fix(trust): quote whitespace argv via one shared MCP trust prompt helper

Author: TheGreatAxios

src/exec/runner.ts

@@ -20,6 +20,7 @@ import {
   registerSourceCredential,
 } from "../config/source-credentials.js";
 import { formatDirectorSystemPrompt } from "../agent/directors/identity.js";
+import { formatMcpTrustQuestion } from "../trust/project-trust.js";
 import { DIRECTOR_REGISTRY } from "../agent/directors/registry.js";
 import type { DirectorId, DirectorPackage } from "../agent/directors/types.js";
 import { submitOutputDefinition } from "../agent/director.js";
@@ -164,14 +165,7 @@ const logger = getLogger([LOG_NAMESPACE_ROOT, "exec"]);
 const SELECTED_PROVIDER_FAILURE = "SelectedProviderFailure";
 
 export function formatExecMcpTrustQuestion(server: MCPServerConfig): string {
-  return (
-    `Trust local MCP server "${server.name}" for this project?` +
-    (server.command !== undefined
-      ? `\nCommand: ${server.command}${(server.args ?? []).length > 0 ? ` ${(server.args ?? []).join(" ")}` : ""}`
-      : server.url !== undefined
-        ? `\nURL: ${server.url}`
-        : "")
-  );
+  return formatMcpTrustQuestion(server);
 }
 
 export async function refreshSelectedProviderCredential<T>(

src/trust/project-trust.ts

@@ -298,6 +298,32 @@ export function mcpServerFingerprint(server: MCPServerConfig): string {
   return createHash("sha256").update(payload).digest("hex");
 }
 
+// Display-only argv quoting for the MCP trust prompt: an arg containing
+// whitespace (or a quote, or empty) renders double-quoted so ["a b"] and
+// ["a", "b"] never look alike. Approval identity still comes from
+// mcpServerFingerprint above, never from this rendering.
+function quoteMcpTrustArg(arg: string): string {
+  if (arg !== "" && !/[\s"]/.test(arg)) return arg;
+  return `"${arg.replace(/\\/g, "\\\\").replace(/"/g, '\\"')}"`;
+}
+
+function formatMcpSpawnCommand(command: string, args: string[]): string {
+  return args.length === 0
+    ? command
+    : `${command} ${args.map(quoteMcpTrustArg).join(" ")}`;
+}
+
+export function formatMcpTrustQuestion(server: MCPServerConfig): string {
+  return (
+    `Trust local MCP server "${server.name}" for this project?` +
+    (server.command !== undefined
+      ? `\nCommand: ${formatMcpSpawnCommand(server.command, server.args ?? [])}`
+      : server.url !== undefined
+        ? `\nURL: ${server.url}`
+        : "")
+  );
+}
+
 export function isMcpServerTrusted(
   store: ProjectTrustStore,
   server: MCPServerConfig,

src/tui/runner/session.ts

@@ -15,6 +15,7 @@ import {
   localSettingsPath,
   shellTimeoutFromSettings,
   toolWatchdogFromSettings,
+  type MCPServerConfig,
 } from "../../config/settings.js";
 import { isCodexProviderName } from "../../config/codex-providers.js";
 import { peekSourceCredentialSecret } from "../../config/source-credentials.js";
@@ -130,6 +131,11 @@ import {
   type TUIStart,
 } from "./state.js";
 import { createParkedOverlayAbortBinding } from "./parked-overlay-abort.js";
+import { formatMcpTrustQuestion } from "../../trust/project-trust.js";
+
+export function formatTuiMcpTrustQuestion(server: MCPServerConfig): string {
+  return formatMcpTrustQuestion(server);
+}
 
 export async function assembleTUISession(
   state: RunnerState,
@@ -414,13 +420,7 @@ export async function assembleTUISession(
         const timeout = approvalTimeout();
         const event: OperatorGateEvent = {
           id: randomUUID(),
-          question:
-            `Trust local MCP server "${server.name}" for this project?` +
-            (server.command !== undefined
-              ? `\nCommand: ${server.command}${(server.args ?? []).length > 0 ? ` ${(server.args ?? []).join(" ")}` : ""}`
-              : server.url !== undefined
-                ? `\nURL: ${server.url}`
-                : ""),
+          question: formatTuiMcpTrustQuestion(server),
           options: ["Trust and connect", "Deny"],
           resolve: finish,
           ...(timeout !== undefined ? timeout : {}),

tests/unit/tui/mcp-trust-prompt-parity.test.ts

@@ -4,7 +4,11 @@ import { formatExecMcpTrustQuestion } from "../../../src/exec/runner.js";
 import { formatTuiMcpTrustQuestion } from "../../../src/tui/runner/session.js";
 
 const parityCases: MCPServerConfig[] = [
-  { name: "plain-stdio", command: "node", args: ["server.js", "--port", "3000"] },
+  {
+    name: "plain-stdio",
+    command: "node",
+    args: ["server.js", "--port", "3000"],
+  },
   { name: "no-args", command: "node" },
   { name: "empty-args", command: "node", args: [] },
   { name: "spaced-path", command: "server", args: ["--dir", "/tmp/my work"] },