SendPulse Service REST API

Introduction

Our API interface is used to integrate SendPulse’s distribution service capabilities with client’s personal projects. The API is designed for developers and is accompanied by detailed documentation.

SendPulse’s REST API works over the HTTPS protocol and is essentially a set of methods used to perform requests and receive responses for each operation. All answers return in the form of JSON structures.

All references to API requests in this document include the root URL:

https://api.sendpulse.com

Cross Domain Queries (jQuery Ajax Example) are not allowed. 

AI agent integration

SendPulse API is fully discoverable by LLMs and AI agents. All tools are documented in the OpenAPI 3.1 format and provide machine-readable llms.txt, a native MCP server, and structured metadata extensions.

Discovery endpoints

AI agents can find the full API from the base URL api.sendpulse.com.

Model Context Protocol (MCP)

Integrate Claude, GPT-4, Cursor, or any MCP-compatible AI client with your SendPulse account. The MCP server exposes SendPulse's chatbot builder, email service, CRM system, and Automation as native tools through the API so that AI can call them without writing code.

OpenAPI specifications

Each SendPulse tool has a standalone OpenAPI 3.1.0 spec at api.sendpulse.com/.well-known/openapi/.

All specs include x-ai-role, x-ai-capabilities, x-ai-reasoning-instructions, and x-ai-responding-instructions extensions for AI agent guidance.

Quick start for AI developers

Step 1. Send a GET request to load llms.txt:

https://api.sendpulse.com/llms.txt

Step 2. Send a GET request to load the OpenAPI index:

https://api.sendpulse.com/.well-known/openapi/index.yaml

Step 2. To use the MCP server for agentic workflows, follow the setup instructions.

Step 4. To connect through GPT Actions, use the ai-plugin.json file to configure a custom GPT with access to all SendPulse tools.

SendPulse libraries

The latest versions of SendPulse API client libraries are available at GitHub.

• PHP wrapper
• Python wrapper
• Ruby wrapper
• Java wrapper
• Node.js wrapper
• C# wrapper 
• Go wrapper (third-party solution)

You can also check other third-party solutions on Github.

Authorization

SendPulse API uses Bearer token authentication. You must include the token in the Authorization header of every request:

Authorization: Bearer <your_token_or_key>

You can authorize your requests in two ways:

• API Key (Static): A long-lived token generated manually in your account.
• OAuth 2.0 (Dynamic): A temporary access token obtained via Client ID and Client Secret.

API keys

An API key is a permanent authentication token. It remains valid until you manually revoke it, making it ideal for simple integrations where you don't want to implement token refresh logic.

Go to Settings > API > API keys and click Generate. Give your key a name and optionally restrict access to specific IP addresses.

You can create up to 5 independent keys. This allows you to manage different integrations separately and revoke them individually if needed.

OAuth 2.0 (Client Credentials)

This method allows you to programmatically obtain a temporary access token using your Client ID and Client Secret.

The access token is valid for 1 hour. You should request a new token only after the current one expires.

Go to Settings > API > API keys and copy your ID and Secret.

To get the token, send a POST request to:

https://api.sendpulse.com/oauth/access_token

Request parameters:

Request example:

{
   "grant_type":"client_credentials",
   "client_id":"0aadb081f2f81c05bafe39621910000",
   "client_secret":"a99e7d506d3701c5c04de3db1913eeee"
}

If request is successful, you will receive a response:

{
  "access_token": "eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImp0aSI6IjI5NTQ4NDVjZWJlZjg5Nzk0YmYzMzk4ZDdiNTQ3OTA2MWUzNDQ2N2I5NTUwMmFlNzE1YmViZmU4MDBmNTMxMjIxMTU2MTcyOWM2MjI5NGRjIn0.eyJhdWQiOiIyMzdiNGFmOWM5OWQwZjg5YmRiZDg3NmRjZDVhMDE3ZiIsImp0aSI6IjI5NTQ4NDVjZWJlZjg5Nzk0YmYzMzk4ZDdiNTQ3OTA2MWUzNDQ2N2I5NTUwMmFlNzE1YmViZmU4MDBmNTMxMjIxMTU2MTcyOWM2MjI5NGRjIiwiaWF0IjaaNjI0NTI0OTA0LCJuYmYiOjE2MjQ1MjQ5MDQsImV4cCI6MTYyNDUyODUwNCwic3ViIjoiIiwic2NvcGVzIjpbXSwidXNlciI6eyJpZCI6Njc0MTgwNCwiZ3JvdXBfaWQiOm51bGwsInBhcmVudF9pZCI6bnVsbCwiYXJlYSI6InJlc3QifX0.jiP3Sv7IF1mHGmW0oGIrPAw0oOiIEnC8Tb6wlWu5eVM2UrHL6RZsDlIslLSQNEvL_e50nDlgtgyfX5Qty4qlQ4XyW53FAgjwHbyQG7DJ6iVRAtVBtFNbkFVNbHvKw8zQy7WyxhICpAF8zdF8-gBHBnzuMhKSnASYEosJ9IAPqUkxQXrd8LpUSk-etzjEqcpMkbGj2M7Y0OxO4_BfRhVNU6ZcbiawD09m0A9uWoSnoZKxXw0o64PE3anJta6lFns5SDuyeGxanOtuZSS5I3umI2OOnUVzNG9_5WjCe6LPVQLAPAPt0m8S5WkI35_jCJ0A-gDBBdsgnUudGCvsDcgEog",
  "token_type": "Bearer",
  "expires_in": 3600
}

Account information

To get information about your account, send a GET request to:

https://api.sendpulse.com/user/info

If request is successful, you will receive a response:

{
  "id": 7043663,
  "name": "Frodo Baggins",
  "first_name": "Frodo",
  "last_name": "Baggins",
  "email": "frodo.baggins@shire.me",
  "phone": "380680899608",
  "lang": "en:English",
  "avatar": "https://login.sendpulse.com/files/avatars/frodo_ring.png",
  "currency": "USD",
  "country": "NZ",
  "city": "Hobbiton",
  "locale": "Pacific/Auckland",
  "time_zone": "12",
  "team_name": "Fellowship of the Ring",
  "team_avatar": "https://login.sendpulse.com/files/avatars/fellowship.png",
  "phone_confirm": true
}

Invited users

To get information about your team members, send a GET request to:

https://api.sendpulse.com/user/invited-users-list

If request is successful, you will receive a response:

[
    {
        "id": 7043663,
        "firstname": "john",
        "lastname": "harrington",
        "email": "john.harrington@example.com",
        "group_id": null,
        "is_active": true,
        "avatar": "https://example.com/avatars/test-user-1.png",
        "lang": "ua:Українська",
        "locale": "Europe/Kyiv",
        "currency": "UAH",
        "country": "UA",
        "phone": 380671112233
    },
    {
        "id": 8802086,
        "firstname": "amelia",
        "lastname": "rowe",
        "email": "amelia.rowe@example.org",
        "group_id": 6,
        "is_active": true,
        "avatar": null,
        "lang": "en:English",
        "locale": "Europe/Berlin",
        "currency": "EUR",
        "country": "DE",
        "phone": 499876543210
    },
    {
        "id": 8700831,
        "firstname": "william",
        "lastname": "dawson",
        "email": "william.dawson@example.net",
        "group_id": 1,
        "is_active": true,
        "avatar": null,
        "lang": "ua:Українська",
        "locale": "Europe/Berlin",
        "currency": "UAH",
        "country": "DE",
        "phone": 380631234567
    }
]

Balance information

To get detailed balance information, send a GET request to:

https://api.sendpulse.com/user/balance/detail

If request is successful, you will receive a response:

{
    "balance": {
        "main": "9.36",
        "bonus": "5.00",
        "currency": "USD"
    },
    "email": {
        "tariff_name": "Pay as you go 10 000",
        "finished_time": "2019-04-25 08:03:02",
        "emails_left": 9914,
        "maximum_subscribers": 10000,
        "current_subscribers": 0
    },
    "smtp": {
        "tariff_name": "SMTP Free",
        "end_date": "2018-11-21 15:05:39",
        "auto_renew": 1
    },
    "push": {
        "tariff_name": "White Label",
        "end_date": "2018-11-30",
        "auto_renew": 1
    }
}

Request limits

There are limits and quotas on SendPulse API requests to protect the system from receiving more data than it can handle and ensure an equitable distribution of the system resources. API limits per minute and per day depend on the category of your selected pricing plan

General quota limits

The following quotas apply when sending API requests:

Exceeding quota limits

If you exceed this quota, the API returns the following error:

429 Too many requests

To be able to send more requests, you need to upgrade your current pricing plan.

Error codes 

Error code	Description
8	No data
10	Sender email address missing
11	Can’t find recipients addresses
13	Empty email message content field
14	Can’t find email address with the specified ID
17	Can’t find the email address
19	Email address already exists
20	Using free email services (not allowed)
21	No such email address awaiting activation
97	Invalid email address type. Using free email services is not allowed.
201	Empty mailing list name
203	This mailing list name already exists
211	Mailing list empty
213	Mailing list not found
303	Can’t find email addresses in the mailing list
400	Specified SMTP user doesn’t exist. Create an SMTP account.
502	Can’t find the email address
602	Can’t find the campaign. Probably, it has already been sent.
701	Sender email address or name not specified.
703	Can’t find the mailing list
704	Can’t find the sender
707	Account balance depleted
708	The number of campaign recipients exceeds your current pricing plan limits
711	Wait before create new push campaign by this website
720	Empty subject field
721	Email message empty
722	Mailing list ID not specified
791	API-campaigns limit exceeded (4 per hour)
799	Incorrect date format. Use YYYY-MM-DD hh:ii:ss that equals or greater than the current date
800	Invalid operation
802	Campaign not found
901	Sender name not specified
902	Selected email address already in use
903	Sender email address not specified
904	Email address blacklisted
905	Sender address quota reached
906	Email address syntax error
1101	Email address not specified
1003	The specified sender doesn’t exist
1004	The activation code has been sent. Wait 15 minutes to retry
1005	Error sending confirmation
1104	Activation code not specified
2020202020	More than 10 requests per second