diff --git a/cli/bin/commands/skills.mjs b/cli/bin/commands/skills.mjs
index 07fd91e44..952a0a560 100644
--- a/cli/bin/commands/skills.mjs
+++ b/cli/bin/commands/skills.mjs
@@ -9,7 +9,7 @@
  */
 
 import { execSync } from 'node:child_process';
-import { existsSync, readFileSync, readdirSync, statSync, lstatSync, unlinkSync, mkdirSync, writeFileSync, rmSync, renameSync, createWriteStream, realpathSync, symlinkSync, readlinkSync, cpSync } from 'node:fs';
+import { existsSync, readFileSync, readdirSync, statSync, lstatSync, unlinkSync, mkdirSync, writeFileSync, rmSync, rmdirSync, renameSync, createWriteStream, realpathSync, symlinkSync, readlinkSync, cpSync } from 'node:fs';
 import { join, resolve, dirname, relative, isAbsolute, sep } from 'node:path';
 import { createInterface, emitKeypressEvents } from 'node:readline';
 import { fileURLToPath } from 'node:url';
@@ -65,11 +65,23 @@ const PROVIDER_DISPLAY = {
 };
 const PROVIDER_INPUT_ORDER = ['claude', 'codex', 'cursor', 'gemini', 'github', 'grok', 'kiro', 'opencode', 'pi', 'qoder', 'trae', 'trae-cn', 'rovo-dev', 'vibe'];
 
-// Providers whose GLOBAL (home) skills dir is not `<provider>/skills`.
-// Pi discovers global skills from ~/.pi/agent/skills/; project scope
-// stays .pi/skills/. See issue #327.
+// OpenCode reads global skills from its config directory, not ~/.opencode:
+// $OPENCODE_CONFIG_DIR, else $XDG_CONFIG_HOME/opencode, else
+// ~/.config/opencode. Writing to ~/.opencode/skills produced an install
+// `opencode debug skill` never listed. See issue #406.
+function opencodeGlobalConfigDir(home) {
+  if (process.env.OPENCODE_CONFIG_DIR) return process.env.OPENCODE_CONFIG_DIR;
+  if (process.env.XDG_CONFIG_HOME) return join(process.env.XDG_CONFIG_HOME, 'opencode');
+  return join(home, '.config', 'opencode');
+}
+
+// Providers whose GLOBAL (home) skills dir is not `<provider>/skills`,
+// as a function of the home dir. Pi discovers global skills from
+// ~/.pi/agent/skills/ (issue #327); OpenCode from its config dir (issue
+// #406). Project scope stays `<provider>/skills` for both.
 const HOME_SKILLS_DIR_OVERRIDES = {
-  '.pi': join('.pi', 'agent', 'skills'),
+  '.pi': (home) => join(home, '.pi', 'agent', 'skills'),
+  '.opencode': (home) => join(opencodeGlobalConfigDir(home), 'skills'),
 };
 
 // When a project has no harness folder yet, infer the target from globally
@@ -83,6 +95,9 @@ const GLOBAL_HARNESS_HINTS = [
   { home: '.grok', provider: '.grok' },
   { home: '.kiro', provider: '.kiro' },
   { home: '.opencode', provider: '.opencode' },
+  // OpenCode's real global config dir (issue #406); the ~/.opencode entry
+  // above keeps recognizing machines that only have the legacy dir.
+  { resolve: opencodeGlobalConfigDir, provider: '.opencode' },
   { home: '.pi', provider: '.pi' },
   { home: '.qoder', provider: '.qoder' },
   { home: '.rovodev', provider: '.rovodev' },
@@ -134,7 +149,8 @@ const PROVIDER_HOOK_ARTIFACTS = {
 };
 
 function userProviderSkillsDir(home, provider) {
-  if (HOME_SKILLS_DIR_OVERRIDES[provider]) return join(home, HOME_SKILLS_DIR_OVERRIDES[provider]);
+  const override = HOME_SKILLS_DIR_OVERRIDES[provider];
+  if (override) return override(home);
   return join(home, provider, 'skills');
 }
 
@@ -861,10 +877,15 @@ function collectInstallDetections(root, home = homedir()) {
     });
   }
 
-  for (const { home: h, provider } of GLOBAL_HARNESS_HINTS) {
-    const foundPath = join(home, h);
+  for (const hint of GLOBAL_HARNESS_HINTS) {
+    const { provider } = hint;
+    // A hint is either a fixed dir under home or a resolver for harnesses
+    // whose location depends on the environment (OpenCode's config dir).
+    const foundPath = hint.resolve ? hint.resolve(home) : join(home, hint.home);
     if (!existsSync(foundPath)) continue;
-    const skillProbePaths = userSkillProbePaths(home, h, provider);
+    const skillProbePaths = hint.resolve
+      ? uniquePaths([userProviderSkillsDir(home, provider), join(foundPath, 'skills')])
+      : userSkillProbePaths(home, hint.home, provider);
     detections.push({
       provider,
       scope: 'user',
@@ -1137,6 +1158,20 @@ function copyProviderSkills(bundleDir, root, targets, { scope } = {}) {
         copyDirSync(src, dest);
         written++;
       }
+      // A pre-#406 global OpenCode install lived at ~/.opencode/skills, a
+      // location OpenCode never reads. Now that the real copy sits in the
+      // config dir, drop exactly the skills just written from the stranded
+      // location; sibling skills and everything else in ~/.opencode stay.
+      if (scope === 'user' && provider === '.opencode') {
+        const legacyDir = join(root, '.opencode', 'skills');
+        if (legacyDir !== localSkillsDir && existsSync(legacyDir)) {
+          for (const skill of readdirSync(srcDir, { withFileTypes: true })) {
+            if (!skill.isDirectory()) continue;
+            rmSync(join(legacyDir, skill.name), { recursive: true, force: true });
+          }
+          try { rmdirSync(legacyDir); } catch { /* not empty: siblings stay */ }
+        }
+      }
     }
   }
   return written;
diff --git a/tests/skills-cli.test.js b/tests/skills-cli.test.js
index 556afe8d5..8b8826cbc 100644
--- a/tests/skills-cli.test.js
+++ b/tests/skills-cli.test.js
@@ -884,6 +884,98 @@ describe('skills install/update: local universal bundle e2e', () => {
     rmSync(home, { recursive: true, force: true });
   }, 15000);
 
+  // OpenCode reads global skills from its config directory, not ~/.opencode:
+  // $OPENCODE_CONFIG_DIR/skills, else $XDG_CONFIG_HOME/opencode/skills, else
+  // ~/.config/opencode/skills. Writing to ~/.opencode/skills produced an
+  // install `opencode debug skill` never saw (#406).
+  test('global install writes OpenCode skills to ~/.config/opencode/skills (#406)', () => {
+    const tmp = mkdtempSync(join(tmpdir(), 'imp-test-scope-user-oc-'));
+    const home = mkdtempSync(join(tmpdir(), 'imp-home-scope-user-oc-'));
+    execSync('git init', { cwd: tmp });
+    mkdirSync(join(home, '.opencode'), { recursive: true });
+    const bundleRoot = createFakeUniversalBundle(tmp, ['.opencode']);
+    const env = { ...process.env, HOME: home, IMPECCABLE_BUNDLE_PATH: bundleRoot };
+    delete env.OPENCODE_CONFIG_DIR;
+    delete env.XDG_CONFIG_HOME;
+
+    const output = run('skills install -y --scope=global --no-hooks', { cwd: tmp, env });
+
+    expect(output).toContain('Installed impeccable into: .opencode (global)');
+    expect(existsSync(join(home, '.config', 'opencode', 'skills', 'impeccable', 'SKILL.md'))).toBe(true);
+    expect(existsSync(join(home, '.opencode', 'skills', 'impeccable'))).toBe(false);
+
+    rmSync(tmp, { recursive: true, force: true });
+    rmSync(home, { recursive: true, force: true });
+  }, 15000);
+
+  test('OpenCode global dir honors OPENCODE_CONFIG_DIR and XDG_CONFIG_HOME (#406)', () => {
+    const tmp = mkdtempSync(join(tmpdir(), 'imp-test-oc-env-'));
+    const home = mkdtempSync(join(tmpdir(), 'imp-home-oc-env-'));
+    execSync('git init', { cwd: tmp });
+    const bundleRoot = createFakeUniversalBundle(tmp, ['.opencode']);
+    const baseEnv = { ...process.env, HOME: home, IMPECCABLE_BUNDLE_PATH: bundleRoot };
+    delete baseEnv.OPENCODE_CONFIG_DIR;
+    delete baseEnv.XDG_CONFIG_HOME;
+
+    run('skills install -y --providers=opencode --scope=global --no-hooks', {
+      cwd: tmp,
+      env: { ...baseEnv, OPENCODE_CONFIG_DIR: join(home, 'occfg') },
+    });
+    expect(existsSync(join(home, 'occfg', 'skills', 'impeccable', 'SKILL.md'))).toBe(true);
+
+    run('skills install -y --providers=opencode --scope=global --no-hooks', {
+      cwd: tmp,
+      env: { ...baseEnv, XDG_CONFIG_HOME: join(home, 'xdg') },
+    });
+    expect(existsSync(join(home, 'xdg', 'opencode', 'skills', 'impeccable', 'SKILL.md'))).toBe(true);
+    expect(existsSync(join(home, '.opencode', 'skills', 'impeccable'))).toBe(false);
+
+    rmSync(tmp, { recursive: true, force: true });
+    rmSync(home, { recursive: true, force: true });
+  }, 20000);
+
+  test('global OpenCode install migrates a legacy ~/.opencode/skills copy, sparing siblings (#406)', () => {
+    const tmp = mkdtempSync(join(tmpdir(), 'imp-test-oc-migrate-'));
+    const home = mkdtempSync(join(tmpdir(), 'imp-home-oc-migrate-'));
+    execSync('git init', { cwd: tmp });
+    writeSkill(home, '.opencode', 'impeccable');
+    writeSkill(home, '.opencode', 'unrelated-skill');
+    const bundleRoot = createFakeUniversalBundle(tmp, ['.opencode']);
+    const env = { ...process.env, HOME: home, IMPECCABLE_BUNDLE_PATH: bundleRoot };
+    delete env.OPENCODE_CONFIG_DIR;
+    delete env.XDG_CONFIG_HOME;
+
+    run('skills install -y --providers=opencode --scope=global --no-hooks', { cwd: tmp, env });
+
+    expect(existsSync(join(home, '.config', 'opencode', 'skills', 'impeccable', 'SKILL.md'))).toBe(true);
+    // The stranded legacy copy is gone; the sibling skill is untouched.
+    expect(existsSync(join(home, '.opencode', 'skills', 'impeccable'))).toBe(false);
+    expect(existsSync(join(home, '.opencode', 'skills', 'unrelated-skill', 'SKILL.md'))).toBe(true);
+
+    rmSync(tmp, { recursive: true, force: true });
+    rmSync(home, { recursive: true, force: true });
+  }, 15000);
+
+  test('global install detects OpenCode from ~/.config/opencode alone (#406)', () => {
+    const tmp = mkdtempSync(join(tmpdir(), 'imp-test-oc-detect-'));
+    const home = mkdtempSync(join(tmpdir(), 'imp-home-oc-detect-'));
+    execSync('git init', { cwd: tmp });
+    // No ~/.opencode at all; only the config dir marks OpenCode as present.
+    mkdirSync(join(home, '.config', 'opencode'), { recursive: true });
+    const bundleRoot = createFakeUniversalBundle(tmp, ['.opencode']);
+    const env = { ...process.env, HOME: home, IMPECCABLE_BUNDLE_PATH: bundleRoot };
+    delete env.OPENCODE_CONFIG_DIR;
+    delete env.XDG_CONFIG_HOME;
+
+    const output = run('skills install -y --scope=global --no-hooks', { cwd: tmp, env });
+
+    expect(output).toContain('Installed impeccable into: .opencode (global)');
+    expect(existsSync(join(home, '.config', 'opencode', 'skills', 'impeccable', 'SKILL.md'))).toBe(true);
+
+    rmSync(tmp, { recursive: true, force: true });
+    rmSync(home, { recursive: true, force: true });
+  }, 15000);
+
   // Project scope must stay at .pi/skills/ even when the git root IS the home
   // dir (dotfiles repos), where scope can't be inferred from the path alone.
   // An existing global install at ~/.pi/agent/skills must not swallow the