peng-post-to-hackernews

name	peng-post-to-hackernews
description	Posts URL stories to Hacker News from Markdown. Uses curl-based HTTP authentication (no browser required). Supports preview mode (verify session) and auto-submit. Use when user asks to "post to Hacker News", "submit to HN", "share on Hacker News", or provides a markdown file for HN submission.

Post to Hacker News

Post a URL story to Hacker News from a Markdown file using curl-based HTTP authentication. No browser required — works entirely via HTTP requests.

Script Directory

{baseDir} = this SKILL.md's directory. Resolve ${BUN_X}: prefer bun; else npx -y bun; else suggest brew install oven-sh/bun/bun.

Script	Purpose
scripts/hn-post.ts	Post a markdown file to Hacker News
scripts/md-to-hn.ts	Parse and preview HN post structure

Prerequisites

• bun runtime (brew install oven-sh/bun/bun)
• curl (usually pre-installed)
• Environment variables set:
  • HN_USERNAME — your Hacker News username
  • HN_PASSWORD — your Hacker News password

Environment Variables

Variable	Required	Description
HN_USERNAME	Yes	Hacker News account username
HN_PASSWORD	Yes	Hacker News account password
HN_PROXY	No	HTTP proxy URL (e.g. http://127.0.0.1:7890)
HN_CHROME_PATH	No	Chrome executable path (for profile detection only)

Set them in your shell:

export HN_USERNAME="your_username"
export HN_PASSWORD="your_password"

Or in a .env file in the project root.

Markdown Format

Use YAML frontmatter with title and url fields.

See references/hn-format.md for full spec.

---
title: "Your post title"
url: "https://example.com/your-article"
auto_submit: false
---

Preview Post Structure

Before posting, preview how the markdown will be parsed:

${BUN_X} {baseDir}/scripts/md-to-hn.ts <file.md>

Post to Hacker News

Preview mode (default)

${BUN_X} {baseDir}/scripts/hn-post.ts <file.md>

Verifies your HN session (logs in if needed), fetches the submit form, and confirms credentials are valid. Does not submit. You can then manually submit via the browser.

Auto-submit

${BUN_X} {baseDir}/scripts/hn-post.ts <file.md> --submit

Logs in (if needed), fetches the CSRF token (fnid), and submits the story automatically. Reports the posted item URL.

With options

${BUN_X} {baseDir}/scripts/hn-post.ts <file.md> --submit --profile ~/.chrome/hn-profile
${BUN_X} {baseDir}/scripts/hn-post.ts <file.md> --submit --chrome /path/to/chrome

Parameters

Parameter	Description
<file.md>	Markdown file with frontmatter (required)
--submit	Submit automatically (default: preview mode)
--profile <dir>	Cookies/profile directory (default: ~/.baoyu-skills/hn-profile)
--chrome <path>	Chrome executable path (for profile detection)

Workflow

1. Parse markdown: extract title and url from frontmatter
2. Validate: check title length, URL validity
3. Check HN_USERNAME and HN_PASSWORD env vars
4. Check for existing session cookies (skip login if valid)
5. If no valid session: POST to /login with credentials, save cookies
6. GET /submit to retrieve fnid (CSRF token)
7. If preview mode: stop, report session status
8. If --submit: POST to /r with fnid + title + url
9. Report result (post URL or error)

Troubleshooting

Issue	Fix
HN_USERNAME not set	export HN_USERNAME="your_username"
HN_PASSWORD not set	export HN_PASSWORD="your_password"
Login failed	Check credentials; password may have changed
This URL has already been posted	HN does not allow duplicate URL submissions
Could not retrieve fnid	Session expired; delete cookies file and retry
Submission failed	Check .err message in response; may need to re-login

Notes

• Session cookies are persisted in the profile directory for subsequent runs
• HN does not allow posting the same URL twice — check if already submitted
• Only URL posts are supported (not text posts like Ask HN / Show HN)
• Cross-platform: macOS, Linux, Windows (requires curl)