For Agents
Push marketing event records and per-attendee state changes from external event platforms into HubSpot so attendance becomes CRM data with breakdown reporting.
Install Jentic One Beta
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Marketing Marketing Events, 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 | shStep 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 instanceJentic 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.
What an agent can do with Marketing Marketing Events API.
Upsert a marketing event record from an external platform using externalEventId
Record per-attendee subscriber-state changes (registered, attended, cancelled) by event id and state
Create attendance records identified by email when the contact has no existing HubSpot id
GET STARTED
Use for: I need to upsert a marketing event from our webinar platform into HubSpot, Record that contact@example.com attended event abc-123, Mark a list of contacts as registered for an upcoming webinar, Pull the attendance breakdown for an event by id
Not supported: Does not host events, send confirmation emails, or process ticketing — use for syncing external marketing event records and attendance state into HubSpot only.
The HubSpot Marketing Events API integrates external event platforms (webinars, conferences, in-person events) with HubSpot so contact attendance and registration become first-class CRM data. It manages marketing event records by externalEventId and externalAccountId, upserts attendance and participation states (registered, attended, cancelled), and exposes participation breakdowns for reporting. With 36 endpoints across event upsert, attendance create, email-create, and participation breakdown paths, it gives event-marketing tools a structured way to push their data into HubSpot timelines and workflows.
Pull a participation breakdown for an event to see attendee state distribution
Bulk-upsert events in one call when syncing an external event platform overnight
Cross-reference participation by externalAccountId and externalEventId for multi-tenant integrations
Patterns agents use Marketing Marketing Events API for, with concrete tasks.
★ Webinar Platform to HubSpot Sync
Push webinar registrations and attendance from Zoom, ON24, or a custom platform into HubSpot so marketing-ops sees the same attendance data CRM workflows act on. POST /marketing/v3/marketing-events/events/{externalEventId} upserts the event record, and the attendance subresources record per-attendee state by email or contact id. The result: webinar engagement appears on the contact timeline and triggers HubSpot workflows.
Call POST /marketing/v3/marketing-events/events/{externalEventId} to upsert the event, then POST /marketing/v3/marketing-events/attendance/{externalEventId}/{subscriberState}/email-create with attendee emails.
In-Person Event Attendance Backfill
After an in-person conference or trade show, backfill attendance into HubSpot in batches so sales follow-up sequences enrol the right contacts. The email-create attendance endpoint accepts a contact list keyed by email, removing the need to resolve HubSpot contact ids client-side. Useful for post-event marketing and demand generation.
Call POST /marketing/v3/marketing-events/attendance/{externalEventId}/attended/email-create with an array of attendee emails.
Participation Breakdown Reporting
Pull a participation breakdown for an event to see how many contacts are registered, attended, and cancelled, broken down by external account where relevant. GET /marketing/v3/marketing-events/participations/{marketingEventId}/breakdown returns the counts an agent can render directly to a dashboard, without aggregating per-attendee records client-side.
Call GET /marketing/v3/marketing-events/participations/{marketingEventId}/breakdown to read the per-state counts for the event.
AI Agent Post-Event Workflow via Jentic
An AI agent automates post-event follow-up by syncing attendance from the webinar platform, then enrolling attendees in a HubSpot workflow. The agent searches Jentic for marketing-event upsert and attendance operations, loads schemas, and runs them in sequence. Jentic stores the OAuth token, so the agent handles no raw credentials and the post-event run takes minutes.
Search Jentic for "upsert hubspot marketing event", load the schema for POST /marketing/v3/marketing-events/events/upsert, and execute with the event payload.
36 endpoints — the hubspot marketing events api integrates external event platforms (webinars, conferences, in-person events) with hubspot so contact attendance and registration become first-class crm data.
METHOD
PATH
DESCRIPTION
/marketing/v3/marketing-events/events/{externalEventId}
Upsert a marketing event by external id
/marketing/v3/marketing-events/events/upsert
Bulk upsert marketing events
/marketing/v3/marketing-events/events/{externalEventId}/{subscriberState}/upsert
Upsert attendance for an event by subscriber state
/marketing/v3/marketing-events/attendance/{externalEventId}/{subscriberState}/create
Create attendance records by subscriber state
/marketing/v3/marketing-events/attendance/{externalEventId}/{subscriberState}/email-create
Create attendance records identified by email
/marketing/v3/marketing-events/participations/{marketingEventId}/breakdown
Get participation breakdown for an event
/marketing/v3/marketing-events/participations/{externalAccountId}/{externalEventId}/breakdown
Get breakdown by external account and event
/marketing/v3/marketing-events/{objectId}
Retrieve a marketing event by HubSpot object id
/marketing/v3/marketing-events/events/{externalEventId}
Upsert a marketing event by external id
/marketing/v3/marketing-events/events/upsert
Bulk upsert marketing events
/marketing/v3/marketing-events/events/{externalEventId}/{subscriberState}/upsert
Upsert attendance for an event by subscriber state
/marketing/v3/marketing-events/attendance/{externalEventId}/{subscriberState}/create
Create attendance records by subscriber state
/marketing/v3/marketing-events/attendance/{externalEventId}/{subscriberState}/email-create
Create attendance records identified by email
Three things that make agents converge on Jentic-routed access.
Credential isolation
HubSpot OAuth, private app tokens, and developer API keys are stored encrypted in the Jentic MAXsystem vault. Agents receive scoped execution access — raw credentials never enter the agent's context.
Intent-based discovery
Agents search Jentic with intents like 'upsert hubspot marketing event' and Jentic returns the matching operation with its input schema, so the agent calls POST /marketing/v3/marketing-events/events/upsert with the right payload without browsing HubSpot docs.
Time to first call
Direct HubSpot integration: 3-5 days for OAuth setup, external-id mapping, attendance sync, and breakdown reporting. Through Jentic: under 1 hour — search, load schema, execute.
Alternatives and complements available in the Jentic catalogue.
Specific to using Marketing Marketing Events API through Jentic.
What authentication does the Marketing Events API use?
It accepts HubSpot OAuth 2.0 access tokens, private app tokens, or developer API keys (developer_hapikey for some operations), sent as Bearer or as a query parameter respectively. Through Jentic, the token is stored encrypted in MAXsystem.
Can I record attendance using only the contact's email?
Yes. POST /marketing/v3/marketing-events/attendance/{externalEventId}/{subscriberState}/email-create accepts an array of attendee emails so you do not need to resolve HubSpot contact ids before sending attendance updates.
How do I sync many events from an external platform in one call?
Use POST /marketing/v3/marketing-events/events/upsert with an inputs array. Each entry carries the externalEventId, externalAccountId, and event metadata; HubSpot upserts based on the external identifiers.
What are the rate limits for the Marketing Events API?
Account-level limits are 100 requests per 10 seconds across HubSpot's authenticated APIs, with daily caps that depend on the subscription tier. Use the bulk upsert endpoints to fit more events inside the per-second window.
How do I push a webinar attendance list through Jentic?
Run pip install jentic, search for "create hubspot event attendance by email", load the schema for POST /marketing/v3/marketing-events/attendance/{externalEventId}/attended/email-create, and execute with the email array. Sign up at https://app.jentic.com/sign-up.
Does this API send registration confirmation emails?
No. Sending confirmation emails is the job of the Marketing Single-send API or the Marketing Emails API. This API records the event and attendance state — confirmation send-outs are a separate call.
/marketing/v3/marketing-events/participations/{marketingEventId}/breakdown
Get participation breakdown for an event
/marketing/v3/marketing-events/participations/{externalAccountId}/{externalEventId}/breakdown
Get breakdown by external account and event
/marketing/v3/marketing-events/{objectId}
Retrieve a marketing event by HubSpot object id