diff --git a/src-tauri/src/parsers/claude.rs b/src-tauri/src/parsers/claude.rs
index fa32fc7..0776555 100644
--- a/src-tauri/src/parsers/claude.rs
+++ b/src-tauri/src/parsers/claude.rs
@@ -53,6 +53,46 @@ fn strip_system_tags(text: &str) -> Option<String> {
 }
 
 /// Check if a JSONL entry is a system meta message (isMeta: true).
+/// Rebuild a standard unified diff from `toolUseResult.structuredPatch`.
+///
+/// Each hunk in `structuredPatch` has `oldStart`, `oldLines`, `newStart`,
+/// `newLines`, and `lines` (prefixed with ` `, `+`, or `-`).
+fn rebuild_diff_from_structured_patch(
+    file_path: &str,
+    structured_patch: &serde_json::Value,
+) -> Option<String> {
+    let hunks = structured_patch.as_array()?;
+    if hunks.is_empty() {
+        return None;
+    }
+
+    let mut output = String::new();
+    output.push_str(&format!("--- a/{}\n+++ b/{}\n", file_path, file_path));
+
+    for hunk in hunks {
+        let old_start = hunk.get("oldStart").and_then(|v| v.as_u64()).unwrap_or(1);
+        let old_lines = hunk.get("oldLines").and_then(|v| v.as_u64()).unwrap_or(0);
+        let new_start = hunk.get("newStart").and_then(|v| v.as_u64()).unwrap_or(1);
+        let new_lines = hunk.get("newLines").and_then(|v| v.as_u64()).unwrap_or(0);
+
+        output.push_str(&format!(
+            "@@ -{},{} +{},{} @@\n",
+            old_start, old_lines, new_start, new_lines
+        ));
+
+        if let Some(lines) = hunk.get("lines").and_then(|v| v.as_array()) {
+            for line in lines {
+                if let Some(text) = line.as_str() {
+                    output.push_str(text);
+                    output.push('\n');
+                }
+            }
+        }
+    }
+
+    Some(output)
+}
+
 fn is_meta_message(value: &serde_json::Value) -> bool {
     value
         .get("isMeta")
@@ -489,7 +529,7 @@ impl ClaudeParser {
                     continue;
                 }
                 "user" => {
-                    let content = extract_user_content(&value);
+                    let mut content = extract_user_content(&value);
 
                     // Skip user messages that are empty after system tag stripping
                     if content.is_empty() {
@@ -518,6 +558,31 @@ impl ClaudeParser {
                         MessageRole::User
                     };
 
+                    // Check toolUseResult.structuredPatch for real line numbers
+                    if let Some(tur) = value.get("toolUseResult") {
+                        if let Some(sp) = tur.get("structuredPatch") {
+                            let fp = tur
+                                .get("filePath")
+                                .and_then(|v| v.as_str())
+                                .unwrap_or("file");
+                            if let Some(diff) = rebuild_diff_from_structured_patch(fp, sp) {
+                                // Find the matching ToolResult in this user message's content
+                                // and replace its output_preview with the real diff
+                                for block in content.iter_mut() {
+                                    if let ContentBlock::ToolResult {
+                                        ref mut output_preview,
+                                        is_error: false,
+                                        ..
+                                    } = block
+                                    {
+                                        *output_preview = Some(diff.clone());
+                                        break;
+                                    }
+                                }
+                            }
+                        }
+                    }
+
                     messages.push(UnifiedMessage {
                         id: uuid,
                         role,
@@ -738,6 +803,7 @@ impl ClaudeParser {
         let mut turns = group_into_turns(messages);
         super::relocate_orphaned_tool_results(&mut turns);
         super::structurize_read_tool_output(&mut turns);
+        super::resolve_patch_line_numbers(&mut turns, cwd.as_deref());
         let context_window_used_tokens = latest_claude_context_window_used_tokens(&turns);
         let context_window_max_tokens =
             claude_context_window_max_tokens_for_model(model.as_deref());
diff --git a/src-tauri/src/parsers/codex.rs b/src-tauri/src/parsers/codex.rs
index a71ba9d..4508f67 100644
--- a/src-tauri/src/parsers/codex.rs
+++ b/src-tauri/src/parsers/codex.rs
@@ -774,6 +774,7 @@ impl CodexParser {
         let mut turns = group_into_turns(messages);
         super::relocate_orphaned_tool_results(&mut turns);
         super::structurize_read_tool_output(&mut turns);
+        super::resolve_patch_line_numbers(&mut turns, cwd.as_deref());
         let mut session_stats = super::compute_session_stats(&turns);
         session_stats =
             merge_codex_total_usage_stats(session_stats, latest_total_usage, latest_total_tokens);
diff --git a/src-tauri/src/parsers/gemini.rs b/src-tauri/src/parsers/gemini.rs
index 9e69a87..3953816 100644
--- a/src-tauri/src/parsers/gemini.rs
+++ b/src-tauri/src/parsers/gemini.rs
@@ -557,6 +557,7 @@ impl GeminiParser {
         let mut turns = group_into_turns(messages);
         super::relocate_orphaned_tool_results(&mut turns);
         super::structurize_read_tool_output(&mut turns);
+        super::resolve_patch_line_numbers(&mut turns, summary.folder_path.as_deref());
         summary.message_count = turns.len() as u32;
         summary.id = conversation_id.to_string();
         let context_window_used_tokens = super::latest_turn_total_usage_tokens(&turns);
diff --git a/src-tauri/src/parsers/mod.rs b/src-tauri/src/parsers/mod.rs
index 56f3377..318c19d 100644
--- a/src-tauri/src/parsers/mod.rs
+++ b/src-tauri/src/parsers/mod.rs
@@ -403,6 +403,206 @@ fn strip_numbered_lines(text: &str) -> Option<String> {
     )
 }
 
+/// Resolve line numbers for `*** Update File` / `*** Add File` style patches.
+///
+/// When a hunk header is just `@@` without `-N,M +N,M`, this reads the actual
+/// file from disk and matches the context lines to calculate real line numbers.
+/// Falls back gracefully if the file doesn't exist or context doesn't match.
+pub fn resolve_patch_line_numbers(turns: &mut [MessageTurn], cwd: Option<&str>) {
+    for turn in turns.iter_mut() {
+        for block in turn.blocks.iter_mut() {
+            if let ContentBlock::ToolUse {
+                ref tool_name,
+                ref mut input_preview,
+                ..
+            } = block
+            {
+                let name = tool_name.to_lowercase();
+                if !matches!(
+                    name.as_str(),
+                    "apply_patch" | "edit" | "patch" | "applypatch"
+                ) {
+                    continue;
+                }
+                if let Some(ref text) = input_preview {
+                    if text.contains("@@\n") || text.contains("@@\r\n") {
+                        if let Some(resolved) = resolve_patch_text(text, cwd) {
+                            *input_preview = Some(resolved);
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+/// Resolve a single patch text, replacing bare `@@` with `@@ -N,M +N,M @@`.
+fn resolve_patch_text(patch: &str, cwd: Option<&str>) -> Option<String> {
+    let mut output = String::with_capacity(patch.len() + 256);
+    let mut current_file_path: Option<String> = None;
+    let mut file_lines: Option<Vec<String>> = None;
+    let mut any_resolved = false;
+
+    let lines: Vec<&str> = patch.lines().collect();
+    let mut i = 0;
+
+    while i < lines.len() {
+        let line = lines[i];
+
+        // Detect file markers
+        if line.starts_with("*** Update File: ") || line.starts_with("*** Add File: ") {
+            let marker_end = if line.starts_with("*** Update File: ") {
+                17
+            } else {
+                14
+            };
+            let path = line[marker_end..].trim();
+            current_file_path = Some(path.to_string());
+            file_lines = load_file_lines(path, cwd);
+            output.push_str(line);
+            output.push('\n');
+            i += 1;
+            continue;
+        }
+
+        // Detect bare @@ hunk header (no line numbers)
+        if line == "@@" {
+            if let (Some(ref fl), true) = (&file_lines, current_file_path.is_some()) {
+                // Collect context lines from this hunk to find match position
+                let hunk_lines = collect_hunk_lines(&lines, i + 1);
+                if let Some((old_start, old_count, new_count)) =
+                    find_hunk_position(fl, &hunk_lines)
+                {
+                    let new_start = old_start; // same start for context-based patches
+                    output.push_str(&format!(
+                        "@@ -{},{} +{},{} @@\n",
+                        old_start, old_count, new_start, new_count
+                    ));
+                    any_resolved = true;
+                    i += 1;
+                    continue;
+                }
+            }
+            // Fallback: keep bare @@
+            output.push_str(line);
+            output.push('\n');
+            i += 1;
+            continue;
+        }
+
+        output.push_str(line);
+        output.push('\n');
+        i += 1;
+    }
+
+    if any_resolved { Some(output) } else { None }
+}
+
+/// Load file lines from disk, trying both absolute path and cwd-relative.
+fn load_file_lines(path: &str, cwd: Option<&str>) -> Option<Vec<String>> {
+    use std::fs;
+    use std::path::Path;
+
+    let p = Path::new(path);
+    if p.is_absolute() {
+        if let Ok(content) = fs::read_to_string(p) {
+            return Some(content.lines().map(|l| l.to_string()).collect());
+        }
+    }
+    if let Some(base) = cwd {
+        let full = Path::new(base).join(path);
+        if let Ok(content) = fs::read_to_string(&full) {
+            return Some(content.lines().map(|l| l.to_string()).collect());
+        }
+    }
+    None
+}
+
+/// Collect lines belonging to a hunk (until next `@@` or `*** ` marker or end).
+fn collect_hunk_lines<'a>(lines: &'a [&'a str], start: usize) -> Vec<&'a str> {
+    let mut result = Vec::new();
+    for &line in &lines[start..] {
+        if line == "@@"
+            || line.starts_with("*** ")
+        {
+            break;
+        }
+        result.push(line);
+    }
+    result
+}
+
+/// Find where a hunk's context lines match in the file, returning (start_line, old_count, new_count).
+/// `start_line` is 1-based.
+fn find_hunk_position(
+    file_lines: &[String],
+    hunk_lines: &[&str],
+) -> Option<(usize, usize, usize)> {
+    // Extract context lines (space-prefixed) with their positions in the hunk
+    let context_entries: Vec<(usize, &str)> = hunk_lines
+        .iter()
+        .enumerate()
+        .filter(|(_, l)| l.starts_with(' '))
+        .map(|(i, l)| (i, &l[1..]))  // strip leading space
+        .collect();
+
+    if context_entries.is_empty() {
+        return None;
+    }
+
+    // Use the first context line to find candidate positions
+    let (first_ctx_idx, first_ctx_text) = context_entries[0];
+
+    for (file_idx, file_line) in file_lines.iter().enumerate() {
+        if file_line.as_str() != first_ctx_text {
+            continue;
+        }
+
+        // Verify all context lines match from this position
+        let hunk_start_in_file = file_idx as isize - first_ctx_idx as isize;
+        if hunk_start_in_file < 0 {
+            continue;
+        }
+
+        let all_match = context_entries.iter().all(|(ctx_idx, ctx_text)| {
+            // Map hunk position to file position: only count context and deleted lines
+            let file_offset = hunk_lines[..*ctx_idx]
+                .iter()
+                .filter(|hl| hl.starts_with(' ') || hl.starts_with('-'))
+                .count();
+            let target = hunk_start_in_file as usize + file_offset;
+            target < file_lines.len() && file_lines[target].as_str() == *ctx_text
+        });
+
+        if all_match {
+            // Calculate old_count (context + deleted) and new_count (context + added)
+            let mut old_count = 0usize;
+            let mut new_count = 0usize;
+            for hl in hunk_lines {
+                if hl.starts_with(' ') {
+                    old_count += 1;
+                    new_count += 1;
+                } else if hl.starts_with('-') {
+                    old_count += 1;
+                } else if hl.starts_with('+') {
+                    new_count += 1;
+                }
+            }
+
+            // file_start is the first line of the old file covered by this hunk
+            // We need to find where context/deleted lines start in the file
+            let file_start_offset = hunk_lines[..first_ctx_idx]
+                .iter()
+                .filter(|hl| hl.starts_with(' ') || hl.starts_with('-'))
+                .count();
+            let start_line = (hunk_start_in_file as usize - file_start_offset) + 1; // 1-based
+            return Some((start_line, old_count, new_count));
+        }
+    }
+
+    None
+}
+
 /// Extract the last path component as the folder name.
 pub fn folder_name_from_path(path: &str) -> String {
     path.rsplit(['/', '\\']).next().unwrap_or(path).to_string()
diff --git a/src-tauri/src/parsers/openclaw.rs b/src-tauri/src/parsers/openclaw.rs
index aaf2876..c8e47a5 100644
--- a/src-tauri/src/parsers/openclaw.rs
+++ b/src-tauri/src/parsers/openclaw.rs
@@ -653,6 +653,7 @@ impl OpenClawParser {
         let mut turns = group_into_turns(messages);
         super::relocate_orphaned_tool_results(&mut turns);
         super::structurize_read_tool_output(&mut turns);
+        super::resolve_patch_line_numbers(&mut turns, cwd.as_deref());
 
         let context_window_used_tokens = latest_turn_total_usage_tokens(&turns);
         let context_window_max_tokens = session_meta
diff --git a/src-tauri/src/parsers/opencode.rs b/src-tauri/src/parsers/opencode.rs
index df799b4..c500acd 100644
--- a/src-tauri/src/parsers/opencode.rs
+++ b/src-tauri/src/parsers/opencode.rs
@@ -190,6 +190,7 @@ impl OpenCodeParser {
         let mut turns = group_into_turns(messages);
         super::relocate_orphaned_tool_results(&mut turns);
         super::structurize_read_tool_output(&mut turns);
+        super::resolve_patch_line_numbers(&mut turns, summary.folder_path.as_deref());
         let context_window_used_tokens = super::latest_turn_total_usage_tokens(&turns);
         let context_window_max_tokens =
             super::infer_context_window_max_tokens(summary.model.as_deref());
diff --git a/src/components/message/content-parts-renderer.tsx b/src/components/message/content-parts-renderer.tsx
index 6f38572..267242b 100644
--- a/src/components/message/content-parts-renderer.tsx
+++ b/src/components/message/content-parts-renderer.tsx
@@ -1755,6 +1755,16 @@ function StructuredToolInput({
         )
       }
     }
+    // Prefer tool output if it contains a structured diff with real line numbers
+    // (injected by backend from toolUseResult.structuredPatch)
+    if (output && typeof output === "string" && /^@@ /m.test(output)) {
+      return (
+        <>
+          {truncationBanner}
+          <UnifiedDiffPreview diffText={output} />
+        </>
+      )
+    }
     if (isCanonicalEditPayload(parsed)) {
       return (
         <>
diff --git a/src/lib/session-files.ts b/src/lib/session-files.ts
index 2fa8a2e..52a2bf6 100644
--- a/src/lib/session-files.ts
+++ b/src/lib/session-files.ts
@@ -1,4 +1,4 @@
-import type { MessageTurn } from "./types"
+import type { ContentBlock, MessageTurn } from "./types"
 import { normalizeToolName } from "./tool-call-normalization"
 import { estimateChangedLineStats } from "./line-change-stats"
 import { generateUnifiedDiff } from "./unified-diff-generator"
@@ -757,10 +757,12 @@ export function extractSessionFilesGrouped(
           block.input_preview,
           normalizedPath
         )
+        const toolOutput = findToolResultOutput(turn.blocks, block.tool_use_id)
         const diffChunk = buildDiffChunk(
           normalized,
           block.input_preview,
-          normalizedPath
+          normalizedPath,
+          toolOutput
         )
 
         currentFiles.push({
@@ -819,10 +821,12 @@ export function buildSessionFileDiff(
       )
       if (!blockPaths.includes(normalizedTargetPath)) continue
 
+      const toolOutput = findToolResultOutput(turn.blocks, block.tool_use_id)
       const chunk = buildDiffChunk(
         normalized,
         block.input_preview,
-        normalizedTargetPath
+        normalizedTargetPath,
+        toolOutput
       )
       if (chunk && chunk.trim().length > 0) chunks.push(chunk.trim())
     }
@@ -835,10 +839,30 @@ export function buildSessionFileDiff(
   return chunks.join("\n\n")
 }
 
+/** Find the tool_result output matching a tool_use_id within the same turn. */
+function findToolResultOutput(
+  blocks: ContentBlock[],
+  toolUseId: string | null
+): string | null {
+  if (!toolUseId) return null
+  for (const block of blocks) {
+    if (
+      block.type === "tool_result" &&
+      block.tool_use_id === toolUseId &&
+      block.output_preview &&
+      !block.is_error
+    ) {
+      return block.output_preview
+    }
+  }
+  return null
+}
+
 function buildDiffChunk(
   op: string,
   inputPreview: string | null,
-  filePath: string
+  filePath: string,
+  toolOutput?: string | null
 ): string | null {
   if (!inputPreview) return null
 
@@ -860,6 +884,11 @@ function buildDiffChunk(
       }
     }
 
+    // Prefer tool output if backend injected a real diff with line numbers
+    if (toolOutput && /^@@ /m.test(toolOutput)) {
+      return toolOutput.trim()
+    }
+
     if (!parsed) return null
 
     const oldStr =