diff --git a/apps/open-swe/langbench/utils.ts b/apps/open-swe/langbench/utils.ts
index 28643dbc..40079d08 100644
--- a/apps/open-swe/langbench/utils.ts
+++ b/apps/open-swe/langbench/utils.ts
@@ -145,6 +145,7 @@ export async function runPytestOnFiles(
     let parsed: Omit<TestResults, "success" | "error">;
     try {
       const jsonReportResult = await readFile({
+        config: {},
         sandbox,
         filePath: "/tmp/pytest_report.json",
         workDir: repoDir,
diff --git a/apps/open-swe/src/graphs/programmer/nodes/open-pr.ts b/apps/open-swe/src/graphs/programmer/nodes/open-pr.ts
index c0a9eda3..2d989912 100644
--- a/apps/open-swe/src/graphs/programmer/nodes/open-pr.ts
+++ b/apps/open-swe/src/graphs/programmer/nodes/open-pr.ts
@@ -173,7 +173,7 @@ export async function openPullRequest(
   }
 
   if (process.env.SKIP_CI_UNTIL_LAST_COMMIT === "true") {
-    await pushEmptyCommit(state.targetRepository, sandbox, {
+    await pushEmptyCommit(state.targetRepository, sandbox, config, {
       githubInstallationToken,
     });
   }
diff --git a/apps/open-swe/src/graphs/programmer/nodes/take-action.ts b/apps/open-swe/src/graphs/programmer/nodes/take-action.ts
index bff9df82..ece57e39 100644
--- a/apps/open-swe/src/graphs/programmer/nodes/take-action.ts
+++ b/apps/open-swe/src/graphs/programmer/nodes/take-action.ts
@@ -263,7 +263,7 @@ export async function takeAction(
     ...toolCallResults,
   ]);
 
-  const codebaseTree = await getCodebaseTree(undefined, undefined, config);
+  const codebaseTree = await getCodebaseTree(config);
   // If the codebase tree failed to generate, fallback to the previous codebase tree, or if that's not defined, use the failed to generate message.
   const codebaseTreeToReturn =
     codebaseTree === FAILED_TO_GENERATE_TREE_MESSAGE
diff --git a/apps/open-swe/src/graphs/shared/initialize-sandbox.ts b/apps/open-swe/src/graphs/shared/initialize-sandbox.ts
index 31e0cd2c..86544cf5 100644
--- a/apps/open-swe/src/graphs/shared/initialize-sandbox.ts
+++ b/apps/open-swe/src/graphs/shared/initialize-sandbox.ts
@@ -189,11 +189,7 @@ export async function initializeSandbox(
       };
       emitStepEvent(baseGenerateCodebaseTreeAction, "pending");
       try {
-        const codebaseTree = await getCodebaseTree(
-          existingSandbox.id,
-          undefined,
-          config,
-        );
+        const codebaseTree = await getCodebaseTree(config, existingSandbox.id);
         if (codebaseTree === FAILED_TO_GENERATE_TREE_MESSAGE) {
           emitStepEvent(
             baseGenerateCodebaseTreeAction,
@@ -208,7 +204,11 @@ export async function initializeSandbox(
           sandboxSessionId: existingSandbox.id,
           codebaseTree,
           messages: createEventsMessage(),
-          customRules: await getCustomRules(existingSandbox, absoluteRepoDir),
+          customRules: await getCustomRules(
+            existingSandbox,
+            absoluteRepoDir,
+            config,
+          ),
         };
       } catch {
         emitStepEvent(
@@ -220,7 +220,11 @@ export async function initializeSandbox(
           sandboxSessionId: existingSandbox.id,
           codebaseTree: FAILED_TO_GENERATE_TREE_MESSAGE,
           messages: createEventsMessage(),
-          customRules: await getCustomRules(existingSandbox, absoluteRepoDir),
+          customRules: await getCustomRules(
+            existingSandbox,
+            absoluteRepoDir,
+            config,
+          ),
         };
       }
     } catch {
@@ -347,7 +351,7 @@ export async function initializeSandbox(
   emitStepEvent(baseGenerateCodebaseTreeAction, "pending");
   let codebaseTree: string | undefined;
   try {
-    codebaseTree = await getCodebaseTree(sandbox.id, undefined, config);
+    codebaseTree = await getCodebaseTree(config, sandbox.id);
     emitStepEvent(baseGenerateCodebaseTreeAction, "success");
   } catch (_) {
     emitStepEvent(
@@ -363,7 +367,7 @@ export async function initializeSandbox(
     codebaseTree,
     messages: createEventsMessage(),
     dependenciesInstalled: false,
-    customRules: await getCustomRules(sandbox, absoluteRepoDir),
+    customRules: await getCustomRules(sandbox, absoluteRepoDir, config),
     branchName: newBranchName,
   };
 }
@@ -455,7 +459,7 @@ async function initializeSandboxLocal(
 
   let codebaseTree = undefined;
   try {
-    codebaseTree = await getCodebaseTree(undefined, targetRepository, config);
+    codebaseTree = await getCodebaseTree(config, undefined, targetRepository);
     emitStepEvent(baseGenerateCodebaseTreeAction, "success");
   } catch (_) {
     emitStepEvent(
diff --git a/apps/open-swe/src/tools/apply-patch.ts b/apps/open-swe/src/tools/apply-patch.ts
index ca0022b4..5ba90b21 100644
--- a/apps/open-swe/src/tools/apply-patch.ts
+++ b/apps/open-swe/src/tools/apply-patch.ts
@@ -14,6 +14,7 @@ import {
 } from "@open-swe/shared/open-swe/local-mode";
 import { createShellExecutor } from "../utils/shell-executor/shell-executor.js";
 import { join } from "path";
+import { v4 as uuidv4 } from "uuid";
 
 type FileOperationResult = {
   success: boolean;
@@ -38,11 +39,8 @@ async function applyPatchWithGit(
 ): Promise<FileOperationResult> {
   // Generate temp patch file path
   const tempPatchFile = isLocalMode(config)
-    ? join(
-        workDir,
-        `patch_${Date.now()}_${Math.random().toString(36).substring(2)}.diff`,
-      )
-    : `/tmp/patch_${Date.now()}_${Math.random().toString(36).substring(2)}.diff`;
+    ? join(workDir, `patch_${uuidv4()}.diff`)
+    : `/tmp/patch_${uuidv4()}.diff`;
 
   try {
     // Create the patch file using unified shell executor
diff --git a/apps/open-swe/src/tools/builtin-tools/handlers.ts b/apps/open-swe/src/tools/builtin-tools/handlers.ts
index 296cb20b..3fe6e2b5 100644
--- a/apps/open-swe/src/tools/builtin-tools/handlers.ts
+++ b/apps/open-swe/src/tools/builtin-tools/handlers.ts
@@ -2,53 +2,36 @@ import { Sandbox } from "@daytonaio/sdk";
 import { readFile, writeFile } from "../../utils/read-write.js";
 import { getSandboxErrorFields } from "../../utils/sandbox-error-fields.js";
 import { GraphConfig } from "@open-swe/shared/open-swe/types";
-import {
-  createShellExecutor,
-  LocalExecuteResponse,
-} from "../../utils/shell-executor/index.js";
+import { createShellExecutor } from "../../utils/shell-executor/index.js";
+
+interface ViewCommandInputs {
+  path: string;
+  workDir: string;
+  viewRange?: [number, number];
+}
 
 export async function handleViewCommand(
   sandbox: Sandbox,
-  path: string,
-  workDir: string,
-  viewRange?: [number, number],
-  config?: GraphConfig,
+  config: GraphConfig,
+  inputs: ViewCommandInputs,
 ): Promise<string> {
+  const { path, workDir, viewRange } = inputs;
   try {
     // Check if path is a directory
-    let statOutput: LocalExecuteResponse;
-    if (!config) {
-      // Fallback to direct sandbox execution if no config provided
-      statOutput = await sandbox.process.executeCommand(
-        `stat -c %F "${path}"`,
-        workDir,
-      );
-    } else {
-      const executor = createShellExecutor(config);
-      statOutput = await executor.executeCommand({
-        command: `stat -c %F "${path}"`,
-        workdir: workDir,
-        sandbox,
-      });
-    }
+    const executor = createShellExecutor(config);
+    const statOutput = await executor.executeCommand({
+      command: `stat -c %F "${path}"`,
+      workdir: workDir,
+      sandbox,
+    });
 
     if (statOutput.exitCode === 0 && statOutput.result?.includes("directory")) {
       // List directory contents
-      let lsOutput: LocalExecuteResponse;
-      if (!config) {
-        // Fallback to direct sandbox execution if no config provided
-        lsOutput = await sandbox.process.executeCommand(
-          `ls -la "${path}"`,
-          workDir,
-        );
-      } else {
-        const executor = createShellExecutor(config);
-        lsOutput = await executor.executeCommand({
-          command: `ls -la "${path}"`,
-          workdir: workDir,
-          sandbox,
-        });
-      }
+      const lsOutput = await executor.executeCommand({
+        command: `ls -la "${path}"`,
+        workdir: workDir,
+        sandbox,
+      });
 
       if (lsOutput.exitCode !== 0) {
         throw new Error(`Failed to list directory: ${lsOutput.result}`);
@@ -99,17 +82,24 @@ export async function handleViewCommand(
   }
 }
 
+interface StrReplaceCommandInputs {
+  path: string;
+  workDir: string;
+  oldStr: string;
+  newStr: string;
+}
+
 export async function handleStrReplaceCommand(
   sandbox: Sandbox,
-  path: string,
-  workDir: string,
-  oldStr: string,
-  newStr: string,
+  config: GraphConfig,
+  inputs: StrReplaceCommandInputs,
 ): Promise<string> {
+  const { path, workDir, oldStr, newStr } = inputs;
   const { success: readSuccess, output: fileContent } = await readFile({
     sandbox,
     filePath: path,
     workDir,
+    config,
   });
 
   if (!readSuccess) {
@@ -152,17 +142,24 @@ export async function handleStrReplaceCommand(
   return `Successfully replaced text in ${path} at exactly one location.`;
 }
 
+interface CreateCommandInputs {
+  path: string;
+  workDir: string;
+  fileText: string;
+}
+
 export async function handleCreateCommand(
   sandbox: Sandbox,
-  path: string,
-  workDir: string,
-  fileText: string,
+  config: GraphConfig,
+  inputs: CreateCommandInputs,
 ): Promise<string> {
+  const { path, workDir, fileText } = inputs;
   // Check if file already exists
   const { success: readSuccess } = await readFile({
     sandbox,
     filePath: path,
     workDir,
+    config,
   });
 
   if (readSuccess) {
@@ -185,17 +182,24 @@ export async function handleCreateCommand(
   return `Successfully created file ${path}.`;
 }
 
+interface InsertCommandInputs {
+  path: string;
+  workDir: string;
+  insertLine: number;
+  newStr: string;
+}
+
 export async function handleInsertCommand(
   sandbox: Sandbox,
-  path: string,
-  workDir: string,
-  insertLine: number,
-  newStr: string,
+  config: GraphConfig,
+  inputs: InsertCommandInputs,
 ): Promise<string> {
+  const { path, workDir, insertLine, newStr } = inputs;
   const { success: readSuccess, output: fileContent } = await readFile({
     sandbox,
     filePath: path,
     workDir,
+    config,
   });
 
   if (!readSuccess) {
diff --git a/apps/open-swe/src/tools/builtin-tools/text-editor.ts b/apps/open-swe/src/tools/builtin-tools/text-editor.ts
index 85b2b11a..03e137a6 100644
--- a/apps/open-swe/src/tools/builtin-tools/text-editor.ts
+++ b/apps/open-swe/src/tools/builtin-tools/text-editor.ts
@@ -169,12 +169,11 @@ export function createTextEditorTool(
 
           switch (command) {
             case "view":
-              result = await handleViewCommand(
-                sandbox,
+              result = await handleViewCommand(sandbox, config, {
                 path,
                 workDir,
-                view_range,
-              );
+                viewRange: view_range,
+              });
               break;
             case "str_replace":
               if (!old_str || new_str === undefined) {
@@ -182,24 +181,22 @@ export function createTextEditorTool(
                   "str_replace command requires both old_str and new_str parameters",
                 );
               }
-              result = await handleStrReplaceCommand(
-                sandbox,
+              result = await handleStrReplaceCommand(sandbox, config, {
                 path,
                 workDir,
-                old_str,
-                new_str,
-              );
+                oldStr: old_str,
+                newStr: new_str,
+              });
               break;
             case "create":
               if (!file_text) {
                 throw new Error("create command requires file_text parameter");
               }
-              result = await handleCreateCommand(
-                sandbox,
+              result = await handleCreateCommand(sandbox, config, {
                 path,
                 workDir,
-                file_text,
-              );
+                fileText: file_text,
+              });
               break;
             case "insert":
               if (insert_line === undefined || new_str === undefined) {
@@ -207,13 +204,12 @@ export function createTextEditorTool(
                   "insert command requires both insert_line and new_str parameters",
                 );
               }
-              result = await handleInsertCommand(
-                sandbox,
+              result = await handleInsertCommand(sandbox, config, {
                 path,
                 workDir,
-                insert_line,
-                new_str,
-              );
+                insertLine: insert_line,
+                newStr: new_str,
+              });
               break;
             default:
               throw new Error(`Unknown command: ${command}`);
diff --git a/apps/open-swe/src/tools/builtin-tools/view.ts b/apps/open-swe/src/tools/builtin-tools/view.ts
index 27996fd4..683d874b 100644
--- a/apps/open-swe/src/tools/builtin-tools/view.ts
+++ b/apps/open-swe/src/tools/builtin-tools/view.ts
@@ -59,12 +59,11 @@ export function createViewTool(
         } else {
           // Sandbox mode: use existing handler
           const sandbox = await getSandboxSessionOrThrow(input);
-          result = await handleViewCommand(
-            sandbox,
+          result = await handleViewCommand(sandbox, config, {
             path,
             workDir,
-            view_range as [number, number] | undefined,
-          );
+            viewRange: view_range as [number, number] | undefined,
+          });
         }
 
         logger.info(`View command executed successfully on ${path}`);
diff --git a/apps/open-swe/src/tools/grep.ts b/apps/open-swe/src/tools/grep.ts
index 23172ff4..4bc95bc9 100644
--- a/apps/open-swe/src/tools/grep.ts
+++ b/apps/open-swe/src/tools/grep.ts
@@ -13,6 +13,7 @@ import {
   formatGrepCommand,
 } from "@open-swe/shared/open-swe/tools";
 import { createShellExecutor } from "../utils/shell-executor/index.js";
+import { wrapScript } from "../utils/wrap-script.js";
 
 const logger = createLogger(LogLevel.INFO, "GrepTool");
 
@@ -23,7 +24,7 @@ export function createGrepTool(
   const grepTool = tool(
     async (input): Promise<{ result: string; status: "success" | "error" }> => {
       try {
-        const command = formatGrepCommand(input as any);
+        const command = formatGrepCommand(input);
         const localMode = isLocalMode(config);
         const localAbsolutePath = getLocalWorkingDirectory();
         const sandboxAbsolutePath = getRepoAbsolutePath(state.targetRepository);
@@ -36,7 +37,7 @@ export function createGrepTool(
 
         const executor = createShellExecutor(config);
         const response = await executor.executeCommand({
-          command,
+          command: wrapScript(command.join(" ")),
           workdir: workDir,
           timeout: TIMEOUT_SEC,
         });
diff --git a/apps/open-swe/src/tools/utils/get-sandbox-id.ts b/apps/open-swe/src/tools/utils/get-sandbox-id.ts
index f3c208fb..89cfcf65 100644
--- a/apps/open-swe/src/tools/utils/get-sandbox-id.ts
+++ b/apps/open-swe/src/tools/utils/get-sandbox-id.ts
@@ -11,7 +11,7 @@ export async function getSandboxSessionOrThrow(
 ): Promise<Sandbox> {
   let sandboxSessionId = "";
   // Attempt to extract from input.
-  if ("xSandboxSessionId" in input) {
+  if ("xSandboxSessionId" in input && input.xSandboxSessionId) {
     sandboxSessionId = input.xSandboxSessionId as string;
   } else {
     const state = getCurrentTaskInput<GraphState>();
diff --git a/apps/open-swe/src/utils/custom-rules.ts b/apps/open-swe/src/utils/custom-rules.ts
index a97499b5..f44ebf0d 100644
--- a/apps/open-swe/src/utils/custom-rules.ts
+++ b/apps/open-swe/src/utils/custom-rules.ts
@@ -9,6 +9,7 @@ import {
 import { promises as fs } from "fs";
 import { join } from "path";
 import { GraphConfig } from "@open-swe/shared/open-swe/types";
+import { createShellExecutor } from "./shell-executor/shell-executor.js";
 
 const logger = createLogger(LogLevel.INFO, "CustomRules");
 
@@ -124,18 +125,21 @@ export function parseCustomRulesFromString(
 export async function getCustomRules(
   sandbox: Sandbox,
   rootDir: string,
-  config?: GraphConfig,
+  config: GraphConfig,
 ): Promise<CustomRules | undefined> {
   try {
-    if (config && isLocalMode(config)) {
+    if (isLocalMode(config)) {
       return getCustomRulesLocal(rootDir);
     }
 
+    const executor = createShellExecutor(config);
+
     const catAgentsMdFileCommand = ["cat", "AGENTS.md"];
-    const agentsMdRes = await sandbox.process.executeCommand(
-      catAgentsMdFileCommand.join(" "),
-      rootDir,
-    );
+    const agentsMdRes = await executor.executeCommand({
+      command: catAgentsMdFileCommand.join(" "),
+      workdir: rootDir,
+      sandbox,
+    });
     if (agentsMdRes.exitCode === 0 && agentsMdRes.result?.length > 0) {
       return parseCustomRulesFromString(agentsMdRes.result);
     }
@@ -144,9 +148,21 @@ export async function getCustomRules(
     const catClaudeMdFileCommand = ["cat", "CLAUDE.md"];
     const catCursorMdFileCommand = ["cat", "CURSOR.md"];
     const [agentMdRes, claudeMdRes, cursorMdRes] = await Promise.all([
-      sandbox.process.executeCommand(catAgentMdFileCommand.join(" "), rootDir),
-      sandbox.process.executeCommand(catClaudeMdFileCommand.join(" "), rootDir),
-      sandbox.process.executeCommand(catCursorMdFileCommand.join(" "), rootDir),
+      executor.executeCommand({
+        command: catAgentMdFileCommand.join(" "),
+        workdir: rootDir,
+        sandbox,
+      }),
+      executor.executeCommand({
+        command: catClaudeMdFileCommand.join(" "),
+        workdir: rootDir,
+        sandbox,
+      }),
+      executor.executeCommand({
+        command: catCursorMdFileCommand.join(" "),
+        workdir: rootDir,
+        sandbox,
+      }),
     ]);
     if (agentMdRes.exitCode === 0 && agentMdRes.result?.length > 0) {
       return parseCustomRulesFromString(agentMdRes.result);
diff --git a/apps/open-swe/src/utils/github/git.ts b/apps/open-swe/src/utils/github/git.ts
index 7e013e5d..2e9c78a7 100644
--- a/apps/open-swe/src/utils/github/git.ts
+++ b/apps/open-swe/src/utils/github/git.ts
@@ -376,6 +376,7 @@ export async function checkoutBranchAndCommit(
 export async function pushEmptyCommit(
   targetRepository: TargetRepository,
   sandbox: Sandbox,
+  config: GraphConfig,
   options: {
     githubInstallationToken: string;
   },
@@ -390,12 +391,12 @@ export async function pushEmptyCommit(
 
   try {
     const absoluteRepoDir = getRepoAbsolutePath(targetRepository);
-    const setGitConfigRes = await sandbox.process.executeCommand(
-      `git config user.name "${userName}" && git config user.email "${userEmail}"`,
-      absoluteRepoDir,
-      undefined,
-      TIMEOUT_SEC,
-    );
+    const executor = createShellExecutor(config);
+    const setGitConfigRes = await executor.executeCommand({
+      command: `git config user.name "${userName}" && git config user.email "${userEmail}"`,
+      workdir: absoluteRepoDir,
+      timeout: TIMEOUT_SEC,
+    });
     if (setGitConfigRes.exitCode !== 0) {
       logger.error(`Failed to set git config`, {
         exitCode: setGitConfigRes.exitCode,
@@ -404,12 +405,11 @@ export async function pushEmptyCommit(
       return;
     }
 
-    const emptyCommitRes = await sandbox.process.executeCommand(
-      "git commit --allow-empty -m 'Empty commit to trigger CI'",
-      absoluteRepoDir,
-      undefined,
-      TIMEOUT_SEC,
-    );
+    const emptyCommitRes = await executor.executeCommand({
+      command: "git commit --allow-empty -m 'Empty commit to trigger CI'",
+      workdir: absoluteRepoDir,
+      timeout: TIMEOUT_SEC,
+    });
     if (emptyCommitRes.exitCode !== 0) {
       logger.error(`Failed to push empty commit`, {
         exitCode: emptyCommitRes.exitCode,
diff --git a/apps/open-swe/src/utils/llms/model-manager.ts b/apps/open-swe/src/utils/llms/model-manager.ts
index 28d28232..b8503d8f 100644
--- a/apps/open-swe/src/utils/llms/model-manager.ts
+++ b/apps/open-swe/src/utils/llms/model-manager.ts
@@ -180,7 +180,6 @@ export class ModelManager {
 
     const modelOptions: InitChatModelArgs = {
       modelProvider: provider,
-      temperature: thinkingModel ? undefined : temperature,
       max_retries: MAX_RETRIES,
       ...(apiKey ? { apiKey } : {}),
       ...(thinkingModel && provider === "anthropic"
@@ -188,7 +187,15 @@ export class ModelManager {
             thinking: { budget_tokens: thinkingBudgetTokens, type: "enabled" },
             maxTokens: thinkingMaxTokens,
           }
-        : { maxTokens: finalMaxTokens }),
+        : modelName.includes("gpt-5")
+          ? {
+              max_completion_tokens: finalMaxTokens,
+              temperature: 1,
+            }
+          : {
+              maxTokens: finalMaxTokens,
+              temperature: thinkingModel ? undefined : temperature,
+            }),
     };
 
     logger.debug("Initializing model", {
@@ -219,8 +226,17 @@ export class ModelManager {
         selectedModelConfig = {
           provider,
           modelName,
-          temperature: defaultConfig.temperature ?? baseConfig.temperature,
-          maxTokens: defaultConfig.maxTokens ?? baseConfig.maxTokens,
+          ...(modelName.includes("gpt-5")
+            ? {
+                max_completion_tokens:
+                  defaultConfig.maxTokens ?? baseConfig.maxTokens,
+                temperature: 1,
+              }
+            : {
+                maxTokens: defaultConfig.maxTokens ?? baseConfig.maxTokens,
+                temperature:
+                  defaultConfig.temperature ?? baseConfig.temperature,
+              }),
           ...(isThinkingModel
             ? {
                 thinkingModel: true,
@@ -247,8 +263,17 @@ export class ModelManager {
 
         const fallbackConfig = {
           ...fallbackModel,
-          temperature: isThinkingModel ? undefined : baseConfig.temperature,
-          maxTokens: baseConfig.maxTokens,
+          ...(fallbackModel.modelName.includes("gpt-5")
+            ? {
+                max_completion_tokens: baseConfig.maxTokens,
+                temperature: 1,
+              }
+            : {
+                maxTokens: baseConfig.maxTokens,
+                temperature: isThinkingModel
+                  ? undefined
+                  : baseConfig.temperature,
+              }),
           ...(isThinkingModel
             ? {
                 thinkingModel: true,
@@ -331,8 +356,15 @@ export class ModelManager {
     return {
       modelName,
       provider: modelProvider as Provider,
-      temperature: taskConfig.temperature,
-      maxTokens: config.configurable?.maxTokens ?? 10_000,
+      ...(modelName.includes("gpt-5")
+        ? {
+            max_completion_tokens: config.configurable?.maxTokens ?? 10_000,
+            temperature: 1,
+          }
+        : {
+            maxTokens: config.configurable?.maxTokens ?? 10_000,
+            temperature: taskConfig.temperature,
+          }),
       thinkingModel,
       thinkingBudgetTokens,
     };
@@ -361,11 +393,11 @@ export class ModelManager {
         [LLMTask.SUMMARIZER]: "gemini-2.5-pro",
       },
       openai: {
-        [LLMTask.PLANNER]: "o3",
-        [LLMTask.PROGRAMMER]: "gpt-4.1",
-        [LLMTask.REVIEWER]: "o3",
-        [LLMTask.ROUTER]: "gpt-4o-mini",
-        [LLMTask.SUMMARIZER]: "gpt-4.1-mini",
+        [LLMTask.PLANNER]: "gpt-5",
+        [LLMTask.PROGRAMMER]: "gpt-5",
+        [LLMTask.REVIEWER]: "gpt-5",
+        [LLMTask.ROUTER]: "gpt-5-nano",
+        [LLMTask.SUMMARIZER]: "gpt-5-mini",
       },
     };
 
diff --git a/apps/open-swe/src/utils/read-write.ts b/apps/open-swe/src/utils/read-write.ts
index 1437a8a2..bc9c8225 100644
--- a/apps/open-swe/src/utils/read-write.ts
+++ b/apps/open-swe/src/utils/read-write.ts
@@ -9,27 +9,30 @@ import {
 import { promises as fs } from "fs";
 import { join, isAbsolute } from "path";
 import { GraphConfig } from "@open-swe/shared/open-swe/types";
+import { createShellExecutor } from "./shell-executor/shell-executor.js";
+import { v4 as uuidv4 } from "uuid";
 
 const logger = createLogger(LogLevel.INFO, "ReadWriteUtil");
 
 async function handleCreateFile(
-  sandbox: Sandbox,
+  sandbox: Sandbox | null,
   filePath: string,
+  config: GraphConfig,
   args?: {
     workDir?: string;
   },
-  config?: GraphConfig,
 ) {
-  if (config && isLocalMode(config)) {
+  if (isLocalMode(config)) {
     return handleCreateFileLocal(filePath, args?.workDir);
   }
 
   try {
-    const touchCommand = `touch "${filePath}"`;
-    const touchOutput = await sandbox.process.executeCommand(
-      touchCommand,
-      args?.workDir,
-    );
+    const executor = createShellExecutor(config);
+    const touchOutput = await executor.executeCommand({
+      command: `touch "${filePath}"`,
+      workdir: args?.workDir,
+      sandbox: sandbox ?? undefined,
+    });
     return touchOutput;
   } catch (e) {
     const errorFields = getSandboxErrorFields(e);
@@ -49,26 +52,25 @@ async function readFileFunc(inputs: {
   sandbox: Sandbox | null;
   filePath: string;
   workDir?: string;
-  config?: GraphConfig;
+  config: GraphConfig;
 }): Promise<{
   success: boolean;
   output: string;
 }> {
   const { sandbox, filePath, workDir, config } = inputs;
 
-  if (config && isLocalMode(config)) {
+  if (isLocalMode(config)) {
     return readFileLocal(filePath, workDir);
   }
 
-  if (!sandbox) {
-    throw new Error("Sandbox is required when not in local mode");
-  }
+  const executor = createShellExecutor(config);
 
   try {
-    const readOutput = await sandbox.process.executeCommand(
-      `cat "${filePath}"`,
-      workDir,
-    );
+    const readOutput = await executor.executeCommand({
+      command: `cat "${filePath}"`,
+      workdir: workDir,
+      sandbox: sandbox ?? undefined,
+    });
 
     if (readOutput.exitCode !== 0) {
       const errorResult = readOutput.result ?? readOutput.artifacts?.stdout;
@@ -90,7 +92,7 @@ async function readFileFunc(inputs: {
         createOutput = await handleCreateFileLocal(filePath, workDir);
       } else {
         // Sandbox mode: use handleCreateFile
-        createOutput = await handleCreateFile(sandbox, filePath, {
+        createOutput = await handleCreateFile(sandbox, filePath, config, {
           workDir,
         });
       }
@@ -164,14 +166,16 @@ async function writeFileFunc(inputs: {
   }
 
   try {
-    const delimiter = "EOF_" + Date.now() + "_" + Math.random().toString(36);
+    const delimiter = `EOF_${uuidv4()}`;
     const writeCommand = `cat > "${filePath}" << '${delimiter}'
 ${content}
 ${delimiter}`;
-    const writeOutput = await sandbox.process.executeCommand(
-      writeCommand,
-      workDir,
-    );
+    const executor = createShellExecutor(config);
+    const writeOutput = await executor.executeCommand({
+      command: writeCommand,
+      workdir: workDir,
+      sandbox: sandbox ?? undefined,
+    });
 
     if (writeOutput.exitCode !== 0) {
       const errorResult = writeOutput.result ?? writeOutput.artifacts?.stdout;
diff --git a/apps/open-swe/src/utils/sandbox.ts b/apps/open-swe/src/utils/sandbox.ts
index 5d125f0f..f57711ef 100644
--- a/apps/open-swe/src/utils/sandbox.ts
+++ b/apps/open-swe/src/utils/sandbox.ts
@@ -169,9 +169,9 @@ export async function getSandboxWithErrorHandling(
 
     // Get codebase tree
     const codebaseTree = await getCodebaseTree(
+      config,
       sandbox.id,
       targetRepository,
-      config,
     );
     const codebaseTreeToReturn =
       codebaseTree === FAILED_TO_GENERATE_TREE_MESSAGE ? null : codebaseTree;
diff --git a/apps/open-swe/src/utils/shell-executor/shell-executor.ts b/apps/open-swe/src/utils/shell-executor/shell-executor.ts
index a0e025f3..d2e3bee1 100644
--- a/apps/open-swe/src/utils/shell-executor/shell-executor.ts
+++ b/apps/open-swe/src/utils/shell-executor/shell-executor.ts
@@ -40,6 +40,7 @@ export class ShellExecutor {
       env = {},
       timeout = TIMEOUT_SEC,
       sandbox,
+      sandboxSessionId,
     } = options;
 
     const commandString = Array.isArray(command) ? command.join(" ") : command;
@@ -60,6 +61,7 @@ export class ShellExecutor {
         environment,
         timeout,
         sandbox,
+        sandboxSessionId,
       );
     }
   }
@@ -93,8 +95,13 @@ export class ShellExecutor {
     env?: Record<string, string>,
     timeout?: number,
     sandbox?: Sandbox,
+    sandboxSessionId?: string,
   ): Promise<LocalExecuteResponse> {
-    const sandbox_ = sandbox ?? (await getSandboxSessionOrThrow({}));
+    const sandbox_ =
+      sandbox ??
+      (await getSandboxSessionOrThrow({
+        xSandboxSessionId: sandboxSessionId,
+      }));
 
     return await sandbox_.process.executeCommand(
       command,
diff --git a/apps/open-swe/src/utils/shell-executor/types.ts b/apps/open-swe/src/utils/shell-executor/types.ts
index 345300b9..4575d13c 100644
--- a/apps/open-swe/src/utils/shell-executor/types.ts
+++ b/apps/open-swe/src/utils/shell-executor/types.ts
@@ -15,4 +15,5 @@ export interface ExecuteCommandOptions {
   env?: Record<string, string>;
   timeout?: number;
   sandbox?: Sandbox;
+  sandboxSessionId?: string;
 }
diff --git a/apps/open-swe/src/utils/tree.ts b/apps/open-swe/src/utils/tree.ts
index 75770a58..64ab4ca1 100644
--- a/apps/open-swe/src/utils/tree.ts
+++ b/apps/open-swe/src/utils/tree.ts
@@ -4,7 +4,6 @@ import {
   TargetRepository,
   GraphConfig,
 } from "@open-swe/shared/open-swe/types";
-import { daytonaClient } from "./sandbox.js";
 import { createLogger, LogLevel } from "./logger.js";
 import path from "node:path";
 import { SANDBOX_ROOT_DIR, TIMEOUT_SEC } from "@open-swe/shared/constants";
@@ -18,9 +17,9 @@ export const FAILED_TO_GENERATE_TREE_MESSAGE =
   "Failed to generate tree. Please try again.";
 
 export async function getCodebaseTree(
+  config: GraphConfig,
   sandboxSessionId_?: string,
   targetRepository_?: TargetRepository,
-  config?: GraphConfig,
 ): Promise<string> {
   try {
     const command = `git ls-files | tree --fromfile -L 3`;
@@ -28,7 +27,7 @@ export async function getCodebaseTree(
     let targetRepository = targetRepository_;
 
     // Check if we're in local mode
-    if (config && isLocalMode(config)) {
+    if (isLocalMode(config)) {
       return getCodebaseTreeLocal(config);
     }
 
@@ -53,14 +52,14 @@ export async function getCodebaseTree(
       throw new Error("Failed generate tree: No target repository provided");
     }
 
-    const sandbox = await daytonaClient().get(sandboxSessionId);
+    const executor = createShellExecutor(config);
     const repoDir = path.join(SANDBOX_ROOT_DIR, targetRepository.repo);
-    const response = await sandbox.process.executeCommand(
+    const response = await executor.executeCommand({
       command,
-      repoDir,
-      undefined,
-      TIMEOUT_SEC,
-    );
+      workdir: repoDir,
+      timeout: TIMEOUT_SEC,
+      sandboxSessionId,
+    });
 
     if (response.exitCode !== 0) {
       logger.error("Failed to generate tree", {
diff --git a/apps/open-swe/src/utils/wrap-script.ts b/apps/open-swe/src/utils/wrap-script.ts
index a866a71e..14f7ac54 100644
--- a/apps/open-swe/src/utils/wrap-script.ts
+++ b/apps/open-swe/src/utils/wrap-script.ts
@@ -1,7 +1,22 @@
+import { v4 as uuidv4 } from "uuid";
+
 export function wrapScript(command: string): string {
-  // Use bash directly to avoid script command compatibility issues
-  return `bash -c "$(cat <<'OPEN_SWE_X'
+  const makeDelim = () => `OPEN_SWE_${uuidv4()}`;
+
+  // Ensure the delimiter does not appear as a standalone line in the command
+  let delim = makeDelim();
+  const containsStandalone = (d: string) =>
+    command === d ||
+    command.startsWith(`${d}\n`) ||
+    command.endsWith(`\n${d}`) ||
+    command.includes(`\n${d}\n`);
+
+  while (containsStandalone(delim)) {
+    delim = makeDelim();
+  }
+
+  return `script --return --quiet -c "$(cat <<'${delim}'
 ${command}
-OPEN_SWE_X
-)"`;
+${delim}
+)" /dev/null`;
 }
diff --git a/packages/shared/src/open-swe/models.ts b/packages/shared/src/open-swe/models.ts
index 965c5760..d0ec8043 100644
--- a/packages/shared/src/open-swe/models.ts
+++ b/packages/shared/src/open-swe/models.ts
@@ -32,6 +32,18 @@ export const MODEL_OPTIONS = [
     label: "Claude 3.5 Haiku",
     value: "anthropic:claude-3-5-haiku-latest",
   },
+  {
+    label: "GPT 5",
+    value: "openai:gpt-5",
+  },
+  {
+    label: "GPT 5 mini",
+    value: "openai:gpt-5-mini",
+  },
+  {
+    label: "GPT 5 nano",
+    value: "openai:gpt-5-nano",
+  },
   {
     label: "o4",
     value: "openai:o4",