What is a webhook?
A webhook is an automatic message your software sends to another tool the moment something happens. Instead of you logging in to check whether a new lead arrived or an invoice was paid, the software pushes a notification, the moment the event occurs, to a web address you provide. The tool at that address receives it and does something in response.
The mental model that helps: a webhook is your software tapping another system on the shoulder to say "this just happened, here are the details." No polling, no manual checking, no you-in-the-middle. It is one of the quiet building blocks that lets modern tools work together, and for agencies it is the mechanism behind a lot of agency workflow automation.
Why webhooks matter for agencies
Agencies run on handoffs between tools, and most of those handoffs are done by hand. A lead comes in, so someone posts it to Slack. A proposal is accepted, so someone starts the onboarding checklist. An invoice is paid, so someone updates a tracker. Each is small, and each is a manual step that depends on a person remembering.
Webhooks remove the person-in-the-middle for these handoffs. When "a new lead arrived" can automatically post to Slack, and "a proposal was accepted" can automatically trigger onboarding, the routine relaying of information stops eating your team’s attention. It is the same goal as reducing admin generally, covered in how to reduce admin work in your agency, applied through automation rather than discipline.
What agencies automate with webhooks
The best way to understand webhooks is through what they do. Common agency uses:
- Notify a Slack channel when a new lead or payment arrives.
- Add new clients to a mailing list or CRM.
- Log events to a spreadsheet or data tool.
- Start an onboarding sequence when a proposal is accepted.
- Sync events into another system your agency runs.
- Trigger a Zapier or Make flow to do multi-step work.
The pattern behind all of them is the same: "when X happens in one tool, do Y in another." Any time you catch yourself manually relaying an event from one system to the next, that is a webhook waiting to happen. Start with the handoff you do most often and automate that one first.
Webhook vs API
These two get mentioned together and confused constantly, but the difference is simple once you see it.
| Aspect | Webhook | API |
|---|---|---|
| Direction | Push (software tells you) | Pull (you ask software) |
| Trigger | An event happens | You make a request |
| Timing | Real time, automatic | On demand |
| Good for | Reacting to events | Fetching or updating data |
Agencies use both. A webhook reacts the instant something happens; an API is how you or another tool reads and writes data when you need to. Between them, they are how your agency workspace connects to the rest of your tools.
Keeping automation under control
Automation is powerful precisely because it acts without you, which is also why it needs guardrails. A webhook that fires the wrong action, or sends data somewhere it should not, is worse than a manual step. The answer is not to avoid automation but to keep it reviewed and intentional.
That means sending webhooks only to endpoints you trust, treating keys and secrets as sensitive, and favoring automation that assists your workflow rather than taking uncontrolled client-facing actions. The goal is to remove the manual relaying, not to hand your client communication to a script, which is the balance we describe in keeping AI and automation under control.
How to set up a webhook
Setting up a webhook is usually simpler than it sounds, especially with a no-code automation tool:
- Decide which event you want to react to, such as a new lead or paid invoice.
- Get a receiving URL, often from an automation tool like Zapier or Make.
- Point the webhook at that URL and select the event.
- Build the downstream action in the receiving tool.
- Test it with a real event to confirm it fires correctly.
- Keep automations under review so nothing acts unintentionally.
The test step matters most. Fire a real event and confirm the downstream action happens as expected before you rely on it. Once it is proven, it runs quietly in the background, and a handoff you used to do by hand simply takes care of itself.
Relaying events by hand, or automating from the workspace
Without automation, agencies relay events between tools manually: paste the lead into Slack, log the payment in a sheet, start the checklist by hand. Arpixa automations and webhooks let events trigger those actions automatically.
Manual updates
Manual logs
Manual filing
Manual trackers
ArpixaAll of it, connectedHow Arpixa supports webhooks
Arpixa’s automations connect triggers, status updates, webhooks, and API keys across the workspace. Events like a new lead in the Lead Inbox, an accepted proposal, or a paid invoice can notify other tools and kick off downstream actions, so the handoffs you do by hand can run on their own.
Because webhooks and API keys are built in, you can connect Arpixa to automation platforms like Zapier and Make, or your own endpoints, and extend your workflow to your wider stack. Automation is positioned around assisted workflow movement and team review, not uncontrolled client-facing actions, so you get the time savings while keeping control. It is the technical backbone of a connected agency workflow.
Automate the handoffs, keep the control
Start free in minutes, or log in to your Arpixa workspace. See pricing for plan details.
Arpixa has a real Free plan (not a trial), with Starter at $12/month, Pro at $29/month, and Advanced at $89/month. Automation and API capabilities can depend on plan level, and annual billing lowers the effective monthly cost. The pricing page is the source of truth for current plan limits.
Frequently asked questions
What is a webhook, in plain terms?
A webhook is an automatic message your software sends to another tool the moment something happens. Instead of you checking for updates, the software pushes a notification, like "a new lead came in" or "an invoice was paid", to a URL you provide. That other tool receives it and acts. Think of it as your software tapping another system on the shoulder as soon as an event occurs.
How do webhooks work in agency software?
You tell the software which event to watch and where to send the notification, a URL for another service. When the event happens, the software sends the event data to that URL, and the receiving service, often an automation tool like Zapier or Make, or your own endpoint, does something with it: posts to Slack, adds a row to a sheet, updates another system. It is a one-way "this just happened" signal that triggers action elsewhere.
What can agencies automate with webhooks?
Common uses: notify a Slack channel when a new lead or payment comes in, add new clients to a mailing list, log events to a spreadsheet or data tool, kick off an onboarding sequence when a proposal is accepted, or sync events into another system your agency uses. Anything that currently means "when X happens in one tool, I go do Y in another" is a candidate for a webhook.
What is the difference between a webhook and an API?
An API is something you call when you want data: you ask, it answers. A webhook is the reverse: the software tells you when something happens, without you asking. APIs are pull, webhooks are push. Agencies use both, an API to fetch or update data on demand, and webhooks to react to events in real time. Together they connect your workspace to the rest of your tools.
Do I need to be technical to use webhooks?
Less than you might think. Setting a webhook up usually means pasting a URL and choosing an event, and automation platforms like Zapier and Make provide that URL and handle the receiving side without code. For simple automations, no programming is needed. Custom endpoints and advanced logic do require a developer, but many agency webhook uses are no-code through an automation tool.
How do webhooks connect to Zapier or Make?
Automation platforms give you a webhook URL to catch events, then let you build "if this, then that" flows visually. You point your agency software’s webhook at that URL, pick the event, and build the downstream steps in the platform, post to Slack, create a task, update a CRM. It is the most common no-code way to turn a webhook into a useful automation without writing any code.
How does Arpixa support webhooks?
Arpixa’s automations connect triggers, status updates, webhooks, and API keys across the workspace, so events like new leads, accepted proposals, or paid invoices can notify other tools and kick off downstream actions. Automation is positioned around assisted workflow movement and team review rather than uncontrolled actions, so you extend your workflow to your wider stack while keeping control.
Are webhooks safe to use?
Yes, with normal care. Send webhooks only to endpoints you trust, treat any keys or secrets as sensitive, and use the review controls your platform offers so automations do not take unintended actions. Webhooks transmit event data, so be mindful of what you send and where. Used sensibly, they are a standard, safe way to connect software, which is why they are everywhere in modern tools.