Add monochrome icon validation with currentColor requirement

Author: ignatov

.github/workflows/build_registry.py

@@ -33,6 +33,7 @@
 
 # Icon requirements
 PREFERRED_ICON_SIZE = 16
+ALLOWED_FILL_STROKE_VALUES = {"currentcolor", "none", "inherit"}
 
 # URL validation
 SKIP_URL_VALIDATION = os.environ.get("SKIP_URL_VALIDATION", "").lower() in ("1", "true", "yes")
@@ -182,6 +183,48 @@ def validate_distribution_urls(distribution: dict) -> list[str]:
     return errors
 
 
+def validate_icon_monochrome(content: str) -> list[str]:
+    """Validate that icon uses currentColor and no hardcoded colors."""
+    errors = []
+    reported_colors = set()
+
+    # Check fill attributes - must be currentColor or none
+    fill_matches = re.findall(r'\bfill\s*=\s*["\']([^"\']+)["\']', content, re.IGNORECASE)
+    for fill_value in fill_matches:
+        normalized = fill_value.strip().lower()
+        if normalized not in ALLOWED_FILL_STROKE_VALUES:
+            errors.append(f"Icon has hardcoded fill=\"{fill_value}\" (use currentColor or none)")
+            reported_colors.add(fill_value.strip())
+
+    # Check stroke attributes - must be currentColor or none
+    stroke_matches = re.findall(r'\bstroke\s*=\s*["\']([^"\']+)["\']', content, re.IGNORECASE)
+    for stroke_value in stroke_matches:
+        normalized = stroke_value.strip().lower()
+        if normalized not in ALLOWED_FILL_STROKE_VALUES:
+            errors.append(f"Icon has hardcoded stroke=\"{stroke_value}\" (use currentColor or none)")
+            reported_colors.add(stroke_value.strip())
+
+    # Check for hardcoded colors in style attributes
+    style_matches = re.findall(r'\bstyle\s*=\s*["\']([^"\']+)["\']', content, re.IGNORECASE)
+    for style_value in style_matches:
+        # Check for fill/stroke with hardcoded colors in style
+        style_fill = re.search(r'\bfill\s*:\s*([^;]+)', style_value, re.IGNORECASE)
+        if style_fill:
+            fill_val = style_fill.group(1).strip().lower()
+            if fill_val not in ALLOWED_FILL_STROKE_VALUES:
+                errors.append(f"Icon has hardcoded style fill: {style_fill.group(1).strip()}")
+                reported_colors.add(style_fill.group(1).strip())
+        style_stroke = re.search(r'\bstroke\s*:\s*([^;]+)', style_value, re.IGNORECASE)
+        if style_stroke:
+            stroke_val = style_stroke.group(1).strip().lower()
+            if stroke_val not in ALLOWED_FILL_STROKE_VALUES:
+                errors.append(f"Icon has hardcoded style stroke: {style_stroke.group(1).strip()}")
+                reported_colors.add(style_stroke.group(1).strip())
+
+    # Deduplicate errors
+    return list(dict.fromkeys(errors))
+
+
 def validate_icon(icon_path: Path) -> list[str]:
     """Validate icon.svg and return list of warnings/errors."""
     errors = []
@@ -216,6 +259,10 @@ def validate_icon(icon_path: Path) -> list[str]:
     if vb_width != PREFERRED_ICON_SIZE or vb_height != PREFERRED_ICON_SIZE:
         errors.append(f"Icon should be {PREFERRED_ICON_SIZE}x{PREFERRED_ICON_SIZE} (got {int(vb_width)}x{int(vb_height)})")
 
+    # Validate monochrome (currentColor) usage
+    monochrome_errors = validate_icon_monochrome(content)
+    errors.extend(monochrome_errors)
+
     return errors
 
 

CLAUDE.md

@@ -19,13 +19,13 @@ This is a registry of ACP (Agent Client Protocol) agents. The structure is:
 ```
 <agent-id>/
 ├── agent.json    # Agent metadata and distribution info (required)
-└── icon.svg      # Agent icon, must be 16x16 (optional)
+└── icon.svg      # Agent icon: 16x16 SVG, monochrome with currentColor (optional)
 ```
 
 **Build process** (`.github/workflows/build_registry.py`):
 1. Scans directories for `agent.json` files
 2. Validates against `agent.schema.json` (JSON Schema)
-3. Validates icon dimensions (16x16 SVG required)
+3. Validates icons (16x16 SVG, monochrome with `currentColor`)
 4. Aggregates all agents into `dist/registry.json`
 5. Copies icons to `dist/<agent-id>.svg`
 
@@ -38,7 +38,7 @@ This is a registry of ACP (Agent Client Protocol) agents. The structure is:
 - `id`: lowercase, hyphens only, must match directory name
 - `version`: semantic versioning (e.g., `1.0.0`)
 - `distribution`: at least one of `binary`, `npx`, `uvx`
-- `icon.svg`: must be 16x16 (warnings for non-compliance)
+- `icon.svg`: must be SVG format, 16x16, monochrome using `currentColor` (enables theming)
 - **URL validation**: All distribution URLs must be accessible (binary archives, npm/PyPI packages)
 
 Set `SKIP_URL_VALIDATION=1` to bypass URL checks during local development.
@@ -48,3 +48,23 @@ Set `SKIP_URL_VALIDATION=1` to bypass URL checks during local development.
 - `binary`: Platform-specific archives (`darwin-aarch64`, `linux-x86_64`, etc.)
 - `npx`: npm packages
 - `uvx`: PyPI packages
+
+## Icon Requirements
+
+Icons must be:
+- **SVG format** (only `.svg` files accepted)
+- **16x16 dimensions** (via width/height attributes or viewBox)
+- **Monochrome using `currentColor`** - all fills and strokes must use `currentColor` or `none`
+
+Using `currentColor` enables icons to adapt to different themes (light/dark mode) automatically.
+
+**Valid example:**
+```svg
+<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16">
+  <path fill="currentColor" d="M..."/>
+</svg>
+```
+
+**Invalid patterns:**
+- Hardcoded colors: `fill="#FF5500"`, `fill="red"`, `stroke="rgb(0,0,0)"`
+- Missing currentColor: `fill` or `stroke` without `currentColor`