Glossary · Triggers & webhooks
Polling vs webhooks
Also called: polling trigger, instant trigger, push vs pull
Polling means your system asks another system for new data on a fixed schedule; webhooks mean the other system pushes each event to you the moment it happens.
Both answer the same question, "what changed?", from opposite ends.
| Polling | Webhooks | |
|---|---|---|
| Who starts it | The receiver, every N minutes | The sender, on each event |
| Delay | Up to one interval | Seconds |
| Works when | The API can list recent records | The app supports webhooks and can reach your URL |
| Cost | A request per check, even when nothing changed | A request per event |
| Missed events | Rare if the poll uses a cursor or "modified since" | Possible if your endpoint is down and the sender doesn't retry |
Why tools use both
Many apps either don't offer webhooks, offer them only on expensive plans, or configure them per app rather than per customer. Polling works anywhere the API can answer "records created after X". Webhooks are faster and lighter where they exist. A good automation platform offers an instant trigger when the app supports it and falls back to polling when it doesn't.
Polling done right
A careful poller remembers a cursor (the last id or timestamp it saw) and asks only for newer records, so each check is cheap and nothing is processed twice. It also respects the API's rate limit: checking every minute against an API that allows a few hundred calls a day won't last.
In Fluxo Flow
App event triggers come in both kinds. Polling triggers (a new HubSpot contact, a new Google Sheets row, a new QuickBooks payment) are checked on your plan's schedule interval, never faster than the app allows, and remember where they left off. Instant triggers arrive by webhook where the app supports it, such as Slack's new-message and reaction-added events or Stripe's instant payment trigger. Each integration page labels which kind each trigger is.
Read next
Related terms
- WebhookA webhook is an HTTP request that one system sends to a URL you give it, automatically, the moment an event happens, so the receiver doesn't have to keep asking.
- TriggerA trigger is the event that starts a workflow run: a person pressing Run, a schedule coming due, a webhook arriving, or a new record or event in a connected app.
- Rate limitA rate limit is a cap an API puts on how many requests a client may make in a time window; requests over the limit are refused, usually with HTTP status 429 Too Many Requests.
- Cron expressionA cron expression is a compact five-field string (minute, hour, day of month, month, day of week) that tells a scheduler exactly when to run a job.
- Prompt injectionPrompt injection is an attack in which text that a language model processes (an email, a web page, a document) contains instructions that override or subvert the instructions the developer gave it.
- OpenAI-compatible endpointAn OpenAI-compatible endpoint is an AI API that accepts requests and returns responses in the same format as OpenAI's API, so software written for OpenAI can call other providers, gateways or self-hosted models by changing the base URL and key.