diff --git a/.changeset/steady-jays-click.md b/.changeset/steady-jays-click.md
new file mode 100644
index 000000000..b22edb239
--- /dev/null
+++ b/.changeset/steady-jays-click.md
@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 3293
+---
+**`gsd-tools.cjs` and CJS fallback bridge work again post-install** — the install manifest now copies `sdk/shared/model-catalog.json` into the get-shit-done payload at `get-shit-done/bin/shared/model-catalog.json`, and `model-catalog.cjs` uses a resolve chain (co-located install path → source-repo dev path → `GSD_MODEL_CATALOG` env override). Regression introduced by #3230.
diff --git a/bin/install.js b/bin/install.js
index 30d000fc6..5830c4333 100755
--- a/bin/install.js
+++ b/bin/install.js
@@ -7951,6 +7951,28 @@ function install(isGlobal, runtime = 'claude') {
     failures.push('get-shit-done');
   }
 
+  // #3288 — Copy sdk/shared/model-catalog.json into the get-shit-done payload
+  // at the co-located path that model-catalog.cjs resolves first:
+  //   get-shit-done/bin/shared/model-catalog.json
+  //
+  // The install copies get-shit-done/ but NOT sdk/ — the CJS module's legacy
+  // path (3 levels up → sdk/shared/) therefore resolves to a non-existent
+  // location in every post-install layout.  Copying the catalog alongside the
+  // CJS files ensures require() succeeds without needing sdk/ to exist.
+  const modelCatalogSrc = path.join(src, 'sdk', 'shared', 'model-catalog.json');
+  const modelCatalogDest = path.join(skillDest, 'bin', 'shared', 'model-catalog.json');
+  if (fs.existsSync(modelCatalogSrc)) {
+    fs.mkdirSync(path.dirname(modelCatalogDest), { recursive: true });
+    fs.copyFileSync(modelCatalogSrc, modelCatalogDest);
+    if (verifyFileInstalled(modelCatalogDest, 'get-shit-done/bin/shared/model-catalog.json')) {
+      console.log(`  ${green}✓${reset} Installed get-shit-done/bin/shared/model-catalog.json`);
+    } else {
+      failures.push('get-shit-done/bin/shared/model-catalog.json');
+    }
+  } else {
+    failures.push('sdk/shared/model-catalog.json (source missing)');
+  }
+
   // Copy agents to agents directory.
   // Skipped under --minimal: gsd-* subagent descriptions are eagerly loaded
   // into the runtime's Agent tool schema, costing ~6k tokens per turn even
diff --git a/get-shit-done/bin/lib/model-catalog.cjs b/get-shit-done/bin/lib/model-catalog.cjs
index ed5e7c3f6..65a35d35f 100644
--- a/get-shit-done/bin/lib/model-catalog.cjs
+++ b/get-shit-done/bin/lib/model-catalog.cjs
@@ -1,7 +1,51 @@
 'use strict';
 
 const path = require('node:path');
-const catalog = require(path.join(__dirname, '..', '..', '..', 'sdk', 'shared', 'model-catalog.json'));
+
+// Resolve model-catalog.json via a prioritised candidate list so the module
+// works in every layout:
+//
+//   1. Co-located install path — get-shit-done/bin/shared/model-catalog.json
+//      Written by bin/install.js (#3288 fix). This is the canonical post-install
+//      location across all runtimes (Claude Code, Codex, OpenCode, etc.).
+//
+//   2. Source-repo dev path — sdk/shared/model-catalog.json
+//      Three levels up from bin/lib/: works when running directly from the
+//      gsd-build/get-shit-done clone (the original path introduced by #3230).
+//
+//   3. GSD_MODEL_CATALOG env override — allows test harnesses and custom
+//      deployments to point at an arbitrary catalog file.
+//
+// Throws with a diagnostic message that lists all candidates when none resolve,
+// so MODULE_NOT_FOUND surfaces as a clear actionable error (PRED.k301).
+const _catalogCandidates = [
+  path.resolve(__dirname, '..', 'shared', 'model-catalog.json'),
+  path.resolve(__dirname, '..', '..', '..', 'sdk', 'shared', 'model-catalog.json'),
+  process.env.GSD_MODEL_CATALOG ? path.resolve(process.env.GSD_MODEL_CATALOG) : null,
+].filter(Boolean);
+
+let catalog = null;
+let _catalogLastErr = null;
+for (const _p of _catalogCandidates) {
+  try {
+    catalog = require(_p);
+    break;
+  } catch (e) {
+    // Only treat missing-file errors as recoverable — rethrow parse errors,
+    // permission errors, and any other real failures so they surface clearly
+    // instead of being silently swallowed (CR finding, PR #3293).
+    const isMissingCandidate =
+      (e && e.code === 'MODULE_NOT_FOUND' && String(e.message || '').includes(_p)) ||
+      (e && e.code === 'ENOENT');
+    if (!isMissingCandidate) throw e;
+    _catalogLastErr = e;
+  }
+}
+if (!catalog) {
+  throw new Error(
+    `model-catalog.json not found. Tried:\n${_catalogCandidates.map((p) => `  ${p}`).join('\n')}\nLast error: ${_catalogLastErr?.message}`
+  );
+}
 
 const VALID_PROFILES = [...catalog.profiles];
 const VALID_PHASE_TYPES = new Set(catalog.phaseTypes);
diff --git a/tests/bug-3288-model-catalog-install-path.test.cjs b/tests/bug-3288-model-catalog-install-path.test.cjs
new file mode 100644
index 000000000..b2077d203
--- /dev/null
+++ b/tests/bug-3288-model-catalog-install-path.test.cjs
@@ -0,0 +1,245 @@
+/**
+ * Regression test for #3288: model-catalog.cjs uses brittle relative path
+ * that breaks after install.
+ *
+ * Repro:
+ *   After `node bin/install.js --global --claude`, the installed
+ *   `~/.claude/get-shit-done/bin/lib/model-catalog.cjs` tries:
+ *     require(path.join(__dirname, '..', '..', '..', 'sdk', 'shared', 'model-catalog.json'))
+ *   which resolves to `~/.claude/sdk/shared/model-catalog.json`.
+ *   The installer copies `get-shit-done/` but never copies `sdk/shared/`,
+ *   so the require throws MODULE_NOT_FOUND.
+ *
+ * Fix contract:
+ *   1. model-catalog.cjs must use a resolve-chain that checks a co-located
+ *      path first (bin/shared/model-catalog.json) before the legacy
+ *      source-repo path.
+ *   2. bin/install.js must copy sdk/shared/model-catalog.json into
+ *      get-shit-done/bin/shared/model-catalog.json (co-located inside the
+ *      get-shit-done/ payload).
+ *
+ * Both halves must be true for the install layout to work.
+ */
+
+'use strict';
+
+process.env.GSD_TEST_MODE = '1';
+
+const { describe, test, beforeEach, afterEach } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const path = require('node:path');
+const os = require('node:os');
+
+const REPO_ROOT = path.join(__dirname, '..');
+const MODEL_CATALOG_CJS = path.join(REPO_ROOT, 'get-shit-done', 'bin', 'lib', 'model-catalog.cjs');
+const MODEL_CATALOG_JSON = path.join(REPO_ROOT, 'sdk', 'shared', 'model-catalog.json');
+
+const { install } = require('../bin/install.js');
+
+// ─── helpers ─────────────────────────────────────────────────────────────────
+
+function makeTmpDir(prefix) {
+  return fs.mkdtempSync(path.join(os.tmpdir(), prefix));
+}
+
+function rmTmpDir(dir) {
+  fs.rmSync(dir, { recursive: true, force: true });
+}
+
+/**
+ * Silence console output during install to avoid noise in test output.
+ */
+function silenceConsole(fn) {
+  const orig = {
+    log: console.log,
+    warn: console.warn,
+    error: console.error,
+  };
+  console.log = () => {};
+  console.warn = () => {};
+  console.error = () => {};
+  try {
+    return fn();
+  } finally {
+    console.log = orig.log;
+    console.warn = orig.warn;
+    console.error = orig.error;
+  }
+}
+
+// ─── test 1: fake-install layout reproduces MODULE_NOT_FOUND ────────────────
+//
+// Build a fake post-install layout that mirrors what the OLD install did:
+//   <tmp>/.claude/get-shit-done/bin/lib/model-catalog.cjs  (copy of real file)
+//   <tmp>/.claude/sdk/shared/model-catalog.json            ABSENT
+//
+// Then attempt to require model-catalog.cjs from that layout.
+// Under the old path scheme (3 levels up → sdk/shared/) this should throw.
+// After the fix, if we DON'T also copy the json, it should still throw — this
+// confirms the co-located path IS required.
+
+describe('bug #3288: model-catalog.cjs install-layout resolution', () => {
+  let tmpRoot;
+  let savedHome;
+  let savedExplicitConfigDir;
+
+  beforeEach(() => {
+    tmpRoot = makeTmpDir('gsd-3288-');
+    savedHome = process.env.HOME;
+    // Stash and clear explicitConfigDir via env so install() picks up our tmp dir.
+    // Must delete (not just save) so any CI-set value doesn't leak into install()
+    // and target a different directory than tmpRoot (CR finding, PR #3293).
+    savedExplicitConfigDir = process.env.GSD_EXPLICIT_CONFIG_DIR;
+    delete process.env.GSD_EXPLICIT_CONFIG_DIR;
+  });
+
+  afterEach(() => {
+    process.env.HOME = savedHome;
+    if (savedExplicitConfigDir === undefined) {
+      delete process.env.GSD_EXPLICIT_CONFIG_DIR;
+    } else {
+      process.env.GSD_EXPLICIT_CONFIG_DIR = savedExplicitConfigDir;
+    }
+    rmTmpDir(tmpRoot);
+  });
+
+  // ── test A ──────────────────────────────────────────────────────────────────
+  test('OLD layout (3-level __dirname, no co-located json) fails to require', () => {
+    // Build the old install layout manually:
+    //   <tmpRoot>/.claude/get-shit-done/bin/lib/model-catalog.cjs  (copy of the real CJS)
+    //   sdk/shared/model-catalog.json                              ABSENT
+    const gsdLibDir = path.join(tmpRoot, '.claude', 'get-shit-done', 'bin', 'lib');
+    fs.mkdirSync(gsdLibDir, { recursive: true });
+
+    // Write a minimal model-catalog.cjs that uses ONLY the 3-level path (the old/broken path).
+    const oldCjsContent = `'use strict';
+const path = require('node:path');
+// This is the BRITTLE path: 3 levels up from bin/lib → sdk/shared/
+const catalog = require(path.join(__dirname, '..', '..', '..', 'sdk', 'shared', 'model-catalog.json'));
+module.exports = { catalog };
+`;
+    const catalogCjsPath = path.join(gsdLibDir, 'model-catalog.cjs');
+    fs.writeFileSync(catalogCjsPath, oldCjsContent);
+
+    // Deliberately do NOT create sdk/shared/model-catalog.json (simulates missing file post-install).
+
+    // Require must fail with MODULE_NOT_FOUND.
+    assert.throws(
+      () => {
+        // Delete from require cache to force a fresh load.
+        delete require.cache[catalogCjsPath];
+        require(catalogCjsPath);
+      },
+      (err) => {
+        assert.ok(
+          err.code === 'MODULE_NOT_FOUND' || err.message.includes('model-catalog.json'),
+          `Expected MODULE_NOT_FOUND or model-catalog.json error, got: ${err.message}`,
+        );
+        return true;
+      },
+      'OLD 3-level path must fail when sdk/shared/model-catalog.json is not present (install layout)',
+    );
+  });
+
+  // ── test B ──────────────────────────────────────────────────────────────────
+  test('NEW layout (co-located bin/shared/model-catalog.json) resolves correctly', () => {
+    // Build the new install layout:
+    //   <tmpRoot>/.claude/get-shit-done/bin/lib/model-catalog.cjs (copy of real CJS)
+    //   <tmpRoot>/.claude/get-shit-done/bin/shared/model-catalog.json (co-located copy)
+    const gsdBinDir = path.join(tmpRoot, '.claude', 'get-shit-done', 'bin');
+    const gsdLibDir = path.join(gsdBinDir, 'lib');
+    const gsdSharedDir = path.join(gsdBinDir, 'shared');
+    fs.mkdirSync(gsdLibDir, { recursive: true });
+    fs.mkdirSync(gsdSharedDir, { recursive: true });
+
+    // Copy the real model-catalog.cjs into the fake install.
+    const catalogCjsPath = path.join(gsdLibDir, 'model-catalog.cjs');
+    fs.copyFileSync(MODEL_CATALOG_CJS, catalogCjsPath);
+
+    // Copy the real model-catalog.json to the co-located path.
+    fs.copyFileSync(MODEL_CATALOG_JSON, path.join(gsdSharedDir, 'model-catalog.json'));
+
+    // Require must succeed and expose catalog with expected shape.
+    delete require.cache[catalogCjsPath];
+    let mod;
+    assert.doesNotThrow(() => {
+      mod = require(catalogCjsPath);
+    }, 'NEW co-located layout must not throw MODULE_NOT_FOUND');
+
+    assert.ok(mod.catalog, 'module must export catalog');
+    assert.ok(Array.isArray(mod.VALID_PROFILES), 'module must export VALID_PROFILES');
+    assert.ok(mod.VALID_PROFILES.length > 0, 'VALID_PROFILES must not be empty');
+  });
+
+  // ── test C ──────────────────────────────────────────────────────────────────
+  test('post-install: install() copies model-catalog.json to co-located path', () => {
+    // Run the real installer against a tmp target dir, then assert the co-located
+    // json is present and parseable.
+    const claudeDir = path.join(tmpRoot, '.claude');
+    fs.mkdirSync(claudeDir, { recursive: true });
+    process.env.HOME = tmpRoot;
+
+    // Capture process.exit to prevent the test from being killed.
+    const origExit = process.exit;
+    let exitCalled = false;
+    process.exit = (code) => {
+      exitCalled = true;
+      throw new Error(`process.exit(${code}) during install — should not happen`);
+    };
+
+    try {
+      silenceConsole(() => {
+        install(true /* isGlobal */, 'claude');
+      });
+    } catch (e) {
+      if (exitCalled) {
+        assert.fail(`install() called process.exit — unexpected: ${e.message}`);
+      }
+      throw e;
+    } finally {
+      process.exit = origExit;
+    }
+
+    // The co-located json must be present after install.
+    const colocatedJson = path.join(
+      claudeDir,
+      'get-shit-done',
+      'bin',
+      'shared',
+      'model-catalog.json',
+    );
+    assert.ok(
+      fs.existsSync(colocatedJson),
+      `model-catalog.json must be present at co-located path post-install: ${colocatedJson}`,
+    );
+
+    // The json must be valid and have expected shape.
+    let parsed;
+    assert.doesNotThrow(() => {
+      parsed = JSON.parse(fs.readFileSync(colocatedJson, 'utf8'));
+    }, 'co-located model-catalog.json must be valid JSON');
+
+    assert.ok(Array.isArray(parsed.profiles), 'catalog.profiles must be an array');
+    assert.ok(parsed.profiles.length > 0, 'catalog.profiles must not be empty');
+
+    // And the installed model-catalog.cjs must be requireable from its install location.
+    const installedCjs = path.join(
+      claudeDir,
+      'get-shit-done',
+      'bin',
+      'lib',
+      'model-catalog.cjs',
+    );
+    assert.ok(fs.existsSync(installedCjs), `model-catalog.cjs must be installed at: ${installedCjs}`);
+
+    delete require.cache[installedCjs];
+    let installedMod;
+    assert.doesNotThrow(() => {
+      installedMod = require(installedCjs);
+    }, 'installed model-catalog.cjs must not throw MODULE_NOT_FOUND after install');
+
+    assert.ok(installedMod.catalog, 'installed module must export catalog');
+    assert.ok(installedMod.VALID_PROFILES.length > 0, 'installed module must have valid profiles');
+  });
+});