Skip to content

HexBot — Calendar ICS

Status: Live on main
Source: lib/calendar-ics.ts
Related issue: hexbot #3

HexBot can detect reminder/note output from its own replies and offer the user a one-click .ics calendar file download, compatible with Google Calendar, Apple Calendar, and Outlook.

Pipeline Overview

User sends message
       │
       ▼
detectTaskIntent(userText)     ← fires before API call
       │
       ▼
Hex API streams reply
       │
       ▼
detectCalendarIntent(reply)    ← fires after stream completes
       │
       ▼
ActionPanel merges task + calendar data
       │
       ▼
User clicks "download .ics" → hexReminderToCalendar() → browser download

Functions

detectCalendarIntent(assistantText)

Scans the assistant reply for reminder/note creation patterns. Returns a CalendarIntent object or null.

import { detectCalendarIntent } from "@/lib/calendar-ics";

const intent = detectCalendarIntent(hexReply);
if (intent) {
  // offer .ics download
}

Trigger patterns matched:

Pattern Example
Reminder set: ... Structured output header
Reminder Details: Structured block header
Note created: ... Legacy note format
Note to Self: ... Format C header
Reminder: <text> at line start Hex's most common inline format
Note: <text> at line start Inline note format
reminder + time signal in same message Catch-all for date-bearing reminders

parseHexReminder(raw)

Extracts structured fields from raw HexBot reminder text. Handles three output formats.

Format A — Structured block

Reminder Details:
Date: 3 days from now
Priority: Medium
Description: Review codebase for bottlenecks.
Notification: You'll receive a notification 1 day before the reminder is due.

Format B — Inline

Reminder: Review HexBot's architecture in the next 6-8 weeks to assess restructuring needs.

Format C — Note to Self

Note to Self: Hex Restructure
Reminder: As Hex continues to evolve...
Priority: Medium-High
Deadline: Review and assessment within 6-8 weeks.

Extracted fields:

Field Source Default
summary Title line (Note to Self > Reminder set > inline Reminder) First non-label line
daysOffset N days from now, N weeks from now, in the next N weeks, range midpoint 3
priority Priority: <value> — supports Medium-High Medium
description Description: block, then Next Steps:, then Deadline: ""
alarmMinutes Notification: N days/hours/minutes before 1440 (1 day)

Date range handling:
6-8 weeks → midpoint → 7 weeks → 49 days. Same logic for day ranges.

buildIcs(config)

Builds a standards-conformant iCalendar string (RFC 5545).

const ics = buildIcs({
  summary: "Review HexBot architecture",
  description: "Identify bottlenecks, consider restructure.",
  start: new Date("2026-05-01T13:00:00"),
  end:   new Date("2026-05-01T14:00:00"),
  alarmMinutes: 1440,
});

Produces: VCALENDAR > VEVENT with optional VALARM block. UIDs are generated via crypto.randomUUID() in the format hexbot-<uuid>@manitec.local.

downloadIcs(filename, content)

Triggers a browser blob download. Browser-only — do not call server-side.

downloadIcs("review-hexbot-architecture.ics", icsString);

hexReminderToCalendar(rawAssistantText, autoDownload?)

Full one-call pipeline: parse → build → download.

const { ics, filename, parsed } = hexReminderToCalendar(hexReply);
// autoDownload defaults to true — triggers browser download immediately

// To get the ICS string without downloading:
const { ics } = hexReminderToCalendar(hexReply, false);

isCalendarRequest(userText)

Detects whether the user's own message is explicitly requesting a calendar action.

isCalendarRequest("add the note as a reminder"); // true
isCalendarRequest("what's the weather");          // false

Confidence Levels

Level Meaning
high Explicit N days/weeks from now or tomorrow found
medium Date range found, or in the next N weeks phrasing
low No date signal detected; defaults used

Known Limitations / Future Work

  • Google Calendar direct insert — OAuth flow not yet implemented; currently .ics download only
  • Note/reminder persistence — reminders are not stored to Firebase; session clear loses them
  • Session persistence — identified in the HexBot architecture review note as a priority gap