diff --git a/crates/zx_document_core/src/document.rs b/crates/zx_document_core/src/document.rs
index 17214e8..3499e06 100644
--- a/crates/zx_document_core/src/document.rs
+++ b/crates/zx_document_core/src/document.rs
@@ -9,7 +9,88 @@ pub struct DocumentInfo {
     pub material_type: MaterialType,
     pub preview_mode: PreviewMode,
     pub file_size: u64,
+
+    // Text stats
     pub page_count: Option<u32>,
     pub word_count: Option<u32>,
+    pub char_count: Option<u32>,
+    pub line_count: Option<u32>,
+
+    // Image
+    pub image_width: Option<u32>,
+    pub image_height: Option<u32>,
+    pub image_format: Option<String>,
+
+    // EPUB
+    pub epub_chapter_count: Option<u32>,
+
+    // Capabilities
+    pub is_searchable: bool,
+    pub supports_position: bool,
+    pub supports_anchor: bool,
+
     pub created_at: Option<String>,
 }
+
+impl DocumentInfo {
+    pub fn new(material_id: String, title: String, material_type: MaterialType, file_size: u64) -> Self {
+        let preview_mode = material_type.preview_mode();
+        let (is_searchable, supports_position, supports_anchor) = match material_type {
+            MaterialType::Markdown | MaterialType::Text => (true, true, true),
+            MaterialType::Pdf => (true, true, true),
+            MaterialType::Image => (false, true, true),
+            MaterialType::Epub => (true, true, true),
+            MaterialType::Word | MaterialType::Excel | MaterialType::PowerPoint => (false, false, true),
+            MaterialType::Unknown => (false, false, false),
+        };
+        Self {
+            material_id,
+            title,
+            material_type,
+            preview_mode,
+            file_size,
+            page_count: None,
+            word_count: None,
+            char_count: None,
+            line_count: None,
+            image_width: None,
+            image_height: None,
+            image_format: None,
+            epub_chapter_count: None,
+            is_searchable,
+            supports_position,
+            supports_anchor,
+            created_at: None,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_markdown_capabilities() {
+        let info = DocumentInfo::new("m1".into(), "test.md".into(), MaterialType::Markdown, 1024);
+        assert!(info.is_searchable);
+        assert!(info.supports_position);
+        assert_eq!(info.preview_mode, PreviewMode::NativeReader);
+    }
+
+    #[test]
+    fn test_office_capabilities() {
+        let info = DocumentInfo::new("m2".into(), "report.docx".into(), MaterialType::Word, 2048);
+        assert!(!info.is_searchable);
+        assert!(!info.supports_position);
+        assert!(info.supports_anchor); // Material-level anchor only
+        assert_eq!(info.preview_mode, PreviewMode::PlatformPreview);
+    }
+
+    #[test]
+    fn test_unknown_capabilities() {
+        let info = DocumentInfo::new("m3".into(), "file.bin".into(), MaterialType::Unknown, 0);
+        assert!(!info.is_searchable);
+        assert!(!info.supports_position);
+        assert!(!info.supports_anchor);
+    }
+}
diff --git a/crates/zx_document_core/src/progress.rs b/crates/zx_document_core/src/progress.rs
index 5643076..5452c3d 100644
--- a/crates/zx_document_core/src/progress.rs
+++ b/crates/zx_document_core/src/progress.rs
@@ -130,6 +130,20 @@ impl ReadingPosition {
         }
     }
 
+    /// Check if a position type is compatible with a material type.
+    pub fn is_compatible_with(&self, mt: &crate::material_type::MaterialType) -> bool {
+        use crate::material_type::MaterialType;
+        matches!(
+            (self, mt),
+            (ReadingPosition::Markdown { .. }, MaterialType::Markdown)
+                | (ReadingPosition::Text { .. }, MaterialType::Text)
+                | (ReadingPosition::Pdf { .. }, MaterialType::Pdf)
+                | (ReadingPosition::Image { .. }, MaterialType::Image)
+                | (ReadingPosition::Epub { .. }, MaterialType::Epub)
+                | (ReadingPosition::Unknown, _)
+        )
+    }
+
     pub fn progress_value(&self) -> Option<f32> {
         match self {
             Self::Markdown { scroll_progress, .. } => Some(clamp_progress(*scroll_progress)),
@@ -186,6 +200,16 @@ mod tests {
         assert!(json.contains("\"overallProgress\":1.0"));
     }
 
+    #[test]
+    fn test_is_compatible() {
+        use crate::material_type::MaterialType;
+        let md = ReadingPosition::Markdown { block_id: "h1".into(), scroll_progress: 0.5 };
+        assert!(md.is_compatible_with(&MaterialType::Markdown));
+        assert!(!md.is_compatible_with(&MaterialType::Pdf));
+        assert!(ReadingPosition::Unknown.is_compatible_with(&MaterialType::Pdf));
+        assert!(ReadingPosition::Unknown.is_compatible_with(&MaterialType::Markdown)); // Unknown = compatible with all
+    }
+
     #[test]
     fn test_progress_value() {
         assert_eq!(ReadingPosition::Unknown.progress_value(), None);