Lob

Lob is a direct mail and print-to-mail API platform that lets businesses send physical postcards, letters, checks, and other marketing materials programmatically. It also provides US address verification and campaign tooling for large mailings. Nexla connects to the Lob REST API so you can ingest Lob resources into your data flows and drive mailings, orders, and address verification from your Nexsets.

Power end-to-end data operations for your Lob API with Nexla. Our bi-directional Lob connector is purpose-built for Lob, making it simple to ingest data, sync it across systems, and deliver it anywhere — all with no coding required. Nexla turns API-sourced data into ready-to-use, reusable data products and makes it easy to send data to Lob or any other destination. With comprehensive monitoring, lineage tracking, and access controls, Nexla keeps your Lob workflows fast, secure, and fully governed.

Features

Type: API

SourceDestination

• Seamless API Integration: Connect to any endpoint as source or destination without coding, with automatic data product creation
• Visual Composition & Chaining: Build complex integrations using visual templates, chain API calls, and compose workflows with data validation and filtering
• API Proxy: Expose curated slices of your data securely with a secure and customizable API proxy that validates and transforms data on the fly
• Request optimization with intelligent batching, retry, and caching to minimize API calls and costs

Prerequisites

Before creating a Lob credential, you need a Lob account and a secret API key. Lob authenticates every API request with HTTP Basic authentication, using your API key as the username and leaving the password blank.

To obtain your Lob API key, follow these steps:

1. Sign in to your Lob dashboard.

2. Open Settings from the bottom of the left-hand navigation menu.

3. Select API Keys.

4. Copy the key you want to use. Lob provides a Test key (prefixed test_) for development and a Live key (prefixed live_) for production mailings. Use your secret API key, which can perform any API request without restriction and should be kept confidential.

The base URL for the Lob API is https://api.lob.com/v1. Secret API keys should be stored securely and never exposed in client-side code. If a key is compromised, roll it from the API Keys page in your dashboard. For more detail, see the Lob API documentation and the API keys help article.

Authenticate

Credentials required

HTTP Basic Authentication using Lob API key. Use your Lob API key as the username; leave password blank.

Field	Required	Secret	Description
API Key	Yes	Yes	Your Lob secret API key (used as the HTTP Basic auth username).
Password	No	No	Leave blank — Lob HTTP Basic auth uses only the API key as the username.
Base URL	Yes	No	The base URL for the Lob API.

Create a credential in Nexla

1. After selecting the data source/destination type, click the Add Credential tile to open the Add New Credential overlay.

2. Enter a name for the credential in the Credential Name field and a short, meaningful description in the Credential Description field.

3. Enter your Lob secret API key in the API Key field. This value is used as the HTTP Basic auth username when Nexla connects to the Lob API.

4. Leave the Password field blank. Lob HTTP Basic authentication relies only on the API key supplied as the username.

5. Enter the Lob API base URL in the Base URL field. Unless you have a specific reason to change it, use https://api.lob.com/v1.

   Use your secret API key. Test keys (prefixed test_) exercise the API without producing real mail, while live keys (prefixed live_) send physical mail and consume Lob credits. Keep secret keys confidential and roll them from the API Keys page in your Lob dashboard if they are ever exposed.

   For more information, see the Lob API documentation.

6. Click the Save button at the bottom of the overlay. The newly added credential will now appear in a tile on the Authenticate screen during data source/destination creation.

Use as a data source

To create a new data flow, navigate to the Integrate section, and click the New Data Flow button. Select the Lob connector tile, then select the credential that will be used to connect to Lob, and click Next; or, create a new Lob credential for use in this flow.

Endpoint templates

Nexla provides pre-built templates that can be used to rapidly configure data sources to ingest data from common Lob endpoints. Select the endpoint from which this source will fetch data from the Endpoint pulldown menu. Available endpoint templates are listed in the expandable boxes below.

[Rest API] List Postcards

Returns a list of postcards in the account.

[Rest API] List Templates

Returns a list of templates in the account.

[Rest API] List Template Versions

Returns a list of versions for a template.

[Rest API] List Campaigns

Returns a list of campaigns in the account.

[Rest API] List Uploads

Returns a list of uploads in the account.

[Rest API] List QR Code Analytics

Returns a list of QR code analytics data.

[Rest API] Get Account Credits Balance

Retrieves the current Lob credits balance for the authenticated account.

[Rest API] Retrieve Address

Retrieves a single address by ID.

[Rest API] Retrieve Bank Account

Retrieves a single bank account by ID.

[Rest API] List Buckslip Orders

Retrieves a paginated list of orders for a specific buckslip.

[Rest API] Get Upload

Retrieves details for a specific file upload by ID.

[Rest API] List (Addresses)

Retrieve a list of addresses from the Lob API.

[Rest API] List (Bank Accounts)

Retrieves a list of bank accounts from the Lob API with optional filtering and pagination parameters.

Once the selected endpoint template has been configured, click the Test button to the right of the endpoint selection menu to retrieve a sample of the data that will be fetched. Sample data will be displayed in the Endpoint Test Result panel on the right, allowing you to verify that the source is configured correctly before saving.

Manual configuration

Lob data sources can also be manually configured to ingest data from any valid Lob API endpoint, including endpoints not covered by the pre-built templates, chained API calls, or custom request parameters. Select the Advanced tab at the top of the configuration screen, and follow the instructions in Connect to Any API to configure the API method, endpoint URL, date/time and lookup macros, path to data, metadata, and request headers.

Once all of the relevant settings have been configured, click the Create button in the upper right corner of the screen to save and create the new Lob data source. Nexla will now begin ingesting data from the configured endpoint and will organize any data that it finds into one or more Nexsets.

Use as a destination

Click the + icon on the Nexset that will be sent to the Lob destination, and select the Send to Destination option from the menu. Select the Lob connector from the list of available destination connectors, then select the credential that will be used to connect to Lob, and click Next; or, create a new Lob credential for use in this flow.

Endpoint templates

Nexla provides pre-built templates that can be used to rapidly configure destinations to send data to common Lob endpoints. Select the endpoint to which data will be sent from the Endpoint pulldown menu. Then, click on the template in the list below to expand it, and follow the instructions to configure additional endpoint settings.

[Rest API] Create Address

Creates a new address in the account.

[Rest API] Verify Bank Account

Verifies a bank account by confirming two microdeposit amounts.

[Rest API] Create Bank Account

Creates a new bank account in the account.

[Rest API] Create Billing Group

Creates a new billing group.

[Rest API] Update Billing Group

Updates a billing group with new name and description.

[Rest API] Create Buckslip Order

Creates a new order for a specific buckslip.

[Rest API] Bulk Verify US Addresses

Verifies a list of US addresses in bulk.

[Rest API] Create Card Order

Creates a new order for a specific card with the specified quantity.

[Rest API] Create Check

Creates a new check to be sent to a recipient.

[Rest API] Create Letter

Creates a new letter to be sent via USPS mail.

[Rest API] Create Postcard

Creates a new postcard object and sends it in the mail.

[Rest API] Create Template

Creates a new template for use in campaigns and mailings.

[Rest API] Create Upload

Creates a new file upload for processing addresses and mail campaigns.

[Rest API] Create a campaign

Create a campaign — required to send bulk/scheduled mailings via the Campaigns API. At minimum, a campaign needs a name, schedule_type, and use_type.

[Rest API] Create a creative

Create a creative and associate a postcard or letter design with a campaign. Requires campaign_id, resource_type, and format-specific fields.

[Rest API] Create a self-mailer

Create a self-mailer (folded mail piece) — one of Lob's four core physical mail formats alongside postcards, letters, and checks.

[Rest API] Upload recipient file to an upload object

Upload the recipient CSV/file to an upload object — required to complete the campaign audience upload workflow. Uploads the file as a byte stream (binary file).

Manual configuration

Lob destinations can also be manually configured to send data to any valid Lob API endpoint. Select the Advanced tab at the top of the configuration screen, and follow the instructions in Connect to Any API to configure the API method, data format, endpoint URL, request headers, attribute exclusions, record batching, and response webhooks.

Lob APIs typically expect JSON request bodies. Live API keys send real physical mail and consume Lob credits, so use a test key (prefixed test_) while validating a new destination.

Save & activate

Once all endpoint settings have been configured, click the Done button in the upper right corner of the screen to save and create the destination. To send the data to the configured Lob endpoint, open the destination resource menu, and select Activate.

The Nexset data will not be sent to the Lob endpoint until the destination is activated. Destinations can be activated immediately or at a later time, providing full control over data movement.