diff --git a/src/cli.ts b/src/cli.ts
index b209567a..6f249a3e 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -626,4 +626,29 @@ program
     }
   });
 
+program
+  .command('doctor')
+  .alias('check-deps')
+  .description('Check Codeman tool dependencies (Node, Claude CLI, tmux, LibreOffice, MS Office)')
+  .option('--json', 'Output structured JSON instead of a table')
+  .option('--category <name>', 'Only check one category (core|office|documents|media|other)')
+  .action(async (options) => {
+    const { createRealHost, checkAll } = await import('./utils/dependency-checker.js');
+    const { renderTable, renderJson, computeExitCode } = await import('./utils/dependency-report.js');
+    const { DEPENDENCY_REGISTRY } = await import('./config/dependency-registry.js');
+
+    const host = createRealHost();
+    const registry = options.category
+      ? DEPENDENCY_REGISTRY.filter((t) => t.category === options.category)
+      : DEPENDENCY_REGISTRY;
+    const results = checkAll(registry, host);
+
+    if (options.json) {
+      console.log(JSON.stringify(renderJson(results, host.environment), null, 2));
+    } else {
+      console.log(renderTable(results, host.environment));
+    }
+    process.exit(computeExitCode(results));
+  });
+
 export { program };
diff --git a/src/config/dependency-registry.ts b/src/config/dependency-registry.ts
new file mode 100644
index 00000000..2e4a6220
--- /dev/null
+++ b/src/config/dependency-registry.ts
@@ -0,0 +1,128 @@
+/**
+ * @fileoverview Static registry of downstream tool dependencies probed by
+ * `codeman doctor`. Each entry declares per-environment resolvers and the
+ * skills that use it. EXTENSION POINT: skill-manifest-driven discovery
+ * (COD follow-up) will merge dynamically-found entries into this list.
+ *
+ * @module config/dependency-registry
+ */
+
+export type ProbeEnvironment = 'linux' | 'darwin' | 'win32' | 'wsl';
+export type ToolCategory = 'core' | 'office' | 'other';
+
+/** Resolve a binary on the PATH and read its version. */
+export interface PathResolver {
+  kind: 'path';
+  bins: string[];
+  versionArg?: string; // default '--version'
+  versionRegex?: RegExp; // default matches first \d+.\d+(.\d+)?
+}
+
+/** Resolve a Windows-installed app reachable from win32 or WSL. */
+export interface WindowsSideResolver {
+  kind: 'windows-side';
+  appDirs: string[]; // relative to a Program Files root
+  exes: string[]; // candidate executables; first found wins
+}
+
+export interface ResolverSpec {
+  match: ProbeEnvironment[];
+  resolver: PathResolver | WindowsSideResolver;
+}
+
+export interface ToolDependency {
+  id: string;
+  label: string;
+  category: ToolCategory;
+  required: boolean;
+  usedBy?: string[];
+  minVersion?: string;
+  resolvers: ResolverSpec[];
+  installHint?: Partial<Record<ProbeEnvironment, string>>;
+}
+
+const ALL: ProbeEnvironment[] = ['linux', 'darwin', 'wsl', 'win32'];
+
+export const DEPENDENCY_REGISTRY: ToolDependency[] = [
+  {
+    id: 'node',
+    label: 'Node.js',
+    category: 'core',
+    required: true,
+    minVersion: '18.0.0',
+    resolvers: [{ match: ALL, resolver: { kind: 'path', bins: ['node'], versionArg: '--version' } }],
+    installHint: { linux: 'https://nodejs.org', darwin: 'brew install node', wsl: 'https://nodejs.org' },
+  },
+  {
+    id: 'claude',
+    label: 'Claude CLI',
+    category: 'core',
+    required: false,
+    usedBy: ['Claude Code sessions (default backend)'],
+    resolvers: [{ match: ALL, resolver: { kind: 'path', bins: ['claude'], versionArg: '--version' } }],
+    installHint: { linux: 'https://docs.claude.com/claude-code', darwin: 'https://docs.claude.com/claude-code' },
+  },
+  {
+    id: 'tmux',
+    label: 'tmux',
+    category: 'core',
+    required: true,
+    resolvers: [{ match: ['linux', 'darwin', 'wsl'], resolver: { kind: 'path', bins: ['tmux'], versionArg: '-V' } }],
+    installHint: { linux: 'sudo apt install tmux', darwin: 'brew install tmux', wsl: 'sudo apt install tmux' },
+  },
+  {
+    id: 'opencode',
+    label: 'OpenCode CLI',
+    category: 'core',
+    required: false,
+    usedBy: ['OpenCode sessions'],
+    resolvers: [{ match: ALL, resolver: { kind: 'path', bins: ['opencode'], versionArg: '--version' } }],
+  },
+  {
+    id: 'codex',
+    label: 'Codex CLI',
+    category: 'core',
+    required: false,
+    usedBy: ['Codex sessions'],
+    resolvers: [{ match: ALL, resolver: { kind: 'path', bins: ['codex'], versionArg: '--version' } }],
+  },
+  {
+    id: 'gemini',
+    label: 'Gemini CLI',
+    category: 'core',
+    required: false,
+    usedBy: ['Gemini sessions'],
+    resolvers: [{ match: ALL, resolver: { kind: 'path', bins: ['gemini'], versionArg: '--version' } }],
+  },
+  {
+    id: 'libreoffice',
+    label: 'LibreOffice',
+    category: 'office',
+    required: false,
+    usedBy: ['document preview', 'thumbnails'],
+    resolvers: [
+      {
+        match: ['linux', 'darwin', 'wsl'],
+        resolver: { kind: 'path', bins: ['libreoffice', 'soffice'], versionArg: '--version' },
+      },
+    ],
+    installHint: { linux: 'sudo apt install libreoffice', darwin: 'brew install --cask libreoffice' },
+  },
+  {
+    id: 'msoffice',
+    label: 'MS Office',
+    category: 'office',
+    required: false,
+    usedBy: ['document preview', 'thumbnails'],
+    resolvers: [
+      {
+        match: ['wsl', 'win32'],
+        resolver: {
+          kind: 'windows-side',
+          appDirs: ['Microsoft Office/root/Office16'],
+          exes: ['WINWORD.EXE', 'POWERPNT.EXE', 'EXCEL.EXE'],
+        },
+      },
+    ],
+  },
+];
diff --git a/src/utils/dependency-checker.ts b/src/utils/dependency-checker.ts
new file mode 100644
index 00000000..beada7a9
--- /dev/null
+++ b/src/utils/dependency-checker.ts
@@ -0,0 +1,211 @@
+/**
+ * @fileoverview Probe engine for `codeman doctor`. Resolves each registry tool
+ * against an injectable ProbeHost (real impl uses child_process/fs; tests inject
+ * fakes) and returns structured results. Pure given the host — no global I/O.
+ *
+ * @module utils/dependency-checker
+ */
+
+import { execFileSync } from 'node:child_process';
+import { existsSync, readdirSync, readFileSync } from 'node:fs';
+import { EXEC_TIMEOUT_MS } from '../config/exec-timeout.js';
+import type { ProbeEnvironment, ToolCategory, ToolDependency } from '../config/dependency-registry.js';
+
+export interface EnvDetectionInputs {
+  platform: NodeJS.Platform;
+  procVersion: string;
+  hasWindowsInterop: boolean;
+}
+
+export function detectEnvironment(inputs: EnvDetectionInputs): ProbeEnvironment {
+  if (inputs.platform === 'win32') return 'win32';
+  if (inputs.platform === 'darwin') return 'darwin';
+  const isWsl = /microsoft|wsl/i.test(inputs.procVersion) && inputs.hasWindowsInterop;
+  return isWsl ? 'wsl' : 'linux';
+}
+
+const DEFAULT_VERSION_RE = /(\d+\.\d+(?:\.\d+)?)/;
+
+export function extractVersion(text: string, re?: RegExp): string | undefined {
+  const m = (re ?? DEFAULT_VERSION_RE).exec(text);
+  return m ? m[1] : undefined;
+}
+
+/** Returns -1 if a < b, 0 if equal, 1 if a > b (numeric, component-wise). */
+export function compareVersions(a: string, b: string): number {
+  const pa = a.split('.').map((n) => parseInt(n, 10) || 0);
+  const pb = b.split('.').map((n) => parseInt(n, 10) || 0);
+  const len = Math.max(pa.length, pb.length);
+  for (let i = 0; i < len; i++) {
+    const d = (pa[i] || 0) - (pb[i] || 0);
+    if (d !== 0) return d < 0 ? -1 : 1;
+  }
+  return 0;
+}
+
+export type ToolStatus = 'ok' | 'missing' | 'outdated' | 'skipped' | 'error';
+
+export interface ToolResult {
+  id: string;
+  label: string;
+  category: ToolCategory;
+  required: boolean;
+  usedBy: string[];
+  status: ToolStatus;
+  version?: string;
+  path?: string;
+  installHint?: string;
+  reason?: string;
+}
+
+export interface ProbeHost {
+  environment: ProbeEnvironment;
+  which(bin: string): string | null;
+  fileExists(path: string): boolean;
+  runVersion(bin: string, args: string[]): string | null;
+  windowsProgramRoots(): string[];
+  windowsFileVersion(winPath: string): string | null;
+}
+
+function finalize(
+  base: Pick<ToolResult, 'id' | 'label' | 'category' | 'required' | 'usedBy'>,
+  tool: ToolDependency,
+  path: string,
+  version: string | undefined
+): ToolResult {
+  if (tool.minVersion) {
+    if (!version) return { ...base, status: 'error', path, reason: 'version required but could not be parsed' };
+    if (compareVersions(version, tool.minVersion) < 0) return { ...base, status: 'outdated', path, version };
+  }
+  return { ...base, status: 'ok', path, version };
+}
+
+export function checkTool(tool: ToolDependency, host: ProbeHost): ToolResult {
+  const base = {
+    id: tool.id,
+    label: tool.label,
+    category: tool.category,
+    required: tool.required,
+    usedBy: tool.usedBy ?? [],
+  };
+  const installHint = tool.installHint?.[host.environment];
+
+  const spec = tool.resolvers.find((r) => r.match.includes(host.environment));
+  if (!spec) return { ...base, status: 'skipped', reason: `not applicable on ${host.environment}` };
+
+  if (spec.resolver.kind === 'path') {
+    const { bins, versionArg, versionRegex } = spec.resolver;
+    for (const bin of bins) {
+      const resolved = host.which(bin);
+      if (resolved) {
+        const out = host.runVersion(bin, [versionArg ?? '--version']);
+        const version = out ? extractVersion(out, versionRegex) : undefined;
+        return finalize(base, tool, resolved, version);
+      }
+    }
+    return { ...base, status: 'missing', installHint };
+  }
+
+  // windows-side
+  const { appDirs, exes } = spec.resolver;
+  for (const root of host.windowsProgramRoots()) {
+    for (const dir of appDirs) {
+      for (const exe of exes) {
+        const winPath = `${root}/${dir}/${exe}`;
+        if (host.fileExists(winPath)) {
+          const raw = host.windowsFileVersion(winPath);
+          const version = raw ? extractVersion(raw) : undefined;
+          return finalize(base, tool, winPath, version);
+        }
+      }
+    }
+  }
+  return { ...base, status: 'missing', installHint };
+}
+
+export function checkAll(registry: ToolDependency[], host: ProbeHost): ToolResult[] {
+  return registry.map((tool) => checkTool(tool, host));
+}
+
+function safeWhich(bin: string): string | null {
+  try {
+    const out = execFileSync(process.platform === 'win32' ? 'where' : 'which', [bin], {
+      encoding: 'utf-8',
+      timeout: EXEC_TIMEOUT_MS,
+    }).trim();
+    const first = out.split(/\r?\n/)[0]?.trim();
+    return first && existsSync(first) ? first : null;
+  } catch {
+    return null;
+  }
+}
+
+function safeRunVersion(bin: string, args: string[]): string | null {
+  try {
+    return execFileSync(bin, args, {
+      encoding: 'utf-8',
+      timeout: EXEC_TIMEOUT_MS,
+      stdio: ['ignore', 'pipe', 'ignore'],
+    });
+  } catch (err: unknown) {
+    // Some tools (e.g. ffmpeg) exit non-zero on -version but still print to stdout
+    const stdout = (err as { stdout?: Buffer | string })?.stdout;
+    return stdout ? stdout.toString() : null;
+  }
+}
+
+function readProcVersion(): string {
+  try {
+    return readFileSync('/proc/version', 'utf-8');
+  } catch {
+    return '';
+  }
+}
+
+function listWindowsProgramRoots(): string[] {
+  const roots: string[] = [];
+  try {
+    for (const entry of readdirSync('/mnt')) {
+      for (const pf of ['Program Files', 'Program Files (x86)']) {
+        const root = `/mnt/${entry}/${pf}`;
+        if (existsSync(root)) roots.push(root);
+      }
+    }
+  } catch {
+    // /mnt absent (not WSL) -> no roots
+  }
+  return roots;
+}
+
+function readWindowsFileVersion(winPath: string): string | null {
+  try {
+    const windowsPath = execFileSync('wslpath', ['-w', winPath], {
+      encoding: 'utf-8',
+      timeout: EXEC_TIMEOUT_MS,
+    }).trim();
+    const out = execFileSync(
+      'powershell.exe',
+      ['-NoProfile', '-Command', `(Get-Item '${windowsPath.replace(/'/g, "''")}').VersionInfo.ProductVersion`],
+      { encoding: 'utf-8', timeout: EXEC_TIMEOUT_MS }
+    ).trim();
+    return out || null;
+  } catch {
+    return null;
+  }
+}
+
+export function createRealHost(): ProbeHost {
+  const environment = detectEnvironment({
+    platform: process.platform,
+    procVersion: readProcVersion(),
+    hasWindowsInterop: safeWhich('cmd.exe') !== null || safeWhich('powershell.exe') !== null,
+  });
+  return {
+    environment,
+    which: safeWhich,
+    fileExists: existsSync,
+    runVersion: safeRunVersion,
+    windowsProgramRoots: listWindowsProgramRoots,
+    windowsFileVersion: readWindowsFileVersion,
+  };
+}
diff --git a/src/utils/dependency-report.ts b/src/utils/dependency-report.ts
new file mode 100644
index 00000000..0737322f
--- /dev/null
+++ b/src/utils/dependency-report.ts
@@ -0,0 +1,75 @@
+/**
+ * @fileoverview Renders ToolResult[] from the dependency checker into a
+ * human-readable grouped table or JSON, and computes the process exit code.
+ * Plain text only (no color) so output is stable and snapshot-friendly; the
+ * CLI layer may colorize.
+ *
+ * @module utils/dependency-report
+ */
+
+import type { ProbeEnvironment, ToolCategory } from '../config/dependency-registry.js';
+import type { ToolResult, ToolStatus } from './dependency-checker.js';
+
+const CATEGORY_ORDER: ToolCategory[] = ['core', 'office', 'other'];
+
+function glyph(r: ToolResult): string {
+  if (r.status === 'ok') return '✓';
+  if (r.status === 'skipped') return '○';
+  return r.required ? '✗' : '○';
+}
+
+function statusText(r: ToolResult): string {
+  if (r.status === 'ok') return r.version ?? 'installed';
+  if (r.status === 'outdated') return `${r.version ?? '?'} (below minimum)`;
+  if (r.status === 'skipped') return 'n/a';
+  if (r.status === 'error') return 'version error';
+  return 'not found';
+}
+
+export function computeExitCode(results: ToolResult[]): number {
+  const failed = results.some(
+    (r) => r.required && (r.status === 'missing' || r.status === 'outdated' || r.status === 'error')
+  );
+  return failed ? 1 : 0;
+}
+
+export function renderTable(results: ToolResult[], environment: ProbeEnvironment): string {
+  const lines: string[] = [`Codeman dependency check — ${environment}`, ''];
+  for (const category of CATEGORY_ORDER) {
+    const rows = results.filter((r) => r.category === category);
+    if (rows.length === 0) continue;
+    lines.push(category.toUpperCase());
+    for (const r of rows) {
+      const detail = r.path ? `  ${r.path}` : '';
+      lines.push(`  ${glyph(r)} ${r.label.padEnd(14)} ${statusText(r).padEnd(22)}${detail}`);
+      if (r.usedBy.length) lines.push(`        used by: ${r.usedBy.join(', ')}`);
+      if (r.installHint) lines.push(`        install: ${r.installHint}`);
+    }
+    lines.push('');
+  }
+  const ok = results.filter((r) => r.status === 'ok').length;
+  const requiredMissing = results.filter((r) => r.required && r.status !== 'ok' && r.status !== 'skipped').length;
+  const optionalMissing = results.filter((r) => !r.required && r.status === 'missing').length;
+  lines.push(`Summary: ${ok} ok · ${requiredMissing} required missing · ${optionalMissing} optional missing`);
+  return lines.join('\n');
+}
+
+export interface DependencyReportJson {
+  platform: { environment: ProbeEnvironment };
+  summary: { ok: number; requiredMissing: number; optionalMissing: number; exitCode: number };
+  tools: ToolResult[];
+}
+
+export function renderJson(results: ToolResult[], environment: ProbeEnvironment): DependencyReportJson {
+  const byStatus = (s: ToolStatus) => results.filter((r) => r.status === s).length;
+  return {
+    platform: { environment },
+    summary: {
+      ok: byStatus('ok'),
+      requiredMissing: results.filter((r) => r.required && r.status !== 'ok' && r.status !== 'skipped').length,
+      optionalMissing: results.filter((r) => !r.required && r.status === 'missing').length,
+      exitCode: computeExitCode(results),
+    },
+    tools: results,
+  };
+}
diff --git a/test/dependency-checker.test.ts b/test/dependency-checker.test.ts
new file mode 100644
index 00000000..cc82966c
--- /dev/null
+++ b/test/dependency-checker.test.ts
@@ -0,0 +1,181 @@
+import { describe, it, expect } from 'vitest';
+import { DEPENDENCY_REGISTRY } from '../src/config/dependency-registry.js';
+import {
+  detectEnvironment,
+  extractVersion,
+  compareVersions,
+  checkTool,
+  checkAll,
+  createRealHost,
+} from '../src/utils/dependency-checker.js';
+import type { ProbeHost } from '../src/utils/dependency-checker.js';
+import type { ProbeEnvironment, ToolDependency } from '../src/config/dependency-registry.js';
+
+describe('DEPENDENCY_REGISTRY', () => {
+  it('has unique ids', () => {
+    const ids = DEPENDENCY_REGISTRY.map((t) => t.id);
+    expect(new Set(ids).size).toBe(ids.length);
+  });
+
+  it('hard-requires only node and tmux; agent CLIs and office are optional', () => {
+    const required = DEPENDENCY_REGISTRY.filter((t) => t.required)
+      .map((t) => t.id)
+      .sort();
+    expect(required).toEqual(['node', 'tmux']);
+    // all four agent CLIs are optional (Codeman runs any of them)
+    const agentClis = ['claude', 'opencode', 'codex', 'gemini'];
+    expect(DEPENDENCY_REGISTRY.filter((t) => agentClis.includes(t.id)).every((t) => t.required === false)).toBe(true);
+    const office = DEPENDENCY_REGISTRY.filter((t) => t.category === 'office');
+    expect(office.every((t) => t.required === false)).toBe(true);
+  });
+
+  it('gives msoffice a windows-side resolver scoped to wsl + win32 only', () => {
+    const ms = DEPENDENCY_REGISTRY.find((t) => t.id === 'msoffice');
+    expect(ms).toBeDefined();
+    const spec = ms!.resolvers.find((r) => r.resolver.kind === 'windows-side');
+    expect(spec).toBeDefined();
+    expect([...spec!.match].sort()).toEqual(['win32', 'wsl']);
+    expect(ms!.resolvers.some((r) => r.match.includes('linux'))).toBe(false);
+  });
+});
+
+describe('detectEnvironment', () => {
+  it('returns win32/darwin straight from platform', () => {
+    expect(detectEnvironment({ platform: 'win32', procVersion: '', hasWindowsInterop: false })).toBe('win32');
+    expect(detectEnvironment({ platform: 'darwin', procVersion: '', hasWindowsInterop: false })).toBe('darwin');
+  });
+
+  it('detects wsl from /proc/version + interop, else linux', () => {
+    const wsl = detectEnvironment({
+      platform: 'linux',
+      procVersion: 'Linux version 6.6 (Microsoft@WSL2)',
+      hasWindowsInterop: true,
+    });
+    expect(wsl).toBe('wsl');
+    expect(detectEnvironment({ platform: 'linux', procVersion: 'Microsoft', hasWindowsInterop: false })).toBe('linux');
+    expect(detectEnvironment({ platform: 'linux', procVersion: 'generic', hasWindowsInterop: true })).toBe('linux');
+  });
+});
+
+describe('extractVersion', () => {
+  it('pulls a dotted version from typical --version output', () => {
+    expect(extractVersion('v22.22.1')).toBe('22.22.1');
+    expect(extractVersion('tmux 3.4')).toBe('3.4');
+    expect(extractVersion('no digits here')).toBeUndefined();
+  });
+  it('honors a custom regex', () => {
+    expect(extractVersion('ProductVersion 16.0.19929.20172', /(\d+\.\d+\.\d+)/)).toBe('16.0.19929');
+  });
+});
+
+describe('compareVersions', () => {
+  it('orders by numeric components', () => {
+    expect(compareVersions('18.0.0', '18.0.0')).toBe(0);
+    expect(compareVersions('16.5.0', '18.0.0')).toBe(-1);
+    expect(compareVersions('22.22.1', '18.0.0')).toBe(1);
+    expect(compareVersions('3.4', '3.4.0')).toBe(0);
+  });
+});
+
+function fakeHost(env: ProbeEnvironment, over: Partial<ProbeHost> = {}): ProbeHost {
+  return {
+    environment: env,
+    which: () => null,
+    fileExists: () => false,
+    runVersion: () => null,
+    windowsProgramRoots: () => [],
+    windowsFileVersion: () => null,
+    ...over,
+  };
+}
+
+const tmuxTool: ToolDependency = {
+  id: 'tmux',
+  label: 'tmux',
+  category: 'core',
+  required: true,
+  resolvers: [{ match: ['linux', 'wsl'], resolver: { kind: 'path', bins: ['tmux'], versionArg: '-V' } }],
+};
+const nodeTool: ToolDependency = {
+  id: 'node',
+  label: 'Node.js',
+  category: 'core',
+  required: true,
+  minVersion: '18.0.0',
+  resolvers: [{ match: ['linux'], resolver: { kind: 'path', bins: ['node'] } }],
+};
+const msTool: ToolDependency = {
+  id: 'msoffice',
+  label: 'MS Office',
+  category: 'office',
+  required: false,
+  resolvers: [
+    {
+      match: ['wsl', 'win32'],
+      resolver: { kind: 'windows-side', appDirs: ['Microsoft Office/root/Office16'], exes: ['WINWORD.EXE'] },
+    },
+  ],
+};
+
+describe('checkTool', () => {
+  it('reports ok with path + version when found on PATH', () => {
+    const host = fakeHost('linux', {
+      which: (b) => (b === 'tmux' ? '/usr/bin/tmux' : null),
+      runVersion: () => 'tmux 3.4',
+    });
+    expect(checkTool(tmuxTool, host)).toMatchObject({
+      id: 'tmux',
+      status: 'ok',
+      version: '3.4',
+      path: '/usr/bin/tmux',
+    });
+  });
+
+  it('reports missing when no bin resolves', () => {
+    expect(checkTool(tmuxTool, fakeHost('linux'))).toMatchObject({ id: 'tmux', status: 'missing' });
+  });
+
+  it('reports outdated when below minVersion', () => {
+    const host = fakeHost('linux', { which: () => '/n', runVersion: () => 'v16.5.0' });
+    expect(checkTool(nodeTool, host)).toMatchObject({ id: 'node', status: 'outdated', version: '16.5.0' });
+  });
+
+  it('reports error when minVersion set but version unparseable', () => {
+    const host = fakeHost('linux', { which: () => '/n', runVersion: () => 'unknown' });
+    expect(checkTool(nodeTool, host)).toMatchObject({ id: 'node', status: 'error' });
+  });
+
+  it('reports skipped when no resolver matches the environment', () => {
+    expect(checkTool(msTool, fakeHost('linux'))).toMatchObject({ id: 'msoffice', status: 'skipped' });
+  });
+
+  it('finds windows-side apps under WSL', () => {
+    const host = fakeHost('wsl', {
+      windowsProgramRoots: () => ['/mnt/c/Program Files'],
+      fileExists: (p) => p === '/mnt/c/Program Files/Microsoft Office/root/Office16/WINWORD.EXE',
+      windowsFileVersion: () => '16.0.19929.20172',
+    });
+    expect(checkTool(msTool, host)).toMatchObject({
+      id: 'msoffice',
+      status: 'ok',
+      version: '16.0.19929',
+      path: '/mnt/c/Program Files/Microsoft Office/root/Office16/WINWORD.EXE',
+    });
+  });
+});
+
+describe('checkAll', () => {
+  it('maps every tool to a result', () => {
+    const results = checkAll([tmuxTool, msTool], fakeHost('linux'));
+    expect(results.map((r) => r.id)).toEqual(['tmux', 'msoffice']);
+  });
+});
+
+describe('createRealHost', () => {
+  it('returns a host with a valid detected environment and callable methods', () => {
+    const host = createRealHost();
+    expect(['linux', 'darwin', 'win32', 'wsl']).toContain(host.environment);
+    expect(typeof host.which).toBe('function');
+    expect(Array.isArray(host.windowsProgramRoots())).toBe(true);
+  });
+});
diff --git a/test/dependency-report.test.ts b/test/dependency-report.test.ts
new file mode 100644
index 00000000..813a9497
--- /dev/null
+++ b/test/dependency-report.test.ts
@@ -0,0 +1,74 @@
+import { describe, it, expect } from 'vitest';
+import { renderTable, renderJson, computeExitCode } from '../src/utils/dependency-report.js';
+import type { ToolResult } from '../src/utils/dependency-checker.js';
+
+const results: ToolResult[] = [
+  {
+    id: 'node',
+    label: 'Node.js',
+    category: 'core',
+    required: true,
+    usedBy: [],
+    status: 'ok',
+    version: '22.22.1',
+    path: '/n',
+  },
+  {
+    id: 'tmux',
+    label: 'tmux',
+    category: 'core',
+    required: true,
+    usedBy: [],
+    status: 'missing',
+    installHint: 'sudo apt install tmux',
+  },
+  {
+    id: 'libreoffice',
+    label: 'LibreOffice',
+    category: 'office',
+    required: false,
+    usedBy: ['document preview', 'thumbnails'],
+    status: 'missing',
+  },
+  {
+    id: 'msoffice',
+    label: 'MS Office',
+    category: 'office',
+    required: false,
+    usedBy: ['document preview', 'thumbnails'],
+    status: 'skipped',
+    reason: 'not applicable on linux',
+  },
+];
+
+describe('computeExitCode', () => {
+  it('non-zero when a required tool is missing/outdated/error', () => {
+    expect(computeExitCode(results)).toBe(1);
+  });
+  it('zero when only optional tools are missing', () => {
+    const ok = results.filter((r) => r.id !== 'tmux');
+    expect(computeExitCode(ok)).toBe(0);
+  });
+});
+
+describe('renderTable', () => {
+  it('groups by category and shows status, version, and install hints', () => {
+    const out = renderTable(results, 'linux');
+    expect(out).toContain('CORE');
+    expect(out).toContain('Node.js');
+    expect(out).toContain('22.22.1');
+    expect(out).toContain('OFFICE');
+    expect(out).toContain('document preview');
+    expect(out).toContain('sudo apt install tmux');
+  });
+});
+
+describe('renderJson', () => {
+  it('includes environment, summary, and per-tool data', () => {
+    const json = renderJson(results, 'linux');
+    expect(json.platform.environment).toBe('linux');
+    expect(json.summary.exitCode).toBe(1);
+    expect(json.summary.ok).toBe(1);
+    expect(json.tools).toHaveLength(4);
+  });
+});