About
Personal site. Home for projects I build outside of work — mostly small, AI-powered tools for myself and people close to me.
SMS Calendar
A personal productivity tool. Text a calendar event in plain English to a dedicated phone number, and the system creates the event on a shared Google Calendar and texts back a one-line confirmation.
How opt-in works
The two recipients on this service opted in via direct verbal consent in person. Below is the verbatim script of that conversation.
David Jung: "Hey, I built a calendar tool. You can text events in plain English to a dedicated number — like 'dinner Friday 7pm at home' — and it'll add them to our shared Google Calendar and text you back a one-line confirmation."
David Jung: "If you opt in, the number will send you about 25 messages per month — confirmations of events you texted in, occasional clarifying questions when a message is too vague to parse, and error messages if something fails. No marketing, no broadcasts, no links."
David Jung: "Standard message and data rates from your carrier may apply. You can reply STOP at any time to stop receiving messages, or HELP to get a short description of the service and a link to davidjung.dev."
David Jung: "Want me to add your number to the allowlist?"
J: "Yes."
David Jung: "Done — sending a confirmation text now."
David Jung: "And let me know any time if you want me to take you off — or just text STOP — I can remove your number whenever, no questions asked."
Who can use it
Two people: myself and one other recipient who has explicitly opted in. The system maintains a hardcoded allowlist of two phone numbers in its environment configuration. Any message received from a number not on the allowlist is rejected with an automated "not authorized" reply, and no further action is taken. The allowlist is not user-editable, not exposed via any interface, and cannot grow beyond what is set in the deployment configuration.
What the system sends
- Confirmations. When an event is added, the system replies with the event title, date, time, and location, plus a short context-appropriate closer (e.g. "Have fun!", "Safe travels!").
- Clarifications. If the inbound text is too vague to parse (e.g. "dinner sometime?"), the system replies with a single short follow-up question.
- Errors. If event creation fails, the system replies with a brief friendly error message and asks the recipient to rephrase.
No marketing, no promotions, no broadcast messaging, no link shortening, and no embedded URLs in outbound content.
Opt-out and help
Replying STOP unsubscribes the sender immediately. Replying HELP returns a short description of the service and this URL.
Volume
Approximately 50 outbound messages per month total — around 25 per person — based on 30 days of operational history.
Privacy
The SMS Calendar tool collects only the data needed to operate. Phone numbers on the allowlist live in deployment environment configuration. Inbound message content is processed in memory to extract calendar event details and is not persisted by this service; Twilio retains its own message logs separately under Twilio's retention policy. Calendar events are written to a Google Calendar shared between the two recipients.
Operational dependencies are limited to: Twilio (SMS transport), Anthropic (natural-language parsing), and Google (calendar storage). No data is shared with any other third party. No analytics, advertising, or tracking pixels are used by this service or this site.
Terms
The SMS Calendar tool is a personal productivity tool operated by David Jung for non-commercial use between two specific recipients. Use of the service is limited to the allowlisted phone numbers. The service is provided as-is for personal scheduling assistance with no guarantee of availability. Standard mobile messaging rates may apply per the recipient's carrier; outbound messages are billed via the operator's Twilio account.