HubSpot Marketing Single-send

Name: Marketing Single-send API
Brand: Marketing Single-send
Availability: InStock

✓ Official Vendor SpecCommunicationsEmail Deliveryoauth21 EndpointsREST

Install Jentic One Beta

Connect the Marketing Single-send to your agent

Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Marketing Single-send, 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 Marketing Single-send API.

Send an existing marketing email to a single recipient identified by email address

Override contact properties at send time so personalisation tokens render with custom values

Pass custom properties to the email template for transactional-style data injection

GET STARTED

Start building with Marketing Single-send API

Explore with Jentic

View OpenAPI Document

For Agents

Trigger a one-off transactional send of an existing HubSpot marketing email to a single recipient with personalisation tokens applied at call time.

Use for: I need to send a one-off marketing email to user@example.com, Trigger a transactional send using an existing HubSpot email template, Send a password-reset style email built as a marketing email, Override the firstName personalisation token at send time

Not supported: Does not send SMS, manage email templates, or update CRM records permanently - use for triggering a one-off send of an existing marketing email only.

Use Cases

Patterns agents use Marketing Single-send API for, with concrete tasks.

★ Transactional Use of Marketing Templates

Reuse a beautifully designed HubSpot marketing email as a transactional send for events like password resets, order confirmations, or webinar reminders. POST /marketing/v4/email/single-send accepts the emailId of the existing marketing email plus the recipient and custom properties, so design teams maintain templates in HubSpot while engineering triggers the sends from application code.

Call POST /marketing/v4/email/single-send with emailId, message.to=user@example.com, and contactProperties overriding firstName.

Webhook-Triggered Email Drops

Connect a webhook handler (Stripe payment success, new signup) directly to HubSpot single-send so the user receives a branded HubSpot email moments after the trigger event. The single-send endpoint is synchronous from the caller's perspective, returning a send status that the webhook handler can log and retry on transient failures.

On Stripe webhook payment_intent.succeeded, call POST /marketing/v4/email/single-send with emailId and the customer's email address.

Personalisation at Call Time

Inject custom property values into a marketing email template at send time using contactProperties and customProperties on the single-send payload. Personalisation tokens in the template (firstName, orderTotal) render with the values you pass in the request rather than the values stored on the contact record. Useful when the data is request-scoped (a specific order, a specific session) and should not persist to the CRM.

Call POST /marketing/v4/email/single-send with customProperties.orderTotal=49.99 and customProperties.orderId=ord_123 to render the template tokens.

AI Agent Notification Send via Jentic

An AI agent fires a HubSpot-branded notification when a watched condition trips (a customer health score drops, a deal stage changes). The agent searches Jentic for HubSpot single-send, loads the schema for POST /marketing/v4/email/single-send, and executes with the recipient and message body. Jentic isolates the OAuth token so the agent never handles raw credentials and the send takes seconds.

Search Jentic for "send hubspot single email", load the schema for POST /marketing/v4/email/single-send, and execute with emailId and message.to.

Key Endpoints

1 endpoints — the hubspot marketing single-send api delivers a one-off send of an existing marketing email to a single recipient with custom contact properties and personalisation tokens applied at send time.

METHOD

PATH

DESCRIPTION

POST

/marketing/v4/email/single-send

Send a marketing email to a single recipient

POST

/marketing/v4/email/single-send

Send a marketing email to a single recipient

Why Jentic?

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

Credential isolation

Your HubSpot OAuth or private-app token 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 'send a one-off HubSpot marketing email', and Jentic returns the single-send operation with its input schema so the agent calls the right endpoint without browsing the HubSpot reference docs.

Time to first call

FAQs

Specific to using Marketing Single-send API through Jentic.

What authentication does the Single-send API use?

It accepts HubSpot OAuth 2.0 access tokens or private app tokens (legacy schemes oauth2_legacy and private_apps_legacy), sent as Bearer in the Authorization header. Through Jentic, the token is stored encrypted in your Jentic One instance and injected at execution time.

Can I send a marketing email to one recipient without enrolling them in a list?

Yes - that is exactly what this API does. POST /marketing/v4/email/single-send takes an emailId and a single recipient, sending one copy without modifying any HubSpot list or workflow enrolment.

How do I override personalisation tokens at send time?

Pass contactProperties (override values for properties on the contact record) and customProperties (per-send values not tied to a contact field) on the request body. Personalisation tokens in the template render with these values for this send only.

What are the rate limits for the Single-send API?

Account-level limits are 100 requests per 10 seconds across HubSpot's authenticated APIs, with daily caps that depend on the subscription tier. Single-send also has its own daily volume cap by tier - check the HubSpot pricing docs for current numbers.

How do I trigger a single send through Jentic?

Run pip install jentic, search for "send hubspot single email", load the schema for POST /marketing/v4/email/single-send, and execute with emailId, message.to, and any contactProperties. Get started with Jentic One, the self-hosted execution layer.

Does this endpoint create or modify contact records?

It does not modify the contact record. The contactProperties on the payload only affect the personalisation rendered in this send; permanent updates require the CRM Contacts API.

Can I limit what my agent is allowed to do with the HubSpot Single-send API?

Yes. Because Jentic One is self-hosted, you decide which operations the agent may call, and here that is a single POST to /marketing/v4/email/single-send that triggers a one-off send of an existing email to a single recipient. You scope the agent to just that send operation, and your own rules govern which token it uses, so it cannot reach beyond posting an emailId and recipient. Since this rollout exposes only the one send operation, that is the full extent of what the agent can do with this API.