OpenAI 2026 hackathon

Tennis Calendar Bridge

Every tennis booking, one dependable calendar.

Solo project by Zongren Liu · 0 likes · 0 comments

Archive position — measured, not model output

0 likes on Devpost

2,264 of the 7,856 archived projects have more likes, and 5,592 share exactly 0 — so this project's #7,192 place in the like-ranked listing is a tie-break inside that group, not a ranking.

Projects (log scale)

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Likes on Devpost. ▲ marks this project's group.

Show the figures
LikesProjectsShare of archive
05,59271.2%
11,75822.4%
22853.6%
3–41321.7%
5–9751.0%
10+140.2%
Devpost like counts for all 7,856 archived projects, captured when this archive was built.

Executive Summary

What the company appears to be

The project described as "Tennis Calendar Bridge" is a self-contained software tool built by one developer (Zongren Liu) that aggregates tennis booking data from multiple club portals into a single calendar view. It offers a private dashboard, an iCalendar feed for external calendar clients, and an optional GPT-5.6-generated weekly summary.

What changed

This is a self-reported personal project submitted to the OpenAI 2026 hackathon. No prior version or commercial product is evidenced; it is described as a v0.2.0 release with synthetic data and a two-minute judge path.

Single most important open question

Is there any evidence of actual usage, customer feedback, or traction beyond the author's own development and testing?

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What The Product Actually Is

The description states that Tennis Calendar Bridge:

  • Signs into configured, authorized club portals
  • Normalizes lessons, clinics, and reservations into one local event store
  • Publishes:
    • A private dashboard
    • A tokenized iCalendar feed for Apple Calendar, Google Calendar, and other clients
    • An opt-in GPT-5.6 weekly brief that turns the next seven days into an at-a-glance plan, logistics, and watch-outs

It uses Playwright adapters to produce normalized Python event models stored in SQLite. The system is described as deterministic and does not write to personal calendars.

Inference The tool appears to be a local utility for managing tennis schedules across multiple platforms, with optional AI summarization features.

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Positioning & Claim Evolution

The author states:

  • “Every tennis booking, one dependable calendar.”
  • The system avoids giving another service permission to write to the user’s personal calendar.
  • It is built to avoid exposing sensitive data like real venue names or credentials.

Inference Positioning centers on privacy and convenience for users who play across multiple clubs. The claim evolution suggests a focus on minimal data exposure, deterministic behavior, and optional AI enhancement.

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Target Customer & ICP

The description states:

  • The tool addresses players who “play across multiple tennis clubs”
  • It helps answer the question: “when am I playing next?”
  • It is designed for users who check several systems and hope nothing changed

Inference The target customer is likely a recreational or semi-professional tennis player who uses multiple club booking systems. The ICP appears to be individuals seeking calendar consolidation without sacrificing privacy.

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Business Model & Pricing Evidence

Not evidenced.

Explanation

There is no mention of pricing, monetization, or business model in the description. No revenue streams, subscriptions, or paid features are described.

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Technical & Delivery Signals

The author states:

  • Built with: codex, github-actions, gpt-5.6, icalendar, openai-responses-api, playwright, python, sqlite
  • Uses provider-specific Playwright adapters to normalize events into a local SQLite store
  • Renders a private dashboard and standards-based .ics feed
  • GPT-5.6 is used for cross-event synthesis only; not for scraping or writing calendar events
  • Credentials and raw data remain local
  • A privacy filter creates minimal API requests with pseudonymous labels
  • The system includes CI with tests, linting, typing, and package builds

Inference The technical stack suggests a lightweight, local-first solution using Python, Playwright, and SQLite. The use of AI is limited to summarization and pattern recognition, not data ingestion or modification.

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Traction & Maturity Signals

Not evidenced.

Explanation

There is no evidence of users, customers, or adoption beyond the author’s own testing and synthetic data. No metrics, usage statistics, or feedback are provided.

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Competitive Context

Not evidenced.

Explanation

No mention of competitors or market context is present in the description. The project does not reference existing tools or platforms in the tennis booking or calendar space.

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Key Risks & Red Flags

  • No commercial traction or users: The tool is described as a personal hackathon submission with no evidence of real-world adoption.
  • Self-reported only: All claims are unverified and based on author’s own account.
  • Limited scope: The system works only for tennis clubs, not general calendar or scheduling tools.
  • AI dependency: While optional, the GPT-5.6 component introduces a potential point of failure or cost if scaled.

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Diligence Questions To Ask The Founders

  1. What is the actual user base or feedback from people using this tool?
  2. Has there been any attempt to monetize or scale this beyond the hackathon version?
  3. Are there plans to support more tennis clubs or extend functionality beyond calendar aggregation?
  4. How does the system handle edge cases like overlapping events, cancellations, or time zone differences?
  5. What are the long-term maintenance and scalability concerns for the Playwright adapters?

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Investment/Partnership Verdict

Not evidenced.

Explanation

There is no evidence of a commercial product, revenue, or traction to support an investment or partnership decision. The project is described as a personal hackathon submission with synthetic data and no real-world usage. Any potential for future development remains speculative.

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Source

Submitted to the OpenAI 2026 hackathon on Devpost. Project home on DevPost.

The analysis above was generated by a language model from the project's own one-line description. It is not independent research and contains no verified traction, revenue or customer data.