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YAML frontmatter syntax error in SKILL.md — description field causes parser failure #3776

Closed
#3779
Closed
YAML frontmatter syntax error in SKILL.md — description field causes parser failure#3776
#3779

Description

@sawetco
sawetco
opened on Aug 25, 2026

Description

The file skills/migrating-workflow-v4-to-v5/SKILL.md has a YAML syntax error in its frontmatter that prevents it from loading on skills.sh.

Error

Error in user YAML: (): mapping values are not allowed in this context at line 2 column 549

Root Cause

The description field on line 3 contains unescaped special characters and is not properly formatted as a YAML string. The line is truncated with [...] mid-value, which breaks YAML parsing.

Current (broken):
description: Upgrades an app from Workflow SDK 4.x to 5.0. Use when bumping the workflow / @workflow/* dependencies to v5, or when hitting removed v4 APIs — runStep, stepEntrypoint, `work[...]

The value contains backticks, forward slashes, and special characters that require proper YAML quoting.

Impact

  • The skill cannot be loaded from skills.sh
  • Users cannot use the migration guide through the CLI

Files Affected

  • skills/migrating-workflow-v4-to-v5/SKILL.md (line 3)

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    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)) { // Add copy buttons to all 
       blocks
(function() {
function addCopyButtons() {
document.querySelectorAll('pre code').forEach(function(codeBlock) {
if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;
codeBlock.parentElement.setAttribute('data-copy-added', 'true');
var btn = document.createElement('button');
btn.textContent = 'Copy';
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;';
btn.onmouseover = function() { this.style.opacity = '1'; };
btn.onmouseout = function() { this.style.opacity = '0.7'; };
btn.onclick = function() {
navigator.clipboard.writeText(codeBlock.textContent).then(function() {
btn.textContent = 'Copied!';
setTimeout(function() { btn.textContent = 'Copy'; }, 1500);
});
};
codeBlock.parentElement.style.position = 'relative';
codeBlock.parentElement.appendChild(btn);
});
}
addCopyButtons();
// Re-run on dynamic content
var observer = new MutationObserver(addCopyButtons);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
YAML frontmatter syntax error in SKILL.md — description field causes parser failure · Issue #3776 · vercel/workflow · GitHub
      Skip to content
      YAML frontmatter syntax error in SKILL.md — description field causes parser failure #3776
      Closed
      #3779
      Closed
      YAML frontmatter syntax error in SKILL.md — description field causes parser failure#3776
      #3779
      Description
      @sawetco
      sawetco
      opened on Aug 25, 2026
      Description
      The file skills/migrating-workflow-v4-to-v5/SKILL.md has a YAML syntax error in its frontmatter that prevents it from loading on skills.sh.
      Error
      Error in user YAML: (): mapping values are not allowed in this context at line 2 column 549
      Root Cause
      The description field on line 3 contains unescaped special characters and is not properly formatted as a YAML string. The line is truncated with [...] mid-value, which breaks YAML parsing.
      Current (broken):
      
description: Upgrades an app from Workflow SDK 4.x to 5.0. Use when bumping the workflow / @workflow/* dependencies to v5, or when hitting removed v4 APIs — runStep, stepEntrypoint, `work[...]
      The value contains backticks, forward slashes, and special characters that require proper YAML quoting.
      Impact
      • The skill cannot be loaded from skills.sh
      • Users cannot use the migration guide through the CLI
      Files Affected
      • skills/migrating-workflow-v4-to-v5/SKILL.md (line 3)
      Metadata
      Metadata
      Assignees
      No one assigned
        Labels
        No labels
        No labels
        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)) {
// Force GitHub README to respect dark mode
(function() {
var style = document.createElement('style');
style.textContent = '
.markdown-body {
color-scheme: dark light;
}
.markdown-body pre { background: #161b22 !important; }
.markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }
.markdown-body table th, .markdown-body table td { border-color: #30363d !important; }
.markdown-body img { background: #0d1117; }
.markdown-body blockquote { border-left-color: #8b949e; }
.markdown-body hr { border-color: #30363d; }
';
document.head.appendChild(style);
})();
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
YAML frontmatter syntax error in SKILL.md — description field causes parser failure · Issue #3776 · vercel/workflow · GitHub
          Skip to content
          YAML frontmatter syntax error in SKILL.md — description field causes parser failure #3776
          Closed
          #3779
          Closed
          YAML frontmatter syntax error in SKILL.md — description field causes parser failure#3776
          #3779
          Description
          @sawetco
          sawetco
          opened on Aug 25, 2026
          Description
          The file skills/migrating-workflow-v4-to-v5/SKILL.md has a YAML syntax error in its frontmatter that prevents it from loading on skills.sh.
          Error
          Error in user YAML: (): mapping values are not allowed in this context at line 2 column 549
          Root Cause
          The description field on line 3 contains unescaped special characters and is not properly formatted as a YAML string. The line is truncated with [...] mid-value, which breaks YAML parsing.
          Current (broken):
          
description: Upgrades an app from Workflow SDK 4.x to 5.0. Use when bumping the workflow / @workflow/* dependencies to v5, or when hitting removed v4 APIs — runStep, stepEntrypoint, `work[...]
          The value contains backticks, forward slashes, and special characters that require proper YAML quoting.
          Impact
          • The skill cannot be loaded from skills.sh
          • Users cannot use the migration guide through the CLI
          Files Affected
          • skills/migrating-workflow-v4-to-v5/SKILL.md (line 3)
          Metadata
          Metadata
          Assignees
          No one assigned
            Labels
            No labels
            No labels
            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)) {
// Highlight search terms from Google/DuckDuckGo/Bing referrer
(function() {
var ref = document.referrer;
var terms = [];
if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {
var url = new URL(ref);
var q = url.searchParams.get('q') || url.searchParams.get('p');
if (q) {
terms = q.split(/\s+/).filter(function(t) { return t.length > 2; });
}
}
if (terms.length === 0) return;
var style = document.createElement('style');
style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';
document.head.appendChild(style);
function highlight(node) {
if (node.nodeType === 3) { // text node
var text = node.textContent;
var found = false;
terms.forEach(function(term) {
var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\]\\]/g, '\\') + ')', 'gi');
if (regex.test(text)) {
found = true;
var frag = document.createDocumentFragment();
var parts = text.split(regex);
parts.forEach(function(part, i) {
if (i % 2 === 0) {
frag.appendChild(document.createTextNode(part));
} else {
var span = document.createElement('span');
span.className = 'userscript-highlight';
span.textContent = part;
frag.appendChild(span);
}
});
node.parentNode.replaceChild(frag, node);
}
});
} else if (node.nodeType === 1 && node.childNodes) { // element
var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];
if (!skipTags.includes(node.tagName)) {
Array.from(node.childNodes).forEach(highlight);
}
}
}
highlight(document.body);
// Re-highlight on dynamic content
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1 || node.nodeType === 3) highlight(node);
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
YAML frontmatter syntax error in SKILL.md — description field causes parser failure · Issue #3776 · vercel/workflow · GitHub
              Skip to content
              YAML frontmatter syntax error in SKILL.md — description field causes parser failure #3776
              Closed
              #3779
              Closed
              YAML frontmatter syntax error in SKILL.md — description field causes parser failure#3776
              #3779
              Description
              @sawetco
              sawetco
              opened on Aug 25, 2026
              Description
              The file skills/migrating-workflow-v4-to-v5/SKILL.md has a YAML syntax error in its frontmatter that prevents it from loading on skills.sh.
              Error
              Error in user YAML: (): mapping values are not allowed in this context at line 2 column 549
              Root Cause
              The description field on line 3 contains unescaped special characters and is not properly formatted as a YAML string. The line is truncated with [...] mid-value, which breaks YAML parsing.
              Current (broken):
              
description: Upgrades an app from Workflow SDK 4.x to 5.0. Use when bumping the workflow / @workflow/* dependencies to v5, or when hitting removed v4 APIs — runStep, stepEntrypoint, `work[...]
              The value contains backticks, forward slashes, and special characters that require proper YAML quoting.
              Impact
              • The skill cannot be loaded from skills.sh
              • Users cannot use the migration guide through the CLI
              Files Affected
              • skills/migrating-workflow-v4-to-v5/SKILL.md (line 3)
              Metadata
              Metadata
              Assignees
              No one assigned
                Labels
                No labels
                No labels
                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
(function() {
var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',
'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',
'ref', 'ref_src', 'source', 'medium', 'campaign'];
function cleanUrl(url) {
try {
var u = new URL(url, window.location.origin);
var changed = false;
trackingParams.forEach(function(p) {
if (u.searchParams.has(p)) {
u.searchParams.delete(p);
changed = true;
}
});
return changed ? u.toString() : url;
} catch (e) {
return url;
}
}
function cleanLinks() {
document.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
cleanLinks();
var observer = new MutationObserver(function(mutations) {
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" + '
YAML frontmatter syntax error in SKILL.md — description field causes parser failure · Issue #3776 · vercel/workflow · GitHub
                  Skip to content
                  YAML frontmatter syntax error in SKILL.md — description field causes parser failure #3776
                  Closed
                  #3779
                  Closed
                  YAML frontmatter syntax error in SKILL.md — description field causes parser failure#3776
                  #3779
                  Description
                  @sawetco
                  sawetco
                  opened on Aug 25, 2026
                  Description
                  The file skills/migrating-workflow-v4-to-v5/SKILL.md has a YAML syntax error in its frontmatter that prevents it from loading on skills.sh.
                  Error
                  Error in user YAML: (): mapping values are not allowed in this context at line 2 column 549
                  Root Cause
                  The description field on line 3 contains unescaped special characters and is not properly formatted as a YAML string. The line is truncated with [...] mid-value, which breaks YAML parsing.
                  Current (broken):
                  
description: Upgrades an app from Workflow SDK 4.x to 5.0. Use when bumping the workflow / @workflow/* dependencies to v5, or when hitting removed v4 APIs — runStep, stepEntrypoint, `work[...]
                  The value contains backticks, forward slashes, and special characters that require proper YAML quoting.
                  Impact
                  • The skill cannot be loaded from skills.sh
                  • Users cannot use the migration guide through the CLI
                  Files Affected
                  • skills/migrating-workflow-v4-to-v5/SKILL.md (line 3)
                  Metadata
                  Metadata
                  Assignees
                  No one assigned
                    Labels
                    No labels
                    No labels
                    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
(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('^' + ".*" + '
YAML frontmatter syntax error in SKILL.md — description field causes parser failure · Issue #3776 · vercel/workflow · GitHub
                      Skip to content
                      YAML frontmatter syntax error in SKILL.md — description field causes parser failure #3776
                      Closed
                      #3779
                      Closed
                      YAML frontmatter syntax error in SKILL.md — description field causes parser failure#3776
                      #3779
                      Description
                      @sawetco
                      sawetco
                      opened on Aug 25, 2026
                      Description
                      The file skills/migrating-workflow-v4-to-v5/SKILL.md has a YAML syntax error in its frontmatter that prevents it from loading on skills.sh.
                      Error
                      Error in user YAML: (): mapping values are not allowed in this context at line 2 column 549
                      Root Cause
                      The description field on line 3 contains unescaped special characters and is not properly formatted as a YAML string. The line is truncated with [...] mid-value, which breaks YAML parsing.
                      Current (broken):
                      
description: Upgrades an app from Workflow SDK 4.x to 5.0. Use when bumping the workflow / @workflow/* dependencies to v5, or when hitting removed v4 APIs — runStep, stepEntrypoint, `work[...]
                      The value contains backticks, forward slashes, and special characters that require proper YAML quoting.
                      Impact
                      • The skill cannot be loaded from skills.sh
                      • Users cannot use the migration guide through the CLI
                      Files Affected
                      • skills/migrating-workflow-v4-to-v5/SKILL.md (line 3)
                      Metadata
                      Metadata
                      Assignees
                      No one assigned
                        Labels
                        No labels
                        No labels
                        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) {
if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {
el.style.position = 'static';
el.style.top = 'auto';
el.style.zIndex = 'auto';
}
});
}
unstick();
var observer = new MutationObserver(unstick);
observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });
})();
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
YAML frontmatter syntax error in SKILL.md — description field causes parser failure · Issue #3776 · vercel/workflow · GitHub
                          Skip to content
                          YAML frontmatter syntax error in SKILL.md — description field causes parser failure #3776
                          Closed
                          #3779
                          Closed
                          YAML frontmatter syntax error in SKILL.md — description field causes parser failure#3776
                          #3779
                          Description
                          @sawetco
                          sawetco
                          opened on Aug 25, 2026
                          Description
                          The file skills/migrating-workflow-v4-to-v5/SKILL.md has a YAML syntax error in its frontmatter that prevents it from loading on skills.sh.
                          Error
                          Error in user YAML: (): mapping values are not allowed in this context at line 2 column 549
                          Root Cause
                          The description field on line 3 contains unescaped special characters and is not properly formatted as a YAML string. The line is truncated with [...] mid-value, which breaks YAML parsing.
                          Current (broken):
                          
description: Upgrades an app from Workflow SDK 4.x to 5.0. Use when bumping the workflow / @workflow/* dependencies to v5, or when hitting removed v4 APIs — runStep, stepEntrypoint, `work[...]
                          The value contains backticks, forward slashes, and special characters that require proper YAML quoting.
                          Impact
                          • The skill cannot be loaded from skills.sh
                          • Users cannot use the migration guide through the CLI
                          Files Affected
                          • skills/migrating-workflow-v4-to-v5/SKILL.md (line 3)
                          Metadata
                          Metadata
                          Assignees
                          No one assigned
                            Labels
                            No labels
                            No labels
                            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 */
img, video, iframe, canvas, svg, picture, [style*="background-image"] {
filter: invert(1) hue-rotate(180deg) !important;
}
/* Preserve specific elements that should not be inverted */
.no-dark-mode, .no-dark-mode *,
[data-theme="light"], [data-theme="light"],
.ace_editor, .ace_editor *,
.CodeMirror, .CodeMirror *,
.monaco-editor, .monaco-editor *,
.markdown-body pre, .markdown-body pre *,
.highlight, .highlight *,
pre code, pre code * {
filter: none !important;
}
/* Fix common UI elements */
.modal, .popup, .dropdown-menu, .tooltip, .popover {
filter: invert(1) hue-rotate(180deg) !important;
background: #2d2d44 !important;
border-color: #444 !important;
}
/* Scrollbars */
::-webkit-scrollbar { background: #1a1a2e !important; }
::-webkit-scrollbar-thumb { background: #444 !important; }
::-webkit-scrollbar-thumb:hover { background: #555 !important; }
/* Selection */
::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
';
}
function removeDarkMode() {
var style = document.getElementById('universal-dark-mode-style');
if (style) style.remove();
}
// Toggle with Alt+Shift+D
document.addEventListener('keydown', function(e) {
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');
}
}
});
// Apply on load
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); }
})();
})();
YAML frontmatter syntax error in SKILL.md — description field causes parser failure · Issue #3776 · vercel/workflow · GitHub
                              Skip to content
                              YAML frontmatter syntax error in SKILL.md — description field causes parser failure #3776
                              Closed
                              #3779
                              Closed
                              YAML frontmatter syntax error in SKILL.md — description field causes parser failure#3776
                              #3779
                              Description
                              @sawetco
                              sawetco
                              opened on Aug 25, 2026
                              Description
                              The file skills/migrating-workflow-v4-to-v5/SKILL.md has a YAML syntax error in its frontmatter that prevents it from loading on skills.sh.
                              Error
                              Error in user YAML: (): mapping values are not allowed in this context at line 2 column 549
                              Root Cause
                              The description field on line 3 contains unescaped special characters and is not properly formatted as a YAML string. The line is truncated with [...] mid-value, which breaks YAML parsing.
                              Current (broken):
                              
description: Upgrades an app from Workflow SDK 4.x to 5.0. Use when bumping the workflow / @workflow/* dependencies to v5, or when hitting removed v4 APIs — runStep, stepEntrypoint, `work[...]
                              The value contains backticks, forward slashes, and special characters that require proper YAML quoting.
                              Impact
                              • The skill cannot be loaded from skills.sh
                              • Users cannot use the migration guide through the CLI
                              Files Affected
                              • skills/migrating-workflow-v4-to-v5/SKILL.md (line 3)
                              Metadata
                              Metadata
                              Assignees
                              No one assigned
                                Labels
                                No labels
                                No labels
                                Type
                                No type
                                Projects
                                No projects
                                  Milestone
                                  No milestone
                                  Relationships
                                  None yet
                                  Development
                                  No branches or pull requests
                                  Issue actions