Every Moment Counts: Build Apps That Respond With Precision

Do you still get excited to watch your favourite movies in theatres when they’re re-released even after watching them countless times on TV, OTT platforms, or downloads? 

We’ve seen them so many times, yet certain scenes still feel iconic. Why? It’s because of the right timing and the perfect triggers in those key moments the chain of reactions that makes a scene memorable and exciting. That’s what makes us put these movies on our favourites list and re-watch them again and again.

Event-driven architecture works the same way. Your app doesn’t need to react to every event; it responds at the right time to the right signal (user actions, notifications, or system events). That’s how apps feel intuitive, engaging, and memorable, just like a perfectly timed scene in our favourite film.

Catalyst Signals is built around this principle: responding precisely when something meaningful occurs—a state change, a transaction, a completion, or a failure.

At its core, Catalyst Signals is an intelligent event bus that helps developers design systems that react in real time without managing infrastructure or custom orchestration layers. 

Developers define where events originate, how they should be routed, and where they should be delivered. Signals handles the rest, from delivery guarantees, retries, batching, sequencing, and visibility, so developers can focus on logic instead of plumbing. Because events are pushed rather than polled, reactions happen quickly, often in under a second, depending on downstream processing.

A Clear, Structured Event Model

1. Events represent meaningful occurrences within an application ecosystem.
2. Publishers act as authenticated sources of events, from Catalyst apps, Zoho products, or external systems.
3. Rules filter, transform, and route events.
4. Targets receive events via webhooks, functions, or orchestration features like Catalyst Circuits.

Example Use Case of Catalyst Signals

A pharmaceutical company uses Zoho Inventory to manage orders and shipments. Every order must be verified before fulfillment to ensure compliance.
There are two scenarios:

• Prescription Order
  • Can be shipped immediately after verification.
  • Non-Prescription Orders
• Require a doctor’s consultation before fulfillment.
  • Order details are sent to a custom doctor app for approval.
  • Only approved orders can be processed and shipped.

Without an event-driven approach, this led to manual checks, frequent API polling between systems, API throttling issues, delayed shipments, and higher integration costs.

How Signals Solves This

With Catalyst Signals, the workflow becomes fully event-driven.

• An order created in Zoho Inventory publishes an event
• Signals checks if a prescription is present
• Prescription orders move straight to fulfillment
• Non-prescription orders are routed to the doctor app
• Once approved, an event updates Zoho Inventory and triggers shipping
• A custom doctor app can be built on Catalyst to handle prescription verification and approvals.
• Catalyst components such as Serverless Functions, APIs, and Data Stores can manage:
  • Order routing from Zoho Inventory
  • Prescription verification workflows
  • Physician consultation and approval
  • Status updates back to Zoho Inventory

Why Signals Makes the Difference

• Faster fulfillment – orders move the moment approvals happen
• No API throttling – events replace constant status checks
• Lower costs – fewer integration calls overall
• Stronger compliance – every decision is automatically logged
• Scales smoothly – handles high order volumes without bottlenecks

Signals stays quiet until something meaningful happens then acts instantly.

Native Fit for the Zoho Ecosystem

Catalyst Signals comes with built-in default publishers to help you get started quickly. These publishers fall into the following categories:

• Zoho Publishers – Events from Zoho products, available when the products are created using the same Zoho ID as the Catalyst account.
• SaaS Publishers – Supported third-party SaaS apps. An API token is required to securely receive event data.
• Catalyst Publishers – Events from Catalyst services within the same project and organization.
• Custom Publisher – This  feature lets you create new publishers for your product, in addition to the existing default publishers

 As shown in the above  image, here’s a glimpse of the events supported for one of the publishers — Zoho Books. These events enable real-time, event-driven workflows across your apps.

1. Bill Created / Updated – React instantly when vendor bills are added or modified.
2. Expense Created / Updated – Track and automate expense approvals in real time.
3. Quote Created / Updated – Trigger sales notifications and follow-ups on quote changes.
4. Credit Note Created / Updated – Automate refunds and customer balance updates.
   Customer Created / Updated – Keep customer data in sync across connected apps.
   Similarly, you can integrate Signals with other Zoho apps like Zoho Bigin, Zoho Survey, and more to build real-time, event-driven workflows. 
    

Sample Payload

To explore the full list of events available for all other publishers,  Explore Signals today.

Wrapping Up

Well-designed systems don’t need to be busy all the time. They need to be aware, responsive, and precise. Catalyst Signals enables exactly that: systems stay quiet until the right moment arrives, then respond with confidence.

Explore More

Cookbook - https://catalyst.zoho.com/cookbook/
Help docs- https://docs.catalyst.zoho.com/en/
CodeLib Templates - https://catalyst.zoho.com/code-lib.html

See you all in the next post
Happy Coding!