DCT
1:24-cv-22361
Cal Bridge Inc v. Onecal
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Cal Bridge, Inc. (Delaware)
- Defendant: OneCal (Albania)
- Plaintiff’s Counsel: Tucker Law; McAndrews, Held & Malloy, Ltd
- Case Identification: 1:24-cv-22361, S.D. Fla., 10/15/2024
- Venue Allegations: Venue is alleged to be proper based on Defendant doing substantial business in the district, offering its products to customers in Florida, and one or more users in the district having purchased and used the accused products.
- Core Dispute: Plaintiff alleges that Defendant’s calendar synchronization service infringes a patent related to privacy-sensitive, multi-calendar synchronization.
- Technical Context: The technology addresses the market need for synchronizing events across disparate calendar platforms (e.g., Google Calendar, Microsoft Outlook) to provide users with a unified schedule.
- Key Procedural History: The complaint alleges that Defendant’s founder signed up for Plaintiff’s service in February 2023, less than two weeks before announcing the launch of the accused competing system. Plaintiff also alleges it sent a cease and desist letter to Defendant in January 2024, to which Defendant’s counsel responded in February 2024.
Case Timeline
| Date | Event |
|---|---|
| 2020-02-18 | '739 Patent Priority Date |
| 2020-05-14 | Plaintiff's CalendarBridge solution launched |
| 2022-10-04 | U.S. Patent 11,461,739 issued |
| 2023-02-03 | Defendant's founder allegedly signed up for Plaintiff's platform |
| 2023-02-15 | Defendant's OneCal system announced |
| 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's counsel responded to cease and desist letter |
| 2024-04-12 | Plaintiff implemented Apple iCal compatibility |
| 2024-04-20 | Defendant announced "coming soon" support for Apple iCal |
| 2024-10-15 | Amended Complaint filed |
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 Invention Explained:
- Problem Addressed: The patent describes the technical challenges arising from users maintaining multiple electronic calendars across different, non-interoperable platforms (e.g., Google, Microsoft Exchange) (ʼ739 Patent, col. 2:8-16). These platforms use proprietary Application Programming Interfaces (APIs), preventing direct host-to-host communication and creating fragmented, non-synchronized user schedules, which can lead to missed meetings or double-bookings (ʼ739 Patent, col. 2:16-21, 44-45).
- The Patented Solution: The invention is a centralized calendar synchronization system that functions as an intermediary between different calendar hosts (ʼ739 Patent, Fig. 1). This system automatically detects events on a source calendar and propagates them to a destination calendar based on a set of user-defined rules, which can control the level of detail shared (e.g., showing only "busy" time versus full event details) to maintain privacy (ʼ739 Patent, Abstract; col. 2:46-62).
- Technical Importance: This approach provides an automated, server-side solution to the problem of calendar interoperability, which previously relied on manual user effort or client-side syncing that was often incomplete or restricted by corporate policies (ʼ739 Patent, col. 2:30-45).
Key Claims at a Glance:
- The complaint asserts independent claim 11 (Compl. ¶28).
- The essential elements of independent claim 11 include:
- A system with circuitry for a "calendar synchronization service" and a "database service."
- The database service stores "rules" for propagating events from a first calendar to a second.
- These rules determine what event "properties" (e.g., summary, description) are propagated.
- The rules also determine if any "notifications" are added to the second calendar.
- The synchronization service is configured to receive, via an API, a notification of a first event on the first calendar.
- In response, the synchronization service issues commands to the second calendar's host to generate a second event based on the stored rules.
- The complaint reserves the right to assert dependent claims 13-17 (Compl. ¶28).
III. The Accused Instrumentality
- Product Identification: The accused instrumentality is Defendant’s "OneCal" or "Accused OneCal System," a cloud-based calendar synchronization service (Compl. ¶20-21).
- Functionality and Market Context: The Accused OneCal System is alleged to be a cloud-based service, using Vercel and AWS infrastructure, that "automatically syncs a user's calendar events across all of the user's calendars" (Compl. ¶21, ¶31). The complaint provides a screenshot from OneCal's documentation showing how it synchronizes events between Google and Outlook calendars (Compl. ¶31, Ex. 4 at 4). The system allows users to configure "sync configuration rules" to control what event information is copied, such as event titles, descriptions, and participants (Compl. ¶32, Ex. 4 at 6-7). The complaint alleges that OneCal is marketed directly as "a CalendarBridge alternative" and targets Plaintiff's customers with a "switching discount" (Compl. ¶23).
IV. Analysis of Infringement Allegations
'739 Patent Infringement Allegations
| Claim Element (from Independent Claim 11) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| circuitry configured to operate as a calendar synchronization service and circuitry configured to operate as a database service | The Accused OneCal System allegedly uses Vercel and AWS cloud computing infrastructure to operate as a calendar synchronization service and a database service. | ¶31 | col. 11:40-44 |
| the database service is configured to store rules for propagating events from a first electronic calendar... to a second electronic calendar | The Accused OneCal System allegedly stores "sync configuration rules in a database." A provided screenshot shows a "Sync Configuration (Rules)" interface for setting these rules. | ¶31, ¶32 | col. 11:45-48 |
| the rules determine what properties of the events on the first electronic calendar are to be propagated to the second electronic calendar | OneCal's "Sync Rules" allegedly determine which event properties (e.g., titles, description, participants) are propagated to the second calendar. A screenshot shows checkboxes for including or excluding these properties. | ¶32-33, ¶42 | col. 11:48-52 |
| 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 allegedly include an option to "Disable reminders for clones," which determines whether reminder notifications are added for cloned events. | ¶34 | col. 11:52-55 |
| 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 OneCal System allegedly uses the Google Calendar API and Microsoft Graph API to register webhooks that receive push notifications when calendar events change. | ¶35 | col. 12:45-50 |
| 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 on the second electronic calendar according to the rules... | The Accused OneCal System allegedly issues commands via the Google Calendar API or Microsoft Graph API to create new "clone" events on the second calendar in accordance with the user-defined sync rules. | ¶36 | col. 12:50-56 |
- Identified Points of Contention:
- Scope Questions: Dependent claim 13, which is asserted, requires "the API" to be "an API of the calendar synchronization service" (Compl. ¶38). The complaint alleges infringement through the use of the hosts' APIs (Google, Microsoft) (Compl. ¶35). This raises the question of whether using a third-party API and a webhook endpoint satisfies the claim limitation of the API being "of the calendar synchronization service" itself.
- Technical Questions: The infringement analysis may focus on whether the specific set of user-configurable "Sync Rules" in the Accused OneCal System, as depicted in the complaint's visual evidence (Compl. ¶32, Ex. 4 at 6-7), directly corresponds to the functions of the "rules" as defined and required by the patent claims.
V. Key Claim Terms for Construction
- The Term: "application programming interface (API)"
- Context and Importance: The construction of this term is critical, particularly in light of asserted dependent claim 13, which specifies "the API is an API of the calendar synchronization service." The complaint alleges infringement based on the accused system's use of the Google and Microsoft APIs, which are APIs of the calendar hosts, not necessarily the accused service itself (Compl. ¶35, ¶39). The defendant may argue that its system merely uses third-party APIs rather than providing its own API for receiving notifications, as the claim may require. Practitioners may focus on this term because the distinction could be dispositive for infringement of claim 13.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification states the web service is operable to "provide one or more endpoints for a receiving... API calls (e.g., from calendar hosts...)" (ʼ739 Patent, col. 3:11-14). Plaintiff may argue that a webhook endpoint, which receives notifications from a host, constitutes an "API of the calendar synchronization service" under this description.
- Evidence for a Narrower Interpretation: The specification appears to distinguish between different APIs, stating the system is operable to "issue API calls to the calendar hosts... [and] receive API calls from the calendar hosts" (ʼ739 Patent, col. 3:21-25). A defendant could argue this language implies a structural distinction and that the "API" in claim 13 must be one provided by the service itself, not one belonging to the host platform that the service merely subscribes to.
VI. Other Allegations
- Indirect Infringement: The complaint alleges inducement by providing access to the accused system and instructing customers on its use through its interface, documentation, and promotional materials (Compl. ¶59). It further alleges contributory infringement, stating the accused system constitutes a material part of the invention, is specially adapted for infringement, and is not a staple article of commerce with substantial non-infringing uses (Compl. ¶61).
- Willful Infringement: The willfulness claim is based on alleged pre-suit and post-suit knowledge. Pre-suit knowledge is alleged based on Defendant’s founder signing up for and accessing Plaintiff’s platform before launching the accused product, the alleged copying of features, and Plaintiff’s patent marking on its website since January 31, 2024 (Compl. ¶20, ¶55-56). Post-suit knowledge is alleged based on a cease-and-desist letter sent in January 2024 and the filing of the original complaint (Compl. ¶54, ¶65).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of claim scope: can the phrase "API of the calendar synchronization service" from asserted claim 13 be construed to cover the accused system’s use of third-party host APIs (e.g., Google, Microsoft) and associated webhook endpoints, or does the claim require an API architecturally distinct from that of the underlying calendar platforms?
- A central factual dispute will likely concern evidence of copying: the complaint presents a timeline suggesting Defendant’s founder accessed Plaintiff’s product immediately before launching a competing system. The resolution of this factual allegation will be critical to the claim for willful infringement.
- An evidentiary question will be one of technical mapping: does the specific functionality of the Accused OneCal System's "Sync Rules," as shown in documentation, perform the functions of determining event "properties" and "notifications" in a manner that falls within the scope of the corresponding limitations in Claim 11?