langchain-goodsender

LangChain tools for GoodSender — the free transactional email API with built-in consent management. Send OTP codes, MFA enrollment, new-device alerts, order confirmations, and more via predefined templates. Send custom/marketing email to recipients who have granted consent via the Permission Loop.

Install

pip install langchain-goodsender

Authentication

Set your API key as an environment variable:

export GOODSENDER_API_KEY="gs_..."

Or pass it directly:

from langchain_goodsender import GoodSenderToolkit

toolkit = GoodSenderToolkit(api_key="gs_...")

Get a free API key at goodsender.com — 100,000 emails/month free, no credit card required.

Quick start

from langchain_goodsender import GoodSenderToolkit
from langchain_openai import ChatOpenAI

toolkit = GoodSenderToolkit()  # reads GOODSENDER_API_KEY
tools = toolkit.get_tools()

model = ChatOpenAI(model="gpt-4o").bind_tools(tools)
result = model.invoke("Send an OTP code 482193 to alice@example.com from noreply@myapp.com with app_name MyApp")

Tools

goodsender_send_template

Send a predefined transactional email instantly to any address — no recipient consent needed.

Available template_id values: mfa_enrollment, new_device_login, order_completed, otp_code, email_changed, password_changed, order_receipt.

goodsender_send_email

Send a custom email (markdown, HTML, or plain text).

Consent caveat: This endpoint is consent-gated. The recipient must have approved via the GoodSender Permission Loop before the email delivers. If the recipient has not granted consent, the send is silently filtered — the email is not delivered. Use goodsender_request_consent first.

goodsender_request_consent

Ask one or more recipients to approve future custom/marketing email from your sending domain. GoodSender sends each recipient a consent request. Once they click approve, their status becomes granted and custom sends will deliver instantly.

Consent caveat

GoodSender has two sending paths:

If your agent needs to send a custom email to a new recipient, it must first call goodsender_request_consent and wait for the recipient to approve. Transactional templates (otp_code, mfa_enrollment, etc.) bypass this entirely.

Template variables

Each template accepts optional string variables. All default to empty if omitted.

API Reference

Full docs: goodsender.com/docs/api-reference

License

MIT