@@ -7,7 +7,7 @@ import {
   ignorePatternsRead,
   matchesIgnore as matchesIgnorePatterns,
 } from "./resource-parse.ts";
-import { VALID_RESOURCE_TYPES } from "./types.ts";
+import { resolveResourceTypes, VALID_TYPE_ARGS } from "./resource-type-args.ts";
 
 // ─────────────────────────────────────────────────────────────────────────────
 // CLI Argument Parsing
@@ -19,23 +19,8 @@ export interface ApplyFilter {
   resourceIds?: string[]; // Pull only specific remote resource IDs
 }
 
-// Group aliases: expand a shorthand into multiple resource types
-const RESOURCE_GROUP_MAP: Record<string, ResourceType[]> = {
-  simulations: [
-    "personalities",
-    "scenarios",
-    "simulations",
-    "simulationSuites",
-  ],
-};
-
-// Path-based aliases: folder paths to resource types
-const RESOURCE_PATH_MAP: Record<string, ResourceType> = {
-  "simulations/personalities": "personalities",
-  "simulations/scenarios": "scenarios",
-  "simulations/tests": "simulations",
-  "simulations/suites": "simulationSuites",
-};
+// The --type aliases (groups like "simulations", paths like
+// "simulations/tests") live in resource-type-args.ts.
 
 const SLUG_RE = /^[a-z0-9]([a-z0-9-]*[a-z0-9])?$/;
 
@@ -67,28 +52,6 @@ function parseEnvironment(): Environment {
   return envArg;
 }
 
-// Resolve a type argument into resource types (handles groups, paths, and direct types)
-function resolveResourceTypes(arg: string): ResourceType[] | null {
-  // Check group aliases first (e.g., "simulations" → all 4 simulation types)
-  if (RESOURCE_GROUP_MAP[arg]) {
-    return RESOURCE_GROUP_MAP[arg];
-  }
-  // Check path-based aliases (e.g., "simulations/personalities" → ["personalities"])
-  if (RESOURCE_PATH_MAP[arg]) {
-    return [RESOURCE_PATH_MAP[arg]];
-  }
-  // Check direct resource type
-  if (VALID_RESOURCE_TYPES.includes(arg as ResourceType)) {
-    return [arg as ResourceType];
-  }
-  return null;
-}
-
-const VALID_TYPE_ARGS = [
-  ...VALID_RESOURCE_TYPES,
-  ...Object.keys(RESOURCE_GROUP_MAP),
-  ...Object.keys(RESOURCE_PATH_MAP),
-];
 
 function parseFlags(): {
   forceDelete: boolean;
 
@@ -0,0 +1,62 @@
+// How a `--type` argument maps to resource types. Config-free on purpose
+// (like api-key.ts): config.ts parses argv and exits at import time, so the
+// mapping lives here where setup.ts and tests can import it.
+
+import type { ResourceType } from "./types.ts";
+import { VALID_RESOURCE_TYPES } from "./types.ts";
+
+// Group aliases: expand a shorthand into multiple resource types
+const RESOURCE_GROUP_MAP: Record<string, ResourceType[]> = {
+  simulations: [
+    "personalities",
+    "scenarios",
+    "simulations",
+    "simulationSuites",
+  ],
+};
+
+// Path-based aliases: folder paths to resource types
+const RESOURCE_PATH_MAP: Record<string, ResourceType> = {
+  "simulations/personalities": "personalities",
+  "simulations/scenarios": "scenarios",
+  "simulations/tests": "simulations",
+  "simulations/suites": "simulationSuites",
+};
+
+// Resolve a type argument into resource types (handles groups, paths, and direct types)
+export function resolveResourceTypes(arg: string): ResourceType[] | null {
+  // Check group aliases first (e.g., "simulations" → all 4 simulation types)
+  if (RESOURCE_GROUP_MAP[arg]) {
+    return RESOURCE_GROUP_MAP[arg];
+  }
+  // Check path-based aliases (e.g., "simulations/personalities" → ["personalities"])
+  if (RESOURCE_PATH_MAP[arg]) {
+    return [RESOURCE_PATH_MAP[arg]];
+  }
+  // Check direct resource type
+  if (VALID_RESOURCE_TYPES.includes(arg as ResourceType)) {
+    return [arg as ResourceType];
+  }
+  return null;
+}
+
+export const VALID_TYPE_ARGS = [
+  ...VALID_RESOURCE_TYPES,
+  ...Object.keys(RESOURCE_GROUP_MAP),
+  ...Object.keys(RESOURCE_PATH_MAP),
+];
+
+/**
+ * The `--type` argument that names exactly one resource type. Usually the
+ * type itself, but `simulations` is also the group alias for all four
+ * simulation types, so the single type is spelled by its folder path,
+ * `simulations/tests`. Use this whenever a command builds a `--type` for one
+ * type, e.g. a single-resource pull with `--id`.
+ */
+export function typeArgFor(type: string): string {
+  if (!(type in RESOURCE_GROUP_MAP)) return type;
+  const pathAlias = Object.keys(RESOURCE_PATH_MAP).find(
+    (path) => RESOURCE_PATH_MAP[path] === type,
+  );
+  return pathAlias ?? type;
+}
@@ -12,6 +12,7 @@ import {
   resolveOrgApiKey,
 } from "./api-key.ts";
 import { updateEnvConnection } from "./bindings.ts";
+import { typeArgFor } from "./resource-type-args.ts";
 import searchableCheckbox, { BACK_SENTINEL } from "./searchableCheckbox.js";
 import {
   type DirectSetupOptions,
@@ -348,7 +349,9 @@ function invokePull(
       "--force",
       "--skip-bindings",
       "--type",
-      typeKey,
+      // Not typeKey itself: "simulations" is also the group alias for all
+      // four simulation types, which a pull by --id refuses.
+      typeArgFor(typeKey),
       ...idArgs,
     ].join(" ");
     execSync(cmd, { cwd: BASE_DIR, stdio: "inherit", env });
 
@@ -0,0 +1,41 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import {
+  resolveResourceTypes,
+  typeArgFor,
+} from "../src/resource-type-args.ts";
+import { VALID_RESOURCE_TYPES } from "../src/types.ts";
+
+// The setup wizard downloads what you pick one type at a time, with
+// `pull.ts <org> --type <type> --id …`, and a pull by --id accepts exactly one
+// type. It passed the internal type name, and "simulations" is also the
+// group alias for all four simulation types, so choosing simulations in the
+// wizard failed with "Single-resource pull requires exactly one resource
+// type" and stopped setup partway.
+
+test("typeArgFor names exactly one type for every resource type", () => {
+  for (const type of VALID_RESOURCE_TYPES) {
+    assert.deepEqual(resolveResourceTypes(typeArgFor(type)), [type], type);
+  }
+});
+
+test("typeArgFor spells simulations by its folder path", () => {
+  assert.equal(typeArgFor("simulations"), "simulations/tests");
+});
+
+test("typeArgFor leaves other types unchanged", () => {
+  assert.equal(typeArgFor("assistants"), "assistants");
+});
+
+test("--type simulations still selects every simulation type", () => {
+  assert.deepEqual(resolveResourceTypes("simulations"), [
+    "personalities",
+    "scenarios",
+    "simulations",
+    "simulationSuites",
+  ]);
+});
+
+test("resolveResourceTypes rejects an unknown type", () => {
+  assert.equal(resolveResourceTypes("widgets"), null);
+});