What This Update Actually Is
HubSpot shipped two things at once here, and it's worth separating them clearly.
First: custom agents. These are AI agents you build for your specific business, not a pre-configured HubSpot agent you turn on. You define the instructions, the tools the agent can use, and the knowledge it draws from. It runs on the contact, company, and deal data already in your CRM.
Second: an automation canvas. This is a new visual workspace inside Agent Builder where you connect agents, actions, and triggers in one view. Think of it as the bridge between what your agent knows and what it actually does inside your portal.
Both are available to Starter tiers and above as of September 2026. That's a significant access expansion. Until now, agent-building capabilities were gated at Professional and above.
Agentic workflows (connecting agents to automated workflow sequences) remain a Professional+ feature. Custom agent creation itself is now Starter+.
Why HubSpot Shipped This
The honest answer is that HubSpot's existing AI features, Breeze agents, Copilot prompts, pre-built tools, were helpful but fixed. You could use what HubSpot built. You couldn't build what your business actually needed.
We've seen this frustration in dozens of portals. Humans running real workflows would ask: can the agent follow our escalation logic? Can it know our product catalog? Can it trigger the right sequence for our sales motion? The answer kept being "not yet."
Custom agents close that gap. HubSpot's position is that AI should conform to how your business works, not the other way around. The no-code build path (describe what you want, Breeze Assistant scaffolds it) removes the technical barrier that would otherwise put this squarely in IT's hands.
The Starter inclusion is strategic too. HubSpot is betting that getting more portals experimenting with agents now builds long-term platform stickiness. The credit model is how they monetize the compute behind it.
How to Use It Step by Step
- Check permissions first. Go to Settings, then Users and Teams. Any user who needs to build, activate, or edit a custom agent must have Agent access turned on. Super Admins can do this now.
- Navigate to Agent Builder. Find it in your main HubSpot nav under Breeze or Automation depending on your portal version. Select "Build a custom agent."
- Describe your intent to Breeze Assistant. Type what you want the agent to do in plain language. Breeze Assistant reads your description and builds the initial agent structure, including suggested tools and knowledge sources, from the data already in your CRM.
- Refine instructions, tools, and knowledge vaults. Edit what the agent knows (your knowledge vault), how it behaves (instructions), and which HubSpot tools or external actions it can take.
- Run simulation mode. Before going live, use simulation mode to see exactly what each agent run will cost in credits. No credits are consumed during simulation. This is your cost-preview and QA pass in one step.
- Set run limits. On the agent details page, set a maximum number of runs per agent. You can also set a total spend cap across all custom agents in your portal.
- Connect to the automation canvas (Professional+). Use the visual canvas to add triggers, branch logic, and follow-up actions. This is where your agent moves from conversational to operational, taking action on records at scale.
- Publish and monitor. Users with Publish permissions for workflows can push the agent live. Watch estimated spend inside your inbox view and on any CRM cards where the agent is configured.
What It Touches in Your HubSpot Strategy
This update doesn't live in one hub. It cuts across your entire front office stack.
On the CRM side, agents can read and act on contact, company, deal, and ticket records. That means any property you've maintained well becomes an input for agent decisions. Dirty data leads to unpredictable agents. This is a strong reason to audit your CRM properties before you build.
On the automation side, agentic workflows replace or extend traditional HubSpot workflows for scenarios that need judgment, not just if/then logic. If you have complex enrollment criteria or multi-step follow-up sequences today, custom agents can now handle the reasoning layer that workflows can't.
Knowledge vaults feed agent behavior. If your agent is supposed to handle customer questions, it needs accurate, current knowledge. That connects to how you manage your content, documentation, and product info inside HubSpot.
Key Takeaway
Your CRM data quality directly determines how well your custom agents perform. Build agents after you've cleaned up the records and properties they'll read, not before.
If you've been watching HubSpot's AI trajectory, this update pairs naturally with the Customer Agent Auto-Setup release. That release auto-configures a support-focused agent using your portal data. Custom agents take the next step: you define the logic entirely from scratch for any use case, not just support.
It also extends what Breeze Assistant can do as a build tool. If you want a deeper look at how Breeze Assistant scaffolds workflows and agents from plain-language prompts, this breakdown of real Breeze Assistant prompts in action is worth reading before you build your first custom agent.
Key Takeaway
Agentic workflows require Publish permissions to go live. Assign those permissions intentionally. Not every agent builder in your portal should have the ability to deploy agents that act on records at scale without a review step.
Who Should Care Most
Not every portal needs a custom agent on day one. But certain roles and company profiles will find immediate leverage here.
- RevOps leaders who manage complex follow-up sequences and want the reasoning layer handled automatically, without adding headcount.
- Marketing ops professionals who need to personalize outreach at scale based on CRM signals that if/then workflows can't interpret well.
- Service teams who want to extend beyond the pre-built Customer Agent with custom escalation logic, product-specific knowledge, or multi-step triage flows.
- Growing companies on Starter plans who previously had no access to agent-building features and now have a real path to AI automation without upgrading.
- Humans in operations roles who want to prototype agents quickly using Breeze Assistant's intent-based builder before involving a developer or consultant.
If you're on Enterprise and already have advanced workflows running, this is the layer that adds judgment to your automation stack. That's a meaningful upgrade worth testing soon.
George's Take
I've been inside hundreds of HubSpot portals, and the single most common frustration I hear isn't "our CRM is missing data." It's "our CRM has all this data and nothing actually does anything with it automatically." Custom agents are the answer HubSpot's been building toward. The no-code intent-based builder via Breeze Assistant removes the excuse that this is "too technical" for a marketing or ops team to own. But I want to be honest with you: an agent is only as smart as the data and instructions you give it. Start with one focused use case, run simulation mode until the cost makes sense, and build from there. Don't try to automate your entire front office in week one. The humans who will flourish with this feature are the ones who treat the first agent as a learning lab, not a silver bullet.
“An agent is only as smart as the data and instructions you give it. Start with one focused use case, test in simulation mode, and build from there. The humans who flourish with this are the ones who treat the first agent as a learning lab.”
If you want help figuring out which use case to start with, how to structure your knowledge vaults, or how to connect your first custom agent to a workflow that actually moves your business forward, let's talk. Book a strategy call with the Sidekick team and we'll map it out with you.
Frequently Asked Questions
What are HubSpot Agent Builder custom agents?
HubSpot Agent Builder custom agents are AI agents you build using your own instructions, tools, and knowledge vaults, running on the CRM data already in your portal. They're different from HubSpot's pre-built agents because you define how they behave and what they know. No code is required. Starter tier portals and above have access as of September 2026.
Do I need a paid HubSpot plan to use custom agents?
You need at least a HubSpot Starter plan to build and use custom agents. Connecting agents to agentic workflows requires a Professional or Enterprise plan. Free portals do not have access to Agent Builder custom agents.
How does HubSpot charge for custom agent runs?
Custom agents consume HubSpot credits per run. You can see an estimated cost per run inside your inbox and on configured CRM cards. Use simulation mode to preview costs before going live. No credits are consumed during simulation. You can also set run limits per agent and a total spend cap across all agents in your portal.
What is simulation mode in HubSpot Agent Builder?
Simulation mode lets you test a custom agent and see what each run would cost in HubSpot credits before the agent goes live. No credits are consumed during simulation. It's the recommended way to QA your agent's behavior and validate cost expectations before activating it in your portal.
What permissions do I need to build and publish a custom agent in HubSpot?
To build, activate, credit, and edit custom agents and their tools and knowledge vaults, a user must have Agent access turned on by a Super Admin. To publish an agent connected to an agentic workflow, the user also needs Publish permissions for workflows. Super Admins have both by default.
How does Breeze Assistant help with building custom agents?
Breeze Assistant lets you describe what you want your agent to do in plain language. It then scaffolds the agent for you based on your intent, pulling from the data already in your CRM. You can refine the instructions, tools, and knowledge it builds. You don't need to start from scratch or write any code.
