    
​​- Solution​​: By merging and properly handling Accept headers, we maintain compatibility across different SDK implementations while preserving the expected behavior.
How Has This Been Tested?
  • Modified the typescript-sdk and verified using the rust-sdk client example (examples/clients/src/streamable_http.rs)
  • Confirmed that:

    • 406 errors no longer occur for valid requests
    • Standard JSON requests (Accept: application/json) continue to work as expected
    • The service remains stable with different Accept header variations
Breaking Changes
No 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
issue:
image
after repair:
image
@4t145
4t145
commented
May 20, 2025

Copy link


Copy Markdown

Contributor
Thanks a lot! Could you fix the clippy and fmt failure?
cargo clippy --fix --all-targets --all-features
cargo +nightly fmt --all
@A-afflatusA-afflatus
changed the title
fix: resolve the server 406 error in API calls (406 is an HTTP "Not A…fix: resolve the server 406 error in API callsMay 21, 2025
@A-afflatus
A-afflatus
commented
May 21, 2025

Copy link


Copy Markdown

ContributorAuthor
@4t145 done
@4t145
4t145
merged commit 8222e18
into
modelcontextprotocol:mainMay 21, 2025
@github-actionsgithub-actionsBot
mentioned this pull request
Jul 2, 2025
 Merged

takumi-earth pushed a commit
to earthlings-dev/rmcp
that referenced
this pull request
Jan 27, 2026
@A-afflatus
fix: resolve the server 406 error in API calls (modelcontextprotocol#203
ccc258c
)
Sign up for freeto join this conversation on GitHub.
Already have an account?
Sign in to comment

Reviewers


1 more reviewer

@4t1454t1454t145 approved these changes
Reviewers whose approvals may not affect merge requirements

Assignees


No one assigned


Labels


None yet


Projects


None yet


Milestone


No milestone


Development

Successfully merging this pull request may close these issues.

2 participants

@A-afflatus@4t145

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

Skip to content
fix: resolve the server 406 error in API calls - #203
Merged
4t145 merged 1 commit into
modelcontextprotocol:mainfrom 
A-afflatus:main
May 21, 2025
Merged
fix: resolve the server 406 error in API calls#203
4t145 merged 1 commit into
modelcontextprotocol:mainfrom 
A-afflatus:main
Conversation
@A-afflatus
@A-afflatusA-afflatus
commented
May 20, 2025•

edited

Loading

Copy link


Copy Markdown

Contributor
Motivation and Context
  • ​​Problem​​: When using the typescript-sdk's StreamableHttp server (from src/examples/server/simpleStreamableHttp.ts), requests from rust-sdk clients would return 406 errors, making the service unusable for these clients.
    
​​- Root Cause​​: The server's Accept header validation was too strict, rejecting valid requests from certain SDK implementations.
    
​​- Solution​​: By merging and properly handling Accept headers, we maintain compatibility across different SDK implementations while preserving the expected behavior.
How Has This Been Tested?
  • Modified the typescript-sdk and verified using the rust-sdk client example (examples/clients/src/streamable_http.rs)
  • Confirmed that:

    • 406 errors no longer occur for valid requests
    • Standard JSON requests (Accept: application/json) continue to work as expected
    • The service remains stable with different Accept header variations
Breaking Changes
No 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
issue:
image
after repair:
image
@4t145
4t145
commented
May 20, 2025

Copy link


Copy Markdown

Contributor
Thanks a lot! Could you fix the clippy and fmt failure?
cargo clippy --fix --all-targets --all-features
cargo +nightly fmt --all
@A-afflatusA-afflatus
changed the title
fix: resolve the server 406 error in API calls (406 is an HTTP "Not A…fix: resolve the server 406 error in API callsMay 21, 2025
@A-afflatus
A-afflatus
commented
May 21, 2025

Copy link


Copy Markdown

ContributorAuthor
@4t145 done
@4t145
4t145
merged commit 8222e18
into
modelcontextprotocol:mainMay 21, 2025
@github-actionsgithub-actionsBot
mentioned this pull request
Jul 2, 2025
 Merged

takumi-earth pushed a commit
to earthlings-dev/rmcp
that referenced
this pull request
Jan 27, 2026
@A-afflatus
fix: resolve the server 406 error in API calls (modelcontextprotocol#203
ccc258c
)
Sign up for freeto join this conversation on GitHub.
Already have an account?
Sign in to comment

Reviewers


1 more reviewer

@4t1454t1454t145 approved these changes
Reviewers whose approvals may not affect merge requirements

Assignees


No one assigned


Labels


None yet


Projects


None yet


Milestone


No milestone


Development

Successfully merging this pull request may close these issues.

2 participants

@A-afflatus@4t145