diff --git a/.changeset/subprocess-integration-tests.md b/.changeset/subprocess-integration-tests.md
new file mode 100644
index 000000000..9535f967c
--- /dev/null
+++ b/.changeset/subprocess-integration-tests.md
@@ -0,0 +1,8 @@
+---
+---
+
+test: add Copilot CLI subprocess integration tests for SQUAD_TEAM_ROOT
+
+8 tests covering SQUAD_TEAM_ROOT env-var resolution, fallback to cwd,
+and resolveSquad() integration. Guards against subprocess working directory
+bugs in Copilot CLI bang commands.
diff --git a/test/cli/team-root-resolution.test.ts b/test/cli/team-root-resolution.test.ts
new file mode 100644
index 000000000..b845d8558
--- /dev/null
+++ b/test/cli/team-root-resolution.test.ts
@@ -0,0 +1,205 @@
+/**
+ * SQUAD_TEAM_ROOT resolution tests (#836)
+ *
+ * Verifies that the SQUAD_TEAM_ROOT env var correctly controls squad
+ * directory resolution across all scenarios:
+ *   - env var set → uses that path
+ *   - env var unset → falls back to process.cwd()
+ *   - env var empty string → falls back to process.cwd()
+ *   - resolveSquad honours the resolved start directory
+ *   - invalid SQUAD_TEAM_ROOT produces a null result (no crash)
+ *
+ * These tests simulate the Copilot CLI bang-command scenario where
+ * the subprocess working directory differs from the interactive shell.
+ *
+ * @see packages/squad-cli/src/cli-entry.ts — getSquadStartDir()
+ * @see packages/squad-sdk/src/resolution.ts  — resolveSquad()
+ * @see https://github.com/bradygaster/squad/issues/836
+ */
+
+import { describe, it, expect, afterEach, beforeEach } from 'vitest';
+import {
+  mkdtempSync,
+  writeFileSync,
+  mkdirSync,
+  rmSync,
+} from 'node:fs';
+import { join } from 'node:path';
+import { tmpdir } from 'node:os';
+
+import { resolveSquad } from '../../packages/squad-sdk/src/resolution.js';
+
+// ============================================================================
+// Helpers
+// ============================================================================
+
+const tmpDirs: string[] = [];
+
+/**
+ * Reproduce the private getSquadStartDir() logic from cli-entry.ts so we
+ * can unit-test the env-var resolution without depending on the private fn.
+ *
+ * The real implementation is:
+ *   function getSquadStartDir(): string {
+ *     return process.env['SQUAD_TEAM_ROOT'] || process.cwd();
+ *   }
+ */
+function getSquadStartDir(): string {
+  return process.env['SQUAD_TEAM_ROOT'] || process.cwd();
+}
+
+/** Create a minimal valid .squad directory tree inside a temp folder. */
+function createSquadProject(): { root: string; squadDir: string } {
+  const root = mkdtempSync(join(tmpdir(), 'squad-team-root-'));
+  tmpDirs.push(root);
+
+  const squadDir = join(root, '.squad');
+  mkdirSync(join(squadDir, 'agents', 'edie'), { recursive: true });
+  mkdirSync(join(squadDir, 'decisions', 'inbox'), { recursive: true });
+  mkdirSync(join(squadDir, 'orchestration-log'), { recursive: true });
+  writeFileSync(join(squadDir, 'team.md'), '# Team\n');
+  writeFileSync(join(squadDir, 'routing.md'), '# Routing\n');
+  writeFileSync(join(squadDir, 'decisions.md'), '# Decisions\n');
+  writeFileSync(
+    join(squadDir, 'agents', 'edie', 'history.md'),
+    '## Core Context\n\nTest agent.\n',
+  );
+
+  // Add a .git directory so resolveSquad stops walking at this level
+  mkdirSync(join(root, '.git'), { recursive: true });
+
+  return { root, squadDir };
+}
+
+// ============================================================================
+// Tests — getSquadStartDir() resolution logic
+// ============================================================================
+
+describe('SQUAD_TEAM_ROOT resolution (#836)', () => {
+  const savedTeamRoot = process.env['SQUAD_TEAM_ROOT'];
+  const originalCwd = process.cwd();
+
+  beforeEach(() => {
+    delete process.env['SQUAD_TEAM_ROOT'];
+  });
+
+  afterEach(() => {
+    // Restore cwd
+    process.chdir(originalCwd);
+    // Restore env
+    if (savedTeamRoot !== undefined) {
+      process.env['SQUAD_TEAM_ROOT'] = savedTeamRoot;
+    } else {
+      delete process.env['SQUAD_TEAM_ROOT'];
+    }
+    // Clean up temp dirs
+    for (const dir of tmpDirs) {
+      rmSync(dir, { recursive: true, force: true });
+    }
+    tmpDirs.length = 0;
+  });
+
+  // --------------------------------------------------------------------------
+  // getSquadStartDir() env-var scenarios
+  // --------------------------------------------------------------------------
+
+  describe('getSquadStartDir() env-var handling', () => {
+    it('returns SQUAD_TEAM_ROOT when the env var is set', () => {
+      const { root } = createSquadProject();
+      process.env['SQUAD_TEAM_ROOT'] = root;
+
+      expect(getSquadStartDir()).toBe(root);
+    });
+
+    it('falls back to process.cwd() when SQUAD_TEAM_ROOT is unset', () => {
+      delete process.env['SQUAD_TEAM_ROOT'];
+
+      expect(getSquadStartDir()).toBe(process.cwd());
+    });
+
+    it('falls back to process.cwd() when SQUAD_TEAM_ROOT is empty string', () => {
+      process.env['SQUAD_TEAM_ROOT'] = '';
+
+      // Empty string is falsy → || falls through to process.cwd()
+      expect(getSquadStartDir()).toBe(process.cwd());
+    });
+  });
+
+  // --------------------------------------------------------------------------
+  // resolveSquad integration with SQUAD_TEAM_ROOT
+  // --------------------------------------------------------------------------
+
+  describe('resolveSquad() uses getSquadStartDir result', () => {
+    it('resolveSquad finds .squad/ when SQUAD_TEAM_ROOT points to a valid project', () => {
+      const { root, squadDir } = createSquadProject();
+      process.env['SQUAD_TEAM_ROOT'] = root;
+
+      const startDir = getSquadStartDir();
+      const result = resolveSquad(startDir);
+
+      expect(result).toBe(squadDir);
+    });
+
+    it('resolveSquad finds .squad/ even when cwd is elsewhere', () => {
+      const { root, squadDir } = createSquadProject();
+      const otherDir = mkdtempSync(join(tmpdir(), 'squad-other-cwd-'));
+      tmpDirs.push(otherDir);
+
+      // Simulate Copilot CLI subprocess scenario:
+      // cwd is some random directory, but SQUAD_TEAM_ROOT points to real project
+      process.chdir(otherDir);
+      process.env['SQUAD_TEAM_ROOT'] = root;
+
+      const startDir = getSquadStartDir();
+      const result = resolveSquad(startDir);
+
+      expect(result).toBe(squadDir);
+    });
+
+    it('resolveSquad returns null when SQUAD_TEAM_ROOT is unset and cwd has no .squad/', () => {
+      const emptyDir = mkdtempSync(join(tmpdir(), 'squad-empty-'));
+      tmpDirs.push(emptyDir);
+      // Add .git so resolveSquad stops walking here
+      mkdirSync(join(emptyDir, '.git'), { recursive: true });
+
+      delete process.env['SQUAD_TEAM_ROOT'];
+      process.chdir(emptyDir);
+
+      const startDir = getSquadStartDir();
+      const result = resolveSquad(startDir);
+
+      expect(result).toBeNull();
+    });
+  });
+
+  // --------------------------------------------------------------------------
+  // Invalid / non-existent SQUAD_TEAM_ROOT
+  // --------------------------------------------------------------------------
+
+  describe('invalid SQUAD_TEAM_ROOT path', () => {
+    it('resolveSquad returns null for a non-existent SQUAD_TEAM_ROOT path', () => {
+      const fakePath = join(tmpdir(), 'squad-nonexistent-' + Date.now());
+      process.env['SQUAD_TEAM_ROOT'] = fakePath;
+
+      const startDir = getSquadStartDir();
+      const result = resolveSquad(startDir);
+
+      // Non-existent path → resolveSquad walks up and finds nothing → null
+      expect(result).toBeNull();
+    });
+
+    it('resolveSquad returns null for a SQUAD_TEAM_ROOT pointing to a dir without .squad/', () => {
+      const dirWithoutSquad = mkdtempSync(join(tmpdir(), 'squad-no-squad-dir-'));
+      tmpDirs.push(dirWithoutSquad);
+      // Add .git so resolveSquad stops walking here
+      mkdirSync(join(dirWithoutSquad, '.git'), { recursive: true });
+
+      process.env['SQUAD_TEAM_ROOT'] = dirWithoutSquad;
+
+      const startDir = getSquadStartDir();
+      const result = resolveSquad(startDir);
+
+      expect(result).toBeNull();
+    });
+  });
+});