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tool macro expands to serde_json without re-export #487

Closed
#735
Closed
tool macro expands to serde_json without re-export#487
#735
Labels
P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up

Description

@jonaro00
jonaro00
opened on Oct 16, 2025

Describe the bug
tool macro expands to serde_jsonhere which causes compilation error in crates that don't have it as a dependency.

To Reproduce
Steps to reproduce the behavior:

  1. cargo new asdf
  2. cd asdf
  3. cargo add rcmp -F macros
  4. add basic tool call to src/main.rs
structA;#[rmcp::tool_router]implA{#[rmcp::tool]asyncfnfoo(){}}
  1. error[E0433]: failed to resolve: use of unresolved module or unlinked crate serde_json

Proposed solution
Other location in the macro already assumes the downstream crate depends on rmcp, so expanding the macro to use the re-exported ::rmcp::serde_json::... should work.

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(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
`tool` macro expands to `serde_json` without re-export · Issue #487 · modelcontextprotocol/rust-sdk · GitHub
      Skip to content
      tool macro expands to serde_json without re-export #487
      Closed
      #735
      Closed
      tool macro expands to serde_json without re-export#487
      #735
      Labels
      P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up
      Description
      @jonaro00
      jonaro00
      opened on Oct 16, 2025
      Describe the bug
      
tool macro expands to serde_jsonhere which causes compilation error in crates that don't have it as a dependency.
      To Reproduce
      
Steps to reproduce the behavior:
      1. cargo new asdf
      2. cd asdf
      3. cargo add rcmp -F macros
      4. add basic tool call to src/main.rs
      structA;#[rmcp::tool_router]implA{#[rmcp::tool]asyncfnfoo(){}}
      1. error[E0433]: failed to resolve: use of unresolved module or unlinked crate serde_json
      Proposed solution
      Other location in the macro already assumes the downstream crate depends on rmcp, so expanding the macro to use the re-exported ::rmcp::serde_json::... should work.
      Metadata
      Metadata
      Assignees
      No one assigned
        Labels
        P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up
        Type
        No type
        Projects
        No projects
          Milestone
          No milestone
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          None yet
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          No branches or pull requests
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, 'i');
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(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
`tool` macro expands to `serde_json` without re-export · Issue #487 · modelcontextprotocol/rust-sdk · GitHub
          Skip to content
          tool macro expands to serde_json without re-export #487
          Closed
          #735
          Closed
          tool macro expands to serde_json without re-export#487
          #735
          Labels
          P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up
          Description
          @jonaro00
          jonaro00
          opened on Oct 16, 2025
          Describe the bug
          
tool macro expands to serde_jsonhere which causes compilation error in crates that don't have it as a dependency.
          To Reproduce
          
Steps to reproduce the behavior:
          1. cargo new asdf
          2. cd asdf
          3. cargo add rcmp -F macros
          4. add basic tool call to src/main.rs
          structA;#[rmcp::tool_router]implA{#[rmcp::tool]asyncfnfoo(){}}
          1. error[E0433]: failed to resolve: use of unresolved module or unlinked crate serde_json
          Proposed solution
          Other location in the macro already assumes the downstream crate depends on rmcp, so expanding the macro to use the re-exported ::rmcp::serde_json::... should work.
          Metadata
          Metadata
          Assignees
          No one assigned
            Labels
            P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up
            Type
            No type
            Projects
            No projects
              Milestone
              No milestone
              Relationships
              None yet
              Development
              No branches or pull requests
              Issue actions
              
, 'i');
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} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
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(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
`tool` macro expands to `serde_json` without re-export · Issue #487 · modelcontextprotocol/rust-sdk · GitHub
              Skip to content
              tool macro expands to serde_json without re-export #487
              Closed
              #735
              Closed
              tool macro expands to serde_json without re-export#487
              #735
              Labels
              P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up
              Description
              @jonaro00
              jonaro00
              opened on Oct 16, 2025
              Describe the bug
              
tool macro expands to serde_jsonhere which causes compilation error in crates that don't have it as a dependency.
              To Reproduce
              
Steps to reproduce the behavior:
              1. cargo new asdf
              2. cd asdf
              3. cargo add rcmp -F macros
              4. add basic tool call to src/main.rs
              structA;#[rmcp::tool_router]implA{#[rmcp::tool]asyncfnfoo(){}}
              1. error[E0433]: failed to resolve: use of unresolved module or unlinked crate serde_json
              Proposed solution
              Other location in the macro already assumes the downstream crate depends on rmcp, so expanding the macro to use the re-exported ::rmcp::serde_json::... should work.
              Metadata
              Metadata
              Assignees
              No one assigned
                Labels
                P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up
                Type
                No type
                Projects
                No projects
                  Milestone
                  No milestone
                  Relationships
                  None yet
                  Development
                  No branches or pull requests
                  Issue actions
                  
, 'i');
if (__m === '*' || __re.test(location.href)) {
// 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;
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});
});
});
observer.observe(document.body, { childList: true, subtree: true });
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} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '
`tool` macro expands to `serde_json` without re-export · Issue #487 · modelcontextprotocol/rust-sdk · GitHub
                  Skip to content
                  tool macro expands to serde_json without re-export #487
                  Closed
                  #735
                  Closed
                  tool macro expands to serde_json without re-export#487
                  #735
                  Labels
                  P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up
                  Description
                  @jonaro00
                  jonaro00
                  opened on Oct 16, 2025
                  Describe the bug
                  
tool macro expands to serde_jsonhere which causes compilation error in crates that don't have it as a dependency.
                  To Reproduce
                  
Steps to reproduce the behavior:
                  1. cargo new asdf
                  2. cd asdf
                  3. cargo add rcmp -F macros
                  4. add basic tool call to src/main.rs
                  structA;#[rmcp::tool_router]implA{#[rmcp::tool]asyncfnfoo(){}}
                  1. error[E0433]: failed to resolve: use of unresolved module or unlinked crate serde_json
                  Proposed solution
                  Other location in the macro already assumes the downstream crate depends on rmcp, so expanding the macro to use the re-exported ::rmcp::serde_json::... should work.
                  Metadata
                  Metadata
                  Assignees
                  No one assigned
                    Labels
                    P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up
                    Type
                    No type
                    Projects
                    No projects
                      Milestone
                      No milestone
                      Relationships
                      None yet
                      Development
                      No branches or pull requests
                      Issue actions
                      
, 'i');
if (__m === '*' || __re.test(location.href)) {
// Auto-enable theater mode on YouTube
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function tryTheater() {
var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]');
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})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
`tool` macro expands to `serde_json` without re-export · Issue #487 · modelcontextprotocol/rust-sdk · GitHub
                      Skip to content
                      tool macro expands to serde_json without re-export #487
                      Closed
                      #735
                      Closed
                      tool macro expands to serde_json without re-export#487
                      #735
                      Labels
                      P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up
                      Description
                      @jonaro00
                      jonaro00
                      opened on Oct 16, 2025
                      Describe the bug
                      
tool macro expands to serde_jsonhere which causes compilation error in crates that don't have it as a dependency.
                      To Reproduce
                      
Steps to reproduce the behavior:
                      1. cargo new asdf
                      2. cd asdf
                      3. cargo add rcmp -F macros
                      4. add basic tool call to src/main.rs
                      structA;#[rmcp::tool_router]implA{#[rmcp::tool]asyncfnfoo(){}}
                      1. error[E0433]: failed to resolve: use of unresolved module or unlinked crate serde_json
                      Proposed solution
                      Other location in the macro already assumes the downstream crate depends on rmcp, so expanding the macro to use the re-exported ::rmcp::serde_json::... should work.
                      Metadata
                      Metadata
                      Assignees
                      No one assigned
                        Labels
                        P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up
                        Type
                        No type
                        Projects
                        No projects
                          Milestone
                          No milestone
                          Relationships
                          None yet
                          Development
                          No branches or pull requests
                          Issue actions
                          
, '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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})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
`tool` macro expands to `serde_json` without re-export · Issue #487 · modelcontextprotocol/rust-sdk · GitHub
                          Skip to content
                          tool macro expands to serde_json without re-export #487
                          Closed
                          #735
                          Closed
                          tool macro expands to serde_json without re-export#487
                          #735
                          Labels
                          P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up
                          Description
                          @jonaro00
                          jonaro00
                          opened on Oct 16, 2025
                          Describe the bug
                          
tool macro expands to serde_jsonhere which causes compilation error in crates that don't have it as a dependency.
                          To Reproduce
                          
Steps to reproduce the behavior:
                          1. cargo new asdf
                          2. cd asdf
                          3. cargo add rcmp -F macros
                          4. add basic tool call to src/main.rs
                          structA;#[rmcp::tool_router]implA{#[rmcp::tool]asyncfnfoo(){}}
                          1. error[E0433]: failed to resolve: use of unresolved module or unlinked crate serde_json
                          Proposed solution
                          Other location in the macro already assumes the downstream crate depends on rmcp, so expanding the macro to use the re-exported ::rmcp::serde_json::... should work.
                          Metadata
                          Metadata
                          Assignees
                          No one assigned
                            Labels
                            P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up
                            Type
                            No type
                            Projects
                            No projects
                              Milestone
                              No milestone
                              Relationships
                              None yet
                              Development
                              No branches or pull requests
                              Issue actions
                              
, 'i');
if (__m === '*' || __re.test(location.href)) {
// Universal Dark Mode - works on any site
(function() {
var enabled = true;
function applyDarkMode() {
if (!enabled) return;
// Create style element if it doesn't exist
var style = document.getElementById('universal-dark-mode-style');
if (!style) {
style = document.createElement('style');
style.id = 'universal-dark-mode-style';
document.head.appendChild(style);
}
// Dark mode CSS - inverts colors but preserves images/video
style.textContent = '
/* Invert everything except media */
html {
filter: invert(1) hue-rotate(180deg) !important;
background: #1a1a2e !important;
}
/* Restore images, videos, iframes, canvas */
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filter: invert(1) hue-rotate(180deg) !important;
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[data-theme="light"], [data-theme="light"],
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.markdown-body pre, .markdown-body pre *,
.highlight, .highlight *,
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filter: none !important;
}
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filter: invert(1) hue-rotate(180deg) !important;
background: #2d2d44 !important;
border-color: #444 !important;
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::-webkit-scrollbar-thumb { background: #444 !important; }
::-webkit-scrollbar-thumb:hover { background: #555 !important; }
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::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
';
}
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var style = document.getElementById('universal-dark-mode-style');
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}
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if (e.altKey && e.shiftKey && e.key === 'D') {
e.preventDefault();
enabled = !enabled;
if (enabled) {
applyDarkMode();
console.log('[Universal Dark Mode] Enabled');
} else {
removeDarkMode();
console.log('[Universal Dark Mode] Disabled');
}
}
});
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applyDarkMode();
// Re-apply on dynamic content
var observer = new MutationObserver(function(mutations) {
if (enabled && !document.getElementById('universal-dark-mode-style')) {
applyDarkMode();
}
});
observer.observe(document.head, { childList: true });
console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');
})();
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();
`tool` macro expands to `serde_json` without re-export · Issue #487 · modelcontextprotocol/rust-sdk · GitHub
                              Skip to content
                              tool macro expands to serde_json without re-export #487
                              Closed
                              #735
                              Closed
                              tool macro expands to serde_json without re-export#487
                              #735
                              Labels
                              P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up
                              Description
                              @jonaro00
                              jonaro00
                              opened on Oct 16, 2025
                              Describe the bug
                              
tool macro expands to serde_jsonhere which causes compilation error in crates that don't have it as a dependency.
                              To Reproduce
                              
Steps to reproduce the behavior:
                              1. cargo new asdf
                              2. cd asdf
                              3. cargo add rcmp -F macros
                              4. add basic tool call to src/main.rs
                              structA;#[rmcp::tool_router]implA{#[rmcp::tool]asyncfnfoo(){}}
                              1. error[E0433]: failed to resolve: use of unresolved module or unlinked crate serde_json
                              Proposed solution
                              Other location in the macro already assumes the downstream crate depends on rmcp, so expanding the macro to use the re-exported ::rmcp::serde_json::... should work.
                              Metadata
                              Metadata
                              Assignees
                              No one assigned
                                Labels
                                P1High: significant functionality gap or spec violationT-macrosMacro changesbugSomething is not workingready for workIssue is well-defined and ready to be picked up
                                Type
                                No type
                                Projects
                                No projects
                                  Milestone
                                  No milestone
                                  Relationships
                                  None yet
                                  Development
                                  No branches or pull requests
                                  Issue actions