HubSpot Marketing Transactional Single Send

Name: Marketing Transactional Single Send API
Brand: HubSpot Marketing Transactional Single Send
Availability: InStock

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✓ Official Vendor SpecCommunicationsEmail Deliveryoauth2,apiKey6 Endpoints

Install Jentic One Beta

Connect the Marketing Transactional Single Send to your agent

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

Send a transactional email from an existing HubSpot email template with merge field substitutions

Create a new HubSpot SMTP API token tied to a specific app and campaign for outbound delivery

List the active SMTP API tokens on a HubSpot portal

GET STARTED

Start building with Marketing Transactional Single Send API

Explore with Jentic

View OpenAPI Document

For Agents

Send a single transactional email from a HubSpot template and manage the SMTP API tokens used for authenticated delivery.

Use for: I need to send a password reset email through HubSpot, Send a one-off receipt email using a HubSpot template, Create an SMTP API token for a new outbound mail integration, List the active HubSpot SMTP tokens on this portal

Not supported: Does not handle bulk marketing campaigns, contact list management, or SMS - use for single-recipient transactional email sends only.

Use Cases

Patterns agents use Marketing Transactional Single Send API for, with concrete tasks.

★ Customer receipt delivery

Send branded order confirmation and receipt emails from a templated HubSpot design at the moment a customer completes checkout. The API substitutes contact properties and custom variables into the template and records the send in HubSpot marketing reports so support teams can see whether the receipt was opened or clicked.

Call POST /marketing/v3/transactional/single-email/send with emailId 12345, the customer's email as the recipient, and orderTotal plus orderNumber as customProperties.

Password reset and account notifications

Deliver password reset, magic link, and account verification emails through HubSpot using SMTP API tokens scoped to the auth service. The API supports per-message custom properties so the reset link, expiry timestamp, and IP can be merged into the template, and tokens can be rotated by resetting the password without changing the token ID.

Send a password reset email via POST /marketing/v3/transactional/single-email/send using emailId 67890 and a customProperty named resetUrl pointing to the per-user link.

SMTP token lifecycle management

Provision, audit, and revoke HubSpot SMTP API tokens used by application backends to authenticate outbound transactional mail. Each token is bound to a campaign so reporting attribution stays clean, and tokens can be deleted instantly when an app is decommissioned or a credential leaks.

List active tokens with GET /marketing/v3/transactional/smtp-tokens, identify the leaked token, then call DELETE /marketing/v3/transactional/smtp-tokens/{tokenId} to revoke it.

Agent-driven transactional sends through Jentic

An AI agent retrieves the send transactional email operation through Jentic's intent search, loads the input schema, and executes a send without ever holding the HubSpot OAuth token in its own context. Jentic handles credential injection so the agent can compose the recipient and template variables and call the operation in a single step.

Through Jentic, search for 'send a transactional email via HubSpot', load the schema for POST /marketing/v3/transactional/single-email/send, and execute it with the customer's email and templated emailId.

Key Endpoints

6 endpoints — the hubspot marketing transactional single send api delivers one-off transactional emails such as receipts, password resets, and account notifications using a hubspot-designed email template.

METHOD

PATH

DESCRIPTION

POST

/marketing/v3/transactional/single-email/send

Send a single transactional email from a HubSpot template

POST

/marketing/v3/transactional/smtp-tokens

Create a new SMTP API token

GET

/marketing/v3/transactional/smtp-tokens

List active SMTP API tokens

GET

/marketing/v3/transactional/smtp-tokens/{tokenId}

Retrieve a single SMTP API token

POST

/marketing/v3/transactional/smtp-tokens/{tokenId}/password-reset

Reset the password on an SMTP API token

DELETE

/marketing/v3/transactional/smtp-tokens/{tokenId}

Delete and revoke an SMTP API token

POST

/marketing/v3/transactional/single-email/send

Send a single transactional email from a HubSpot template

POST

/marketing/v3/transactional/smtp-tokens

Create a new SMTP API token

GET

/marketing/v3/transactional/smtp-tokens

List active SMTP API tokens

GET

/marketing/v3/transactional/smtp-tokens/{tokenId}

Retrieve a single SMTP API token

POST

/marketing/v3/transactional/smtp-tokens/{tokenId}/password-reset

Reset the password on an SMTP API token

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 transactional email via HubSpot', and Jentic returns the single-email send operation with its input schema, including the emailId and customProperties shape, so the agent calls the right endpoint without browsing the HubSpot reference docs.

Time to first call

FAQs

Specific to using Marketing Transactional Single Send API through Jentic.

What authentication does the HubSpot Transactional Single Send API use?

The API accepts HubSpot OAuth 2.0 access tokens or HubSpot private-app tokens passed as a Bearer header. Through Jentic, these credentials live in your encrypted Jentic One instance and are injected at execution time so they never enter the agent's prompt context.

Can I send password reset emails with the Transactional Single Send API?

Yes. Call POST /marketing/v3/transactional/single-email/send with the emailId of a HubSpot transactional template and pass the reset URL and expiry timestamp as customProperties so they merge into the rendered email.

What are the rate limits for the HubSpot Transactional Single Send API?

HubSpot's standard public API limits apply: 100 requests per 10 seconds for OAuth apps and 110 requests per 10 seconds for private apps, with a separate transactional email send quota tied to the Marketing Hub subscription tier.

How do I rotate an SMTP API token through Jentic?

Use the Jentic search query 'rotate HubSpot SMTP token' to find POST /marketing/v3/transactional/smtp-tokens/{tokenId}/password-reset, load its schema, and execute it with the existing tokenId. The token ID stays stable so downstream apps continue to work after the password rotation.

Does this API support marketing campaign emails or bulk sends?

No. This API sends one transactional email per request and is scoped to single-recipient sends like receipts, password resets, and notifications. For marketing campaign sends, use the HubSpot Marketing Single Send or Marketing Emails API instead.

Can I delete a leaked SMTP token immediately?

Yes. Call DELETE /marketing/v3/transactional/smtp-tokens/{tokenId} to revoke the token instantly. Any application still using that token will start receiving authentication errors on the next send attempt.

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

Yes. Because you run Jentic One yourself, your own rules decide which of this API's operations the agent may call and which credential it uses, so you can allow the single-email send while withholding token deletion or password reset. Since the SMTP token id sits in the URL path (/marketing/v3/transactional/smtp-tokens/{tokenId}), a rule can pin the agent to one token and let it read only that token and nothing else. Operations you do not explicitly grant, such as DELETE on an SMTP token, stay unavailable to the agent.

HubSpot Marketing Transactional Single Send

Connect the Marketing Transactional Single Send to your agent

Capabilities

Start building with Marketing Transactional Single Send API

Use Cases

Key Endpoints

Why Jentic?

Related APIs

FAQs