Daily Pulse Dev Skill

Follow this workflow for every code change, no matter how small.

Project Structure

daily-pulse/
├── daily-pulse.html      ← frontend UI only, no API key
├── api/
│   └── digest.js         ← Vercel serverless function, all Gemini calls
├── SKILL.md              ← this file
└── COWORK_HANDOFF.md     ← full app context and bug list

Live app: https://daily-pulse-theta.vercel.app/daily-pulse.html
API endpoint: https://daily-pulse-theta.vercel.app/api/digest
Vercel auto-deploys on every push to main.

---

Step 1 — Identify which file to edit

• API calls, URL validation, prompt logic, source filtering → api/digest.js
• UI rendering, card display, copy, persistence, merge logic → daily-pulse.html

Step 2 — Make the Edit

• Use surgical string replacement — never rewrite the whole file unless necessary
• After each replacement, verify the old string was found and replaced (print confirmation)
• If a replacement fails, print surrounding content to diagnose before retrying

Step 3 — Syntax Checks (for daily-pulse.html JS only)

import re
with open('daily-pulse.html', 'r') as f:
    content = f.read()
script_content = re.search(r'<script>([\s\S]*?)</script>', content).group(1)
backticks = script_content.count('`')
opens     = script_content.count('{')
closes    = script_content.count('}')
parens_o  = script_content.count('(')
parens_c  = script_content.count(')')
print(f"Backticks: {backticks} ({'OK' if backticks % 2 == 0 else 'UNBALANCED'})")
print(f"Braces:    {opens}/{closes} ({'OK' if opens == closes else 'UNBALANCED'})")
print(f"Parens:    {parens_o}/{parens_c} ({'OK' if parens_o == parens_c else 'UNBALANCED'})")

Do not commit if any check fails.

Common failure causes:

• Raw {} inside a template literal
• Duplicate closing backtick after a template literal
• Extra } left over from a regex replacement

Step 4 — Runtime JS Check (for daily-pulse.html JS only)

import re, subprocess, tempfile, os
with open('daily-pulse.html', 'r') as f:
    content = f.read()
script_content = re.search(r'<script>([\s\S]*?)</script>', content).group(1)
stub = '''
const localStorage = { getItem: () => null, setItem: () => {}, removeItem: () => {} };
const document = {
  getElementById: () => ({ style: {}, className: '', textContent: '', innerHTML: '', insertAdjacentHTML: () => {} }),
  createElement: () => ({ className: '', innerHTML: '', appendChild: () => {} }),
  querySelector: () => ({ textContent: '', className: '' }),
  body: { appendChild: () => {}, removeChild: () => {} }
};
const window = { addEventListener: () => {} };
const navigator = { clipboard: { writeText: () => Promise.resolve() } };
const fetch = () => Promise.resolve({ ok: true, json: () => Promise.resolve({}) });
'''
wrapped = stub + '\n(function() {\n' + script_content + '\n})();'
with tempfile.NamedTemporaryFile(mode='w', suffix='.js', delete=False) as f:
    f.write(wrapped); tmpfile = f.name
result = subprocess.run(['node', '--check', tmpfile], capture_output=True, text=True)
os.unlink(tmpfile)
print("✅ Runtime OK" if result.returncode == 0 else "❌ " + result.stderr)

Do not commit if this fails.

This catches: undefined function references, scoping issues, syntax errors that brace-counting misses.

Step 5 — Feature Integrity Check

Run before every commit. Verify these strings exist in each file:

daily-pulse.html must contain:

API_BASE, daily-pulse-theta.vercel.app, PAYWALLED_SOURCES, SOURCE_HOMES,
function runDigest, function mergeDigests, function renderSection,
function makeCard, function copyDigest, function restoreDigests,
currentSession, no_update_intl, no_update_local, source-chip-paywall,
card-time, Copy Morning to Capacities, Copy Evening to Capacities,
dp_digests, updateSubtitles

api/digest.js must contain:

GEMINI_KEY, PAYWALLED, APPROVED_DOMAINS, foxbusiness.com, hongkongfp.com,
apnews.com, theguardian.com, nbcnews.com, isArticleUrl, isApprovedDomain,
verifyUrl, validateAndClean, call1Prompt, call2Prompt, call3Prompt,
callGemini, placeholder, example.com, export default,
Access-Control-Allow-Origin

Do not commit if any are missing.

Step 6 — Commit and Push

• Push to main branch — Vercel auto-deploys within 30 seconds
• Wait for green Ready status in Vercel dashboard before testing

Step 7 — Test the Live App

Open https://daily-pulse-theta.vercel.app/daily-pulse.html

• Tap ☀️ Morning — wait up to 90 seconds
• Run at least 3 times before declaring a fix successful
• Check all items in the testing checklist (see COWORK_HANDOFF.md)

Step 8 — Draft Commit Message

Title (fewer than 50 characters)

• Imperative tense: "Fix", "Add", "Remove", "Update"
• Specific — name the thing that changed
• No full stop
• Examples:
  • Fix STOP grounding empty response retry
  • Reject fabricated placeholder sources
  • Add URL verification to digest.js

Extended description

• Bullet points only
• Each bullet: what changed and why
• End with: No changes to [X] for anything deliberately untouched
• Under 100 words total

---

App Reference

Property	Value
Live app	https://daily-pulse-theta.vercel.app/daily-pulse.html
API	https://daily-pulse-theta.vercel.app/api/digest
GitHub	https://github.com/claywintringham/daily-pulse
API key	In Vercel env as GEMINI_API_KEY — never in code
Primary model	gemini-2.5-flash
Fallback model	gemini-2.5-flash-lite
Morning	2 intl + 2 local headlines
Evening	1 intl + 1 local headline
Paywalled	WSJ, Bloomberg, FT — chip shown 🔒, never linked
Recency	Morning: last 12h · Evening: last 6h
Summary limit	70 words, complete sentences only
Story time	"Published X hours ago" in accent colour