Support Gpt-5.2 in Tokenizer library - #7571

Merged
tarekgh merged 1 commit into
dotnet:mainfrom
tarekgh:SupportGpt-5.2Toknizer
Jan 22, 2026
Merged

Support Gpt-5.2 in Tokenizer library#7571
tarekgh merged 1 commit into
dotnet:mainfrom
tarekgh:SupportGpt-5.2Toknizer

Conversation

@tarekgh

@tarekghtarekgh commented Jan 22, 2026

Copy link
Copy Markdown
Member

No description provided.

CopilotAI review requested due to automatic review settings January 22, 2026 19:41
@tarekghtarekgh self-assigned this Jan 22, 2026
@tarekgh
tarekgh enabled auto-merge (squash) January 22, 2026 19:44
CopilotAI reviewed Jan 22, 2026
View reviewed changes

CopilotAI left a comment

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Pull request overview

This PR adds support for the GPT-5.2 model to the Tokenizer library, following the same pattern as GPT-5 and GPT-5.1 models which use the O200kBase encoding.

Changes:

  • Added GPT-5.2 model support with O200kBase encoding
  • Updated test cases to include GPT-5.2 and GPT-5.2-mini variants
  • Added model mappings for both exact match and prefix matching

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

FileDescription
src/Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.csAdded "gpt-5.2" and "gpt-5.2-" mappings to O200kBase encoding in both exact match dictionary and prefix array
test/Microsoft.ML.Tokenizers.Tests/TiktokenTests.csAdded GPT5_2 tokenizer property, included it in O200kBase encoding test, and added test cases for "gpt-5.2" and "gpt-5.2-mini" model names

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

@codecov

codecovBot commented Jan 22, 2026•
edited
Loading

Copy link
Copy Markdown

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 69.02%. Comparing base (adf0cec) to head (6ba8b78).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files
@@ Coverage Diff @@## main #7571 +/- ##
=======================================
Coverage 69.02% 69.02% =======================================
Files 1482 1482 Lines 274096 274099 +3 Branches 28266 28266 =======================================
+ Hits 189191 189199 +8 
Misses 77518 77518 + Partials 7387 7382 -5
FlagCoverage Δ
Debug69.02% <100.00%> (+<0.01%)⬆️
production63.31% <100.00%> (+<0.01%)⬆️
test89.47% <100.00%> (+<0.01%)⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing linesCoverage Δ
...Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.cs79.95% <100.00%> (+0.04%)⬆️
...est/Microsoft.ML.Tokenizers.Tests/TiktokenTests.cs99.09% <100.00%> (+<0.01%)⬆️

... and 7 files with indirect coverage changes

🚀 New features to boost your workflow:
  • ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

@tarekgh

tarekgh commented Jan 22, 2026

Copy link
Copy Markdown
MemberAuthor

/ba-g unrelated failures

@tarekgh
tarekgh merged commit 25b977e into dotnet:mainJan 22, 2026
27 of 31 checks passed
@github-actionsgithub-actionsBot locked and limited conversation to collaborators Feb 22, 2026
Sign up for freeto subscribe to this conversation on GitHub. Already have an account? Sign in.

Reviewers

Copilot code reviewCopilot
Copilot review effort
Applies to this pull request for everyone.Learn more about Copilot code review.
Copilot left review comments
@stephentoubstephentoubstephentoub approved these changes

Assignees

@tarekghtarekgh

Labels

Tokenizers

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

3 participants

@tarekgh@stephentoub
, '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
Support Gpt-5.2 in Tokenizer library - #7571
Merged
tarekgh merged 1 commit into
dotnet:mainfrom 
tarekgh:SupportGpt-5.2Toknizer
Jan 22, 2026
Merged
Support Gpt-5.2 in Tokenizer library#7571
tarekgh merged 1 commit into
dotnet:mainfrom 
tarekgh:SupportGpt-5.2Toknizer
Conversation
@tarekgh
@tarekghtarekgh
commented
Jan 22, 2026

Copy link


Copy Markdown

Member
 No description provided. 
CopilotAI
review requested due to automatic review settings
January 22, 2026 19:41
@tarekghtarekgh
self-assigned this
Jan 22, 2026
@tarekgh
tarekgh
enabled auto-merge (squash)
January 22, 2026 19:44
CopilotAI
reviewed
Jan 22, 2026
View reviewed changes
CopilotAI
left a comment


Copy link


Copy Markdown

Contributor
Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Pull request overview
This PR adds support for the GPT-5.2 model to the Tokenizer library, following the same pattern as GPT-5 and GPT-5.1 models which use the O200kBase encoding.
Changes:
  • Added GPT-5.2 model support with O200kBase encoding
  • Updated test cases to include GPT-5.2 and GPT-5.2-mini variants
  • Added model mappings for both exact match and prefix matching
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
FileDescription
src/Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.csAdded "gpt-5.2" and "gpt-5.2-" mappings to O200kBase encoding in both exact match dictionary and prefix array
test/Microsoft.ML.Tokenizers.Tests/TiktokenTests.csAdded GPT5_2 tokenizer property, included it in O200kBase encoding test, and added test cases for "gpt-5.2" and "gpt-5.2-mini" model names
💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.
@codecov
codecovBot
commented
Jan 22, 2026•

edited

Loading

Copy link


Copy Markdown

Codecov Report
✅ All modified and coverable lines are covered by tests.

✅ Project coverage is 69.02%. Comparing base (adf0cec) to head (6ba8b78).
⚠️ Report is 2 commits behind head on main.
Additional details and impacted files
@@ Coverage Diff @@## main #7571 +/- ##
=======================================
Coverage 69.02% 69.02% =======================================
Files 1482 1482 Lines 274096 274099 +3 Branches 28266 28266 =======================================
+ Hits 189191 189199 +8 
Misses 77518 77518 + Partials 7387 7382 -5 
FlagCoverage Δ
Debug69.02% <100.00%> (+<0.01%)⬆️
production63.31% <100.00%> (+<0.01%)⬆️
test89.47% <100.00%> (+<0.01%)⬆️
Flags with carried forward coverage won't be shown. Click here to find out more.
Files with missing linesCoverage Δ
...Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.cs79.95% <100.00%> (+0.04%)⬆️
...est/Microsoft.ML.Tokenizers.Tests/TiktokenTests.cs99.09% <100.00%> (+<0.01%)⬆️
... and 7 files with indirect coverage changes
 🚀 New features to boost your workflow: 
  • ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
@tarekgh
tarekgh
commented
Jan 22, 2026

Copy link


Copy Markdown

MemberAuthor
/ba-g unrelated failures
@tarekgh
tarekgh
merged commit 25b977e
into
dotnet:mainJan 22, 2026

27 of 31 checks passed

@github-actionsgithub-actionsBot
locked and limited conversation to collaborators
Feb 22, 2026
Sign up for freeto subscribe to this conversation on GitHub.
Already have an account?
Sign in.


Reviewers

Copilot code reviewCopilot
Copilot review effort
Applies to this pull request for everyone.Learn more about Copilot code review.
Copilot left review comments
@stephentoubstephentoubstephentoub approved these changes

Assignees

@tarekghtarekgh

Labels

Tokenizers

Projects


None yet


Milestone


No milestone


Development

Successfully merging this pull request may close these issues.

3 participants

@tarekgh@stephentoub

, '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
Support Gpt-5.2 in Tokenizer library - #7571
Merged
tarekgh merged 1 commit into
dotnet:mainfrom 
tarekgh:SupportGpt-5.2Toknizer
Jan 22, 2026
Merged
Support Gpt-5.2 in Tokenizer library#7571
tarekgh merged 1 commit into
dotnet:mainfrom 
tarekgh:SupportGpt-5.2Toknizer
Conversation
@tarekgh
@tarekghtarekgh
commented
Jan 22, 2026

Copy link


Copy Markdown

Member
 No description provided. 
CopilotAI
review requested due to automatic review settings
January 22, 2026 19:41
@tarekghtarekgh
self-assigned this
Jan 22, 2026
@tarekgh
tarekgh
enabled auto-merge (squash)
January 22, 2026 19:44
CopilotAI
reviewed
Jan 22, 2026
View reviewed changes
CopilotAI
left a comment


Copy link


Copy Markdown

Contributor
Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Pull request overview
This PR adds support for the GPT-5.2 model to the Tokenizer library, following the same pattern as GPT-5 and GPT-5.1 models which use the O200kBase encoding.
Changes:
  • Added GPT-5.2 model support with O200kBase encoding
  • Updated test cases to include GPT-5.2 and GPT-5.2-mini variants
  • Added model mappings for both exact match and prefix matching
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
FileDescription
src/Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.csAdded "gpt-5.2" and "gpt-5.2-" mappings to O200kBase encoding in both exact match dictionary and prefix array
test/Microsoft.ML.Tokenizers.Tests/TiktokenTests.csAdded GPT5_2 tokenizer property, included it in O200kBase encoding test, and added test cases for "gpt-5.2" and "gpt-5.2-mini" model names
💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.
@codecov
codecovBot
commented
Jan 22, 2026•

edited

Loading

Copy link


Copy Markdown

Codecov Report
✅ All modified and coverable lines are covered by tests.

✅ Project coverage is 69.02%. Comparing base (adf0cec) to head (6ba8b78).
⚠️ Report is 2 commits behind head on main.
Additional details and impacted files
@@ Coverage Diff @@## main #7571 +/- ##
=======================================
Coverage 69.02% 69.02% =======================================
Files 1482 1482 Lines 274096 274099 +3 Branches 28266 28266 =======================================
+ Hits 189191 189199 +8 
Misses 77518 77518 + Partials 7387 7382 -5 
FlagCoverage Δ
Debug69.02% <100.00%> (+<0.01%)⬆️
production63.31% <100.00%> (+<0.01%)⬆️
test89.47% <100.00%> (+<0.01%)⬆️
Flags with carried forward coverage won't be shown. Click here to find out more.
Files with missing linesCoverage Δ
...Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.cs79.95% <100.00%> (+0.04%)⬆️
...est/Microsoft.ML.Tokenizers.Tests/TiktokenTests.cs99.09% <100.00%> (+<0.01%)⬆️
... and 7 files with indirect coverage changes
 🚀 New features to boost your workflow: 
  • ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
@tarekgh
tarekgh
commented
Jan 22, 2026

Copy link


Copy Markdown

MemberAuthor
/ba-g unrelated failures
@tarekgh
tarekgh
merged commit 25b977e
into
dotnet:mainJan 22, 2026

27 of 31 checks passed

@github-actionsgithub-actionsBot
locked and limited conversation to collaborators
Feb 22, 2026
Sign up for freeto subscribe to this conversation on GitHub.
Already have an account?
Sign in.


Reviewers

Copilot code reviewCopilot
Copilot review effort
Applies to this pull request for everyone.Learn more about Copilot code review.
Copilot left review comments
@stephentoubstephentoubstephentoub approved these changes

Assignees

@tarekghtarekgh

Labels

Tokenizers

Projects


None yet


Milestone


No milestone


Development

Successfully merging this pull request may close these issues.

3 participants

@tarekgh@stephentoub

, '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
Support Gpt-5.2 in Tokenizer library - #7571
Merged
tarekgh merged 1 commit into
dotnet:mainfrom 
tarekgh:SupportGpt-5.2Toknizer
Jan 22, 2026
Merged
Support Gpt-5.2 in Tokenizer library#7571
tarekgh merged 1 commit into
dotnet:mainfrom 
tarekgh:SupportGpt-5.2Toknizer
Conversation
@tarekgh
@tarekghtarekgh
commented
Jan 22, 2026

Copy link


Copy Markdown

Member
 No description provided. 
CopilotAI
review requested due to automatic review settings
January 22, 2026 19:41
@tarekghtarekgh
self-assigned this
Jan 22, 2026
@tarekgh
tarekgh
enabled auto-merge (squash)
January 22, 2026 19:44
CopilotAI
reviewed
Jan 22, 2026
View reviewed changes
CopilotAI
left a comment


Copy link


Copy Markdown

Contributor
Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Pull request overview
This PR adds support for the GPT-5.2 model to the Tokenizer library, following the same pattern as GPT-5 and GPT-5.1 models which use the O200kBase encoding.
Changes:
  • Added GPT-5.2 model support with O200kBase encoding
  • Updated test cases to include GPT-5.2 and GPT-5.2-mini variants
  • Added model mappings for both exact match and prefix matching
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
FileDescription
src/Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.csAdded "gpt-5.2" and "gpt-5.2-" mappings to O200kBase encoding in both exact match dictionary and prefix array
test/Microsoft.ML.Tokenizers.Tests/TiktokenTests.csAdded GPT5_2 tokenizer property, included it in O200kBase encoding test, and added test cases for "gpt-5.2" and "gpt-5.2-mini" model names
💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.
@codecov
codecovBot
commented
Jan 22, 2026•

edited

Loading

Copy link


Copy Markdown

Codecov Report
✅ All modified and coverable lines are covered by tests.

✅ Project coverage is 69.02%. Comparing base (adf0cec) to head (6ba8b78).
⚠️ Report is 2 commits behind head on main.
Additional details and impacted files
@@ Coverage Diff @@## main #7571 +/- ##
=======================================
Coverage 69.02% 69.02% =======================================
Files 1482 1482 Lines 274096 274099 +3 Branches 28266 28266 =======================================
+ Hits 189191 189199 +8 
Misses 77518 77518 + Partials 7387 7382 -5 
FlagCoverage Δ
Debug69.02% <100.00%> (+<0.01%)⬆️
production63.31% <100.00%> (+<0.01%)⬆️
test89.47% <100.00%> (+<0.01%)⬆️
Flags with carried forward coverage won't be shown. Click here to find out more.
Files with missing linesCoverage Δ
...Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.cs79.95% <100.00%> (+0.04%)⬆️
...est/Microsoft.ML.Tokenizers.Tests/TiktokenTests.cs99.09% <100.00%> (+<0.01%)⬆️
... and 7 files with indirect coverage changes
 🚀 New features to boost your workflow: 
  • ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
@tarekgh
tarekgh
commented
Jan 22, 2026

Copy link


Copy Markdown

MemberAuthor
/ba-g unrelated failures
@tarekgh
tarekgh
merged commit 25b977e
into
dotnet:mainJan 22, 2026

27 of 31 checks passed

@github-actionsgithub-actionsBot
locked and limited conversation to collaborators
Feb 22, 2026
Sign up for freeto subscribe to this conversation on GitHub.
Already have an account?
Sign in.


Reviewers

Copilot code reviewCopilot
Copilot review effort
Applies to this pull request for everyone.Learn more about Copilot code review.
Copilot left review comments
@stephentoubstephentoubstephentoub approved these changes

Assignees

@tarekghtarekgh

Labels

Tokenizers

Projects


None yet


Milestone


No milestone


Development

Successfully merging this pull request may close these issues.

3 participants

@tarekgh@stephentoub

, '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
Support Gpt-5.2 in Tokenizer library - #7571
Merged
tarekgh merged 1 commit into
dotnet:mainfrom 
tarekgh:SupportGpt-5.2Toknizer
Jan 22, 2026
Merged
Support Gpt-5.2 in Tokenizer library#7571
tarekgh merged 1 commit into
dotnet:mainfrom 
tarekgh:SupportGpt-5.2Toknizer
Conversation
@tarekgh
@tarekghtarekgh
commented
Jan 22, 2026

Copy link


Copy Markdown

Member
 No description provided. 
CopilotAI
review requested due to automatic review settings
January 22, 2026 19:41
@tarekghtarekgh
self-assigned this
Jan 22, 2026
@tarekgh
tarekgh
enabled auto-merge (squash)
January 22, 2026 19:44
CopilotAI
reviewed
Jan 22, 2026
View reviewed changes
CopilotAI
left a comment


Copy link


Copy Markdown

Contributor
Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Pull request overview
This PR adds support for the GPT-5.2 model to the Tokenizer library, following the same pattern as GPT-5 and GPT-5.1 models which use the O200kBase encoding.
Changes:
  • Added GPT-5.2 model support with O200kBase encoding
  • Updated test cases to include GPT-5.2 and GPT-5.2-mini variants
  • Added model mappings for both exact match and prefix matching
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
FileDescription
src/Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.csAdded "gpt-5.2" and "gpt-5.2-" mappings to O200kBase encoding in both exact match dictionary and prefix array
test/Microsoft.ML.Tokenizers.Tests/TiktokenTests.csAdded GPT5_2 tokenizer property, included it in O200kBase encoding test, and added test cases for "gpt-5.2" and "gpt-5.2-mini" model names
💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.
@codecov
codecovBot
commented
Jan 22, 2026•

edited

Loading

Copy link


Copy Markdown

Codecov Report
✅ All modified and coverable lines are covered by tests.

✅ Project coverage is 69.02%. Comparing base (adf0cec) to head (6ba8b78).
⚠️ Report is 2 commits behind head on main.
Additional details and impacted files
@@ Coverage Diff @@## main #7571 +/- ##
=======================================
Coverage 69.02% 69.02% =======================================
Files 1482 1482 Lines 274096 274099 +3 Branches 28266 28266 =======================================
+ Hits 189191 189199 +8 
Misses 77518 77518 + Partials 7387 7382 -5 
FlagCoverage Δ
Debug69.02% <100.00%> (+<0.01%)⬆️
production63.31% <100.00%> (+<0.01%)⬆️
test89.47% <100.00%> (+<0.01%)⬆️
Flags with carried forward coverage won't be shown. Click here to find out more.
Files with missing linesCoverage Δ
...Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.cs79.95% <100.00%> (+0.04%)⬆️
...est/Microsoft.ML.Tokenizers.Tests/TiktokenTests.cs99.09% <100.00%> (+<0.01%)⬆️
... and 7 files with indirect coverage changes
 🚀 New features to boost your workflow: 
  • ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
@tarekgh
tarekgh
commented
Jan 22, 2026

Copy link


Copy Markdown

MemberAuthor
/ba-g unrelated failures
@tarekgh
tarekgh
merged commit 25b977e
into
dotnet:mainJan 22, 2026

27 of 31 checks passed

@github-actionsgithub-actionsBot
locked and limited conversation to collaborators
Feb 22, 2026
Sign up for freeto subscribe to this conversation on GitHub.
Already have an account?
Sign in.


Reviewers

Copilot code reviewCopilot
Copilot review effort
Applies to this pull request for everyone.Learn more about Copilot code review.
Copilot left review comments
@stephentoubstephentoubstephentoub approved these changes

Assignees

@tarekghtarekgh

Labels

Tokenizers

Projects


None yet


Milestone


No milestone


Development

Successfully merging this pull request may close these issues.

3 participants

@tarekgh@stephentoub

, '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
Support Gpt-5.2 in Tokenizer library - #7571
Merged
tarekgh merged 1 commit into
dotnet:mainfrom 
tarekgh:SupportGpt-5.2Toknizer
Jan 22, 2026
Merged
Support Gpt-5.2 in Tokenizer library#7571
tarekgh merged 1 commit into
dotnet:mainfrom 
tarekgh:SupportGpt-5.2Toknizer
Conversation
@tarekgh
@tarekghtarekgh
commented
Jan 22, 2026

Copy link


Copy Markdown

Member
 No description provided. 
CopilotAI
review requested due to automatic review settings
January 22, 2026 19:41
@tarekghtarekgh
self-assigned this
Jan 22, 2026
@tarekgh
tarekgh
enabled auto-merge (squash)
January 22, 2026 19:44
CopilotAI
reviewed
Jan 22, 2026
View reviewed changes
CopilotAI
left a comment


Copy link


Copy Markdown

Contributor
Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Pull request overview
This PR adds support for the GPT-5.2 model to the Tokenizer library, following the same pattern as GPT-5 and GPT-5.1 models which use the O200kBase encoding.
Changes:
  • Added GPT-5.2 model support with O200kBase encoding
  • Updated test cases to include GPT-5.2 and GPT-5.2-mini variants
  • Added model mappings for both exact match and prefix matching
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
FileDescription
src/Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.csAdded "gpt-5.2" and "gpt-5.2-" mappings to O200kBase encoding in both exact match dictionary and prefix array
test/Microsoft.ML.Tokenizers.Tests/TiktokenTests.csAdded GPT5_2 tokenizer property, included it in O200kBase encoding test, and added test cases for "gpt-5.2" and "gpt-5.2-mini" model names
💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.
@codecov
codecovBot
commented
Jan 22, 2026•

edited

Loading

Copy link


Copy Markdown

Codecov Report
✅ All modified and coverable lines are covered by tests.

✅ Project coverage is 69.02%. Comparing base (adf0cec) to head (6ba8b78).
⚠️ Report is 2 commits behind head on main.
Additional details and impacted files
@@ Coverage Diff @@## main #7571 +/- ##
=======================================
Coverage 69.02% 69.02% =======================================
Files 1482 1482 Lines 274096 274099 +3 Branches 28266 28266 =======================================
+ Hits 189191 189199 +8 
Misses 77518 77518 + Partials 7387 7382 -5 
FlagCoverage Δ
Debug69.02% <100.00%> (+<0.01%)⬆️
production63.31% <100.00%> (+<0.01%)⬆️
test89.47% <100.00%> (+<0.01%)⬆️
Flags with carried forward coverage won't be shown. Click here to find out more.
Files with missing linesCoverage Δ
...Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.cs79.95% <100.00%> (+0.04%)⬆️
...est/Microsoft.ML.Tokenizers.Tests/TiktokenTests.cs99.09% <100.00%> (+<0.01%)⬆️
... and 7 files with indirect coverage changes
 🚀 New features to boost your workflow: 
  • ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
@tarekgh
tarekgh
commented
Jan 22, 2026

Copy link


Copy Markdown

MemberAuthor
/ba-g unrelated failures
@tarekgh
tarekgh
merged commit 25b977e
into
dotnet:mainJan 22, 2026

27 of 31 checks passed

@github-actionsgithub-actionsBot
locked and limited conversation to collaborators
Feb 22, 2026
Sign up for freeto subscribe to this conversation on GitHub.
Already have an account?
Sign in.


Reviewers

Copilot code reviewCopilot
Copilot review effort
Applies to this pull request for everyone.Learn more about Copilot code review.
Copilot left review comments
@stephentoubstephentoubstephentoub approved these changes

Assignees

@tarekghtarekgh

Labels

Tokenizers

Projects


None yet


Milestone


No milestone


Development

Successfully merging this pull request may close these issues.

3 participants

@tarekgh@stephentoub

, '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
Support Gpt-5.2 in Tokenizer library - #7571
Merged
tarekgh merged 1 commit into
dotnet:mainfrom 
tarekgh:SupportGpt-5.2Toknizer
Jan 22, 2026
Merged
Support Gpt-5.2 in Tokenizer library#7571
tarekgh merged 1 commit into
dotnet:mainfrom 
tarekgh:SupportGpt-5.2Toknizer
Conversation
@tarekgh
@tarekghtarekgh
commented
Jan 22, 2026

Copy link


Copy Markdown

Member
 No description provided. 
CopilotAI
review requested due to automatic review settings
January 22, 2026 19:41
@tarekghtarekgh
self-assigned this
Jan 22, 2026
@tarekgh
tarekgh
enabled auto-merge (squash)
January 22, 2026 19:44
CopilotAI
reviewed
Jan 22, 2026
View reviewed changes
CopilotAI
left a comment


Copy link


Copy Markdown

Contributor
Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Pull request overview
This PR adds support for the GPT-5.2 model to the Tokenizer library, following the same pattern as GPT-5 and GPT-5.1 models which use the O200kBase encoding.
Changes:
  • Added GPT-5.2 model support with O200kBase encoding
  • Updated test cases to include GPT-5.2 and GPT-5.2-mini variants
  • Added model mappings for both exact match and prefix matching
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
FileDescription
src/Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.csAdded "gpt-5.2" and "gpt-5.2-" mappings to O200kBase encoding in both exact match dictionary and prefix array
test/Microsoft.ML.Tokenizers.Tests/TiktokenTests.csAdded GPT5_2 tokenizer property, included it in O200kBase encoding test, and added test cases for "gpt-5.2" and "gpt-5.2-mini" model names
💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.
@codecov
codecovBot
commented
Jan 22, 2026•

edited

Loading

Copy link


Copy Markdown

Codecov Report
✅ All modified and coverable lines are covered by tests.

✅ Project coverage is 69.02%. Comparing base (adf0cec) to head (6ba8b78).
⚠️ Report is 2 commits behind head on main.
Additional details and impacted files
@@ Coverage Diff @@## main #7571 +/- ##
=======================================
Coverage 69.02% 69.02% =======================================
Files 1482 1482 Lines 274096 274099 +3 Branches 28266 28266 =======================================
+ Hits 189191 189199 +8 
Misses 77518 77518 + Partials 7387 7382 -5 
FlagCoverage Δ
Debug69.02% <100.00%> (+<0.01%)⬆️
production63.31% <100.00%> (+<0.01%)⬆️
test89.47% <100.00%> (+<0.01%)⬆️
Flags with carried forward coverage won't be shown. Click here to find out more.
Files with missing linesCoverage Δ
...Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.cs79.95% <100.00%> (+0.04%)⬆️
...est/Microsoft.ML.Tokenizers.Tests/TiktokenTests.cs99.09% <100.00%> (+<0.01%)⬆️
... and 7 files with indirect coverage changes
 🚀 New features to boost your workflow: 
  • ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
@tarekgh
tarekgh
commented
Jan 22, 2026

Copy link


Copy Markdown

MemberAuthor
/ba-g unrelated failures
@tarekgh
tarekgh
merged commit 25b977e
into
dotnet:mainJan 22, 2026

27 of 31 checks passed

@github-actionsgithub-actionsBot
locked and limited conversation to collaborators
Feb 22, 2026
Sign up for freeto subscribe to this conversation on GitHub.
Already have an account?
Sign in.


Reviewers

Copilot code reviewCopilot
Copilot review effort
Applies to this pull request for everyone.Learn more about Copilot code review.
Copilot left review comments
@stephentoubstephentoubstephentoub approved these changes

Assignees

@tarekghtarekgh

Labels

Tokenizers

Projects


None yet


Milestone


No milestone


Development

Successfully merging this pull request may close these issues.

3 participants

@tarekgh@stephentoub

, '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
Support Gpt-5.2 in Tokenizer library - #7571
Merged
tarekgh merged 1 commit into
dotnet:mainfrom 
tarekgh:SupportGpt-5.2Toknizer
Jan 22, 2026
Merged
Support Gpt-5.2 in Tokenizer library#7571
tarekgh merged 1 commit into
dotnet:mainfrom 
tarekgh:SupportGpt-5.2Toknizer
Conversation
@tarekgh
@tarekghtarekgh
commented
Jan 22, 2026

Copy link


Copy Markdown

Member
 No description provided. 
CopilotAI
review requested due to automatic review settings
January 22, 2026 19:41
@tarekghtarekgh
self-assigned this
Jan 22, 2026
@tarekgh
tarekgh
enabled auto-merge (squash)
January 22, 2026 19:44
CopilotAI
reviewed
Jan 22, 2026
View reviewed changes
CopilotAI
left a comment


Copy link


Copy Markdown

Contributor
Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Pull request overview
This PR adds support for the GPT-5.2 model to the Tokenizer library, following the same pattern as GPT-5 and GPT-5.1 models which use the O200kBase encoding.
Changes:
  • Added GPT-5.2 model support with O200kBase encoding
  • Updated test cases to include GPT-5.2 and GPT-5.2-mini variants
  • Added model mappings for both exact match and prefix matching
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
FileDescription
src/Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.csAdded "gpt-5.2" and "gpt-5.2-" mappings to O200kBase encoding in both exact match dictionary and prefix array
test/Microsoft.ML.Tokenizers.Tests/TiktokenTests.csAdded GPT5_2 tokenizer property, included it in O200kBase encoding test, and added test cases for "gpt-5.2" and "gpt-5.2-mini" model names
💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.
@codecov
codecovBot
commented
Jan 22, 2026•

edited

Loading

Copy link


Copy Markdown

Codecov Report
✅ All modified and coverable lines are covered by tests.

✅ Project coverage is 69.02%. Comparing base (adf0cec) to head (6ba8b78).
⚠️ Report is 2 commits behind head on main.
Additional details and impacted files
@@ Coverage Diff @@## main #7571 +/- ##
=======================================
Coverage 69.02% 69.02% =======================================
Files 1482 1482 Lines 274096 274099 +3 Branches 28266 28266 =======================================
+ Hits 189191 189199 +8 
Misses 77518 77518 + Partials 7387 7382 -5 
FlagCoverage Δ
Debug69.02% <100.00%> (+<0.01%)⬆️
production63.31% <100.00%> (+<0.01%)⬆️
test89.47% <100.00%> (+<0.01%)⬆️
Flags with carried forward coverage won't be shown. Click here to find out more.
Files with missing linesCoverage Δ
...Microsoft.ML.Tokenizers/Model/TiktokenTokenizer.cs79.95% <100.00%> (+0.04%)⬆️
...est/Microsoft.ML.Tokenizers.Tests/TiktokenTests.cs99.09% <100.00%> (+<0.01%)⬆️
... and 7 files with indirect coverage changes
 🚀 New features to boost your workflow: 
  • ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
@tarekgh
tarekgh
commented
Jan 22, 2026

Copy link


Copy Markdown

MemberAuthor
/ba-g unrelated failures
@tarekgh
tarekgh
merged commit 25b977e
into
dotnet:mainJan 22, 2026

27 of 31 checks passed

@github-actionsgithub-actionsBot
locked and limited conversation to collaborators
Feb 22, 2026
Sign up for freeto subscribe to this conversation on GitHub.
Already have an account?
Sign in.


Reviewers

Copilot code reviewCopilot
Copilot review effort
Applies to this pull request for everyone.Learn more about Copilot code review.
Copilot left review comments
@stephentoubstephentoubstephentoub approved these changes

Assignees

@tarekghtarekgh

Labels

Tokenizers

Projects


None yet


Milestone


No milestone


Development

Successfully merging this pull request may close these issues.

3 participants

@tarekgh@stephentoub