feat(wbfy): add generate-user-agent-instructions command

packages/wbfy/README.md

@@ -17,3 +17,4 @@ This tool must keep idempotency, i.e., it always yields the same result when a u
 ## How to Use
 
 1. `bunx @willbooster/wbfy <project directory>`
+2. `bunx @willbooster/wbfy generate-user-agent-instructions` to overwrite your user-level agent instruction files (`~/.codex/AGENTS.md`, `~/.claude/CLAUDE.md`, `~/.gemini/GEMINI.md`) with the organization's fixed content

packages/wbfy/src/generators/userAgentInstructions.ts

@@ -0,0 +1,29 @@
+import os from 'node:os';
+import path from 'node:path';
+
+import { fsUtil } from '../utils/fsUtil.js';
+
+/**
+ * The user-level instruction file of each supported agent, relative to the home directory. These
+ * apply to every repository the agent works in, so they hold only the conventions that are true on
+ * every WillBooster developer machine rather than in a particular repository.
+ */
+const userAgentInstructionFilePaths = ['.codex/AGENTS.md', '.claude/CLAUDE.md', '.gemini/GEMINI.md'] as const;
+
+const userAgentInstructionContent = `- Repos live under \`~/ghq/github.com\`; always clone with \`ghq get -p\`, never \`git clone\`.
+- LLM/AI agent responses may take 1–2 hours; wait patiently, don't assume failure.
+- No AI attribution (e.g., \`Co-Authored-By\` trailers, "Generated with ..." footers) in commits, issues, or PRs unless explicitly requested. This hides nothing: if asked which AI agent did the work, answer truthfully.
+`;
+
+/**
+ * Overwrites the user-level instruction files of every supported agent with the fixed content.
+ * Returns false when any file was skipped (e.g. a symlinked file), so the command can fail loudly.
+ */
+export async function generateUserAgentInstructions(): Promise<boolean> {
+  let hasWrittenAll = true;
+  for (const relativePath of userAgentInstructionFilePaths) {
+    const hasWritten = await fsUtil.generateFile(path.join(os.homedir(), relativePath), userAgentInstructionContent);
+    hasWrittenAll &&= hasWritten;
+  }
+  return hasWrittenAll;
+}

packages/wbfy/src/index.ts

@@ -30,6 +30,7 @@ import { generateReadme, readAppliedWbfyVersionLabel } from './generators/readme
 import { generateReleaserc } from './generators/releaserc.js';
 import { generateRenovateJsonc } from './generators/renovateJsonc.js';
 import { generateTsconfig } from './generators/tsconfig.js';
+import { generateUserAgentInstructions } from './generators/userAgentInstructions.js';
 import { generateVscodeSettings } from './generators/vscodeSettings.js';
 import { ensureWbEnvDefinitions } from './generators/wbEnv.js';
 import { generateSelfContainedWorkflows } from './generators/selfContainedWorkflow.js';
@@ -58,13 +59,19 @@ import { getWorkspaceSubDirPaths } from './utils/workspaceUtil.js';
  * name would swallow a directory that happens to share it.
  */
 const applyReleaseAgeGateCommand = 'apply-release-age-gate';
+/** Same naming rationale as applyReleaseAgeGateCommand. */
+const generateUserAgentInstructionsCommand = 'generate-user-agent-instructions';
 
 async function main(): Promise<void> {
   const argv = await yargs(process.argv.slice(2))
     .command(
       applyReleaseAgeGateCommand,
       "Apply only the organization's minimum-release-age policy to this machine's global package-manager configs"
     )
+    .command(
+      generateUserAgentInstructionsCommand,
+      "Overwrite this user's agent instruction files (~/.codex/AGENTS.md, ~/.claude/CLAUDE.md, ~/.gemini/GEMINI.md) with the organization's fixed content"
+    )
     .command('$0 [paths..]', 'Make a given project follow the WillBooster standard', (yargs) => {
       yargs.positional('paths', {
         describe: 'project paths to be wbfied',
@@ -104,6 +111,10 @@ async function main(): Promise<void> {
     if (!ensureGlobalReleaseAgeGates()) process.exitCode = 1;
     return;
   }
+  if (argv._[0] === generateUserAgentInstructionsCommand) {
+    if (!(await generateUserAgentInstructions())) process.exitCode = 1;
+    return;
+  }
 
   let hasInvalidPackageConfig = false;
   try {