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@simonw
Created August 13, 2026 18:35
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2026-08-13T18:32:17 conversation: 01kzy6anj0fh2ngwcgcssmb67k id: 01kzy6azgy7znhxd2r1fpeydmt

Model: gemini/gemini-3.7-flash (resolved: gemini-3.7-flash)

Prompt

tell me about the svg markdown render tool

System

You are a coding agent working in /Users/simon/Dropbox/dev/tools on Darwin. Today's date is 2026-08-13.

You help with software engineering tasks: fixing bugs, implementing features, refactoring, and answering questions about the code. You have tools for reading, searching and editing files and for running shell commands, all confined to the directory above.

Workflow:

  • Explore before you change anything: use list_files and search_files to find the relevant code, and always read_file a file before editing it.
  • Prefer edit_file (exact string replacement) over write_file for existing files, and keep edits minimal - match the style, naming and conventions of the surrounding code.
  • Verify your work: after making changes, run the project's tests or another relevant command with execute_command and check the result.
  • If a tool returns an error, read the message and correct your approach rather than repeating the same call.

Honesty matters more than appearing successful. If tests fail, report the failure and include the relevant output. If you cannot complete something, say so plainly. If the task is ambiguous, stop and ask rather than guessing.

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b0ed6d4d87987157d1ec40ff219b19c41b25aea4c08587cdce568c130f
      Replace an exact string in a file.

      old_string must match the file contents exactly (including whitespace) and must identify a unique location unless replace_all is true. Returns a diff of the change so it can be verified.
      Arguments: {"path": {"type": "string"}, "old_string": {"type": "string"}, "new_string": {"type": "string"}, "replace_all": {"default": false, "type": "boolean"}}

    • CodingTools_execute_command: 87b7dfec15f45f2fe80f0e7584916a06e2e8b0765125978b0279eefe144414fe
      Run a shell command in the session root directory.

      Returns combined stdout and stderr followed by an Exit code line. timeout is in seconds (maximum 600); on timeout the whole process tree is killed.
      Arguments: {"command": {"type": "string"}, "timeout": {"default": 120, "type": "integer"}}

    • CodingTools_list_files: 4d779da979d758d08d20e797ed0a3ae43dad9258acbc042a8f999eeb01d958eb
      List files matching a glob pattern, newest first.

      Skips hidden directories, node_modules, pycache and (in a git repository) anything covered by .gitignore. Returns at most 200 paths relative to the searched directory.
      Arguments: {"pattern": {"default": "**/*", "type": "string"}, "path": {"default": ".", "type": "string"}}

    • CodingTools_read_file: d952137aaa58fa9d23863195293e92e96711422b524fab58d35eac0770b821e9
      Read a text file, returning numbered lines like cat -n.

      Paths are relative to the session root. Use offset (0-based first line) and limit (max lines) to page through files too large to read in one call.
      Arguments: {"path": {"type": "string"}, "offset": {"default": 0, "type": "integer"}, "limit": {"default": 2000, "type": "integer"}}

    • CodingTools_search_files: 6b947859f5aaf573042944cb27b9517d5534bf2435fd651b8388f0f9386ad263
      Search file contents for a regular expression.

      Returns matches as path:line_number:line, capped at max_results. Use glob (e.g. "*.py") to restrict which files are searched.
      Arguments: {"pattern": {"type": "string"}, "path": {"default": ".", "type": "string"}, "glob": {"default": null, "type": "string"}, "max_results": {"default": 100, "type": "integer"}}

    • CodingTools_write_file: 0678eb459804f184686f58c5f9936f6d60e69b7cb5c9187596df7935383efe64
      Create or overwrite a file with the given content.

      Parent directories are created as needed. Prefer edit_file for modifying existing files.
      Arguments: {"path": {"type": "string"}, "content": {"type": "string"}}

Response

Tool calls

  • CodingTools_search_files: call_325995
    pattern:
    svg.*markdown|markdown.*svg|render.*svg|svg.*render
    

Token usage

937 input, 51 output, {"candidatesTokenCount": 33, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 937}], "thoughtsTokenCount": 18, "serviceTier": "standard"}

2026-08-13T18:32:18

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_search_files: call_325995
    TOOLS_GUIDE.md:270:Used in `ocr.html`, `svg-render.html`:
    dates.json:1:{"ai-adoption.html": "2025-09-08", "alt-text-extractor.html": "2025-11-13", "analytics.html": "2025-12-01", "animated-rainbow-border.html": "2024-11-03", "annotated-presentations.html": "2025-05-15", "apsw-query.html": "2025-02-06", "arena-animated.html": "2024-06-26", "ares.html": "2024-10-20", "aria-live-regions.html": "2025-01-07", "audio-spectrum.html": "2024-08-23", "avatar-web-component.html": "2025-03-24", "badge-drawer.html": "2025-09-16", "badge-repl.html": "2025-10-28", "base64-gzip-decoder.html": "2025-04-17", "bbox-cropper.html": "2024-11-12", "bluesky-faves.html": "2025-11-27", "bluesky-firehose.html": "2025-01-06", "bluesky-quote-finder.html": "2025-11-28", "bluesky-resolve.html": "2025-01-06", "bluesky-thread.html": "2025-11-28", "bluesky-timeline.html": "2024-11-20", "box-shadow.html": "2024-07-08", "broadcast-channel-chat.html": "2025-06-08", "bullish-bearish.html": "2025-07-21", "california-clock-change.html": "2025-03-10", "census-reporter-claude.html": "2025-04-04", "census-reporter-gemini.html": "2025-04-04", "chrome-prompt-playground.html": "2025-07-15", "claude-token-counter.html": "2025-10-30", "click-grid-to-expand.html": "2024-10-13", "clipboard-viewer.html": "2025-03-25", "code-with-claude-2025.html": "2025-05-22", "compare-pdfs.html": "2024-07-02", "cors-fetch.html": "2025-11-30", "css-text-wrapping.html": "2025-03-11", "csv-marker-map.html": "2024-05-02", "date-calculator.html": "2025-07-10", "deep-research-viewer.html": "2025-10-18", "devon-lanes.html": "2025-09-04", "dot.html": "2025-10-10", "emoji-identifier.html": "2025-11-13", "encrypt.html": "2025-03-07", "escape-entities.html": "2025-11-04", "event-planner.html": "2024-10-10", "exif.html": "2024-07-17", "extract-urls.html": "2024-10-15", "ffmpeg-crop.html": "2025-11-30", "flexbox-playground.html": "2025-05-24", "footnotes-experiment.html": "2025-04-08", "gemini-bbox-tool.html": "2024-08-26", "gemini-bbox.html": "2025-11-19", "gemini-chat.html": "2025-06-17", "gemini-image-json.html": "2025-05-07", "gemini-mask.html": "2025-06-17", "github-account.html": "2025-09-11", "github-api-write.html": "2024-09-20", "github-graphiql.html": "2025-10-25", "github-issue-to-markdown.html": "2025-11-29", "github-issue.html": "2025-11-29", "github-ratelimit.html": "2025-11-04", "gpt-4o-audio-player.html": "2024-12-17", "hacker-news-filtered.html": "2025-07-15", "hacker-news-histogram.html": "2025-10-10", "hacker-news-thread-export.html": "2025-04-12", "haiku.html": "2025-10-15", "hn-comments-for-user.html": "2025-08-19", "html-preview.html": "2025-04-29", "huggingface-storage.html": "2025-03-24", "icon-editor.html": "2025-10-27", "iframe-api-explorer.html": "2024-11-14", "iframe-sandbox.html": "2024-11-07", "image-resize-quality.html": "2025-09-06", "image-to-jpeg.html": "2025-07-17", "image-to-svg.html": "2024-10-06", "incomplete-json-printer.html": "2025-03-27", "index.html": "2025-10-17", "jina-embeddings-image-token-calculator.html": "2024-09-19", "jina-reader.html": "2025-02-12", "json-schema-builder.html": "2025-03-07", "json-string-extractor.html": "2025-10-18", "json-to-markdown-transcript.html": "2025-06-17", "json-to-yaml.html": "2024-12-15", "keyboard-debug.html": "2025-09-28", "keyboard-filters.html": "2025-03-18", "lightning-timer.html": "2025-04-03", "link-extractor.html": "2025-11-26", "link-temp.html": "2024-10-27", "llm-prices.html": "2025-05-07", "markdown-math.html": "2024-09-20", "mask-visualizer.html": "2025-04-18", "mdn-timelines.html": "2024-11-11", "micropython.html": "2025-09-25", "nav-for-headings.html": "2024-12-15", "new-yorker-style.html": "2025-11-27", "notes-to-markdown.html": "2025-12-01", "numpy-pyodide-lab.html": "2025-09-24", "ocr.html": "2025-09-04", "octave-explainer.html": "2025-12-01", "omit-needless-words.html": "2025-11-30", "open-sauce-2025.html": "2025-07-19", "openai-audio-output.html": "2025-10-24", "openai-audio.html": "2024-10-18", "openai-webrtc.html": "2024-12-18", "openfreemap-demo.html": "2024-09-28", "passkeys.html": "2025-04-04", "paste-html-subset.html": "2025-04-04", "paste-rich-text.html": "2025-03-07", "pdf-ocr.html": "2024-03-30", "percentage-recalculator.html": "2025-08-08", "php-deserializer.html": "2025-01-22", "pipfile.html": "2025-03-03", "pomodoro.html": "2024-08-30", "progress.html": "2025-03-18", "prompt-caching.html": "2025-10-16", "prompts-js.html": "2024-12-07", "pyodide-bar-chart.html": "2025-09-09", "qr.html": "2024-10-21", "query-string-stripper.html": "2025-10-19", "reading-time.html": "2025-06-17", "render-claude-citations.html": "2025-01-23", "render-markdown.html": "2025-04-22", "rich-text-to-markdown.html": "2025-10-10", "rtf-to-html.html": "2025-10-17", "schema-dsl.html": "2025-03-05", "side-panel-dialog.html": "2025-10-22", "sloccount.html": "2025-10-25", "social-media-cropper.html": "2025-10-22", "space-invaders-6bit-mlx-Qwen3-Coder-30B-A3B-Instruct.html": "2025-07-31", "space-invaders-GLM-4.5-Air-3bit.html": "2025-07-28", "space-invaders-gpt-oss-20b-mxfp4-medium.html": "2025-08-05", "space-invaders-qwen3-30b-a3b-thinking-2507.html": "2025-07-30", "space-invaders-xbai-o4-6bit-mlx.html": "2025-08-03", "species-observation-map.html": "2025-03-14", "speech-synthesis.html": "2025-07-22", "sql-pretty-printer.html": "2025-02-03", "sqlite-wasm.html": "2024-10-15", "svg-progressive-render.html": "2024-10-25", "svg-render.html": "2025-10-14", "svg-sandbox.html": "2024-10-26", "swagger-subset.html": "2025-03-14", "terminal-to-html.html": "2025-11-24", "text-diff.html": "2025-11-24", "text-indentation.html": "2025-10-15", "text-wrap-balance-nav.html": "2024-10-20", "tiff-orientation.html": "2024-08-26", "timezones.html": "2024-12-10", "token-usage.html": "2025-03-13", "transfer-time.html": "2025-06-07", "unix-timestamp.html": "2024-11-20", "user-agent.html": "2024-09-26", "wikipedia-wikitext.html": "2025-11-30", "word-counter.html": "2025-02-25", "writing-style.html": "2024-12-14", "xml-validator.html": "2025-11-19", "yaml-explorer.html": "2024-12-22", "youtube-thumbnails.html": "2024-09-19", "zip-wheel-explorer.html": "2024-11-19"}
    markdown-copy-component.html:153:      btn.innerHTML = svgIcon + (this._showRaw ? ' See rendered' : ' See code');
    dot.html:216:    const svg = await viz.renderSVGElement(dotContent);
    

Response

Tool calls

  • CodingTools_list_files: call_43928
    pattern:
    *svg*
    

Token usage

4,352 input, 35 output, {"candidatesTokenCount": 21, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 4352}], "thoughtsTokenCount": 14, "serviceTier": "standard"}

2026-08-13T18:32:19

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_list_files: call_43928
    markdown-svg-renderer.html
    markdown-svg-renderer.docs.md
    svg-sandbox.docs.md
    svg-progressive-render.docs.md
    image-to-svg.docs.md
    svg-render.docs.md
    svg-render.html
    image-to-svg.html
    svg-progressive-render.html
    svg-sandbox.html
    

Response

Tool calls

  • CodingTools_read_file: call_145960
    limit: 200 path:
    markdown-svg-renderer.docs.md
    
    offset: 0

Token usage

4,484 input, 121 output, {"candidatesTokenCount": 37, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 4484}], "thoughtsTokenCount": 84, "serviceTier": "standard"}

2026-08-13T18:32:20

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_read_file: call_145960
         1	View and render markdown content with live preview. Paste markdown directly or load from a raw URL or GitHub Gist, with support for standard formatting, tables, code blocks, and SVG previews with tabbed display for rendered output and source code. Toggle between split editor and full-screen viewer modes.
         2	
         3	<!-- Generated from commit: 7464a989637510a65316962470f55d9c2d8ad0c6 -->
    

Response

Tool calls

  • CodingTools_read_file: call_148338
    offset: 0 limit: 200 path:
    markdown-svg-renderer.html
    

Token usage

4,737 input, 48 output, {"candidatesTokenCount": 35, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 4737}], "thoughtsTokenCount": 13, "serviceTier": "standard"}

2026-08-13T18:32:21

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_read_file: call_148338
         1	<style>
         2	* {
         3	  box-sizing: border-box;
         4	}
         5	
         6	body {
         7	  font-family: Helvetica, Arial, sans-serif;
         8	  margin: 0;
         9	  background: #fafafa;
        10	  color: #1a1a1a;
        11	}
        12	
        13	.app {
        14	  display: grid;
        15	  grid-template-columns: 1fr 1fr;
        16	  height: 100vh;
        17	}
        18	
        19	.app.viewer-mode {
        20	  grid-template-columns: minmax(0, 1fr);
        21	}
        22	
        23	.app.viewer-mode .editor-pane {
        24	  display: none;
        25	}
        26	
        27	.pane {
        28	  display: flex;
        29	  flex-direction: column;
        30	  min-width: 0;
        31	}
        32	
        33	.pane-header {
        34	  padding: 10px 16px;
        35	  font-size: 13px;
        36	  font-weight: bold;
        37	  text-transform: uppercase;
        38	  letter-spacing: 0.5px;
        39	  color: #888;
        40	  border-bottom: 1px solid #e2e2e2;
        41	  background: #fff;
        42	}
        43	
        44	.editor-pane {
        45	  border-right: 1px solid #e2e2e2;
        46	}
        47	
        48	.preview-header {
        49	  display: flex;
        50	  align-items: center;
        51	  justify-content: space-between;
        52	  gap: 12px;
        53	}
        54	
        55	.source-toggle {
        56	  display: none;
        57	  align-items: center;
        58	  justify-content: center;
        59	  width: 28px;
        60	  height: 28px;
        61	  border: 1px solid #e2e2e2;
        62	  border-radius: 6px;
        63	  background: #fff;
        64	  color: #777;
        65	  cursor: pointer;
        66	}
        67	
        68	.source-toggle:hover,
        69	.source-toggle:focus-visible {
        70	  color: #2563eb;
        71	  border-color: #bfdbfe;
        72	  outline: none;
        73	}
        74	
        75	.source-toggle svg {
        76	  width: 16px;
        77	  height: 16px;
        78	  stroke: currentColor;
        79	}
        80	
        81	.app.has-url-content .source-toggle {
        82	  display: inline-flex;
        83	}
        84	
        85	.app.viewer-mode .source-toggle {
        86	  opacity: 0.72;
        87	}
        88	
        89	.app.viewer-mode #output {
        90	  max-width: 980px;
        91	  width: 100%;
        92	  margin: 0 auto;
        93	}
        94	
        95	.source-tabs {
        96	  display: flex;
        97	  gap: 4px;
        98	}
        99	
       100	.source-tabs button {
       101	  font-family: Helvetica, Arial, sans-serif;
       102	  font-size: 12px;
       103	  font-weight: bold;
       104	  text-transform: uppercase;
       105	  letter-spacing: 0.5px;
       106	  border: 1px solid #e2e2e2;
       107	  background: #f6f6f6;
       108	  color: #888;
       109	  padding: 4px 10px;
       110	  border-radius: 5px;
       111	  cursor: pointer;
       112	}
       113	
       114	.source-tabs button.active {
       115	  background: #2563eb;
       116	  border-color: #2563eb;
       117	  color: #fff;
       118	}
       119	
       120	.url-bar {
       121	  display: none;
       122	  gap: 8px;
       123	  padding: 12px 16px;
       124	  border-bottom: 1px solid #e2e2e2;
       125	  background: #fff;
       126	}
       127	
       128	.url-bar.active { display: flex; }
       129	
       130	#url-input {
       131	  flex: 1;
       132	  border: 1px solid #ddd;
       133	  border-radius: 6px;
       134	  padding: 8px 10px;
       135	  font-family: Helvetica, Arial, sans-serif;
       136	  font-size: 16px;
       137	  outline: none;
       138	}
       139	
       140	#url-input:focus { border-color: #2563eb; }
       141	
       142	#url-load {
       143	  font-family: Helvetica, Arial, sans-serif;
       144	  font-size: 14px;
       145	  border: none;
       146	  background: #2563eb;
       147	  color: #fff;
       148	  padding: 8px 16px;
       149	  border-radius: 6px;
       150	  cursor: pointer;
       151	}
       152	
       153	#url-status {
       154	  padding: 8px 16px;
       155	  font-size: 13px;
       156	  color: #888;
       157	  border-bottom: 1px solid #e2e2e2;
       158	  background: #fff;
       159	  display: none;
       160	}
       161	
       162	#url-status.active { display: block; }
       163	#url-status.error { color: #dc2626; }
       164	
       165	#input {
       166	  flex: 1;
       167	  border: none;
       168	  outline: none;
       169	  resize: none;
       170	  padding: 16px;
       171	  font-family: "SF Mono", Menlo, Monaco, Consolas, monospace;
       172	  font-size: 16px;
       173	  line-height: 1.5;
       174	  background: #fff;
       175	}
       176	
       177	#output {
       178	  flex: 1;
       179	  overflow-y: auto;
       180	  padding: 24px 32px;
       181	  line-height: 1.6;
       182	}
       183	
       184	#output h1, #output h2, #output h3, #output h4 {
       185	  line-height: 1.25;
       186	  margin-top: 1.5em;
       187	  margin-bottom: 0.5em;
       188	}
       189	
       190	#output h1 { font-size: 2em; border-bottom: 1px solid #e2e2e2; padding-bottom: 0.3em; }
       191	#output h2 { font-size: 1.5em; border-bottom: 1px solid #e2e2e2; padding-bottom: 0.3em; }
       192	#output h3 { font-size: 1.25em; }
       193	
       194	#output p { margin: 0.8em 0; }
       195	
       196	#output code {
       197	  background: #f0f0f0;
       198	  padding: 2px 5px;
       199	  border-radius: 3px;
       200	  font-family: "SF Mono", Menlo, Monaco, Consolas, monospace;
    ... 504 more lines, use offset=200 to continue
    

Response

Tool calls

  • CodingTools_read_file: call_266867
    limit: 200 offset: 200 path:
    markdown-svg-renderer.html
    

Token usage

7,261 input, 62 output, {"candidatesTokenCount": 37, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 7261}], "thoughtsTokenCount": 25, "serviceTier": "standard"}

2026-08-13T18:32:22

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_read_file: call_266867
       201	  font-size: 0.9em;
       202	}
       203	
       204	#output pre {
       205	  background: #f6f6f6;
       206	  padding: 14px 16px;
       207	  border-radius: 6px;
       208	  overflow-x: auto;
       209	  border: 1px solid #e8e8e8;
       210	}
       211	
       212	#output pre code {
       213	  background: none;
       214	  padding: 0;
       215	}
       216	
       217	#output blockquote {
       218	  margin: 0.8em 0;
       219	  padding-left: 16px;
       220	  border-left: 4px solid #ddd;
       221	  color: #666;
       222	}
       223	
       224	#output table {
       225	  border-collapse: collapse;
       226	  margin: 1em 0;
       227	}
       228	
       229	#output th, #output td {
       230	  border: 1px solid #ddd;
       231	  padding: 6px 12px;
       232	}
       233	
       234	#output th { background: #f6f6f6; }
       235	
       236	#output a { color: #2563eb; }
       237	
       238	#output img { max-width: 100%; }
       239	
       240	#output hr {
       241	  border: none;
       242	  border-top: 1px solid #e2e2e2;
       243	  margin: 1.5em 0;
       244	}
       245	
       246	@media (max-width: 700px) {
       247	  .app { grid-template-columns: 1fr; grid-template-rows: 1fr 1fr; }
       248	  .app.viewer-mode { grid-template-rows: 1fr; }
       249	  .editor-pane { border-right: none; border-bottom: 1px solid #e2e2e2; }
       250	}
       251	</style>
       252	
       253	<div class="app">
       254	  <div class="pane editor-pane">
       255	    <div class="pane-header">
       256	      <span class="source-tabs">
       257	        <button id="tab-paste" class="active" type="button">Paste</button>
       258	        <button id="tab-url" type="button">URL</button>
       259	      </span>
       260	    </div>
       261	    <div class="url-bar" id="url-bar">
       262	      <input id="url-input" type="url" spellcheck="false"
       263	        placeholder="Raw markdown URL or https://gist.github.com/...">
       264	      <button id="url-load" type="button">Load</button>
       265	    </div>
       266	    <div id="url-status"></div>
       267	    <textarea id="input" spellcheck="false"></textarea>
       268	  </div>
       269	  <div class="pane preview-pane">
       270	    <div class="pane-header preview-header">
       271	      <span>Preview</span>
       272	      <button id="source-toggle" class="source-toggle" type="button"
       273	        title="Show source" aria-label="Show source" aria-pressed="false">
       274	        <svg viewBox="0 0 24 24" fill="none" stroke-width="2"
       275	          stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
       276	          <rect x="3" y="4" width="18" height="16" rx="2"></rect>
       277	          <path d="M9 4v16"></path>
       278	          <path d="m14 9 3 3-3 3"></path>
       279	        </svg>
       280	      </button>
       281	    </div>
       282	    <div id="output"></div>
       283	  </div>
       284	</div>
       285	
       286	<script
       287	  src="https://cdn.jsdelivr.net/npm/markdown-it@14.1.1/dist/markdown-it.min.js"
       288	  integrity="sha384-VjNpj0uWy3ya2VFiHXeS6MxjLjWGb1mSZTNAF0xfbZguX+9CXmTkYSmOxEyUWJ9S"
       289	  crossorigin="anonymous"></script>
       290	<script
       291	  src="https://cdn.jsdelivr.net/npm/dompurify@3.3.3/dist/purify.min.js"
       292	  integrity="sha384-pcBjnGbkyKeOXaoFkmJiuR9E08/6gkmus6/Strimnxtl3uk0Hx23v345pWyC/MMr"
       293	  crossorigin="anonymous"></script>
       294	
       295	<script type="module">
       296	// ---- SVG tab web component ----
       297	function svgAspectRatio(svg) {
       298	  let ratio = "1 / 1";
       299	  const m = svg.match(/viewBox\s*=\s*["']([\d.\s-]+)["']/i);
       300	  if (m) {
       301	    const parts = m[1].trim().split(/\s+/).map(Number);
       302	    if (parts.length === 4 && parts[2] > 0 && parts[3] > 0) {
       303	      ratio = `${parts[2]} / ${parts[3]}`;
       304	    }
       305	  } else {
       306	    const w = svg.match(/\bwidth\s*=\s*["']?([\d.]+)/i);
       307	    const h = svg.match(/\bheight\s*=\s*["']?([\d.]+)/i);
       308	    if (w && h && +h[1] > 0) ratio = `${+w[1]} / ${+h[1]}`;
       309	  }
       310	  return ratio;
       311	}
       312	
       313	function svgPreviewDocument(svg) {
       314	  return `<!doctype html>
       315	<html>
       316	<head>
       317	<meta charset="utf-8">
       318	<style>
       319	html, body {
       320	  width: 100%;
       321	  height: 100%;
       322	  margin: 0;
       323	  overflow: hidden;
       324	  background: #fff;
       325	}
       326	svg {
       327	  width: 100%;
       328	  height: 100%;
       329	  display: block;
       330	}
       331	</style>
       332	</head>
       333	<body>${svg}${"</" + "body>"}
       334	${"</" + "html>"}`;
       335	}
       336	
       337	class SvgBlock extends HTMLElement {
       338	  connectedCallback() {
       339	    if (this.shadowRoot) return;
       340	
       341	    const code = this.getAttribute("data-svg") || "";
       342	    const shadow = this.attachShadow({ mode: "open" });
       343	
       344	    shadow.innerHTML = `
       345	      <style>
       346	        :host {
       347	          display: block;
       348	          max-width: 100%;
       349	          margin: 1em 0;
       350	          border: 1px solid #e2e2e2;
       351	          border-radius: 8px;
       352	          overflow: hidden;
       353	          font-family: Helvetica, Arial, sans-serif;
       354	        }
       355	        .tabs {
       356	          display: flex;
       357	          border-bottom: 1px solid #e2e2e2;
       358	          background: #f6f6f6;
       359	        }
       360	        button {
       361	          font-family: inherit;
       362	          font-size: 13px;
       363	          border: none;
       364	          background: none;
       365	          padding: 8px 16px;
       366	          cursor: pointer;
       367	          color: #666;
       368	          border-bottom: 2px solid transparent;
       369	          margin-bottom: -1px;
       370	        }
       371	        button.active {
       372	          color: #1a1a1a;
       373	          font-weight: bold;
       374	          border-bottom-color: #2563eb;
       375	          background: #fff;
       376	        }
       377	        .panel { display: none; }
       378	        .panel.active { display: block; }
       379	        .svg-wrap {
       380	          width: 100%;
       381	          background: #fff;
       382	          padding: 12px;
       383	        }
       384	        iframe {
       385	          display: block;
       386	          width: 100%;
       387	          height: 100%;
       388	          border: 0;
       389	          background: #fff;
       390	        }
       391	        pre {
       392	          margin: 0;
       393	          padding: 14px 16px;
       394	          overflow-x: auto;
       395	          background: #1e1e1e;
       396	          color: #e8e8e8;
       397	          font-family: "SF Mono", Menlo, Monaco, Consolas, monospace;
       398	          font-size: 13px;
       399	          line-height: 1.5;
       400	        }
    ... 304 more lines, use offset=400 to continue
    

Response

Tool calls

  • CodingTools_read_file: call_226581
    limit: 200 path:
    markdown-svg-renderer.html
    
    offset: 400

Token usage

10,281 input, 61 output, {"candidatesTokenCount": 37, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 10281}], "thoughtsTokenCount": 24, "serviceTier": "standard"}

2026-08-13T18:32:23

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_read_file: call_226581
       401	      </style>
       402	      <div class="tabs">
       403	        <button class="active" data-tab="render">Rendered</button>
       404	        <button data-tab="code">Code</button>
       405	      </div>
       406	      <div class="panel active" data-panel="render">
       407	        <div class="svg-wrap">
       408	          <iframe title="Rendered SVG" sandbox="" referrerpolicy="no-referrer"></iframe>
       409	        </div>
       410	      </div>
       411	      <div class="panel" data-panel="code"><pre></pre></div>
       412	    `;
       413	
       414	    shadow.querySelector(".svg-wrap").style.aspectRatio = svgAspectRatio(code);
       415	    shadow.querySelector("iframe").srcdoc = svgPreviewDocument(code);
       416	    shadow.querySelector("pre").textContent = code;
       417	
       418	    const buttons = shadow.querySelectorAll("button");
       419	    const panels = shadow.querySelectorAll(".panel");
       420	    buttons.forEach((btn) => {
       421	      btn.addEventListener("click", () => {
       422	        const tab = btn.dataset.tab;
       423	        buttons.forEach((b) => b.classList.toggle("active", b === btn));
       424	        panels.forEach((p) =>
       425	          p.classList.toggle("active", p.dataset.panel === tab)
       426	        );
       427	      });
       428	    });
       429	  }
       430	}
       431	customElements.define("svg-block", SvgBlock);
       432	
       433	// ---- Markdown rendering ----
       434	const markdownSanitizeConfig = {
       435	  USE_PROFILES: { html: true },
       436	  ADD_ATTR: ["data-svg-id"],
       437	  FORBID_ATTR: ["style"],
       438	  FORBID_TAGS: ["style"]
       439	};
       440	
       441	const svgSanitizeConfig = {
       442	  USE_PROFILES: { svg: true },
       443	  FORBID_ATTR: ["href", "xlink:href", "src", "style"],
       444	  FORBID_TAGS: [
       445	    "animate",
       446	    "animateMotion",
       447	    "animatemotion",
       448	    "animateTransform",
       449	    "animatetransform",
       450	    "audio",
       451	    "embed",
       452	    "foreignObject",
       453	    "foreignobject",
       454	    "iframe",
       455	    "image",
       456	    "link",
       457	    "object",
       458	    "script",
       459	    "set",
       460	    "style",
       461	    "use",
       462	    "video"
       463	  ]
       464	};
       465	
       466	const md = window.markdownit({
       467	  html: false,
       468	  linkify: false,
       469	  typographer: false
       470	});
       471	
       472	// Sanitized SVG sources are stashed here and referenced by id, rather than
       473	// embedded in a data- attribute: DOMPurify's SAFE_FOR_XML protection strips
       474	// any attribute whose value contains strings like "</title>" or "</style>",
       475	// which silently dropped legitimate SVGs during the second sanitize pass.
       476	const svgStore = new Map();
       477	
       478	const defaultFenceRenderer = md.renderer.rules.fence;
       479	md.renderer.rules.fence = (tokens, idx, options, env, self) => {
       480	  const token = tokens[idx];
       481	  const lang = (token.info || "").trim().split(/\s+/)[0].toLowerCase();
       482	
       483	  if (lang === "svg") {
       484	    const svg = window.DOMPurify.sanitize(token.content, svgSanitizeConfig).trim();
       485	    if (svg) {
       486	      const id = String(svgStore.size);
       487	      svgStore.set(id, svg);
       488	      return `<div class="svg-block-placeholder" data-svg-id="${id}"></div>\n`;
       489	    }
       490	  }
       491	
       492	  return defaultFenceRenderer(tokens, idx, options, env, self);
       493	};
       494	
       495	function hydrateSvgBlocks(root) {
       496	  root.querySelectorAll(".svg-block-placeholder[data-svg-id]").forEach((placeholder) => {
       497	    const svg = svgStore.get(placeholder.getAttribute("data-svg-id"));
       498	    if (!svg) {
       499	      placeholder.remove();
       500	      return;
       501	    }
       502	    const block = document.createElement("svg-block");
       503	    block.setAttribute("data-svg", svg);
       504	    placeholder.replaceWith(block);
       505	  });
       506	}
       507	
       508	function renderMarkdown(src) {
       509	  svgStore.clear();
       510	  const html = md.render(src);
       511	  return window.DOMPurify.sanitize(html, markdownSanitizeConfig);
       512	}
       513	
       514	const app = document.querySelector(".app");
       515	const input = document.getElementById("input");
       516	const output = document.getElementById("output");
       517	const tabPaste = document.getElementById("tab-paste");
       518	const tabUrl = document.getElementById("tab-url");
       519	const urlBar = document.getElementById("url-bar");
       520	const urlInput = document.getElementById("url-input");
       521	const urlLoad = document.getElementById("url-load");
       522	const urlStatus = document.getElementById("url-status");
       523	const sourceToggle = document.getElementById("source-toggle");
       524	
       525	function update() {
       526	  output.innerHTML = renderMarkdown(input.value);
       527	  hydrateSvgBlocks(output);
       528	}
       529	
       530	input.addEventListener("input", update);
       531	
       532	function setViewerMode(enabled) {
       533	  app.classList.toggle("viewer-mode", enabled);
       534	  sourceToggle.setAttribute("aria-pressed", enabled ? "true" : "false");
       535	  sourceToggle.setAttribute("aria-label", enabled ? "Show source" : "Hide source");
       536	  sourceToggle.title = enabled ? "Show source" : "Hide source";
       537	}
       538	
       539	function setUrlContentLoaded(enabled) {
       540	  app.classList.toggle("has-url-content", enabled);
       541	  if (!enabled) setViewerMode(false);
       542	}
       543	
       544	sourceToggle.addEventListener("click", () => {
       545	  setViewerMode(!app.classList.contains("viewer-mode"));
       546	});
       547	
       548	// ---- Source mode switching ----
       549	function setMode(mode) {
       550	  const isUrl = mode === "url";
       551	  tabUrl.classList.toggle("active", isUrl);
       552	  tabPaste.classList.toggle("active", !isUrl);
       553	  urlBar.classList.toggle("active", isUrl);
       554	  input.readOnly = isUrl;
       555	  input.style.background = isUrl ? "#f9f9f9" : "#fff";
       556	}
       557	
       558	tabPaste.addEventListener("click", () => {
       559	  setUrlContentLoaded(false);
       560	  setMode("paste");
       561	  input.readOnly = false;
       562	  input.style.background = "#fff";
       563	  if (location.hash) history.pushState("", document.title, location.pathname + location.search);
       564	});
       565	
       566	tabUrl.addEventListener("click", () => setMode("url"));
       567	
       568	function setStatus(msg, isError) {
       569	  if (!msg) {
       570	    urlStatus.classList.remove("active", "error");
       571	    urlStatus.textContent = "";
       572	    return;
       573	  }
       574	  urlStatus.textContent = msg;
       575	  urlStatus.classList.add("active");
       576	  urlStatus.classList.toggle("error", !!isError);
       577	}
       578	
       579	// Match a gist URL and capture the gist id (the long hex segment).
       580	const gistRe = /^https?:\/\/gist\.github\.com\/(?:[^/]+\/)?([0-9a-f]+)/i;
       581	
       582	function normalizeSourceUrl(rawUrl) {
       583	  let parsed;
       584	  try {
       585	    parsed = new URL(rawUrl.trim());
       586	  } catch {
       587	    throw new Error("Enter a valid URL");
       588	  }
       589	  if (parsed.protocol !== "http:" && parsed.protocol !== "https:") {
       590	    throw new Error("Only http and https URLs are supported");
       591	  }
       592	  return parsed.href;
       593	}
       594	
       595	async function fetchSource(url) {
       596	  const sourceUrl = normalizeSourceUrl(url);
       597	  const gistMatch = gistRe.exec(sourceUrl);
       598	  if (gistMatch) {
       599	    const id = gistMatch[1];
       600	    const res = await fetch(`https://api.github.com/gists/${id}`);
    ... 104 more lines, use offset=600 to continue
    

Response

Tool calls

  • CodingTools_read_file: call_360767
    offset: 600 path:
    markdown-svg-renderer.html
    
    limit: 120

Token usage

13,163 input, 54 output, {"candidatesTokenCount": 37, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 13163}], "thoughtsTokenCount": 17, "serviceTier": "standard"}

2026-08-13T18:32:24

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_read_file: call_360767
       601	    if (!res.ok) throw new Error(`Gist API returned ${res.status}`);
       602	    const data = await res.json();
       603	    const files = data.files || {};
       604	    const names = Object.keys(files);
       605	    if (!names.length) throw new Error("Gist contains no files");
       606	    const first = files[names[0]];
       607	    // The API truncates large files; fall back to raw_url if so.
       608	    if (first.truncated && first.raw_url) {
       609	      const raw = await fetch(first.raw_url);
       610	      if (!raw.ok) throw new Error(`Raw fetch returned ${raw.status}`);
       611	      return await raw.text();
       612	    }
       613	    return first.content;
       614	  }
       615	  // Plain raw markdown URL.
       616	  const res = await fetch(sourceUrl);
       617	  if (!res.ok) throw new Error(`Fetch returned ${res.status}`);
       618	  return await res.text();
       619	}
       620	
       621	async function loadFromUrl(url, recordHash) {
       622	  setMode("url");
       623	  urlInput.value = url;
       624	  setStatus("Loading…");
       625	  try {
       626	    const text = await fetchSource(url);
       627	    input.value = text;
       628	    update();
       629	    setStatus("");
       630	    setUrlContentLoaded(true);
       631	    setViewerMode(true);
       632	    if (recordHash) {
       633	      const newHash = "#url=" + encodeURIComponent(url);
       634	      if (location.hash !== newHash) {
       635	        history.pushState({ url }, "", newHash);
       636	      }
       637	    }
       638	  } catch (err) {
       639	    setStatus("Error: " + err.message, true);
       640	  }
       641	}
       642	
       643	urlLoad.addEventListener("click", () => {
       644	  const url = urlInput.value.trim();
       645	  if (url) loadFromUrl(url, true);
       646	});
       647	
       648	urlInput.addEventListener("keydown", (e) => {
       649	  if (e.key === "Enter") {
       650	    e.preventDefault();
       651	    urlLoad.click();
       652	  }
       653	});
       654	
       655	// ---- Fragment-based load on startup / navigation ----
       656	function urlFromHash() {
       657	  const m = /^#url=(.+)$/.exec(location.hash);
       658	  return m ? decodeURIComponent(m[1]) : null;
       659	}
       660	
       661	window.addEventListener("popstate", () => {
       662	  const url = urlFromHash();
       663	  if (url) {
       664	    loadFromUrl(url, false);
       665	  }
       666	});
       667	
       668	const sample = `# Markdown renderer
       669	
       670	Paste **markdown** here and watch it render on the right.
       671	
       672	## Features
       673	
       674	- Headings, *emphasis*, and \`inline code\`
       675	- Lists, tables, blockquotes
       676	- Standard \`\`\`code\`\`\` blocks
       677	- Special SVG blocks with tabs
       678	- Load from a raw markdown URL or a Gist
       679	
       680	> SVG fenced blocks render as a tabbed component.
       681	
       682	\`\`\`svg
       683	<svg viewBox="0 0 200 120" xmlns="http://www.w3.org/2000/svg">
       684	  <rect x="0" y="0" width="200" height="120" fill="#2563eb"/>
       685	  <circle cx="100" cy="60" r="40" fill="#fbbf24"/>
       686	  <text x="100" y="66" text-anchor="middle" font-family="Helvetica" font-size="18" fill="#1a1a1a">SVG</text>
       687	</svg>
       688	\`\`\`
       689	
       690	| Feature | Supported |
       691	|---------|-----------|
       692	| Tables  | Yes       |
       693	| SVG tabs| Yes       |
       694	`;
       695	
       696	// On load: if a URL is in the fragment, switch to URL tab and load it.
       697	const startupUrl = urlFromHash();
       698	if (startupUrl) {
       699	  loadFromUrl(startupUrl, false);
       700	} else {
       701	  input.value = sample;
       702	  update();
       703	}
       704	</script>
    

Response

Tool calls

  • CodingTools_read_file: call_100785
    offset: 0 limit: 100 path:
    svg-render.docs.md
    

Token usage

14,667 input, 100 output, {"candidatesTokenCount": 35, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 14667}], "thoughtsTokenCount": 65, "serviceTier": "standard"}

2026-08-13T18:32:25

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_read_file: call_100785
         1	Convert SVG images to JPEG or PNG format with customizable dimensions, padding, and background colors. The tool allows you to paste SVG code directly, upload SVG files via drag-and-drop, or load SVG images from URLs, then instantly previews the converted result and provides download and base64 embedding options. URL hashes preserve your work for easy sharing and recovery.
         2	
         3	<!-- Generated from commit: aa44951cdb23b63465877c5f7787f09c83874276 -->
    

Response

Tool calls

  • CodingTools_list_files: call_181009
    pattern:
    *render-markdown*
    

Token usage

14,910 input, 38 output, {"candidatesTokenCount": 23, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 14910}], "thoughtsTokenCount": 15, "serviceTier": "standard"}

2026-08-13T18:32:26

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_list_files: call_181009
    render-markdown.html
    render-markdown.docs.md
    

Response

Tool calls

  • CodingTools_read_file: call_354984
    path:
    render-markdown.docs.md
    
    limit: 100 offset: 0

Token usage

14,977 input, 48 output, {"candidatesTokenCount": 35, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 14977}], "thoughtsTokenCount": 13, "serviceTier": "standard"}

2026-08-13T18:32:27

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_read_file: call_354984
         1	Convert markdown text to HTML using GitHub's markdown rendering API. The tool provides a live preview of the rendered output and allows you to copy the generated HTML or rich text to your clipboard. Additional options include GitHub Flavored Markdown support and automatic cleanup of hidden HTML elements and metadata.
         2	
         3	<!-- Generated from commit: 91bfd29ff0279ad7e7666b1f6047ab571007990c -->
    

Reasoning

Defining the Project Scope

Okay, I've got a solid grasp of markdown-svg-renderer.html. I'm focusing on structuring a complete response. I'm starting by establishing a clear overview. I'm defining the tool, which is a live Markdown viewer and editor.

Response

The SVG Markdown Renderer (markdown-svg-renderer.html) is an in-browser tool designed to view and edit Markdown documents that contain embedded SVG code blocks.


Key Features & How It Works

1. Tabbed SVG Code Blocks

When Markdown contains fenced code blocks tagged with ```svg, the tool transforms them into a custom web component (<svg-block>) that gives the user two interactive tabs:

  • Rendered: Displays the live rendered graphic.
  • Code: Displays the raw SVG source code with syntax formatting.

The SVG container automatically calculates and applies the correct aspect ratio by parsing the viewBox or width/height attributes.

2. Sandboxing and Security

To prevent XSS and malicious scripts from executing within SVG blocks:

  • DOMPurify Sanitization: Markdown output and SVG code are sanitized separately. Disallowed SVG elements and attributes (such as <script>, <foreignObject>, <animate>, <use>, href, style, etc.) are stripped out.
  • Sandboxed <iframe>: The rendered SVG is isolated inside a sandboxed iframe (sandbox="" referrerpolicy="no-referrer").
  • Two-Pass Hydration: Sanitized SVGs are held in an in-memory store (svgStore) during Markdown compilation and hydrated into the DOM as custom elements, avoiding DOMPurify issues with raw SVG code embedded in data attributes.

3. Dual Input Methods

  • Paste Mode: A split-screen layout with an interactive plain-text editor on the left and a live-updating rendered preview on the right.
  • URL / Gist Mode: Load Markdown directly from:
    • Any raw HTTP/HTTPS Markdown URL.
    • GitHub Gist links (automatically resolves the Gist ID via GitHub's API and handles truncated files).
    • Deep-linking support via URL hash fragments (#url=https://...), allowing shareable direct links.

4. Split-Pane vs. Viewer Mode

  • Loading content via URL opens directly in Viewer Mode (a clean, full-width document reading view).
  • A toggle button in the header allows expanding or collapsing the source editor pane at any time.

5. Libraries Used

  • markdown-it (v14.1.1) for standard Markdown parsing (tables, lists, blockquotes, code blocks).
  • DOMPurify (v3.3.3) for client-side HTML and SVG sanitization.

Token usage

15,151 input, 942 output, {"candidatesTokenCount": 540, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 15151}], "thoughtsTokenCount": 402, "serviceTier": "standard"}

2026-08-13T18:32:59

Prompt

I want it to also treat a ```xml block as SVG if that block starts with <svg and ends with (after trimming whitespace)

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Response

Tool calls

  • CodingTools_read_file: call_267502
    limit: 50 path:
    markdown-svg-renderer.html
    
    offset: 470

Token usage

15,871 input, 86 output, {"candidatesTokenCount": 36, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 15871}], "thoughtsTokenCount": 50, "serviceTier": "standard"}

2026-08-13T18:33:00

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_read_file: call_267502
       471	
       472	// Sanitized SVG sources are stashed here and referenced by id, rather than
       473	// embedded in a data- attribute: DOMPurify's SAFE_FOR_XML protection strips
       474	// any attribute whose value contains strings like "</title>" or "</style>",
       475	// which silently dropped legitimate SVGs during the second sanitize pass.
       476	const svgStore = new Map();
       477	
       478	const defaultFenceRenderer = md.renderer.rules.fence;
       479	md.renderer.rules.fence = (tokens, idx, options, env, self) => {
       480	  const token = tokens[idx];
       481	  const lang = (token.info || "").trim().split(/\s+/)[0].toLowerCase();
       482	
       483	  if (lang === "svg") {
       484	    const svg = window.DOMPurify.sanitize(token.content, svgSanitizeConfig).trim();
       485	    if (svg) {
       486	      const id = String(svgStore.size);
       487	      svgStore.set(id, svg);
       488	      return `<div class="svg-block-placeholder" data-svg-id="${id}"></div>\n`;
       489	    }
       490	  }
       491	
       492	  return defaultFenceRenderer(tokens, idx, options, env, self);
       493	};
       494	
       495	function hydrateSvgBlocks(root) {
       496	  root.querySelectorAll(".svg-block-placeholder[data-svg-id]").forEach((placeholder) => {
       497	    const svg = svgStore.get(placeholder.getAttribute("data-svg-id"));
       498	    if (!svg) {
       499	      placeholder.remove();
       500	      return;
       501	    }
       502	    const block = document.createElement("svg-block");
       503	    block.setAttribute("data-svg", svg);
       504	    placeholder.replaceWith(block);
       505	  });
       506	}
       507	
       508	function renderMarkdown(src) {
       509	  svgStore.clear();
       510	  const html = md.render(src);
       511	  return window.DOMPurify.sanitize(html, markdownSanitizeConfig);
       512	}
       513	
       514	const app = document.querySelector(".app");
       515	const input = document.getElementById("input");
       516	const output = document.getElementById("output");
       517	const tabPaste = document.getElementById("tab-paste");
       518	const tabUrl = document.getElementById("tab-url");
       519	const urlBar = document.getElementById("url-bar");
       520	const urlInput = document.getElementById("url-input");
    ... 184 more lines, use offset=520 to continue
    

Response

Tool calls

  • CodingTools_list_files: call_168818
    pattern:
    *test*
    

Token usage

16,743 input, 96 output, {"candidatesTokenCount": 21, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 16743}], "thoughtsTokenCount": 75, "serviceTier": "standard"}

2026-08-13T18:33:01

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_list_files: call_168818
    test_microquickjs.py
    

Response

Tool calls

  • CodingTools_search_files: call_130152
    pattern:
    markdown-svg-renderer
    

Token usage

16,862 input, 40 output, {"candidatesTokenCount": 23, "cachedContentTokenCount": 12148, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 16862}], "cacheTokensDetails": [{"modality": "TEXT", "tokenCount": 12148}], "thoughtsTokenCount": 17, "serviceTier": "standard"}

2026-08-13T18:33:02

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_search_files: call_130152
    No matches found for markdown-svg-renderer in .
    

Response

Tool calls

  • CodingTools_execute_command: call_202475
    command:
    git status
    

Token usage

16,929 input, 39 output, {"candidatesTokenCount": 20, "cachedContentTokenCount": 12142, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 16929}], "cacheTokensDetails": [{"modality": "TEXT", "tokenCount": 12142}], "thoughtsTokenCount": 19, "serviceTier": "standard"}

2026-08-13T18:33:08

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_execute_command: call_202475
    On branch main
    Your branch is up to date with 'origin/main'.
    
    Changes not staged for commit:
      (use "git add <file>..." to update what will be committed)
      (use "git restore <file>..." to discard changes in working directory)
    	modified:   image-resize-quality.html
    
    Untracked files:
      (use "git add <file>..." to include in what will be committed)
    	.playwright-mcp/
    
    no changes added to commit (use "git add" and/or "git commit -a")
    Exit code: 0
    

Reasoning

Analyzing Code Logic

I'm currently focused on the markdown-svg-renderer.html logic, specifically how it identifies SVG blocks. I've been dissecting the conditional logic that determines if a code block is treated as an SVG. It seems to hinge on the lang attribute, checking if it's "svg" directly, or "xml" with some additional content checks. I'm exploring the implications of these conditions.

Refining Conditional Logic

I'm now diving deeper into the case sensitivity aspect. My current focus is refining the SVG block detection logic within the markdown-svg-renderer.html file. Specifically, I am reviewing how startsWith("<svg") and endsWith("</svg>") are implemented in the code. I'm wondering if case-insensitivity should be considered during that checks, to accommodate variations like <svg or <SVG>. The current approach seems to be case-sensitive, which might need adjustment to handle all SVG variations.

Response

Tool calls

  • CodingTools_edit_file: call_250672
    path:
    markdown-svg-renderer.html
    
    old_string:
    const defaultFenceRenderer = md.renderer.rules.fence;
    md.renderer.rules.fence = (tokens, idx, options, env, self) => {
      const token = tokens[idx];
      const lang = (token.info || "").trim().split(/\s+/)[0].toLowerCase();
    
      if (lang === "svg") {
        const svg = window.DOMPurify.sanitize(token.content, svgSanitizeConfig).trim();
        if (svg) {
          const id = String(svgStore.size);
          svgStore.set(id, svg);
          return `<div class="svg-block-placeholder" data-svg-id="${id}"></div>\n`;
        }
      }
    
      return defaultFenceRenderer(tokens, idx, options, env, self);
    };
    
    new_string:
    const defaultFenceRenderer = md.renderer.rules.fence;
    md.renderer.rules.fence = (tokens, idx, options, env, self) => {
      const token = tokens[idx];
      const lang = (token.info || "").trim().split(/\s+/)[0].toLowerCase();
      const trimmed = token.content.trim();
      const isSvg = lang === "svg" || (lang === "xml" && trimmed.startsWith("<svg") && trimmed.endsWith("</svg>"));
    
      if (isSvg) {
        const svg = window.DOMPurify.sanitize(token.content, svgSanitizeConfig).trim();
        if (svg) {
          const id = String(svgStore.size);
          svgStore.set(id, svg);
          return `<div class="svg-block-placeholder" data-svg-id="${id}"></div>\n`;
        }
      }
    
      return defaultFenceRenderer(tokens, idx, options, env, self);
    };
    

Token usage

17,116 input, 1,265 output, {"candidatesTokenCount": 442, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 17116}], "thoughtsTokenCount": 823, "serviceTier": "standard"}

2026-08-13T18:33:42

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_edit_file: call_250672
    Made 1 replacement in markdown-svg-renderer.html:
    --- markdown-svg-renderer.html (before)
    +++ markdown-svg-renderer.html (after)
    @@ -480,6 +480,8 @@
       const token = tokens[idx];
       const lang = (token.info || "").trim().split(/\s+/)[0].toLowerCase();
    -
    -  if (lang === "svg") {
    +  const trimmed = token.content.trim();
    +  const isSvg = lang === "svg" || (lang === "xml" && trimmed.startsWith("<svg") && trimmed.endsWith("</svg>"));
    +
    +  if (isSvg) {
         const svg = window.DOMPurify.sanitize(token.content, svgSanitizeConfig).trim();
         if (svg) {
    

Response

Tool calls

  • CodingTools_execute_command: call_203353
    command:
    git diff markdown-svg-renderer.html
    

Token usage

18,582 input, 38 output, {"candidatesTokenCount": 27, "cachedContentTokenCount": 16189, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 18582}], "cacheTokensDetails": [{"modality": "TEXT", "tokenCount": 16189}], "thoughtsTokenCount": 11, "serviceTier": "standard"}

2026-08-13T18:33:45

Prompt

-- none --

Tools

  • CodingTools({"root": "/Users/simon/dev/tools"}):
    • CodingTools_edit_file: 0c5e06b
    • CodingTools_execute_command: 87b7dfe
    • CodingTools_list_files: 4d779da
    • CodingTools_read_file: d952137
    • CodingTools_search_files: 6b94785
    • CodingTools_write_file: 0678eb4

Tool results

  • CodingTools_execute_command: call_203353
    diff --git a/markdown-svg-renderer.html b/markdown-svg-renderer.html
    index f0fe4e3..2a3024b 100644
    --- a/markdown-svg-renderer.html
    +++ b/markdown-svg-renderer.html
    @@ -479,8 +479,10 @@ const defaultFenceRenderer = md.renderer.rules.fence;
     md.renderer.rules.fence = (tokens, idx, options, env, self) => {
       const token = tokens[idx];
       const lang = (token.info || "").trim().split(/\s+/)[0].toLowerCase();
    +  const trimmed = token.content.trim();
    +  const isSvg = lang === "svg" || (lang === "xml" && trimmed.startsWith("<svg") && trimmed.endsWith("</svg>"));
    
    -  if (lang === "svg") {
    +  if (isSvg) {
         const svg = window.DOMPurify.sanitize(token.content, svgSanitizeConfig).trim();
         if (svg) {
           const id = String(svgStore.size);
    Exit code: 0
    

Response

I have updated markdown-svg-renderer.html so that ```xml code blocks are also treated and rendered as interactive SVG blocks if their content (after trimming whitespace) starts with <svg and ends with </svg>.

Change Summary

In the custom fence renderer:

const token = tokens[idx];
const lang = (token.info || "").trim().split(/\s+/)[0].toLowerCase();
const trimmed = token.content.trim();
const isSvg = lang === "svg" || (lang === "xml" && trimmed.startsWith("<svg") && trimmed.endsWith("</svg>"));

if (isSvg) {
  const svg = window.DOMPurify.sanitize(token.content, svgSanitizeConfig).trim();
  // ... creates SVG block placeholder ...
}

Any ```xml block containing an SVG root element will now display with the tabbed preview/code component, while other XML code blocks will continue to render as standard code fences.

Token usage

18,902 input, 367 output, {"candidatesTokenCount": 222, "cachedContentTokenCount": 16184, "promptTokensDetails": [{"modality": "TEXT", "tokenCount": 18902}], "cacheTokensDetails": [{"modality": "TEXT", "tokenCount": 16184}], "thoughtsTokenCount": 145, "serviceTier": "standard"}

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