Integrate HighLevel with existing tools via API

You open your CRM. Then your email marketing platform. Then your scheduling tool. Then Slack. Then Stripe. Then a spreadsheet.

By the time you’ve pulled everything together, you’ve wasted 45 minutes and are still just prepping for work, not actually doing it.

That’s the problem with a fragmented tech stack.

HighLevel already replaces a lot of tools out of the box. But if you’re working with specialized software, custom data flows or existing infrastructure, there’s good news: HighLevel doesn’t just work in isolation. It integrates.

This guide is your blueprint for HighLevel API integration and building a tech stack that actually works together.

Let’s get into it.

Why API access matters for agencies and tech-savvy businesses

Not every CRM gives you full access to your data. Some lock key features behind premium plans. Others force you into manual exports or make integrations hard to manage.

HighLevel takes a different approach.

It gives users, and especially agencies, full API access to automate tasks, sync systems and extend functionality across the board.

Whether you’re looking to:

• Build a custom dashboard for clients.

• Connect HighLevel with internal apps.

• Trigger workflows from external form fills or call events.

• Or automate billing, reporting or tagging.

You can do it with the HighLevel API, webhooks and Zapier-friendly connections.

If your agency has outgrown basic integrations or needs to unify tools under one source of truth, API access is what unlocks that.

Where to find HighLevel’s API documentation

HighLevel’s public API documentation lives at developers.gohighlevel.com.

Inside, you’ll find:

• Full lists of endpoints for contacts, opportunities, tags, pipelines and users.

• Authentication guidance.

• Parameters, payload formats and response examples.

• Instructions for working with tokens and keys.

If you’re familiar with RESTful APIs, the structure will feel intuitive.

If not, there are beginner-friendly guides and active developer communities available to help!

Some of the most-used categories in the HighLevel API docs include:

• Contacts and contact tags.

• Pipelines and opportunities.

• Calendars and appointments.

• Users and roles.

• Webhooks and custom triggers.

Popular use cases: What you can automate with the API

You don’t need to be an enterprise developer to make use of the API.

Here are examples of real-world workflows agencies and small teams have built using CRM API integration inside HighLevel:

1. Push form submissions from external landing pages

Using the HighLevel contacts endpoint, you can automatically send lead data from Webflow, Squarespace or custom HTML forms into your HighLevel CRM.

2. Trigger workflows when a deal is closed in another CRM

Using the HighLevel webhook endpoint, you can notify HighLevel when a deal is marked “won” in, for example, Salesforce triggering email or SMS follow-ups.

3. Sync appointment data to Google Sheets

Use HighLevel's calendar endpoints in combination with Zapier or Make to send scheduled appointment data into a spreadsheet, analytics tool or project board.

4. Auto-create contacts and tags from payment systems

When someone pays via Stripe or PayPal, use Zapier or a direct API call to create a new contact, apply a tag and enroll them in a post-purchase automation.

5. Custom analytics dashboards

Pull reporting data like opportunity stages, call outcomes or email opens and use it to build a client-facing dashboard using tools like Google Data Studio or Tableau.

The flexibility here is one of the reasons HighLevel automation tools are trusted by thousands of agencies.

Using webhooks, custom workflows, and Zapier to extend HighLevel

If the word “API” sounds intimidating, start with HighLevel Zapier integration or webhooks.

These options don’t require writing code and allow you to plug HighLevel into tools like:

• Google Sheets.

• Slack.

• Stripe.

• Calendly.

• Airtable.

• Typeform.

• Zoom.

• Shopify.

You can also use HighLevel webhooks inside workflows. Here’s how that works:

• Set a trigger in HighLevel (e.g., form submission).

• Add a webhook action step to send that data to another tool.

• Or, create an external trigger that sends data into HighLevel.

For example, when a Typeform is submitted, you can use Zapier to call the HighLevel API and create a contact, then launch a follow-up sequence using custom API workflows.

This gives you full control over how systems talk to each other without being stuck inside one ecosystem.

Tips for developers: Authentication, endpoints, and best practices

If you’re writing custom code or integrating with internal systems, here’s what you need to know about using the HighLevel API effectively.

Authentication

HighLevel uses OAuth2 for secure API access. You’ll need to:

• Create an API key from your agency settings.

• Use client ID and secret to authenticate.

• Include bearer tokens in headers for each request.

Rate limits

HighLevel’s API is well-structured and scalable, but like most SaaS platforms, it enforces rate limits to prevent abuse. Keep requests efficient and cache where possible.

Error handling

Use try/catch logic and check for common HTTP errors (400, 401, 403, 500). HighLevel includes error responses in JSON with helpful messages.

Development tips

• Test your requests using Postman or Insomnia first.

• Always test in a dummy sub-account before running live.

• Use HighLevel’s support forums or community Slack to ask questions.

If you’re building for clients, white-labeled platforms or high-volume operations, the ability to build on top of HighLevel and third-party tools is key to scaling smoothly.

Conclusion: Build your ideal stack around HighLevel’s core

The more your business grows, the more complex your tech stack becomes.

But does it have to stay that way?

With the HighLevel API, Zapier support and native webhooks, you can build a custom stack where data flows cleanly, automations run reliably and clients get results faster.

Whether you're syncing data across platforms, triggering campaigns from outside tools or consolidating dashboards, automation integration for agencies has never been more within reach.

HighLevel gives you the base: CRM, workflows, AI tools and automation.

Then, you can connect everything else to it, build on top of it or replace half the tools you're using now.

Try out HighLevel for free!

By now, you’re probably wondering how many tools you’ll replace if you get started with HighLevel…

And you might also be skeptical about this. That’s fair.

To make the decision easier, start a free 14-day trial and try it for yourself.

Test the API. Run a webhook. See how much you can automate with less hassle.

Whether you’re a developer, a power user or just tired of copy-pasting between tools, HighLevel gives you control, flexibility and simplicity in one place.

FAQs

1. What is the benefit of using the HighLevel API for my agency or business?

HighLevel’s API gives you full control over your data and workflows. You can automate repetitive tasks, connect HighLevel with your internal systems, and build custom dashboards or reporting tools. Instead of being limited to native integrations, you can extend HighLevel’s capabilities to match your unique operations—whether that means syncing CRMs, automating billing, or triggering campaigns from external tools.

2. Where can I find HighLevel’s API documentation?

All public API documentation is available at developers.gohighlevel.com. It includes complete endpoint lists (for contacts, opportunities, tags, users, and more), authentication instructions, sample requests, and detailed parameters. Whether you’re new to APIs or an experienced developer, you’ll find clear examples and community resources to guide you.

3. What kinds of automations can I build with the HighLevel API?

You can automate virtually any data-driven task using the HighLevel API. Popular examples include:

• Sending external form submissions directly into HighLevel as contacts.

• Triggering workflows when deals close in another CRM.

• Syncing calendar or appointment data with Google Sheets.

• Auto-creating contacts and tags from Stripe or PayPal payments.

• Building client dashboards that pull real-time CRM and performance metrics.
  These workflows save hours of manual work and ensure your systems always stay in sync.

4. Do I need to know how to code to use HighLevel integrations?

Not necessarily. If you’re not comfortable writing code, you can use Zapier or webhooks within HighLevel to connect tools like Google Sheets, Slack, Typeform, Calendly, and Shopify—no programming required. However, if you want to build custom logic or deeper integrations, the API gives developers full flexibility to code their own automations and apps.

5. What are best practices for developers using the HighLevel API?

When working with the API, follow these key practices:

• Authenticate securely using OAuth2 with your client ID, secret, and bearer tokens.

• Respect rate limits and cache data to reduce unnecessary requests.

• Handle errors gracefully using try/catch and checking response codes.

• Test in Postman or Insomnia before deploying live.

• Use a sandbox or dummy sub-account for experimentation.
  Following these ensures your integration runs smoothly, securely, and scales as your agency grows.