Cal Bridge Inc v. Onecal

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Cal Bridge, Inc. (Delaware)
  • Defendant: OneCal, SH.P.K. (Albania)
  • Plaintiff’s Counsel: Tucker Law; McAndrews, Held & Malloy, Ltd.
• Case Identification: 1:24-cv-22361, S.D. Fla., 02/17/2026
• Venue Allegations: Plaintiff alleges venue is proper because Defendant does substantial business in the district, offers the accused products to customers in Florida, and one or more users in Florida have purchased and used the accused products.
• Core Dispute: Plaintiff alleges that Defendant’s OneCal calendar synchronization system infringes a patent related to privacy-sensitive, multi-calendar synchronization technology.
• Technical Context: The technology addresses the problem of synchronizing events across multiple, disparate electronic calendar platforms (e.g., Google Calendar, Microsoft Outlook) while providing user control over privacy, notifications, and the specific event details that are shared.
• Key Procedural History: The complaint alleges that Defendant’s founder signed up for Plaintiff’s CalendarBridge platform on February 3, 2023, and announced the launch of the accused competing product less than two weeks later. The complaint also states that Plaintiff’s counsel sent a cease and desist letter to Defendant in January 2024, providing pre-suit notice of the patent-in-suit.

Case Timeline

Date	Event
2020-02-18	U.S. Patent No. 11,461,739 Priority Date
2020-05-14	Plaintiff's CalendarBridge solution launched
2022-10-04	U.S. Patent No. 11,461,739 issued
2023-02-03	Defendant's founder allegedly signed up for Plaintiff's platform
2023-02-15	Defendant's founder announced launch of Accused OneCal System
2024-01-XX	Plaintiff sent cease and desist letter to Defendant
2024-01-31	Plaintiff allegedly began marking its website with the '739 patent number
2024-02-26	Defendant responded to Plaintiff's cease and desist letter
2026-02-17	Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 11,461,739 - "Privacy-Sensitive, Multi-Calendar Synchronization"

• Issued: October 4, 2022 (the “’739 Patent”)

The Invention Explained

• Problem Addressed: The patent describes the technical challenges users face when managing schedules across multiple electronic calendars, often hosted by different providers like Google and Microsoft (’739 Patent, col. 2:21-30). Conventional systems require syncing each calendar locally to a specific client device, leading to fragmented views, double-bookings, and difficulties in maintaining privacy when sharing calendar information across different personal and professional contexts (’739 Patent, col. 2:1-20; ’739 Patent, col. 2:45-49). Different calendar hosts use proprietary Application Programming Interfaces (APIs), creating a barrier to direct, server-side synchronization between hosts (’739 Patent, col. 2:8-14).
• The Patented Solution: The invention is a centralized calendar synchronization system that acts as a bridge between different calendar hosts (’739 Patent, FIG. 1). The system uses a database service to store user-defined rules that dictate how event information is propagated from a source calendar to a destination calendar (’739 Patent, col. 3:15-21; ’739 Patent, FIG. 7C). A calendar synchronization service receives notifications of new or changed events from one calendar host via an API and, based on the stored rules, issues commands to the other calendar host to create a corresponding event, allowing for granular control over what information (e.g., full details, subject only, or just "busy") is shared (’739 Patent, col. 4:15-39).
• Technical Importance: This approach centralizes synchronization logic, removing the dependency on individual client devices and enabling real-time, rule-based sharing of calendar data across otherwise incompatible platforms (Compl. ¶¶14, 16).

Key Claims at a Glance

• The complaint asserts independent claim 11 and dependent claims 13-17 (Compl. ¶29).
• Independent Claim 11:
  • A system comprising circuitry configured to operate as a calendar synchronization service and circuitry configured to operate as a database service.
  • The database service is configured to store rules for propagating events from a first electronic calendar to a second.
  • The rules determine what event properties are propagated and what notifications, if any, are added to the second calendar.
  • The calendar synchronization service is configured to receive, via an API, a notification of a first event on the first calendar.
  • The calendar synchronization service is configured to issue one or more commands to the second calendar host to generate a second event according to the stored rules.
• The complaint alleges infringement of dependent claims 13-17 but does not reserve the right to assert other dependent claims (Compl. ¶29).

III. The Accused Instrumentality

Product Identification

• The "Accused OneCal System," a cloud-based calendar synchronization service (Compl. ¶¶21-22).

Functionality and Market Context

• The Accused OneCal System is a cloud-based service that automatically synchronizes a user's calendar events across multiple calendars, such as those on Google and Microsoft platforms (Compl. ¶22). Users connect their calendar accounts and establish "sync configuration" rules that control how events are copied, or "cloned," from one calendar to another (Compl. ¶33). These rules allow users to choose which event properties (e.g., titles, description, participants) are synchronized and to manage reminder notifications for the cloned events (Compl. ¶¶33-35). The system uses APIs from calendar providers like Google and Microsoft to receive notifications of calendar changes and to create new events on other calendars (Compl. ¶¶36-37). A screenshot from the OneCal documentation shows a side-by-side view of a Google Calendar and an Outlook Calendar with events synchronized between them (Compl. ¶32).
• The complaint alleges that Defendant explicitly markets the Accused OneCal System as "a CalendarBridge alternative" and directly targets Plaintiff's customers (Compl. ¶24).

IV. Analysis of Infringement Allegations

’739 Patent Infringement Allegations

Claim Element (from Independent Claim 11)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
A system comprising: circuitry configured to operate as a calendar synchronization service and circuitry configured to operate as a database service...	The Accused OneCal System is a system using Vercel and AWS cloud computing infrastructure, which allegedly contains circuitry configured to operate as a calendar synchronization and database service.	¶32	col. 3:5-8
the database service is configured to store rules for propagating events from a first electronic calendar hosted by a first calendar host to a second electronic calendar hosted on a second calendar host...	The accused system stores "sync configuration rules" in a database that govern how events are propagated between user-connected calendars. A screenshot shows the user interface for setting these rules.	¶33	col. 3:15-21
the rules determine what properties of the events on the first electronic calendar are to be propagated to the second electronic calendar...	The sync rules allow users to select which event properties, such as "Event titles," "Event description," and "Event participants," are propagated.	¶34	col. 4:15-28
and the rules determine what, if any, notifications are to be added to the second electronic calendar for events propagated from the first electronic calendar;	The sync rules include an option to "Disable reminders for clones," which allegedly determines whether notifications are added to the second calendar for propagated events.	¶35	col. 5:19-24
the calendar synchronization service is configured to receive, via an application programming interface (API), a notification of a first event on the first electronic calendar...	The accused system allegedly uses OAuth to access user calendars via the Google Calendar API and Microsoft Graph API and registers webhooks to receive push notifications of calendar changes.	¶36	col. 3:21-29
the calendar synchronization service is configured to issue, in response to the receive of the notification, one or more commands to the second calendar host to generate a second event...according to the rules...	The accused system allegedly issues commands via the Google Calendar API or Microsoft Graph API to create new "clone" events on a second calendar in accordance with the user-defined sync rules.	¶37	col. 12:44-55

Identified Points of Contention:

• Scope Questions: A primary question may be whether the term "circuitry," as used in the patent, reads on the accused cloud-based software system, which is alleged to run on third-party infrastructure like Vercel and AWS (Compl. ¶32). The outcome may depend on how the court construes the patent's specific definition of "circuitry." Another question may arise from dependent claim 13, which requires "the API" to be "an API of the calendar synchronization service." The complaint alleges the accused system uses third-party APIs (e.g., Google Calendar API), raising the question of whether using an external API satisfies this limitation (Compl. ¶36; Compl. ¶40).
• Technical Questions: The analysis may focus on whether the user-selectable "Sync Configuration" options in the Accused OneCal System (Compl. ¶33) function as the "rules for propagating events" as required by the claim. A screenshot of the configuration page provides a visual basis for comparing the accused functionality to the claim requirements (Compl. ¶33).

V. Key Claim Terms for Construction

• The Term: "circuitry"
• Context and Importance: This term appears in the preamble of independent claim 11 and is foundational to the infringement analysis. Defendant may argue that its cloud-based software system, which runs on general-purpose, third-party servers, does not constitute "circuitry." The construction of this term will be critical in determining whether the claim applies to a software-as-a-service (SaaS) product.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification provides an explicit definition: "As used herein the terms 'circuits' and 'circuitry' refer to physical electronic components (i.e. hardware) and any software and/or firmware ('code') which may configure the hardware, be executed by the hardware, and or otherwise be associated with the hardware" (’739 Patent, col. 13:30-35). This language may support an interpretation that includes software running on hardware.
  • Evidence for a Narrower Interpretation: A defendant might argue that despite the definition, the context of the patent requires a more specific hardware configuration rather than generic cloud infrastructure. The patent also discusses implementation via an "application specific integrated circuit (ASIC)" or "field programmable gate array (FPGA)," which could be used to argue for a more hardware-centric interpretation (’739 Patent, col. 14:1-2).

VI. Other Allegations

• Indirect Infringement: The complaint alleges inducement by asserting that Defendant encourages infringement by providing access to the Accused OneCal System and instructing customers on how to use its infringing features through its interface and documentation (Compl. ¶60). It also alleges contributory infringement, stating the system is a material part of the invention and not a staple article of commerce suitable for substantial non-infringing use (Compl. ¶62).
• Willful Infringement: Willfulness is alleged based on both pre-suit and post-suit knowledge (Compl. ¶66). The complaint alleges pre-suit knowledge based on a cease and desist letter sent in January 2024 (Compl. ¶55), Defendant's alleged monitoring of Plaintiff's product (Compl. ¶56; Compl. ¶58), and the alleged copying of Plaintiff's solution after the defendant's founder signed up for the service (Compl. ¶57).

VII. Analyst’s Conclusion: Key Questions for the Case

• A core issue will be one of definitional scope: Can the term "circuitry", as defined and used in the ’739 patent, be construed to cover a cloud-based software service operating on third-party, general-purpose computing infrastructure? The patent’s explicit definition including "software and/or firmware" will be central to this dispute.
• A second key question will be one of infringement and claim scope: For dependent claim 13, does the accused system's alleged use of third-party APIs (e.g., Google's) meet the limitation that "the API is an API of the calendar synchronization service," or does this language require a proprietary API hosted by the accused service itself?
• A third area of focus will be on the evidence of copying and willfulness: The complaint makes detailed allegations that Defendant’s founder accessed Plaintiff’s service shortly before launching a competing product, which is alleged to be "strikingly similar" (Compl. ¶¶21, 57). The strength of the evidence supporting these allegations of copying and pre-suit knowledge will be critical to the claims for willful infringement.