docs(config): document the full opener configuration

docs-lab/reference/configuration/config-json.md

@@ -15,7 +15,7 @@ The CLI keeps its machine-level settings at `~/.config/openspec/config.json` on
 | `workflows` | list of strings | No | The workflow list a `custom` profile installs |
 | `featureFlags` | map: flag → boolean | No | Boolean feature toggles |
 | `defaultStore` | string | No | Machine-level fallback store for root resolution |
-| `openers` | list | No | The tools worksets open in, and how each is launched |
+| `openers` | map: tool id → settings | No | The tools worksets open in, and how each is launched |
 | `telemetry` | map | No | State the CLI keeps: anonymous id and notice-seen |
 
 ### profile
@@ -40,7 +40,41 @@ The machine-level fallback store id for root resolution, consulted only when no
 
 ### openers
 
-The tools a workset can open in, and how each is launched. Entries are hand-edited and validated on use. Each may set `style` (`workspace-file` or `attach-dirs`), `label`, `command`, `args`, and `attach_flag`, and is merged over the built-in defaults.
+The tools a workset can open in, keyed by tool id. Edit `openers` in the global `config.json` with `openspec config edit` in your terminal.
+
+| Field | Contract |
+| --- | --- |
+| `style` | `workspace-file` or `attach-dirs`. Required for a new tool; optional for a built-in. |
+| `label` | Non-empty string shown in the tool picker. Defaults to the id for a new tool. |
+| `command` | Non-empty executable name or path. Defaults to the id for a new tool. Put arguments in `args`, not in this string. |
+| `args` | Array of strings passed before the workspace file or attach flags. Defaults to `[]` for a new tool. |
+| `attach_flag` | Non-empty string paired with each member path for `attach-dirs`. Defaults to `--add-dir` for a new tool. Ignored for `workspace-file`. |
+
+**Built-in overrides:** `code`, `cursor`, `claude`, and `codex` retain any fields you omit. Setting `args` replaces the entire argument list; `[]` clears it.
+
+**Launch styles:** `workspace-file` passes the generated `.code-workspace` path to the executable, which must support that format. `attach-dirs` passes one flag/path pair per member, including the primary member.
+
+**Availability:** `attach-dirs` openers, including Claude Code and Codex, are temporarily disabled by default. They are hidden from the picker and rejected by `workset create --tool` and `workset open --tool`. Configuration overrides do not enable the `attach-dirs` launch style.
+
+**Validation:** unknown fields, invalid types, and a new tool without `style` fail when a workset command reads the opener table.
+
+This example adds VS Code Insiders and passes `--new-window` whenever the built-in VS Code opener launches:
+
+```json
+{
+  "openers": {
+    "code-insiders": {
+      "style": "workspace-file",
+      "label": "VS Code Insiders"
+    },
+    "code": {
+      "args": ["--new-window"]
+    }
+  }
+}
+```
+
+The corresponding `code-insiders` or `code` executable must be installed and available on `PATH`.
 
 ### telemetry
 

test/commands/workset.test.ts

@@ -613,20 +613,29 @@ describe('openspec workset (7.1)', () => {
   });
 
   describe('opener config', () => {
-    it('adds a new workspace-file tool from config', async () => {
-      writeOpenersConfig({ zed: { style: 'workspace-file' } });
-      await createPlatform(['--tool', 'zed']);
-      const fakeZed = createFakeTool(tempDir, 'zed');
+    it.each([
+      { tool: 'code-insiders', args: [] },
+      { tool: 'code', args: ['--new-window'] },
+    ])('launches the documented $tool opener configuration', async ({ tool, args }) => {
+      delete process.env.OPENSPEC_ENABLE_CLI_AGENT_OPENERS;
+      writeOpenersConfig({
+        'code-insiders': { style: 'workspace-file', label: 'VS Code Insiders' },
+        code: { args: ['--new-window'] },
+      });
+      const created = await createPlatform(['--tool', tool]);
+      expect(created.exitCode).toBe(0);
+      const fakeEditor = createFakeTool(tempDir, tool);
 
       const result = await runCLI(['workset', 'open', 'platform'], {
         cwd: tempDir,
-        env: envWithFakeTools(env, [fakeZed]),
+        env: envWithFakeTools(env, [fakeEditor]),
       });
 
       expect(result.exitCode).toBe(0);
-      expect(readLaunchLog(fakeZed.logPath).args).toEqual([
-        getWorksetCodeWorkspacePath('platform', pathOptions()),
-      ]);
+      expect(readLaunchLog(fakeEditor.logPath)).toEqual({
+        cwd: memberA,
+        args: [...args, getWorksetCodeWorkspacePath('platform', pathOptions())],
+      });
     });
 
     it('renaming an attach flag is a one-line local fix', async () => {

test/core/openers.test.ts

@@ -71,6 +71,17 @@ describe('openers core', () => {
       expect(claude?.style).toBe('attach-dirs');
     });
 
+    it.each([{ args: [] }, { args: ['--model', 'custom model'] }])(
+      'replaces built-in args with $args without changing omitted fields',
+      ({ args }) => {
+        const builtin = findOpener([...BUILTIN_OPENERS], 'codex')!;
+        const table = mergeOpenerTable({ codex: { args } }, CONFIG_PATH);
+
+        expect(findOpener(table, 'codex')).toEqual({ ...builtin, args });
+        expect(builtin.args).toEqual(['--sandbox', 'workspace-write']);
+      }
+    );
+
     it('rejects an unknown style naming the two valid styles', () => {
       try {
         mergeOpenerTable({ vim: { style: 'tabs' } }, CONFIG_PATH);