Chicago Free Museum Days

A Bluesky bot that posts weekly updates about free museum days in Chicago, built on Val Town.

🤖 Follow the bot: chicagomuseumdays.bsky.social

Many Chicago museums offer free admission days for Illinois residents, but finding this information is scattered and hard to track. This project:

1. Scrapes free museum day data from Choose Chicago
2. Normalizes dates (handles ranges, recurring patterns like "every Wednesday")
3. Stores data in SQLite with manual override support
4. Posts weekly summaries to Bluesky every Monday morning
5. Serves data via a public JSON API

Choose Chicago (HTML)
    ↓
scrapeChooseChicago() → [{institution, rawLines[], url}]
    ↓
normalizeDates() → [{institution, date, time, proof_required, notes}]
    ↓
loadToSQLite() → scraped_free_days table
    ↓
    ├── bot.cron.ts → Bluesky post (weekly)
    └── api.http.ts → JSON API (on-demand)

Once deployed, the HTTP val exposes:

{
  "data": [
    {
      "institution": "Art Institute of Chicago",
      "date": "2025-01-27",
      "time": "11am-close",
      "proof_required": "Illinois residents with ID",
      "notes": null
    }
  ],
  "count": 1
}

Two SQLite tables with override support:

• scraped_free_days — Auto-populated by scrapers, replaced on each run
• free_days_overrides — Manual corrections that take precedence

Uses institution_key (slugified name) for reliable matching across sources. Overrides can also cancel incorrect scraped entries via is_cancelled.

Copy the backend files to your Val Town project. Files ending in .cron.ts become cron vals, .http.ts becomes an HTTP val.

In Val Town secrets, add:

BLUESKY_HANDLE=your-handle.bsky.social
BLUESKY_PASSWORD=your-app-password

Tip: Use a Bluesky App Password instead of your main password.

Run scraper.cron.ts manually to populate initial data.

Timezone Note: Val Town cron runs in UTC. For 8am Central Time:

• Winter (CST, UTC-6): 0 14 * * 1
• Summer (CDT, UTC-5): 0 13 * * 1

The utils module handles various date formats:

• Specific dates: "January 15" → 2025-01-15
• Date ranges: "January 5 - February 28" → expands to individual dates
• Recurring: "every Wednesday" → generates dates for next 12 months
• Weekdays: "weekdays only" → generates Mon-Fri for next 12 months

Lines are classified as either date-ish or note-ish using pattern matching, since Choose Chicago mixes dates and eligibility requirements in the same lists.

• cheerio — HTML parsing
• chrono-node — Natural language date parsing
• @atproto/api — Bluesky SDK
• hono — Lightweight web framework

Data corrections can be added via the free_days_overrides table:

import { addOverride } from "./db.ts";

await addOverride("Art Institute of Chicago", "2025-02-15", {
  time: "10am-5pm",
  notes: "Presidents Day special hours",
  override_reason: "Confirmed via museum website",
});

To cancel an incorrect scraped entry:

await addOverride("Some Museum", "2025-03-01", {
  is_cancelled: true,
  override_reason: "Event was cancelled per museum announcement",
});

Monthly:

• Review scraper logs for parsing failures
• Add overrides for unparseable dates

Quarterly:

• Audit data against official museum websites
• Update parser patterns if needed

• Implementation Spec — Full technical details
• Val Town Docs
• Choose Chicago Source

MIT