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Guides

Python

1. Installation

Install the SDK via pip:

2. Send your first email

Initialize the client with your API token:

Code
import os
from lettermint import Lettermint

client = Lettermint(api_token=os.environ.get("LETTERMINT_API_TOKEN"))

Send your first email:

Code
response = (
    client.email
    .from_("John Doe <john@yourdomain.com>")
    .to("recipient@example.com")
    .subject("Hello from Lettermint")
    .text("This is a test email sent using the Lettermint Python SDK.")
    .send()
)

print(f"Email sent with ID: {response['message_id']}")

3. Email Features

Basic Email

Send a simple text or HTML email:

Code
response = (
    client.email
    .from_("John Doe <john@yourdomain.com>")
    .to("recipient@example.com")
    .subject("Your account is ready!")
    .html("<h1>Welcome!</h1><p>Thanks for signing up.</p>")
    .text("Welcome! Thanks for signing up.")
    .send()
)

Multiple Recipients

Send to multiple recipients using CC and BCC:

Code
response = (
    client.email
    .from_("John Doe <john@yourdomain.com>")
    .to("user1@example.com", "user2@example.com")
    .cc("manager@yourdomain.com")
    .bcc("archive@yourdomain.com")
    .subject("Monthly Newsletter")
    .html("<h1>This Month's Updates</h1>")
    .send()
)

Custom Headers and Reply-To

Add custom headers and set reply-to addresses:

Code
response = (
    client.email
    .from_("support@yourdomain.com")
    .to("customer@example.com")
    .reply_to("help@yourdomain.com")
    .subject("Support Ticket #12345")
    .headers({
        "X-Priority": "1",
        "X-Ticket-ID": "12345"
    })
    .html("<p>Your support ticket has been updated.</p>")
    .send()
)

Metadata

Add metadata for tracking and webhook payloads:

Code
response = (
    client.email
    .from_("notifications@yourdomain.com")
    .to("user@example.com")
    .subject("Order Confirmation")
    .metadata({
        "order_id": "12345",
        "customer_id": "cust_789",
        "campaign": "order_confirmation"
    })
    .html("<p>Your order has been confirmed.</p>")
    .send()
)

Tags

Categorize emails for filtering and analytics:

Code
response = (
    client.email
    .from_("alerts@yourdomain.com")
    .to("admin@example.com")
    .subject("System Alert")
    .tag("system-alerts")
    .html("<p>Critical system alert detected.</p>")
    .send()
)

Route Selection

Direct emails to specific routes within your project:

Code
response = (
    client.email
    .from_("notifications@yourdomain.com")
    .to("user@example.com")
    .subject("Welcome!")
    .route("transactional")
    .html("<p>Welcome to our platform.</p>")
    .send()
)

File Attachments

Attach files to your emails:

Code
import base64

# Read and encode file
with open("/path/to/document.pdf", "rb") as f:
    encoded_content = base64.b64encode(f.read()).decode()

response = (
    client.email
    .from_("invoices@yourdomain.com")
    .to("customer@example.com")
    .subject("Your Invoice")
    .html("<p>Please find your invoice attached.</p>")
    .attach("invoice.pdf", encoded_content)
    .send()
)

Inline Images

Embed images directly in your HTML using Content-ID:

Code
import base64

with open("/path/to/logo.png", "rb") as f:
    encoded_logo = base64.b64encode(f.read()).decode()

response = (
    client.email
    .from_("marketing@yourdomain.com")
    .to("customer@example.com")
    .subject("Welcome to Our Platform")
    .html('<p>Welcome!</p><img src="cid:logo@yourdomain.com" alt="Logo">')
    .attach("logo.png", encoded_logo, "logo@yourdomain.com")
    .send()
)

Idempotency

Prevent duplicate emails with idempotency keys:

Code
response = (
    client.email
    .from_("notifications@yourdomain.com")
    .to("user@example.com")
    .subject("Order Confirmation")
    .html("<p>Your order has been confirmed.</p>")
    .idempotency_key("order-12345-confirmation")
    .send()
)

4. Async Support

The SDK provides an async client for use with asyncio:

Code
import asyncio
import os
from lettermint import AsyncLettermint

async def send_email():
    async with AsyncLettermint(api_token=os.environ.get("LETTERMINT_API_TOKEN")) as client:
        response = await (
            client.email
            .from_("John Doe <john@yourdomain.com>")
            .to("recipient@example.com")
            .subject("Hello from Lettermint")
            .text("This is a test email.")
            .send()
        )
        print(f"Email sent with ID: {response['message_id']}")

asyncio.run(send_email())

5. Client Configuration

Customize the client with optional parameters:

Code
client = Lettermint(
    api_token=os.environ.get("LETTERMINT_API_TOKEN"),
    base_url="https://api.lettermint.co/v1",  # Custom API URL
    timeout=60.0,  # Request timeout in seconds
)

Use the client as a context manager for automatic resource cleanup:

Code
with Lettermint(api_token=os.environ.get("LETTERMINT_API_TOKEN")) as client:
    response = (
        client.email
        .from_("sender@yourdomain.com")
        .to("recipient@example.com")
        .subject("Test")
        .text("Hello!")
        .send()
    )

6. Response

Code
response = (
    client.email
    .from_("John Doe <john@yourdomain.com>")
    .to("recipient@example.com")
    .subject("Test")
    .text("Hello!")
    .send()
)

print(response["message_id"])  # Unique email ID

7. Error Handling

Handle errors with specific exception types:

Code
from lettermint import Lettermint
from lettermint.exceptions import (
    ValidationError,
    ClientError,
    TimeoutError,
    HttpRequestError,
)

client = Lettermint(api_token=os.environ.get("LETTERMINT_API_TOKEN"))

try:
    response = (
        client.email
        .from_("sender@yourdomain.com")
        .to("recipient@example.com")
        .subject("Test")
        .text("Hello!")
        .send()
    )
except ValidationError as e:
    # 422 errors (invalid parameters, daily limit exceeded, etc.)
    print(f"Validation error: {e.error_type}")
except ClientError as e:
    # 400 errors (bad request)
    print(f"Client error: {e}")
except TimeoutError as e:
    # Request timed out
    print(f"Timeout: {e}")
except HttpRequestError as e:
    # Other HTTP errors
    print(f"HTTP error {e.status_code}: {e}")

Next Steps