feat(nvim): add dedicated mcp tools for file reading and regex searching

nvim-core/src/lib.rs

@@ -999,6 +999,31 @@ pub async fn run_mcp_loop(app_name: &str, app_version: &str) {
                                         "type": "object",
                                         "properties": {}
                                     }
+                                },
+                                {
+                                    "name": "nvim_read_file",
+                                    "description": "Read specific lines from a file buffer (like cat or sed -n). Reads unsaved changes if open.",
+                                    "inputSchema": {
+                                        "type": "object",
+                                        "properties": {
+                                            "file": { "type": "string" },
+                                            "start_line": { "type": "integer", "description": "1-indexed start line (optional, defaults to 1)" },
+                                            "end_line": { "type": "integer", "description": "1-indexed end line (optional, defaults to end of file)" }
+                                        },
+                                        "required": ["file"]
+                                    }
+                                },
+                                {
+                                    "name": "nvim_search_file",
+                                    "description": "Search for a regex pattern within a file buffer (like grep). Searches unsaved changes if open.",
+                                    "inputSchema": {
+                                        "type": "object",
+                                        "properties": {
+                                            "file": { "type": "string" },
+                                            "pattern": { "type": "string", "description": "Lua-compatible regex pattern to search for" }
+                                        },
+                                        "required": ["file", "pattern"]
+                                    }
                                 }
                             ]
                         })),
@@ -1330,6 +1355,72 @@ pub async fn run_mcp_loop(app_name: &str, app_version: &str) {
                             }
                         }
                         
+                        "nvim_read_file" => {
+                            if let Some(file) = args.get("file").and_then(|v| v.as_str()) {
+                                let start_line = args.get("start_line").and_then(|v| v.as_i64()).unwrap_or(1);
+                                let end_line = args.get("end_line").and_then(|v| v.as_i64()).unwrap_or(-1);
+                                
+                                let escaped_file = file.replace('\\', "\\\\").replace('"', "\\\"");
+                                let code = format!("
+                                    local file = \"{escaped_file}\"
+                                    local start_idx = {start_line} - 1
+                                    local end_idx = {end_line}
+                                    local bufnr = vim.fn.bufnr(file, true)
+                                    if vim.fn.bufloaded(bufnr) == 0 then
+                                        vim.fn.bufload(bufnr)
+                                    end
+                                    local lines = vim.api.nvim_buf_get_lines(bufnr, start_idx, end_idx, false)
+                                    local res = {{}}
+                                    for i, line in ipairs(lines) do
+                                        local line_num = start_idx + i
+                                        table.insert(res, tostring(line_num) .. ': ' .. line)
+                                    end
+                                    return table.concat(res, '\\n')
+                                ");
+                                match execute_nvim_lua(&code).await {
+                                    Ok(res) => send_text_result!(id.clone(), res),
+                                    Err(e) => send_error(id, -32603, &e).await,
+                                }
+                            } else {
+                                send_error(id, -32602, "Missing 'file'").await;
+                            }
+                        }
+                        
+                        "nvim_search_file" => {
+                            if let (Some(file), Some(pattern)) = (
+                                args.get("file").and_then(|v| v.as_str()),
+                                args.get("pattern").and_then(|v| v.as_str()),
+                            ) {
+                                let escaped_file = file.replace('\\', "\\\\").replace('"', "\\\"");
+                                let escaped_pattern = pattern.replace('\\', "\\\\").replace('"', "\\\"");
+                                let code = format!("
+                                    local file = \"{escaped_file}\"
+                                    local pattern = \"{escaped_pattern}\"
+                                    local bufnr = vim.fn.bufnr(file, true)
+                                    if vim.fn.bufloaded(bufnr) == 0 then
+                                        vim.fn.bufload(bufnr)
+                                    end
+                                    local lines = vim.api.nvim_buf_get_lines(bufnr, 0, -1, false)
+                                    local matches = {{}}
+                                    for i, line in ipairs(lines) do
+                                        if string.match(line, pattern) then
+                                            table.insert(matches, tostring(i) .. ': ' .. line)
+                                        end
+                                    end
+                                    if #matches == 0 then
+                                        return 'No matches found.'
+                                    end
+                                    return table.concat(matches, '\\n')
+                                ");
+                                match execute_nvim_lua(&code).await {
+                                    Ok(res) => send_text_result!(id.clone(), res),
+                                    Err(e) => send_error(id, -32603, &e).await,
+                                }
+                            } else {
+                                send_error(id, -32602, "Missing 'file' or 'pattern'").await;
+                            }
+                        }
+
                         "nvim_execute_lua" => {
                             if let Some(code) = args.get("code").and_then(|v| v.as_str()) {
                                 // BAKE IN: Block interactive prompts that cause server deadlocks

server/src/handlers/graph.rs

@@ -631,7 +631,7 @@ mod tests {
         let create_handler = CreateEntitiesHandler;
         let args = json!({
             "entities": [
-                {"name": "Alice", "entityType": "Person", "observations": ["Likes Bob"]}
+                {"name": "Alice", "entity_type": "Person", "observations": ["Likes Bob"]}
             ]
         });
 
@@ -677,7 +677,7 @@ mod tests {
         let handler = CreateRelationsHandler;
         let args = json!({
             "relations": [
-                {"from": "A", "to": "B", "relationType": "knows"}
+                {"from": "A", "to": "B", "relation_type": "knows"}
             ]
         });
         let res = handler.execute(args, state.clone()).await.unwrap();
@@ -706,7 +706,7 @@ mod tests {
         let add_obs = AddObservationsHandler;
         let args_obs = json!({
             "observations": [
-                {"entityName": "A", "contents": ["Obs 1", "Obs 2"]}
+                {"entity_name": "A", "contents": ["Obs 1", "Obs 2"]}
             ]
         });
         let res1 = add_obs.execute(args_obs, state.clone()).await.unwrap();
@@ -722,7 +722,7 @@ mod tests {
 
         let del_entity = DeleteEntitiesHandler;
         let res4 = del_entity
-            .execute(json!({"entityNames": ["A"]}), state.clone())
+            .execute(json!({"entity_names": ["A"]}), state.clone())
             .await
             .unwrap();
         assert_eq!(res4, "Entities deleted");
@@ -742,8 +742,8 @@ mod tests {
         let create_handler = CreateEntitiesHandler;
         let args_ent = json!({
             "entities": [
-                {"name": "X", "entityType": "File", "observations": ["Obs X"], "namespace": "global"},
-                {"name": "Y", "entityType": "File", "observations": ["Obs Y"], "namespace": "global"}
+                {"name": "X", "entity_type": "File", "observations": ["Obs X"], "namespace": "global"},
+                {"name": "Y", "entity_type": "File", "observations": ["Obs Y"], "namespace": "global"}
             ]
         });
         create_handler
@@ -754,7 +754,7 @@ mod tests {
         let rel_handler = CreateRelationsHandler;
         let args_rel = json!({
             "relations": [
-                {"from": "X", "to": "Y", "relationType": "depends_on", "namespace": "global"}
+                {"from": "X", "to": "Y", "relation_type": "depends_on", "namespace": "global"}
             ]
         });
         rel_handler.execute(args_rel, state.clone()).await.unwrap();
@@ -784,7 +784,7 @@ mod tests {
         let condense = CondenseEntityHandler;
         let res_cond = condense
             .execute(
-                json!({"entityName": "X", "summarized_observations": ["X condensed"]}),
+                json!({"entity_name": "X", "summarized_observations": ["X condensed"]}),
                 state.clone(),
             )
             .await
@@ -794,7 +794,7 @@ mod tests {
         let merge = MergeEntitiesHandler;
         let res_merge = merge
             .execute(
-                json!({"sourceEntity": "X", "targetEntity": "Y"}),
+                json!({"source_entity": "X", "target_entity": "Y"}),
                 state.clone(),
             )
             .await

server/src/handlers/meta.rs

@@ -609,7 +609,7 @@ mod tests {
 
         let code_handler = LogCodeChangeHandler;
         let args_code = json!({
-            "filePath": "main.rs",
+            "file_path": "main.rs",
             "description": "refactor",
             "git_commit": "def",
             "git_branch": "main"