HubSpot Custom Workflow Actions

Name: Custom Workflow Actions API
Brand: Custom Workflow Actions
Availability: InStock

★ Only Publicly Available OpenAPI DocumentMarketingMarketing Automationoauth2, apiKey16 Endpoints

Install Jentic One Beta

Connect the Custom Workflow Actions to your agent

Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Custom Workflow Actions, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.

Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.

Step 1: Jentic One Host machine

# On the machine that will host your Jentic One instance:
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh

Step 2: Agent machine

# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh
jentic register       # connects your agent to your Jentic One instance

Jentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.

Capabilities

What an agent can do with Custom Workflow Actions API.

Update action definition input fields and labels across revisions

List and inspect prior revisions of a workflow action definition

GET STARTED

Start building with Custom Workflow Actions API

Explore with Jentic

View OpenAPI Document

For Agents

Define and manage custom workflow action extensions in HubSpot, including registering definitions, handling revisions, and completing async action callbacks.

Use for: I need to register a new custom workflow action for my HubSpot app, I want to complete a pending workflow action callback, List all revisions of a workflow action definition, Retrieve the input field schema for a workflow action

Not supported: Does not handle CRM record CRUD, marketing email sends, or contact lists - use for registering and operating custom workflow action extensions only.

Use Cases

Patterns agents use Custom Workflow Actions API for, with concrete tasks.

★ Custom Workflow Action Registration

ISVs and integration builders register custom action definitions so HubSpot users can drag the action into a workflow. The API accepts the action label, input fields, output type, and the URL HubSpot will call when the action runs. Once registered, the action appears in the workflow editor for any portal that has installed the app.

Create a custom workflow action definition for app 12345 with a webhook URL https://example.com/hooks/hubspot and a single text input field called 'message'

Async Action Callback Completion

When a custom action runs asynchronously, HubSpot waits for a callback before proceeding. The complete-callback endpoint signals success or failure for one callback ID, and the batch endpoint handles many callbacks at once. This pattern lets long-running external processes participate in HubSpot workflows without blocking.

Send a successful completion for callback ID abc-123 with output payload { 'status': 'approved', 'score': 87 }

Action Revision Management

When the input schema or behaviour of a custom action changes, a new revision is published rather than overwriting the original. The revisions endpoints list every published version and let you fetch a specific revision by ID, which keeps existing workflows running on the older schema until they are migrated.

List all revisions for action definition 67890 under app 12345 and identify the most recent published revision

Agent-Driven Workflow Extension

An AI agent uses Jentic to register a custom workflow action that wraps an internal API. The agent searches for 'create hubspot workflow action', loads the schema, and executes a POST to /automation/v4/actions/{appId} with the action definition body. The agent then keeps the registration up to date as the wrapped API evolves.

Search Jentic for 'create hubspot workflow action', load the schema, and register a custom action that calls the internal lead-scoring service

Key Endpoints

16 endpoints — jentic publishes the only available openapi specification for custom workflow actions, keeping it validated and agent-ready.

METHOD

PATH

DESCRIPTION

POST

/automation/v4/actions/{appId}

Create a custom workflow action definition

GET

/automation/v4/actions/{appId}

List all action definitions for an app

PATCH

/automation/v4/actions/{appId}/{definitionId}

Update an action definition

DELETE

/automation/v4/actions/{appId}/{definitionId}

Archive an action definition

POST

/automation/v4/actions/callbacks/complete

Batch-complete async action callbacks

POST

/automation/v4/actions/callbacks/{callbackId}/complete

Complete a single async action callback

GET

/automation/v4/actions/{appId}/{definitionId}/revisions

List revisions of an action definition

POST

/automation/v4/actions/{appId}

Create a custom workflow action definition

GET

/automation/v4/actions/{appId}

List all action definitions for an app

PATCH

/automation/v4/actions/{appId}/{definitionId}

Update an action definition

DELETE

/automation/v4/actions/{appId}/{definitionId}

Archive an action definition

POST

/automation/v4/actions/callbacks/complete

Batch-complete async action callbacks

Why Jentic?

Three things that make agents converge on Jentic-routed access.

Credential isolation

Your HubSpot credential is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context.

Intent-based discovery

Agents search Jentic by intent such as 'register a hubspot workflow action', and Jentic returns the matching operation under /automation/v4/actions/{appId} with its input schema so the agent calls the right endpoint without browsing the reference docs.

Time to first call

FAQs

Specific to using Custom Workflow Actions API through Jentic.

Why is there no official OpenAPI spec for Custom Workflow Actions?

HubSpot does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call Custom Workflow Actions via structured tooling. It is validated against the live API and kept up to date. Get started with Jentic One, the self-hosted execution layer.

What authentication does the Custom Workflow Actions API use?

It accepts a developer hapikey query parameter for app-level operations, OAuth 2.0 access tokens for user-installed app calls, and the private-app-legacy header for private apps. Jentic stores all of these in the encrypted vault, so agents call the API with a scoped token and never see the raw developer key.

Can I register multiple revisions of the same workflow action?

Yes. Each PATCH on /automation/v4/actions/{appId}/{definitionId} that changes the input schema or labels creates a new revision. The /automation/v4/actions/{appId}/{definitionId}/revisions endpoint lists every published revision so existing workflows keep running on the version they were built on.

What are the rate limits for the Custom Workflow Actions API?

HubSpot enforces standard public app rate limits: 100 requests per 10 seconds per private app token and 110 per 10 seconds per OAuth app per portal. Daily limits depend on the HubSpot subscription tier. Workflow callback completions count against the same buckets.

How do I complete an async workflow action callback through Jentic?

Search Jentic for 'complete hubspot workflow callback', load the schema for POST /automation/v4/actions/callbacks/{callbackId}/complete, and execute with the callbackId and an outputFields payload. For high-volume callbacks use the batch endpoint /automation/v4/actions/callbacks/complete.

Is the Custom Workflow Actions API free?

API access is included with any HubSpot subscription that has access to workflows (Marketing, Sales, or Service Hub Professional and above). Custom workflow actions specifically require a public app installed in a portal that has workflow access.

Can I limit what my agent is allowed to do with the Custom Workflow Actions API?

Yes. Because you run Jentic One yourself, your own rules decide which operations and credentials the agent may use. Since HubSpot puts the app id in the URL path (/automation/v4/actions/{appId}), you can pin the agent to a single app so it only registers and reads that app's workflow action definitions. You also choose the exact operations it may call, so destructive ones like PATCH or DELETE on a definition, or callback completions, are excluded unless you add them.

HubSpot Custom Workflow Actions

Connect the Custom Workflow Actions to your agent

Capabilities

Start building with Custom Workflow Actions API

Use Cases

Key Endpoints

Why Jentic?

Related APIs

FAQs