feat(prdy): migrate @mosaic/prdy from v0 to v1

Port full PRD wizard implementation: types, YAML persistence (js-yaml),
built-in templates (software/feature/spike), @clack/prompts interactive
wizard, and Commander.js CLI (init/list/show). Adapted for v1 conventions:
ESM .js imports, NodeNext resolution, noUncheckedIndexedAccess-safe lookups,
and consistent-type-imports lint rule.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/prdy/package.json

@@ -15,7 +15,15 @@
     "typecheck": "tsc --noEmit",
     "test": "vitest run --passWithNoTests"
   },
+  "dependencies": {
+    "@clack/prompts": "^0.9.0",
+    "commander": "^12.0.0",
+    "js-yaml": "^4.1.0",
+    "zod": "^3.22.0"
+  },
   "devDependencies": {
+    "@types/js-yaml": "^4.0.9",
+    "@types/node": "^22.0.0",
     "typescript": "^5.8.0",
     "vitest": "^2.0.0"
   }

packages/prdy/src/cli.ts

@@ -0,0 +1,100 @@
+import { Command } from 'commander';
+
+import { createPrd, listPrds, loadPrd } from './prd.js';
+import { runPrdWizard } from './wizard.js';
+
+interface InitCommandOptions {
+  readonly name: string;
+  readonly project: string;
+  readonly template?: 'software' | 'feature' | 'spike';
+}
+
+interface ListCommandOptions {
+  readonly project: string;
+}
+
+interface ShowCommandOptions {
+  readonly project: string;
+  readonly id?: string;
+}
+
+export function buildPrdyCli(): Command {
+  const program = new Command();
+  program.name('mosaic').description('Mosaic CLI').exitOverride();
+
+  const prdy = program.command('prdy').description('PRD wizard commands');
+
+  prdy
+    .command('init')
+    .description('Create a PRD document')
+    .requiredOption('--name <name>', 'PRD name')
+    .requiredOption('--project <path>', 'Project path')
+    .option('--template <template>', 'Template (software|feature|spike)')
+    .action(async (options: InitCommandOptions) => {
+      const doc = process.stdout.isTTY
+        ? await runPrdWizard({
+            name: options.name,
+            projectPath: options.project,
+            template: options.template,
+            interactive: true,
+          })
+        : await createPrd({
+            name: options.name,
+            projectPath: options.project,
+            template: options.template,
+            interactive: false,
+          });
+
+      console.log(
+        JSON.stringify(
+          {
+            ok: true,
+            id: doc.id,
+            title: doc.title,
+            status: doc.status,
+            projectPath: doc.projectPath,
+          },
+          null,
+          2,
+        ),
+      );
+    });
+
+  prdy
+    .command('list')
+    .description('List PRD documents for a project')
+    .requiredOption('--project <path>', 'Project path')
+    .action(async (options: ListCommandOptions) => {
+      const docs = await listPrds(options.project);
+      console.log(JSON.stringify(docs, null, 2));
+    });
+
+  prdy
+    .command('show')
+    .description('Show a PRD document')
+    .requiredOption('--project <path>', 'Project path')
+    .option('--id <id>', 'PRD document id')
+    .action(async (options: ShowCommandOptions) => {
+      if (options.id !== undefined) {
+        const docs = await listPrds(options.project);
+        const match = docs.find((doc) => doc.id === options.id);
+
+        if (match === undefined) {
+          throw new Error(`PRD id not found: ${options.id}`);
+        }
+
+        console.log(JSON.stringify(match, null, 2));
+        return;
+      }
+
+      const doc = await loadPrd(options.project);
+      console.log(JSON.stringify(doc, null, 2));
+    });
+
+  return program;
+}
+
+export async function runPrdyCli(argv: readonly string[] = process.argv): Promise<void> {
+  const program = buildPrdyCli();
+  await program.parseAsync(argv);
+}

packages/prdy/src/index.ts

@@ -1 +1,12 @@
-export const VERSION = '0.0.0';
+export { createPrd, loadPrd, savePrd, listPrds } from './prd.js';
+export { runPrdWizard } from './wizard.js';
+export { buildPrdyCli, runPrdyCli } from './cli.js';
+export { BUILTIN_PRD_TEMPLATES, resolveTemplate } from './templates.js';
+export type {
+  PrdStatus,
+  PrdTemplate,
+  PrdTemplateSection,
+  PrdSection,
+  PrdDocument,
+  CreatePrdOptions,
+} from './types.js';

packages/prdy/src/prd.ts

@@ -0,0 +1,199 @@
+import { type Dirent, promises as fs } from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+
+import yaml from 'js-yaml';
+import { z } from 'zod';
+
+import { resolveTemplate } from './templates.js';
+import type { CreatePrdOptions, PrdDocument } from './types.js';
+
+const PRD_DIRECTORY = path.join('docs', 'prdy');
+const PRD_FILE_EXTENSIONS = new Set(['.yaml', '.yml']);
+
+const prdSectionSchema = z.object({
+  id: z.string().min(1),
+  title: z.string().min(1),
+  fields: z.record(z.string(), z.string()),
+});
+
+const prdDocumentSchema = z.object({
+  id: z.string().min(1),
+  title: z.string().min(1),
+  status: z.enum(['draft', 'review', 'approved', 'archived']),
+  projectPath: z.string().min(1),
+  template: z.string().min(1),
+  sections: z.array(prdSectionSchema),
+  createdAt: z.string().datetime(),
+  updatedAt: z.string().datetime(),
+});
+
+function expandHome(projectPath: string): string {
+  if (!projectPath.startsWith('~')) {
+    return projectPath;
+  }
+
+  if (projectPath === '~') {
+    return os.homedir();
+  }
+
+  if (projectPath.startsWith('~/')) {
+    return path.join(os.homedir(), projectPath.slice(2));
+  }
+
+  return projectPath;
+}
+
+function resolveProjectPath(projectPath: string): string {
+  return path.resolve(expandHome(projectPath));
+}
+
+function toSlug(value: string): string {
+  return value
+    .toLowerCase()
+    .replace(/[^a-z0-9]+/g, '-')
+    .replace(/^-+|-+$/g, '')
+    .replace(/-{2,}/g, '-');
+}
+
+function buildTimestamp(date: Date): { datePart: string; timePart: string } {
+  const iso = date.toISOString();
+  return {
+    datePart: iso.slice(0, 10).replace(/-/g, ''),
+    timePart: iso.slice(11, 19).replace(/:/g, ''),
+  };
+}
+
+function buildPrdId(name: string): string {
+  const slug = toSlug(name);
+  const { datePart, timePart } = buildTimestamp(new Date());
+  return `${slug || 'prd'}-${datePart}-${timePart}`;
+}
+
+function prdDirectory(projectPath: string): string {
+  return path.join(projectPath, PRD_DIRECTORY);
+}
+
+function prdFilePath(projectPath: string, id: string): string {
+  return path.join(prdDirectory(projectPath), `${id}.yaml`);
+}
+
+function isNodeErrorWithCode(error: unknown, code: string): boolean {
+  return (
+    typeof error === 'object' &&
+    error !== null &&
+    'code' in error &&
+    (error as { code?: string }).code === code
+  );
+}
+
+async function writeFileAtomic(filePath: string, content: string): Promise<void> {
+  const directory = path.dirname(filePath);
+  await fs.mkdir(directory, { recursive: true });
+
+  const tempPath = path.join(
+    directory,
+    `.${path.basename(filePath)}.tmp-${process.pid}-${Date.now()}-${Math.random()
+      .toString(16)
+      .slice(2)}`,
+  );
+
+  await fs.writeFile(tempPath, content, 'utf8');
+  await fs.rename(tempPath, filePath);
+}
+
+export async function createPrd(options: CreatePrdOptions): Promise<PrdDocument> {
+  const resolvedProjectPath = resolveProjectPath(options.projectPath);
+  const template = resolveTemplate(options.template);
+  const now = new Date().toISOString();
+
+  const document: PrdDocument = {
+    id: buildPrdId(options.name),
+    title: options.name.trim(),
+    status: 'draft',
+    projectPath: resolvedProjectPath,
+    template: template.id,
+    sections: template.sections.map((section) => ({
+      id: section.id,
+      title: section.title,
+      fields: Object.fromEntries(section.fields.map((field) => [field, ''])),
+    })),
+    createdAt: now,
+    updatedAt: now,
+  };
+
+  await savePrd(document);
+  return document;
+}
+
+export async function loadPrd(projectPath: string): Promise<PrdDocument> {
+  const documents = await listPrds(projectPath);
+  if (documents.length === 0) {
+    const resolvedProjectPath = resolveProjectPath(projectPath);
+    throw new Error(`No PRD documents found in ${prdDirectory(resolvedProjectPath)}`);
+  }
+
+  return documents[0]!;
+}
+
+export async function savePrd(doc: PrdDocument): Promise<void> {
+  const normalized = prdDocumentSchema.parse({
+    ...doc,
+    projectPath: resolveProjectPath(doc.projectPath),
+  });
+
+  const filePath = prdFilePath(normalized.projectPath, normalized.id);
+  const serialized = yaml.dump(normalized, {
+    noRefs: true,
+    sortKeys: false,
+    lineWidth: 120,
+  });
+
+  const content = serialized.endsWith('\n') ? serialized : `${serialized}\n`;
+  await writeFileAtomic(filePath, content);
+}
+
+export async function listPrds(projectPath: string): Promise<PrdDocument[]> {
+  const resolvedProjectPath = resolveProjectPath(projectPath);
+  const directory = prdDirectory(resolvedProjectPath);
+
+  let entries: Dirent[];
+  try {
+    entries = await fs.readdir(directory, { withFileTypes: true, encoding: 'utf8' });
+  } catch (error) {
+    if (isNodeErrorWithCode(error, 'ENOENT')) {
+      return [];
+    }
+
+    throw error;
+  }
+
+  const documents: PrdDocument[] = [];
+
+  for (const entry of entries) {
+    if (!entry.isFile()) {
+      continue;
+    }
+
+    const ext = path.extname(entry.name);
+    if (!PRD_FILE_EXTENSIONS.has(ext)) {
+      continue;
+    }
+
+    const filePath = path.join(directory, entry.name);
+    const raw = await fs.readFile(filePath, 'utf8');
+
+    let parsed: unknown;
+    try {
+      parsed = yaml.load(raw);
+    } catch (error) {
+      throw new Error(`Failed to parse PRD file ${filePath}: ${String(error)}`);
+    }
+
+    const document = prdDocumentSchema.parse(parsed);
+    documents.push(document);
+  }
+
+  documents.sort((left, right) => right.updatedAt.localeCompare(left.updatedAt));
+  return documents;
+}

packages/prdy/src/templates.ts

@@ -0,0 +1,93 @@
+import type { PrdTemplate } from './types.js';
+
+export const BUILTIN_PRD_TEMPLATES: Record<string, PrdTemplate> = {
+  software: {
+    id: 'software',
+    name: 'Software Project',
+    fields: ['owner', 'status', 'scopeVersion', 'successMetrics'],
+    sections: [
+      { id: 'introduction', title: 'Introduction', fields: ['context', 'objective'] },
+      { id: 'problem-statement', title: 'Problem Statement', fields: ['painPoints'] },
+      { id: 'scope-non-goals', title: 'Scope / Non-Goals', fields: ['inScope', 'outOfScope'] },
+      { id: 'user-stories', title: 'User Stories / Requirements', fields: ['stories'] },
+      { id: 'functional-requirements', title: 'Functional Requirements', fields: ['requirements'] },
+      {
+        id: 'non-functional-requirements',
+        title: 'Non-Functional Requirements',
+        fields: ['performance', 'reliability', 'security'],
+      },
+      { id: 'acceptance-criteria', title: 'Acceptance Criteria', fields: ['criteria'] },
+      {
+        id: 'technical-considerations',
+        title: 'Technical Considerations',
+        fields: ['constraints', 'dependencies'],
+      },
+      {
+        id: 'risks-open-questions',
+        title: 'Risks / Open Questions',
+        fields: ['risks', 'openQuestions'],
+      },
+      {
+        id: 'milestones-delivery',
+        title: 'Milestones / Delivery',
+        fields: ['milestones', 'timeline'],
+      },
+    ],
+  },
+  feature: {
+    id: 'feature',
+    name: 'Feature PRD',
+    fields: ['owner', 'status', 'releaseTarget'],
+    sections: [
+      { id: 'problem-statement', title: 'Problem Statement', fields: ['problem'] },
+      { id: 'goals', title: 'Goals', fields: ['goals'] },
+      { id: 'scope', title: 'Scope', fields: ['inScope', 'outOfScope'] },
+      { id: 'user-stories', title: 'User Stories', fields: ['stories'] },
+      { id: 'requirements', title: 'Requirements', fields: ['functional', 'nonFunctional'] },
+      { id: 'acceptance-criteria', title: 'Acceptance Criteria', fields: ['criteria'] },
+      {
+        id: 'technical-considerations',
+        title: 'Technical Considerations',
+        fields: ['constraints'],
+      },
+      {
+        id: 'risks-open-questions',
+        title: 'Risks / Open Questions',
+        fields: ['risks', 'questions'],
+      },
+      { id: 'milestones', title: 'Milestones', fields: ['milestones'] },
+      { id: 'success-metrics', title: 'Success Metrics / Testing', fields: ['metrics', 'testing'] },
+    ],
+  },
+  spike: {
+    id: 'spike',
+    name: 'Research Spike',
+    fields: ['owner', 'status', 'decisionDeadline'],
+    sections: [
+      { id: 'background', title: 'Background', fields: ['context'] },
+      { id: 'research-questions', title: 'Research Questions', fields: ['questions'] },
+      { id: 'constraints', title: 'Constraints', fields: ['constraints'] },
+      { id: 'options', title: 'Options Considered', fields: ['options'] },
+      { id: 'evaluation', title: 'Evaluation Criteria', fields: ['criteria'] },
+      { id: 'findings', title: 'Findings', fields: ['findings'] },
+      { id: 'recommendation', title: 'Recommendation', fields: ['recommendation'] },
+      { id: 'risks', title: 'Risks / Unknowns', fields: ['risks', 'unknowns'] },
+      { id: 'next-steps', title: 'Next Steps', fields: ['nextSteps'] },
+      { id: 'milestones', title: 'Milestones / Delivery', fields: ['milestones'] },
+    ],
+  },
+};
+
+export function resolveTemplate(templateName?: string): PrdTemplate {
+  const name =
+    templateName === undefined || templateName.trim().length === 0 ? 'software' : templateName;
+
+  const template = BUILTIN_PRD_TEMPLATES[name];
+  if (template === undefined) {
+    throw new Error(
+      `Unknown PRD template: ${name}. Expected one of: ${Object.keys(BUILTIN_PRD_TEMPLATES).join(', ')}`,
+    );
+  }
+
+  return template;
+}

packages/prdy/src/types.ts

@@ -0,0 +1,38 @@
+export type PrdStatus = 'draft' | 'review' | 'approved' | 'archived';
+
+export interface PrdTemplateSection {
+  id: string;
+  title: string;
+  fields: string[];
+}
+
+export interface PrdTemplate {
+  id: string;
+  name: string;
+  sections: PrdTemplateSection[];
+  fields: string[];
+}
+
+export interface PrdSection {
+  id: string;
+  title: string;
+  fields: Record<string, string>;
+}
+
+export interface PrdDocument {
+  id: string;
+  title: string;
+  status: PrdStatus;
+  projectPath: string;
+  template: string;
+  sections: PrdSection[];
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface CreatePrdOptions {
+  name: string;
+  projectPath: string;
+  template?: string;
+  interactive?: boolean;
+}

packages/prdy/src/wizard.ts

@@ -0,0 +1,103 @@
+import path from 'node:path';
+
+import { cancel, intro, isCancel, outro, select, text } from '@clack/prompts';
+
+import { createPrd, savePrd } from './prd.js';
+import type { CreatePrdOptions, PrdDocument } from './types.js';
+
+interface WizardAnswers {
+  goals: string;
+  constraints: string;
+  milestones: string;
+}
+
+function updateSectionField(doc: PrdDocument, sectionKeyword: string, value: string): void {
+  const section = doc.sections.find((candidate) => candidate.id.includes(sectionKeyword));
+
+  if (section === undefined) {
+    return;
+  }
+
+  const fieldName =
+    Object.keys(section.fields).find((field) => field.toLowerCase().includes(sectionKeyword)) ??
+    Object.keys(section.fields)[0];
+
+  if (fieldName !== undefined) {
+    section.fields[fieldName] = value;
+  }
+}
+
+async function promptText(message: string, initialValue = ''): Promise<string> {
+  const response = await text({
+    message,
+    initialValue,
+  });
+
+  if (isCancel(response)) {
+    cancel('PRD wizard cancelled.');
+    throw new Error('PRD wizard cancelled');
+  }
+
+  return response.trim();
+}
+
+async function promptTemplate(template?: string): Promise<string> {
+  if (template !== undefined && template.trim().length > 0) {
+    return template;
+  }
+
+  const choice = await select({
+    message: 'PRD type',
+    options: [
+      { value: 'software', label: 'Software project' },
+      { value: 'feature', label: 'Feature' },
+      { value: 'spike', label: 'Research spike' },
+    ],
+  });
+
+  if (isCancel(choice)) {
+    cancel('PRD wizard cancelled.');
+    throw new Error('PRD wizard cancelled');
+  }
+
+  return choice;
+}
+
+function applyWizardAnswers(doc: PrdDocument, answers: WizardAnswers): PrdDocument {
+  updateSectionField(doc, 'goal', answers.goals);
+  updateSectionField(doc, 'constraint', answers.constraints);
+  updateSectionField(doc, 'milestone', answers.milestones);
+
+  doc.updatedAt = new Date().toISOString();
+  return doc;
+}
+
+export async function runPrdWizard(options: CreatePrdOptions): Promise<PrdDocument> {
+  intro('Mosaic PRD wizard');
+
+  const name =
+    options.name.trim().length > 0 ? options.name.trim() : await promptText('Project name');
+  const template = await promptTemplate(options.template);
+  const goals = await promptText('Primary goals');
+  const constraints = await promptText('Key constraints');
+  const milestones = await promptText('Planned milestones');
+
+  const doc = await createPrd({
+    ...options,
+    name,
+    template,
+    interactive: true,
+  });
+
+  const updated = applyWizardAnswers(doc, {
+    goals,
+    constraints,
+    milestones,
+  });
+
+  await savePrd(updated);
+
+  outro(`PRD created: ${path.join(updated.projectPath, 'docs', 'prdy', `${updated.id}.yaml`)}`);
+
+  return updated;
+}

packages/quality-rails/package.json

@@ -1,6 +1,7 @@
 {
   "name": "@mosaic/quality-rails",
   "version": "0.0.0",
+  "type": "module",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "exports": {
@@ -15,7 +16,11 @@
     "typecheck": "tsc --noEmit",
     "test": "vitest run --passWithNoTests"
   },
+  "dependencies": {
+    "commander": "^12.0.0"
+  },
   "devDependencies": {
+    "@types/node": "^22.0.0",
     "typescript": "^5.8.0",
     "vitest": "^2.0.0"
   }

packages/quality-rails/src/cli.ts

@@ -0,0 +1,202 @@
+import { constants } from 'node:fs';
+import { access } from 'node:fs/promises';
+import { resolve } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+import { Command } from 'commander';
+
+import { detectProjectKind } from './detect.js';
+import { scaffoldQualityRails } from './scaffolder.js';
+import type { ProjectKind, QualityProfile, RailsConfig } from './types.js';
+
+const VALID_PROFILES: readonly QualityProfile[] = ['strict', 'standard', 'minimal'];
+
+async function fileExists(filePath: string): Promise<boolean> {
+  try {
+    await access(filePath, constants.F_OK);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+function parseProfile(rawProfile: string): QualityProfile {
+  if (VALID_PROFILES.includes(rawProfile as QualityProfile)) {
+    return rawProfile as QualityProfile;
+  }
+  throw new Error(`Invalid profile: ${rawProfile}. Use one of ${VALID_PROFILES.join(', ')}.`);
+}
+
+function defaultLinters(kind: ProjectKind): string[] {
+  if (kind === 'node') {
+    return ['eslint', 'biome'];
+  }
+
+  if (kind === 'python') {
+    return ['ruff'];
+  }
+
+  if (kind === 'rust') {
+    return ['clippy'];
+  }
+
+  return [];
+}
+
+function defaultFormatters(kind: ProjectKind): string[] {
+  if (kind === 'node') {
+    return ['prettier'];
+  }
+
+  if (kind === 'python') {
+    return ['black'];
+  }
+
+  if (kind === 'rust') {
+    return ['rustfmt'];
+  }
+
+  return [];
+}
+
+function expectedFilesForKind(kind: ProjectKind): string[] {
+  if (kind === 'node') {
+    return ['.eslintrc', 'biome.json', '.githooks/pre-commit', 'PR-CHECKLIST.md'];
+  }
+
+  if (kind === 'python') {
+    return ['pyproject.toml', '.githooks/pre-commit', 'PR-CHECKLIST.md'];
+  }
+
+  if (kind === 'rust') {
+    return ['rustfmt.toml', '.githooks/pre-commit', 'PR-CHECKLIST.md'];
+  }
+
+  return ['.githooks/pre-commit', 'PR-CHECKLIST.md'];
+}
+
+function printScaffoldResult(
+  config: RailsConfig,
+  filesWritten: string[],
+  warnings: string[],
+  commandsToRun: string[],
+): void {
+  console.log(`[quality-rails] initialized at ${config.projectPath}`);
+  console.log(`kind=${config.kind} profile=${config.profile}`);
+
+  if (filesWritten.length > 0) {
+    console.log('files written:');
+    for (const filePath of filesWritten) {
+      console.log(`  - ${filePath}`);
+    }
+  }
+
+  if (commandsToRun.length > 0) {
+    console.log('run next:');
+    for (const command of commandsToRun) {
+      console.log(`  - ${command}`);
+    }
+  }
+
+  if (warnings.length > 0) {
+    console.log('warnings:');
+    for (const warning of warnings) {
+      console.log(`  - ${warning}`);
+    }
+  }
+}
+
+export function createQualityRailsCli(): Command {
+  const program = new Command('mosaic');
+  const qualityRails = program
+    .command('quality-rails')
+    .description('Manage quality rails scaffolding');
+
+  qualityRails
+    .command('init')
+    .requiredOption('--project <path>', 'Project path')
+    .option('--profile <profile>', 'strict|standard|minimal', 'standard')
+    .action(async (options: { project: string; profile: string }) => {
+      const profile = parseProfile(options.profile);
+      const projectPath = resolve(options.project);
+      const kind = await detectProjectKind(projectPath);
+
+      const config: RailsConfig = {
+        projectPath,
+        kind,
+        profile,
+        linters: defaultLinters(kind),
+        formatters: defaultFormatters(kind),
+        hooks: true,
+      };
+
+      const result = await scaffoldQualityRails(config);
+      printScaffoldResult(config, result.filesWritten, result.warnings, result.commandsToRun);
+    });
+
+  qualityRails
+    .command('check')
+    .requiredOption('--project <path>', 'Project path')
+    .action(async (options: { project: string }) => {
+      const projectPath = resolve(options.project);
+      const kind = await detectProjectKind(projectPath);
+      const expected = expectedFilesForKind(kind);
+      const missing: string[] = [];
+
+      for (const relativePath of expected) {
+        const exists = await fileExists(resolve(projectPath, relativePath));
+        if (!exists) {
+          missing.push(relativePath);
+        }
+      }
+
+      if (missing.length > 0) {
+        console.error('[quality-rails] missing files:');
+        for (const relativePath of missing) {
+          console.error(`  - ${relativePath}`);
+        }
+        process.exitCode = 1;
+        return;
+      }
+
+      console.log(`[quality-rails] all expected files present for ${kind} project`);
+    });
+
+  qualityRails
+    .command('doctor')
+    .requiredOption('--project <path>', 'Project path')
+    .action(async (options: { project: string }) => {
+      const projectPath = resolve(options.project);
+      const kind = await detectProjectKind(projectPath);
+      const expected = expectedFilesForKind(kind);
+
+      console.log(`[quality-rails] doctor for ${projectPath}`);
+      console.log(`detected project kind: ${kind}`);
+
+      for (const relativePath of expected) {
+        const exists = await fileExists(resolve(projectPath, relativePath));
+        console.log(`  - ${exists ? 'ok' : 'missing'}: ${relativePath}`);
+      }
+
+      if (kind === 'unknown') {
+        console.log(
+          'recommendation: add package.json, pyproject.toml, or Cargo.toml for better defaults.',
+        );
+      }
+    });
+
+  return program;
+}
+
+export async function runQualityRailsCli(argv: string[] = process.argv): Promise<void> {
+  const program = createQualityRailsCli();
+  await program.parseAsync(argv);
+}
+
+const entryPath = process.argv[1] ? resolve(process.argv[1]) : '';
+if (entryPath.length > 0 && entryPath === fileURLToPath(import.meta.url)) {
+  runQualityRailsCli().catch((error: unknown) => {
+    console.error(error instanceof Error ? error.message : String(error));
+    process.exit(1);
+  });
+}

packages/quality-rails/src/detect.ts

@@ -0,0 +1,30 @@
+import { constants } from 'node:fs';
+import { access } from 'node:fs/promises';
+import { join } from 'node:path';
+
+import type { ProjectKind } from './types.js';
+
+async function fileExists(filePath: string): Promise<boolean> {
+  try {
+    await access(filePath, constants.F_OK);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+export async function detectProjectKind(projectPath: string): Promise<ProjectKind> {
+  if (await fileExists(join(projectPath, 'package.json'))) {
+    return 'node';
+  }
+
+  if (await fileExists(join(projectPath, 'pyproject.toml'))) {
+    return 'python';
+  }
+
+  if (await fileExists(join(projectPath, 'Cargo.toml'))) {
+    return 'rust';
+  }
+
+  return 'unknown';
+}

packages/quality-rails/src/index.ts

@@ -1 +1,5 @@
-export const VERSION = '0.0.0';
+export * from './cli.js';
+export * from './detect.js';
+export * from './scaffolder.js';
+export * from './templates.js';
+export * from './types.js';

packages/quality-rails/src/scaffolder.ts

@@ -0,0 +1,206 @@
+import { spawn } from 'node:child_process';
+import { chmod, mkdir, readFile, writeFile } from 'node:fs/promises';
+import { dirname, join } from 'node:path';
+
+import {
+  biomeTemplate,
+  eslintTemplate,
+  prChecklistTemplate,
+  preCommitHookTemplate,
+  pyprojectSection,
+  rustfmtTemplate,
+} from './templates.js';
+import type { RailsConfig, ScaffoldResult } from './types.js';
+
+const PYPROJECT_START_MARKER = '# >>> mosaic-quality-rails >>>';
+const PYPROJECT_END_MARKER = '# <<< mosaic-quality-rails <<<';
+
+async function ensureDirectory(filePath: string): Promise<void> {
+  await mkdir(dirname(filePath), { recursive: true });
+}
+
+async function writeRelativeFile(
+  projectPath: string,
+  relativePath: string,
+  contents: string,
+  result: ScaffoldResult,
+): Promise<void> {
+  const absolutePath = join(projectPath, relativePath);
+  await ensureDirectory(absolutePath);
+  await writeFile(absolutePath, contents, { encoding: 'utf8', mode: 0o644 });
+  result.filesWritten.push(relativePath);
+}
+
+async function upsertPyproject(
+  projectPath: string,
+  profile: RailsConfig['profile'],
+  result: ScaffoldResult,
+): Promise<void> {
+  const pyprojectPath = join(projectPath, 'pyproject.toml');
+  const nextSection = pyprojectSection(profile);
+
+  let previous = '';
+  try {
+    previous = await readFile(pyprojectPath, 'utf8');
+  } catch {
+    previous = '';
+  }
+
+  const existingStart = previous.indexOf(PYPROJECT_START_MARKER);
+  const existingEnd = previous.indexOf(PYPROJECT_END_MARKER);
+
+  if (existingStart >= 0 && existingEnd > existingStart) {
+    const before = previous.slice(0, existingStart).trimEnd();
+    const after = previous.slice(existingEnd + PYPROJECT_END_MARKER.length).trimStart();
+    const rebuilt = [before, nextSection.trim(), after]
+      .filter((segment) => segment.length > 0)
+      .join('\n\n');
+    await writeRelativeFile(projectPath, 'pyproject.toml', `${rebuilt}\n`, result);
+    return;
+  }
+
+  const separator = previous.trim().length > 0 ? '\n\n' : '';
+  await writeRelativeFile(
+    projectPath,
+    'pyproject.toml',
+    `${previous.trimEnd()}${separator}${nextSection}`,
+    result,
+  );
+}
+
+function runCommand(command: string, args: string[], cwd: string): Promise<void> {
+  return new Promise((resolve, reject) => {
+    const child = spawn(command, args, {
+      cwd,
+      stdio: 'ignore',
+      env: process.env,
+    });
+
+    child.on('error', reject);
+    child.on('exit', (code) => {
+      if (code === 0) {
+        resolve();
+        return;
+      }
+      reject(new Error(`Command failed (${code ?? 'unknown'}): ${command} ${args.join(' ')}`));
+    });
+  });
+}
+
+function buildNodeDevDependencies(config: RailsConfig): string[] {
+  const dependencies = new Set<string>();
+
+  if (config.linters.some((linter) => linter.toLowerCase() === 'eslint')) {
+    dependencies.add('eslint');
+    dependencies.add('@typescript-eslint/parser');
+    dependencies.add('@typescript-eslint/eslint-plugin');
+  }
+
+  if (config.linters.some((linter) => linter.toLowerCase() === 'biome')) {
+    dependencies.add('@biomejs/biome');
+  }
+
+  if (config.formatters.some((formatter) => formatter.toLowerCase() === 'prettier')) {
+    dependencies.add('prettier');
+  }
+
+  if (config.hooks) {
+    dependencies.add('husky');
+  }
+
+  return [...dependencies];
+}
+
+async function installNodeDependencies(config: RailsConfig, result: ScaffoldResult): Promise<void> {
+  const dependencies = buildNodeDevDependencies(config);
+  if (dependencies.length === 0) {
+    return;
+  }
+
+  const commandLine = `pnpm add -D ${dependencies.join(' ')}`;
+
+  if (process.env['MOSAIC_QUALITY_RAILS_SKIP_INSTALL'] === '1') {
+    result.commandsToRun.push(commandLine);
+    return;
+  }
+
+  try {
+    await runCommand('pnpm', ['add', '-D', ...dependencies], config.projectPath);
+  } catch (error) {
+    result.warnings.push(
+      `Failed to auto-install Node dependencies: ${error instanceof Error ? error.message : String(error)}`,
+    );
+    result.commandsToRun.push(commandLine);
+  }
+}
+
+export async function scaffoldQualityRails(config: RailsConfig): Promise<ScaffoldResult> {
+  const result: ScaffoldResult = {
+    filesWritten: [],
+    commandsToRun: [],
+    warnings: [],
+  };
+
+  const normalizedLinters = new Set(config.linters.map((linter) => linter.toLowerCase()));
+
+  if (config.kind === 'node') {
+    if (normalizedLinters.has('eslint')) {
+      await writeRelativeFile(
+        config.projectPath,
+        '.eslintrc',
+        eslintTemplate(config.profile),
+        result,
+      );
+    }
+
+    if (normalizedLinters.has('biome')) {
+      await writeRelativeFile(
+        config.projectPath,
+        'biome.json',
+        biomeTemplate(config.profile),
+        result,
+      );
+    }
+
+    await installNodeDependencies(config, result);
+  }
+
+  if (config.kind === 'python') {
+    await upsertPyproject(config.projectPath, config.profile, result);
+  }
+
+  if (config.kind === 'rust') {
+    await writeRelativeFile(
+      config.projectPath,
+      'rustfmt.toml',
+      rustfmtTemplate(config.profile),
+      result,
+    );
+  }
+
+  if (config.hooks) {
+    await writeRelativeFile(
+      config.projectPath,
+      '.githooks/pre-commit',
+      preCommitHookTemplate(config),
+      result,
+    );
+    await chmod(join(config.projectPath, '.githooks/pre-commit'), 0o755);
+    result.commandsToRun.push('git config core.hooksPath .githooks');
+  }
+
+  await writeRelativeFile(
+    config.projectPath,
+    'PR-CHECKLIST.md',
+    prChecklistTemplate(config.profile),
+    result,
+  );
+
+  if (config.kind === 'unknown') {
+    result.warnings.push(
+      'Unable to detect project kind. Generated generic rails only (hooks + PR checklist).',
+    );
+  }
+
+  return result;
+}

packages/quality-rails/src/templates.ts

@@ -0,0 +1,181 @@
+import type { QualityProfile, RailsConfig } from './types.js';
+
+const PROFILE_TO_MAX_WARNINGS: Record<QualityProfile, number> = {
+  strict: 0,
+  standard: 10,
+  minimal: 50,
+};
+
+const PROFILE_TO_LINE_LENGTH: Record<QualityProfile, number> = {
+  strict: 100,
+  standard: 110,
+  minimal: 120,
+};
+
+export function eslintTemplate(profile: QualityProfile): string {
+  return `${JSON.stringify(
+    {
+      root: true,
+      parser: '@typescript-eslint/parser',
+      plugins: ['@typescript-eslint'],
+      extends: ['eslint:recommended', 'plugin:@typescript-eslint/recommended'],
+      env: {
+        node: true,
+        es2022: true,
+      },
+      parserOptions: {
+        ecmaVersion: 'latest',
+        sourceType: 'module',
+      },
+      rules: {
+        'no-console': profile === 'strict' ? 'error' : 'warn',
+        '@typescript-eslint/no-explicit-any':
+          profile === 'minimal' ? 'off' : profile === 'strict' ? 'error' : 'warn',
+        '@typescript-eslint/explicit-function-return-type': profile === 'strict' ? 'warn' : 'off',
+        'max-lines-per-function': [
+          profile === 'minimal' ? 'off' : 'warn',
+          {
+            max: profile === 'strict' ? 60 : 100,
+            skipBlankLines: true,
+            skipComments: true,
+          },
+        ],
+      },
+    },
+    null,
+    2,
+  )}\n`;
+}
+
+export function biomeTemplate(profile: QualityProfile): string {
+  return `${JSON.stringify(
+    {
+      $schema: 'https://biomejs.dev/schemas/1.8.3/schema.json',
+      formatter: {
+        enabled: true,
+        indentStyle: 'space',
+        indentWidth: 2,
+        lineWidth: PROFILE_TO_LINE_LENGTH[profile],
+      },
+      linter: {
+        enabled: true,
+        rules: {
+          recommended: true,
+          suspicious: {
+            noConsole: profile === 'strict' ? 'error' : 'warn',
+          },
+          complexity: {
+            noExcessiveCognitiveComplexity:
+              profile === 'strict' ? 'warn' : profile === 'standard' ? 'info' : 'off',
+          },
+        },
+      },
+      javascript: {
+        formatter: {
+          quoteStyle: 'single',
+          trailingCommas: 'all',
+        },
+      },
+    },
+    null,
+    2,
+  )}\n`;
+}
+
+export function pyprojectSection(profile: QualityProfile): string {
+  const lineLength = PROFILE_TO_LINE_LENGTH[profile];
+  return [
+    '# >>> mosaic-quality-rails >>>',
+    '[tool.ruff]',
+    `line-length = ${lineLength}`,
+    'target-version = "py311"',
+    '',
+    '[tool.ruff.lint]',
+    'select = ["E", "F", "I", "UP", "B"]',
+    `ignore = ${profile === 'minimal' ? '[]' : '["E501"]'}`,
+    '',
+    '[tool.black]',
+    `line-length = ${lineLength}`,
+    '',
+    '# <<< mosaic-quality-rails <<<',
+    '',
+  ].join('\n');
+}
+
+export function rustfmtTemplate(profile: QualityProfile): string {
+  const maxWidth = PROFILE_TO_LINE_LENGTH[profile];
+  const useSmallHeuristics = profile === 'strict' ? 'Max' : 'Default';
+
+  return [
+    `max_width = ${maxWidth}`,
+    `use_small_heuristics = "${useSmallHeuristics}"`,
+    `imports_granularity = "${profile === 'minimal' ? 'Crate' : 'Module'}"`,
+    `group_imports = "${profile === 'strict' ? 'StdExternalCrate' : 'Preserve'}"`,
+    '',
+  ].join('\n');
+}
+
+function resolveHookCommands(config: RailsConfig): string[] {
+  const commands: string[] = [];
+
+  if (config.kind === 'node') {
+    if (config.linters.some((linter) => linter.toLowerCase() === 'eslint')) {
+      commands.push('pnpm lint');
+    }
+    if (config.linters.some((linter) => linter.toLowerCase() === 'biome')) {
+      commands.push('pnpm biome check .');
+    }
+    if (config.formatters.some((formatter) => formatter.toLowerCase() === 'prettier')) {
+      commands.push('pnpm prettier --check .');
+    }
+    commands.push('pnpm test --if-present');
+  }
+
+  if (config.kind === 'python') {
+    commands.push('ruff check .');
+    commands.push('black --check .');
+  }
+
+  if (config.kind === 'rust') {
+    commands.push('cargo fmt --check');
+    commands.push('cargo clippy --all-targets --all-features -- -D warnings');
+  }
+
+  if (commands.length === 0) {
+    commands.push('echo "No quality commands configured for this project kind"');
+  }
+
+  return commands;
+}
+
+export function preCommitHookTemplate(config: RailsConfig): string {
+  const commands = resolveHookCommands(config)
+    .map((command) => `${command} || exit 1`)
+    .join('\n');
+
+  return [
+    '#!/usr/bin/env sh',
+    'set -eu',
+    '',
+    'echo "[quality-rails] Running pre-commit checks..."',
+    commands,
+    'echo "[quality-rails] Checks passed."',
+    '',
+  ].join('\n');
+}
+
+export function prChecklistTemplate(profile: QualityProfile): string {
+  return [
+    '# Code Review Checklist',
+    '',
+    `Profile: **${profile}**`,
+    '',
+    '- [ ] Requirements mapped to tests',
+    '- [ ] Error handling covers unhappy paths',
+    '- [ ] Lint and typecheck are clean',
+    '- [ ] Test suite passes',
+    '- [ ] Security-sensitive paths reviewed',
+    `- [ ] Warnings count <= ${PROFILE_TO_MAX_WARNINGS[profile]}`,
+    '',
+  ].join('\n');
+}

packages/quality-rails/src/types.ts

@@ -0,0 +1,18 @@
+export type ProjectKind = 'node' | 'python' | 'rust' | 'unknown';
+
+export type QualityProfile = 'strict' | 'standard' | 'minimal';
+
+export interface RailsConfig {
+  projectPath: string;
+  kind: ProjectKind;
+  profile: QualityProfile;
+  linters: string[];
+  formatters: string[];
+  hooks: boolean;
+}
+
+export interface ScaffoldResult {
+  filesWritten: string[];
+  commandsToRun: string[];
+  warnings: string[];
+}

pnpm-lock.yaml

@@ -395,7 +395,26 @@ importers:
         version: 2.1.9(@types/node@22.19.15)(lightningcss@1.31.1)
 
   packages/prdy:
+    dependencies:
+      '@clack/prompts':
+        specifier: ^0.9.0
+        version: 0.9.1
+      commander:
+        specifier: ^12.0.0
+        version: 12.1.0
+      js-yaml:
+        specifier: ^4.1.0
+        version: 4.1.1
+      zod:
+        specifier: ^3.22.0
+        version: 3.25.76
     devDependencies:
+      '@types/js-yaml':
+        specifier: ^4.0.9
+        version: 4.0.9
+      '@types/node':
+        specifier: ^22.0.0
+        version: 22.19.15
       typescript:
         specifier: ^5.8.0
         version: 5.9.3
@@ -404,7 +423,14 @@ importers:
         version: 2.1.9(@types/node@22.19.15)(lightningcss@1.31.1)
 
   packages/quality-rails:
+    dependencies:
+      commander:
+        specifier: ^12.0.0
+        version: 12.1.0
     devDependencies:
+      '@types/node':
+        specifier: ^22.0.0
+        version: 22.19.15
       typescript:
         specifier: ^5.8.0
         version: 5.9.3
@@ -706,6 +732,12 @@ packages:
   '@borewit/text-codec@0.2.2':
     resolution: {integrity: sha512-DDaRehssg1aNrH4+2hnj1B7vnUGEjU6OIlyRdkMd0aUdIUvKXrJfXsy8LVtXAy7DRvYVluWbMspsRhz2lcW0mQ==}
 
+  '@clack/core@0.4.1':
+    resolution: {integrity: sha512-Pxhij4UXg8KSr7rPek6Zowm+5M22rbd2g1nfojHJkxp5YkFqiZ2+YLEM/XGVIzvGOcM0nqjIFxrpDwWRZYWYjA==}
+
+  '@clack/prompts@0.9.1':
+    resolution: {integrity: sha512-JIpyaboYZeWYlyP0H+OoPPxd6nqueG/CmN6ixBiNFsIDHREevjIf0n0Ohh5gr5C8pEDknzgvz+pIJ8dMhzWIeg==}
+
   '@discordjs/builders@1.13.1':
     resolution: {integrity: sha512-cOU0UDHc3lp/5nKByDxkmRiNZBpdp0kx55aarbiAfakfKJHlxv/yFW1zmIqCAmwH5CRlrH9iMFKJMpvW4DPB+w==}
     engines: {node: '>=16.11.0'}
@@ -2779,6 +2811,9 @@ packages:
   '@types/estree@1.0.8':
     resolution: {integrity: sha512-dWHzHa2WqEXI/O1E9OjrocMTKJl2mSrEolh1Iomrv6U+JuNwaHXsXx9bLu5gG7BUWFIN0skIQJQ/L1rIex4X6w==}
 
+  '@types/js-yaml@4.0.9':
+    resolution: {integrity: sha512-k4MGaQl5TGo/iipqb2UDG2UwjXziSWkh0uysQelTlJpX1qGlpUZYm8PnO4DxG1qBomtJUdYJ6qR6xdIah10JLg==}
+
   '@types/json-schema@7.0.15':
     resolution: {integrity: sha512-5+fP8P8MFNC+AyZCDxrB2pkZFPGzqQWUzpSeuuVLvm8VMcorNYavBqoFcxK8bQz4Qsbn4oUEEem4wDLfcysGHA==}
 
@@ -3253,6 +3288,10 @@ packages:
   colorette@2.0.20:
     resolution: {integrity: sha512-IfEDxwoWIjkeXL1eXcDiow4UbKjhLdq6/EuSVR9GMN7KVH3r9gQ83e73hsz1Nd1T3ijd5xv1wcWRYO+D6kCI2w==}
 
+  commander@12.1.0:
+    resolution: {integrity: sha512-Vw8qHK3bZM9y/P10u3Vib8o/DdkvA2OtPtZvD871QKjy74Wj1WSKFILMPRPSdUSx5RFK1arlJzEtA4PkFgnbuA==}
+    engines: {node: '>=18'}
+
   commander@13.1.0:
     resolution: {integrity: sha512-/rFeCpNJQbhSZjGVwO9RFV3xPqbnERS8MmIQzCtD/zl6gpJuV/bMLuN92oG3F7d8oDEHHRrujSXNUr8fpjntKw==}
     engines: {node: '>=18'}
@@ -4658,6 +4697,9 @@ packages:
     resolution: {integrity: sha512-bzyZ1e88w9O1iNJbKnOlvYTrWPDl46O1bG0D3XInv+9tkPrxrN8jUUTiFlDkkmKWgn1M6CfIA13SuGqOa9Korw==}
     engines: {node: '>=14'}
 
+  sisteransi@1.0.5:
+    resolution: {integrity: sha512-bLGGlR1QxBcynn2d5YmDX4MGjlZvy2MRBDRNHLJ8VI6l6+9FUiyTFNJ0IveOSP0bcXgVDPRcfGqA0pjaqUpfVg==}
+
   slice-ansi@5.0.0:
     resolution: {integrity: sha512-FC+lgizVPfie0kkhqUScwRu1O/lF6NOgJmlCgK+/LYxDCTk8sGelYaHDhFcDN+Sn3Cv+3VSa4Byeo+IMCzpMgQ==}
     engines: {node: '>=12'}
@@ -5146,6 +5188,9 @@ packages:
     peerDependencies:
       zod: ^3.25 || ^4
 
+  zod@3.25.76:
+    resolution: {integrity: sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==}
+
   zod@4.3.6:
     resolution: {integrity: sha512-rftlrkhHZOcjDwkGlnUtZZkvaPHCsDATp4pGpuOOMDaTdDDXF91wuVDJoWoPsKX/3YPQ5fHuF3STjcYyKr+Qhg==}
 
@@ -5594,6 +5639,17 @@ snapshots:
 
   '@borewit/text-codec@0.2.2': {}
 
+  '@clack/core@0.4.1':
+    dependencies:
+      picocolors: 1.1.1
+      sisteransi: 1.0.5
+
+  '@clack/prompts@0.9.1':
+    dependencies:
+      '@clack/core': 0.4.1
+      picocolors: 1.1.1
+      sisteransi: 1.0.5
+
   '@discordjs/builders@1.13.1':
     dependencies:
       '@discordjs/formatters': 0.6.2
@@ -6330,8 +6386,8 @@ snapshots:
   '@mistralai/mistralai@1.14.1':
     dependencies:
       ws: 8.19.0
-      zod: 4.3.6
-      zod-to-json-schema: 3.25.1(zod@4.3.6)
+      zod: 3.25.76
+      zod-to-json-schema: 3.25.1(zod@3.25.76)
     transitivePeerDependencies:
       - bufferutil
       - utf-8-validate
@@ -7659,6 +7715,8 @@ snapshots:
 
   '@types/estree@1.0.8': {}
 
+  '@types/js-yaml@4.0.9': {}
+
   '@types/json-schema@7.0.15': {}
 
   '@types/memcached@2.2.10':
@@ -8116,6 +8174,8 @@ snapshots:
 
   colorette@2.0.20: {}
 
+  commander@12.1.0: {}
+
   commander@13.1.0: {}
 
   concat-map@0.0.1: {}
@@ -9568,6 +9628,8 @@ snapshots:
 
   signal-exit@4.1.0: {}
 
+  sisteransi@1.0.5: {}
+
   slice-ansi@5.0.0:
     dependencies:
       ansi-styles: 6.2.3
@@ -10021,8 +10083,14 @@ snapshots:
 
   yoga-layout@3.2.1: {}
 
+  zod-to-json-schema@3.25.1(zod@3.25.76):
+    dependencies:
+      zod: 3.25.76
+
   zod-to-json-schema@3.25.1(zod@4.3.6):
     dependencies:
       zod: 4.3.6
 
+  zod@3.25.76: {}
+
   zod@4.3.6: {}