add edit_file tool for targeted string replacement edits

Author: alexylon

src/tools/mod.rs

@@ -389,6 +389,43 @@ impl ToolExecutor {
                 let results = code_search.search(pattern, file_type, max_results)?;
                 Ok(format!("Code search results:\n\n{}", results))
             }
+            ToolName::EditFile => {
+                let path = input["path"].as_str().ok_or_else(|| {
+                    SofosError::ToolExecution("Missing 'path' parameter".to_string())
+                })?;
+                let old_string = input["old_string"].as_str().ok_or_else(|| {
+                    SofosError::ToolExecution("Missing 'old_string' parameter".to_string())
+                })?;
+                let new_string = input["new_string"].as_str().ok_or_else(|| {
+                    SofosError::ToolExecution("Missing 'new_string' parameter".to_string())
+                })?;
+                let replace_all = input["replace_all"].as_bool().unwrap_or(false);
+
+                let original = self.fs_tool.read_file(path)?;
+
+                if !original.contains(old_string) {
+                    return Err(SofosError::ToolExecution(format!(
+                        "old_string not found in '{}'. Make sure it matches the file content exactly, \
+                         including whitespace and indentation.",
+                        path
+                    )));
+                }
+
+                let modified = if replace_all {
+                    original.replace(old_string, new_string)
+                } else {
+                    original.replacen(old_string, new_string, 1)
+                };
+
+                self.fs_tool.write_file(path, &modified)?;
+
+                let diff_output = diff::generate_compact_diff(&original, &modified, path);
+
+                Ok(format!(
+                    "Successfully edited '{}'\n\nChanges:\n{}",
+                    path, diff_output
+                ))
+            }
             ToolName::MorphEditFile => {
                 let morph = self.morph_client.as_ref().ok_or_else(|| {
                     SofosError::ToolExecution(

src/tools/tool_name.rs

@@ -13,6 +13,7 @@ pub enum ToolName {
     CopyFile,
     ExecuteBash,
     SearchCode,
+    EditFile,
     MorphEditFile,
     WebSearch,
 }
@@ -30,6 +31,7 @@ impl ToolName {
             ToolName::CopyFile => "copy_file",
             ToolName::ExecuteBash => "execute_bash",
             ToolName::SearchCode => "search_code",
+            ToolName::EditFile => "edit_file",
             ToolName::MorphEditFile => "morph_edit_file",
             ToolName::WebSearch => "web_search",
         }
@@ -47,6 +49,7 @@ impl ToolName {
             "copy_file" => Ok(ToolName::CopyFile),
             "execute_bash" => Ok(ToolName::ExecuteBash),
             "search_code" => Ok(ToolName::SearchCode),
+            "edit_file" => Ok(ToolName::EditFile),
             "morph_edit_file" => Ok(ToolName::MorphEditFile),
             "web_search" => Ok(ToolName::WebSearch),
             _ => Err(SofosError::ToolExecution(format!("Unknown tool: {}", s))),

src/tools/types.rs

@@ -198,6 +198,36 @@ fn copy_file_tool() -> Tool {
     }
 }
 
+fn edit_file_tool() -> Tool {
+    Tool::Regular {
+        name: "edit_file".to_string(),
+        description: "Make targeted edits to a file by replacing exact string matches. Preferred over write_file for modifying existing files — safer and more efficient since only the changed portion is specified.".to_string(),
+        input_schema: json!({
+            "type": "object",
+            "properties": {
+                "path": {
+                    "type": "string",
+                    "description": "The relative path to the file (e.g., 'src/main.rs')"
+                },
+                "old_string": {
+                    "type": "string",
+                    "description": "The exact text to find and replace. Must match the file content exactly, including whitespace and indentation."
+                },
+                "new_string": {
+                    "type": "string",
+                    "description": "The replacement text. Use an empty string to delete the matched text."
+                },
+                "replace_all": {
+                    "type": "boolean",
+                    "description": "If true, replace all occurrences. Default: false (replace first match only)."
+                }
+            },
+            "required": ["path", "old_string", "new_string"]
+        }),
+        cache_control: None,
+    }
+}
+
 fn morph_edit_file_tool() -> Tool {
     Tool::Regular {
         name: "morph_edit_file".to_string(),
@@ -230,15 +260,14 @@ pub fn get_all_tools() -> Vec<Tool> {
         list_directory_tool(),
         read_file_tool(),
         write_file_tool(false),
+        edit_file_tool(),
         create_directory_tool(),
         delete_file_tool(),
         delete_directory_tool(),
         move_file_tool(),
         copy_file_tool(),
         execute_bash_tool(),
-        // Anthropic web search tool
         anthropic_web_search_tool(),
-        // OpenAI web search tool
         openai_web_search_tool(),
     ]
 }
@@ -248,16 +277,15 @@ pub fn get_all_tools_with_morph() -> Vec<Tool> {
         list_directory_tool(),
         read_file_tool(),
         write_file_tool(true),
+        edit_file_tool(),
         create_directory_tool(),
         delete_file_tool(),
         delete_directory_tool(),
         move_file_tool(),
         copy_file_tool(),
         execute_bash_tool(),
         morph_edit_file_tool(),
-        // Anthropic web search tool
         anthropic_web_search_tool(),
-        // OpenAI web search tool
         openai_web_search_tool(),
     ]
 }