feat(install): reject --set with multi-preset install

README.md

@@ -64,10 +64,12 @@ opencode-presets install mcp-http \
   --set-env headerValue=BITBUCKET_TOKEN
 ```
 
-When installing several modules in one call, scope a value with
-`<preset>.<name>` if the same prompt name appears in more than one
-of them: `--set mcp-http.name=openrag`. Unscoped values across
-ambiguous prompts are rejected with a clear error.
+`--set` / `--set-env` apply to a single preset per invocation — run
+the command once per preset rather than bundling several with shared
+flags. This keeps the wiring obvious ("this `--set` goes to *that*
+preset") and avoids surprise: in a non-TTY shell script, a bundled
+install would happily fill the first preset's prompts and then hang
+on a readline for the next.
 
 ## Built-in presets
 

bin/opencode-presets.ts

@@ -10,7 +10,7 @@ import { backup } from '../src/backup.js';
 import { c, confirm, closeUi } from '../src/ui.js';
 import { listConfs } from '../src/list.js';
 import { runBatch, runRemoveBatch } from '../src/batch.js';
-import { parseInstallArgs, CliArgsError } from '../src/cli-args.js';
+import { parseInstallArgs, validateInstallPolicy, CliArgsError } from '../src/cli-args.js';
 import { validateAgainstSchema } from '../src/validate.js';
 
 const CACHE_DIR = process.env.OPENCODE_PRESETS_CACHE
@@ -104,6 +104,11 @@ async function main(): Promise<void> {
       printUsage();
       process.exit(1);
     }
+    const policyError = validateInstallPolicy(parsed);
+    if (policyError !== null) {
+      console.error(c.err('error: ') + policyError);
+      process.exit(1);
+    }
     const resolved = await Promise.all(confPaths.map(resolveConfArg));
     await runBatch({
       resets,

package.json

@@ -1,6 +1,6 @@
 {
   "name": "opencode-presets",
-  "version": "0.4.0",
+  "version": "0.5.0",
   "description": "Interactive CLI that patches opencode.json with curated config presets — LSP, MCP, permissions.",
   "type": "module",
   "bin": {

src/cli-args.ts

@@ -28,6 +28,20 @@ export class CliArgsError extends Error {
   }
 }
 
+// Policy check separate from syntax parsing: --set / --set-env target a
+// single preset, so combining them with a multi-preset install is rejected.
+// Returns null if the args are policy-valid, or an error message otherwise.
+export function validateInstallPolicy(parsed: InstallArgs): string | null {
+  if (parsed.setValues.length > 0 && parsed.confPaths.length !== 1) {
+    if (parsed.confPaths.length === 0) {
+      return '--set / --set-env requires a preset to install.';
+    }
+    return '--set / --set-env requires installing exactly one preset; got ' +
+      `${parsed.confPaths.length}. Run the command once per preset, or drop --set.`;
+  }
+  return null;
+}
+
 // args is everything after `install` (so --reset, --set, --set-env, and conf paths).
 // Forms accepted:
 //   --reset <path>            --reset=<path>

test/cli-args.test.ts

@@ -1,6 +1,6 @@
 import { test, describe } from 'node:test';
 import assert from 'node:assert/strict';
-import { parseInstallArgs, CliArgsError } from '../src/cli-args.js';
+import { parseInstallArgs, validateInstallPolicy, CliArgsError } from '../src/cli-args.js';
 
 describe('parseInstallArgs — existing behavior', () => {
   test('plain conf paths', () => {
@@ -141,3 +141,34 @@ describe('parseInstallArgs — mixed', () => {
     assert.equal(r.setValues.length, 2);
   });
 });
+
+describe('validateInstallPolicy', () => {
+  test('null when no --set is used (any number of presets)', () => {
+    assert.equal(validateInstallPolicy(parseInstallArgs(['a', 'b', 'c'])), null);
+    assert.equal(validateInstallPolicy(parseInstallArgs([])), null);
+  });
+
+  test('null when --set targets exactly one preset', () => {
+    const r = parseInstallArgs(['mcp-http', '--set', 'name=x']);
+    assert.equal(validateInstallPolicy(r), null);
+  });
+
+  test('null when --set + one preset + --reset', () => {
+    const r = parseInstallArgs(['--reset', 'mcp.foo', 'mcp-http', '--set', 'name=x']);
+    assert.equal(validateInstallPolicy(r), null);
+  });
+
+  test('errors when --set is used with multiple presets', () => {
+    const r = parseInstallArgs(['mcp-http', 'mcp-http-noauth', '--set', 'name=x']);
+    const err = validateInstallPolicy(r);
+    assert.ok(err, 'expected an error');
+    assert.match(err!, /exactly one preset/);
+  });
+
+  test('errors when --set is used with no presets', () => {
+    const r = parseInstallArgs(['--set', 'name=x']);
+    const err = validateInstallPolicy(r);
+    assert.ok(err, 'expected an error');
+    assert.match(err!, /requires a preset/);
+  });
+});