diff --git a/bin/gstack-platform-detect b/bin/gstack-platform-detect
index 4fef7331..766a585b 100755
--- a/bin/gstack-platform-detect
+++ b/bin/gstack-platform-detect
@@ -2,19 +2,26 @@
 set -euo pipefail
 
 # gstack-platform-detect: show which AI coding agents are installed and gstack status
+# Config-driven: reads host definitions from hosts/*.ts via host-config-export.ts
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+GSTACK_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"
+
 printf "%-16s %-10s %-40s %s\n" "Agent" "Version" "Skill Path" "gstack"
 printf "%-16s %-10s %-40s %s\n" "-----" "-------" "----------" "------"
-for entry in "claude:claude" "codex:codex" "droid:factory" "kiro-cli:kiro"; do
-  bin="${entry%%:*}"; label="${entry##*:}"
-  if command -v "$bin" >/dev/null 2>&1; then
-    ver=$("$bin" --version 2>/dev/null | head -1 || echo "unknown")
-    case "$label" in
-      claude)  spath="$HOME/.claude/skills/gstack" ;;
-      codex)   spath="$HOME/.codex/skills/gstack" ;;
-      factory) spath="$HOME/.factory/skills/gstack" ;;
-      kiro)    spath="$HOME/.kiro/skills/gstack" ;;
-    esac
-    status=$([ -d "$spath" ] && echo "INSTALLED" || echo "NOT INSTALLED")
-    printf "%-16s %-10s %-40s %s\n" "$label" "$ver" "$spath" "$status"
+
+for host in $(bun run "$GSTACK_DIR/scripts/host-config-export.ts" list 2>/dev/null); do
+  cmd=$(bun run "$GSTACK_DIR/scripts/host-config-export.ts" get "$host" cliCommand 2>/dev/null)
+  root=$(bun run "$GSTACK_DIR/scripts/host-config-export.ts" get "$host" globalRoot 2>/dev/null)
+  spath="$HOME/$root"
+
+  if command -v "$cmd" >/dev/null 2>&1; then
+    ver=$("$cmd" --version 2>/dev/null | head -1 || echo "unknown")
+    if [ -d "$spath" ] || [ -L "$spath" ]; then
+      status="INSTALLED"
+    else
+      status="NOT INSTALLED"
+    fi
+    printf "%-16s %-10s %-40s %s\n" "$host" "$ver" "$spath" "$status"
   fi
 done
diff --git a/lib/worktree.ts b/lib/worktree.ts
index 2337399f..1e68884b 100644
--- a/lib/worktree.ts
+++ b/lib/worktree.ts
@@ -123,10 +123,13 @@ export class WorktreeManager {
     // Create detached worktree at current HEAD
     git(['worktree', 'add', '--detach', worktreePath, 'HEAD'], this.repoRoot);
 
-    // Copy gitignored build artifacts that tests need
-    const agentsSrc = path.join(this.repoRoot, '.agents');
-    if (fs.existsSync(agentsSrc)) {
-      copyDirSync(agentsSrc, path.join(worktreePath, '.agents'));
+    // Copy gitignored build artifacts that tests need (config-driven)
+    const { getExternalHosts } = require('../hosts/index');
+    for (const hostConfig of getExternalHosts()) {
+      const hostSrc = path.join(this.repoRoot, hostConfig.hostSubdir);
+      if (fs.existsSync(hostSrc)) {
+        copyDirSync(hostSrc, path.join(worktreePath, hostConfig.hostSubdir));
+      }
     }
 
     const browseDist = path.join(this.repoRoot, 'browse', 'dist');
diff --git a/scripts/host-config-export.ts b/scripts/host-config-export.ts
new file mode 100644
index 00000000..bca436f2
--- /dev/null
+++ b/scripts/host-config-export.ts
@@ -0,0 +1,119 @@
+#!/usr/bin/env bun
+/**
+ * Export host configs as shell-safe values for consumption by the bash setup script.
+ *
+ * Usage: bun run scripts/host-config-export.ts <command> [args]
+ *
+ * Commands:
+ *   list                    Print all host names, one per line
+ *   get <host> <field>      Print a single config field value
+ *   detect                  Print names of hosts whose CLI binary is on PATH
+ *   validate                Validate all configs, exit 1 on error
+ *
+ * All output is shell-safe (single-quoted values, no eval needed).
+ */
+
+import { ALL_HOST_CONFIGS, getHostConfig, ALL_HOST_NAMES } from '../hosts/index';
+import { validateAllConfigs } from './host-config';
+import { execSync } from 'child_process';
+
+const CLI_REGEX = /^[a-z][a-z0-9_-]*$/;
+const PATH_REGEX = /^[a-zA-Z0-9_.\/${}~-]+$/;
+
+function shellEscape(s: string): string {
+  return "'" + s.replace(/'/g, "'\\''") + "'";
+}
+
+function validateValue(val: string, context: string): void {
+  if (!PATH_REGEX.test(val) && !CLI_REGEX.test(val)) {
+    throw new Error(`Unsafe value for ${context}: ${val}`);
+  }
+}
+
+const [command, ...args] = process.argv.slice(2);
+
+switch (command) {
+  case 'list':
+    for (const name of ALL_HOST_NAMES) {
+      console.log(name);
+    }
+    break;
+
+  case 'get': {
+    const [hostName, field] = args;
+    if (!hostName || !field) {
+      console.error('Usage: host-config-export.ts get <host> <field>');
+      process.exit(1);
+    }
+    const config = getHostConfig(hostName);
+    const value = (config as any)[field];
+    if (value === undefined) {
+      console.error(`Unknown field: ${field}`);
+      process.exit(1);
+    }
+    if (typeof value === 'string') {
+      console.log(value);
+    } else if (typeof value === 'boolean') {
+      console.log(value ? '1' : '0');
+    } else if (Array.isArray(value)) {
+      for (const item of value) {
+        console.log(typeof item === 'string' ? item : JSON.stringify(item));
+      }
+    } else {
+      console.log(JSON.stringify(value));
+    }
+    break;
+  }
+
+  case 'detect': {
+    for (const config of ALL_HOST_CONFIGS) {
+      const commands = [config.cliCommand, ...(config.cliAliases || [])];
+      for (const cmd of commands) {
+        try {
+          execSync(`command -v ${shellEscape(cmd)}`, { stdio: 'pipe' });
+          console.log(config.name);
+          break;  // Found this host, move to next
+        } catch {
+          // Binary not found, try next alias
+        }
+      }
+    }
+    break;
+  }
+
+  case 'validate': {
+    const errors = validateAllConfigs(ALL_HOST_CONFIGS);
+    if (errors.length > 0) {
+      for (const error of errors) {
+        console.error(`ERROR: ${error}`);
+      }
+      process.exit(1);
+    }
+    console.log(`All ${ALL_HOST_CONFIGS.length} configs valid`);
+    break;
+  }
+
+  case 'symlinks': {
+    const [hostName] = args;
+    if (!hostName) {
+      console.error('Usage: host-config-export.ts symlinks <host>');
+      process.exit(1);
+    }
+    const config = getHostConfig(hostName);
+    for (const link of config.runtimeRoot.globalSymlinks) {
+      console.log(link);
+    }
+    if (config.runtimeRoot.globalFiles) {
+      for (const [dir, files] of Object.entries(config.runtimeRoot.globalFiles)) {
+        for (const file of files) {
+          console.log(`${dir}/${file}`);
+        }
+      }
+    }
+    break;
+  }
+
+  default:
+    console.error('Usage: host-config-export.ts <list|get|detect|validate|symlinks> [args]');
+    process.exit(1);
+}
diff --git a/scripts/skill-check.ts b/scripts/skill-check.ts
index e859d9b5..ebcced40 100644
--- a/scripts/skill-check.ts
+++ b/scripts/skill-check.ts
@@ -79,111 +79,60 @@ for (const file of SKILL_FILES) {
   }
 }
 
-// ─── Codex Skills ───────────────────────────────────────────
+// ─── External Host Skills (config-driven) ───────────────────
 
-const AGENTS_DIR = path.join(ROOT, '.agents', 'skills');
-if (fs.existsSync(AGENTS_DIR)) {
-  console.log('\n  Codex Skills (.agents/skills/):');
-  const codexDirs = fs.readdirSync(AGENTS_DIR).sort();
-  let codexCount = 0;
-  let codexMissing = 0;
-  for (const dir of codexDirs) {
-    const skillMd = path.join(AGENTS_DIR, dir, 'SKILL.md');
-    if (fs.existsSync(skillMd)) {
-      codexCount++;
-      const content = fs.readFileSync(skillMd, 'utf-8');
-      // Quick validation: must have frontmatter with name + description only
-      const hasClaude = content.includes('.claude/skills');
-      if (hasClaude) {
-        hasErrors = true;
-        console.log(`  \u274c ${dir.padEnd(30)} — contains .claude/skills reference`);
+import { getExternalHosts } from '../hosts/index';
+
+for (const hostConfig of getExternalHosts()) {
+  const hostDir = path.join(ROOT, hostConfig.hostSubdir, 'skills');
+  if (fs.existsSync(hostDir)) {
+    console.log(`\n  ${hostConfig.displayName} Skills (${hostConfig.hostSubdir}/skills/):`);
+    const dirs = fs.readdirSync(hostDir).sort();
+    let count = 0;
+    let missing = 0;
+    for (const dir of dirs) {
+      const skillMd = path.join(hostDir, dir, 'SKILL.md');
+      if (fs.existsSync(skillMd)) {
+        count++;
+        const content = fs.readFileSync(skillMd, 'utf-8');
+        const hasClaude = content.includes('.claude/skills');
+        if (hasClaude) {
+          hasErrors = true;
+          console.log(`  \u274c ${dir.padEnd(30)} — contains .claude/skills reference`);
+        } else {
+          console.log(`  \u2705 ${dir.padEnd(30)} — OK`);
+        }
       } else {
-        console.log(`  \u2705 ${dir.padEnd(30)} — OK`);
-      }
-    } else {
-      codexMissing++;
-      hasErrors = true;
-      console.log(`  \u274c ${dir.padEnd(30)} — SKILL.md missing`);
-    }
-  }
-  console.log(`  Total: ${codexCount} skills, ${codexMissing} missing`);
-} else {
-  console.log('\n  Codex Skills: .agents/skills/ not found (run: bun run gen:skill-docs --host codex)');
-}
-
-// ─── Factory Skills ─────────────────────────────────────────
-
-const FACTORY_DIR = path.join(ROOT, '.factory', 'skills');
-if (fs.existsSync(FACTORY_DIR)) {
-  console.log('\n  Factory Skills (.factory/skills/):');
-  const factoryDirs = fs.readdirSync(FACTORY_DIR).sort();
-  let factoryCount = 0;
-  let factoryMissing = 0;
-  for (const dir of factoryDirs) {
-    const skillMd = path.join(FACTORY_DIR, dir, 'SKILL.md');
-    if (fs.existsSync(skillMd)) {
-      factoryCount++;
-      const content = fs.readFileSync(skillMd, 'utf-8');
-      const hasClaude = content.includes('.claude/skills');
-      if (hasClaude) {
+        missing++;
         hasErrors = true;
-        console.log(`  \u274c ${dir.padEnd(30)} — contains .claude/skills reference`);
-      } else {
-        console.log(`  \u2705 ${dir.padEnd(30)} — OK`);
+        console.log(`  \u274c ${dir.padEnd(30)} — SKILL.md missing`);
       }
-    } else {
-      factoryMissing++;
-      hasErrors = true;
-      console.log(`  \u274c ${dir.padEnd(30)} — SKILL.md missing`);
     }
+    console.log(`  Total: ${count} skills, ${missing} missing`);
+  } else {
+    console.log(`\n  ${hostConfig.displayName} Skills: ${hostConfig.hostSubdir}/skills/ not found (run: bun run gen:skill-docs --host ${hostConfig.name})`);
   }
-  console.log(`  Total: ${factoryCount} skills, ${factoryMissing} missing`);
-} else {
-  console.log('\n  Factory Skills: .factory/skills/ not found (run: bun run gen:skill-docs --host factory)');
 }
 
-// ─── Freshness ──────────────────────────────────────────────
+// ─── Freshness (config-driven) ──────────────────────────────
 
-console.log('\n  Freshness (Claude):');
-try {
-  execSync('bun run scripts/gen-skill-docs.ts --dry-run', { cwd: ROOT, stdio: 'pipe' });
-  console.log('  \u2705 All Claude generated files are fresh');
-} catch (err: any) {
-  hasErrors = true;
-  const output = err.stdout?.toString() || '';
-  console.log('  \u274c Claude generated files are stale:');
-  for (const line of output.split('\n').filter((l: string) => l.startsWith('STALE'))) {
-    console.log(`      ${line}`);
-  }
-  console.log('      Run: bun run gen:skill-docs');
-}
+import { ALL_HOST_CONFIGS } from '../hosts/index';
 
-console.log('\n  Freshness (Codex):');
-try {
-  execSync('bun run scripts/gen-skill-docs.ts --host codex --dry-run', { cwd: ROOT, stdio: 'pipe' });
-  console.log('  \u2705 All Codex generated files are fresh');
-} catch (err: any) {
-  hasErrors = true;
-  const output = err.stdout?.toString() || '';
-  console.log('  \u274c Codex generated files are stale:');
-  for (const line of output.split('\n').filter((l: string) => l.startsWith('STALE'))) {
-    console.log(`      ${line}`);
+for (const hostConfig of ALL_HOST_CONFIGS) {
+  const hostFlag = hostConfig.name === 'claude' ? '' : ` --host ${hostConfig.name}`;
+  console.log(`\n  Freshness (${hostConfig.displayName}):`);
+  try {
+    execSync(`bun run scripts/gen-skill-docs.ts${hostFlag} --dry-run`, { cwd: ROOT, stdio: 'pipe' });
+    console.log(`  \u2705 All ${hostConfig.displayName} generated files are fresh`);
+  } catch (err: any) {
+    hasErrors = true;
+    const output = err.stdout?.toString() || '';
+    console.log(`  \u274c ${hostConfig.displayName} generated files are stale:`);
+    for (const line of output.split('\n').filter((l: string) => l.startsWith('STALE'))) {
+      console.log(`      ${line}`);
+    }
+    console.log(`      Run: bun run gen:skill-docs${hostFlag}`);
   }
-  console.log('      Run: bun run gen:skill-docs --host codex');
-}
-
-console.log('\n  Freshness (Factory):');
-try {
-  execSync('bun run scripts/gen-skill-docs.ts --host factory --dry-run', { cwd: ROOT, stdio: 'pipe' });
-  console.log('  \u2705 All Factory generated files are fresh');
-} catch (err: any) {
-  hasErrors = true;
-  const output = err.stdout?.toString() || '';
-  console.log('  \u274c Factory generated files are stale:');
-  for (const line of output.split('\n').filter((l: string) => l.startsWith('STALE'))) {
-    console.log(`      ${line}`);
-  }
-  console.log('      Run: bun run gen:skill-docs --host factory');
 }
 
 console.log('');