Lob connector for AI agents

Tools your direct mail agent reaches for on Lob, scoped per user.

CALL ANY TOOL

63 tools for direct mail in Lob: create and cancel mailpieces, send campaigns, verify addresses, and manage templates, bank accounts, and short links.

lob_autocomplete_us_address

Autocomplete us address

Suggest US street addresses that match a typed prefix, optionally filtered by city, state or ZIP. Returns an object with `suggestions`, each holding a `primary_line`, `city`, `state` and `zip_code`. Use autocomplete_us_address for type-ahead address entry. Use verify_us_address to confirm a full address.

Parameters

Name

Type

Required

Description

address_prefix

string

Required

Street number and street name typed so far, alphanumeric only. Example: `210 King`.

case

string

Optional

Casing of suggestions: `upper` (default) or `proper`. One of: `upper`, `proper`.

city

string

Optional

City to filter suggestions by. Case insensitive; partial names do not match.

state

string

Optional

State to filter suggestions by. Case insensitive.

valid_addresses_only

boolean

Optional

If true, every suggestion is a valid deliverable address. If false (default), suggestions may need verification.

zip_code

string

Optional

ZIP code to filter suggestions by. Partial entries match.

lob_cancel_check

Check cancel

lob_cancel_postcard

Cancel postcard

lob_create_address

Create address

lob_create_billing_group

Create billing group

lob_create_check

Check create

Create and mail a physical check drawn on a verified bank account. In live mode this mails a real check and is billed. Returns the check with `id` (starts with `chk_`), `to`, `from`, `amount`, `bank_account`, `check_number`, `expected_delivery_date`, `thumbnails` and `url`. Use create_check to pay someone by mail. The bank account must first be created with create_bank_account and verified with verify_bank_account. Provide either `message` (printed under the check) or `check_bottom` artwork.

Parameters

Name

Type

Required

Description

amount

number

Required

Payment amount in US dollars, up to 999999.99, rounded to two decimals.

bank_account

string

Required

ID of a verified bank account (starts with `bank_`) the check is drawn on.

from

string

Required

Sender address. Either the ID of a saved address (starts with `adr_`) or an inline address object. An inline object needs name, address_line1, address_city, address_state and address_zip for US addresses, or address_line1 and address_country for international ones; address_line2, company, phone and email are optional. Example: {"name": "Ada Lovelace", "address_line1": "210 King St", "address_city": "San Francisco", "address_state": "CA", "address_zip": "94107"}.

string

Required

Payee address. Checks can only be sent within the US. Either the ID of a saved address (starts with `adr_`) or an inline address object. An inline object needs name, address_line1, address_city, address_state and address_zip for US addresses, or address_line1 and address_country for international ones; address_line2, company, phone and email are optional. Example: {"name": "Ada Lovelace", "address_line1": "210 King St", "address_city": "San Francisco", "address_state": "CA", "address_zip": "94107"}.

use_type

string

Required

Declares the purpose of the mailpiece: `marketing` or `operational`. Required by Lob unless your account has a default use type set. One of: `marketing`, `operational`.

attachment

string

Optional

Document to include with the check: HTML, a template ID or a URL to a PDF.

billing_group_id

string

Optional

ID of a billing group (starts with `bg_`) to tag usage with. Requires special activation on your Lob account.

check_bottom

string

Optional

Artwork for the bottom of the check page: HTML, a template ID or a URL to a PDF, PNG or JPG. Required if `message` is not given.

check_number

integer

Optional

Check number, up to 500000000. If omitted, numbering starts at 10000 and increments.

description

string

Optional

Internal description for this resource, up to 255 characters.

idempotency_key

string

Optional

Unique string (up to 256 characters) that makes the create call safe to retry; repeating it returns the original resource instead of mailing twice.

logo

string

Optional

URL of an image printed in grayscale in the upper-left corner of the check.

mail_type

string

Optional

Checks are always sent `usps_first_class`; leave empty. One of: `usps_first_class`.

memo

string

Optional

Text for the memo line of the check.

merge_variables

object

Optional

Values for the merge variables in your HTML template or QR code redirect URL, as a JSON object. Example: {"first_name": "Ada"}.

message

string

Optional

Text printed at the bottom of the check page, up to 400 characters. Required if `check_bottom` is not given.

metadata

object

Optional

Custom key-value pairs for tagging this resource (up to 20 pairs; keys up to 40 characters, values up to 500 characters; string values only). Example: {"customer_id": "cus_42"}.

print_speed

string

Optional

Production speed. Only `core` (2 production business days) is available. One of: `core`.

send_date

string

Optional

ISO 8601 date or datetime, after now and up to 180 days ahead, at which to send the piece to production. Omit to send immediately.

service_request_number

string

Optional

Service request number of an approved USPS promotion to apply to this mailpiece.

lob_create_domain

Create domain

lob_create_link

Create link

lob_create_self_mailer

Create self mailer

Create and mail a folded self mailer. In live mode this prints and mails a real piece and is billed. Returns the self mailer with `id` (starts with `sfm_`), `to`, `from`, `size`, `expected_delivery_date`, `thumbnails` and `url`. Use create_self_mailer for bifold or trifold mailers. Use create_postcard for single-card pieces. Test API keys render a proof without mailing anything.

Parameters

Name

Type

Required

Description

inside

string

Required

Artwork for the inside of the self mailer: an HTML string (up to 10,000 characters), a template ID (starts with `tmpl_`), or a publicly reachable URL to a PDF, PNG or JPG file of the correct dimensions.

outside

string

Required

Artwork for the outside of the self mailer: an HTML string (up to 10,000 characters), a template ID (starts with `tmpl_`), or a publicly reachable URL to a PDF, PNG or JPG file of the correct dimensions.

string

Required

Recipient address. Either the ID of a saved address (starts with `adr_`) or an inline address object. An inline object needs name, address_line1, address_city, address_state and address_zip for US addresses, or address_line1 and address_country for international ones; address_line2, company, phone and email are optional. Example: {"name": "Ada Lovelace", "address_line1": "210 King St", "address_city": "San Francisco", "address_state": "CA", "address_zip": "94107"}.

use_type

string

Required

Declares the purpose of the mailpiece: `marketing` or `operational`. Required by Lob unless your account has a default use type set. One of: `marketing`, `operational`.

billing_group_id

string

Optional

ID of a billing group (starts with `bg_`) to tag usage with. Requires special activation on your Lob account.

description

string

Optional

Internal description for this resource, up to 255 characters.

from

string

Optional

Sender address, required if the recipient is international. Either the ID of a saved address (starts with `adr_`) or an inline address object. An inline object needs name, address_line1, address_city, address_state and address_zip for US addresses, or address_line1 and address_country for international ones; address_line2, company, phone and email are optional. Example: {"name": "Ada Lovelace", "address_line1": "210 King St", "address_city": "San Francisco", "address_state": "CA", "address_zip": "94107"}.

fsc

boolean

Optional

Beta: print the mailpiece on Forest Stewardship Council certified paper. Contact Lob to enable.

idempotency_key

string

Optional

Unique string (up to 256 characters) that makes the create call safe to retry; repeating it returns the original resource instead of mailing twice.

mail_type

string

Optional

Postage type: `usps_first_class` (default) or `usps_standard` (cheaper, slower, marketing only). One of: `usps_first_class`, `usps_standard`.

merge_variables

object

Optional

Values for the merge variables in your HTML template or QR code redirect URL, as a JSON object. Example: {"first_name": "Ada"}.

metadata

object

Optional

Custom key-value pairs for tagging this resource (up to 20 pairs; keys up to 40 characters, values up to 500 characters; string values only). Example: {"customer_id": "cus_42"}.

print_speed

string

Optional

Production speed. Only `core` (2 production business days) is available. One of: `core`.

qr_code

object

Optional

Places a QR code on the artwork. Give a position (for example `top_left`, `bottom_right`) or explicit offsets, a redirect_url the code points to, and optionally width and pages. Example: {"position": "bottom_right", "redirect_url": "https://example.com/offer", "width": "1.5"}.

send_date

string

Optional

ISO 8601 date or datetime, after now and up to 180 days ahead, at which to send the piece to production. Omit to send immediately.

service_request_number

string

Optional

Service request number of an approved USPS promotion to apply to this mailpiece.

size

string

Optional

Self mailer size: `6x18_bifold` (default), `11x9_bifold`, `12x9_bifold` or `17.75x9_trifold` (beta). One of: `6x18_bifold`, `11x9_bifold`, `12x9_bifold`, `17.75x9_trifold`.

lob_delete_address

Delete address

lob_delete_campaign

Delete campaign

lob_delete_link

Delete link

lob_get_address

Get address

lob_get_billing_group

Get billing group

lob_get_check

Check get

lob_get_domain

Get domain

lob_get_link

Get link

lob_get_self_mailer

Get self mailer

lob_list_addresses

List addresses

lob_list_billing_groups

List billing groups

lob_list_checks

List checks

lob_list_letters

List letters

lob_list_postcards

List postcards

lob_list_template_versions

List template versions

lob_reverse_geocode

Reverse geocode

lob_send_campaign

Send campaign

lob_update_billing_group

Update billing group

lob_update_creative

Update creative

lob_update_template

Update template

lob_verify_intl_address

Verify intl address

For more tools, view docs.

Build your Agent

Same auth pattern across LangChain, OpenAI, Anthropic, and Google ADK.

import { ScalekitClient } from "@scalekit-sdk/node";
import { createReactAgent } from "@langchain/langgraph/prebuilt";

const sk = new ScalekitClient(env.SCALEKIT_ENV_URL, env.SCALEKIT_CLIENT_ID, env.SCALEKIT_CLIENT_SECRET);

// Lob tools scoped to this user
const { tools } = await sk.tools.listScopedTools("user_123", {
  filter: { connectionNames: ["lob"], toolNames: [
    "lob_verify_us_address",
    "lob_create_postcard",
    "lob_list_postcards"] },
  pageSize: 100,
});

const agent = createReactAgent({ llm, tools });
await agent.invoke({ messages: [{ role: "user", content: "Verify this address and mail it the welcome postcard" }] });

import OpenAI from "openai";
import { ScalekitClient } from "@scalekit-sdk/node";

const sk = new ScalekitClient(env.SCALEKIT_ENV_URL, env.SCALEKIT_CLIENT_ID, env.SCALEKIT_CLIENT_SECRET);
const openai = new OpenAI();

const { tools } = await sk.tools.listScopedTools("user_123", {
  filter: { connectionNames: ["lob"] }, pageSize: 100,
});

const res = await openai.chat.completions.create({
  model: "gpt-5",
  messages: [{ role: "user", content: "Verify this address and mail it the welcome postcard" }],
  tools,
});

// Execute the tool call with the user's vaulted Lob API key
await sk.tools.executeTool(res.choices[0].message.tool_calls[0], "user_123");

import Anthropic from "@anthropic-ai/sdk";
import { ScalekitClient } from "@scalekit-sdk/node";

const sk = new ScalekitClient(env.SCALEKIT_ENV_URL, env.SCALEKIT_CLIENT_ID, env.SCALEKIT_CLIENT_SECRET);
const anthropic = new Anthropic();

const { tools } = await sk.tools.listScopedTools("user_123", {
  filter: { connectionNames: ["lob"] }, pageSize: 100,
});

const msg = await anthropic.messages.create({
  model: "claude-sonnet-5",
  max_tokens: 1024,
  messages: [{ role: "user", content: "Verify this address and mail it the welcome postcard" }],
  tools,
});

// Tool call runs with the user's vaulted Lob API key
await sk.tools.executeTool(msg.content, "user_123");

import { Agent } from "@google/adk/agents";
import { ScalekitClient } from "@scalekit-sdk/node";

const sk = new ScalekitClient(env.SCALEKIT_ENV_URL, env.SCALEKIT_CLIENT_ID, env.SCALEKIT_CLIENT_SECRET);

const { tools } = await sk.tools.listScopedTools("user_123", {
  filter: { connectionNames: ["lob"] }, pageSize: 100,
});

const agent = new Agent({
  name: "direct_mail_agent",
  model: "gemini-2.5-pro",
  instruction: "Lob tools scoped to this user",
  tools,
});

await agent.run("Verify this address and mail it the welcome postcard");

Try these prompts

Copy any prompt into your agent. Each maps directly to a Lob tool. Click to copy, paste into your agent, done.

Mailpieces

Copy the prompt

Copied

Send a postcard to 120 Market St, San Francisco using the welcome template.

Copy the prompt

Copied

Cancel the letter to Jordan Lee before it goes to production.

Copy the prompt

Copied

List the self mailers we sent this week.

Addresses

Copy the prompt

Copied

Verify 500 Main Street, Springfield, IL 62701.

Copy the prompt

Copied

Which cities belong to ZIP code 94107?

Copy the prompt

Copied

Save Acme Corp's headquarters address to the address book.

Campaigns and templates

Copy the prompt

Copied

Create a draft campaign for the spring catalog mailing.

Copy the prompt

Copied

Publish version 3 of the renewal letter template.

Copy the prompt

Copied

Create a short link to acme.com/offer for the postcard QR code.

SEE HOW AUTH WORKS

Each user connects their own Lob API key once, and Scalekit sends it with every call. Keys stay vaulted, every call is scope checked, and every action is logged.

Authorize

Your user connects

Lob

once. We tie it to their identity and the meetings they approved — no shared bot account, no org-wide access

Who:

user ‘A’

when:

Once per user

access:

Limited to user

Store

Their

Lob

token lives in a vault scoped to them. User A's meetings are never reachable by an agent acting for user B, even on the same connection

vault:

encrypted

scope:

per-user

tokens:

auto-refreshed

Resolve

When your agent calls a

Lob

tool, we fetch the right token server-side. It never touches your agent, never appears in the LLM context, never shows up in your logs

speed:

~40ms

check:

before every call

seen by:

nobody

Audit

Every

Lob

tool call is logged — who triggered it, which meeting was fetched, what came back. 90 days of history, tied to the user who authorized it

history:

90 days

export:

SIEM-ready

logged:

every call

Test other agents

See the same per-user auth pattern across other marketing and messaging connectors.

GTM and RevOps Teams

Outbound prospecting agent

Searches Apollo for prospects matching your ICP, scores and ranks them, drafts personalized outreach in Gmail, and logs every send to Google Sheets. Mail goes out as the rep, not from a shared inbox.

Why Scalekit

Secure your agent's access. Connectors ship in minutes

01.

Shared tokens break per-user analytics

A shared Lob API key looks fine in a demo. In production every mailpiece and check looks like one service account, and you cannot tell which user triggered it. Scalekit resolves the credential of the actual user who triggered the agent, never a shared bot.

// shared key
audit → bot_service_account

// scalekit
audit → user_abc ✓

02.

Authentication is not authorization

03.

Multi-tenancy is architectural

04.

Lob today. Ten connectors tomorrow.

“Our agents act across Salesforce, Gong, Google Drive, and more, on behalf of every customer. Scalekit behind the scenes meant we can keep adding tools without ever rebuilding how credentials or tool calling work.”

Venu Madhav Kattagoni

Head of Engineering / Von

FAQs

Frequently Asked Questions

Does the agent access Lob as the user or through a shared key?

As the user. Each user connects their own Lob API key once, and Scalekit sends it with every call. Audit logs attribute every mailpiece, check, and campaign to that user, not a shared service account.

Where is the Lob API key stored?

In Scalekit's managed AES-256 token vault, namespaced per tenant. To rotate it, the user reconnects with a new API key. Revocation is a single dashboard action. Credentials never appear in prompts, logs, or LLM context.

Can I limit what the agent does in Lob?

Yes. Filter by tool name in listScopedTools to expose only what you want, for example the address verification and list tools without lob_create_check or lob_send_campaign, which mail real, billed pieces in live mode. Scalekit also enforces scope checks before every API call.

What happens when a user revokes Lob access?

The connection is invalidated on the next tool call. Subsequent requests for that user fail closed with a clear error. Other users in the tenant remain unaffected. The event is logged for audit.

Does the agent mail real pieces through Lob?

In live mode, yes. lob_create_postcard, lob_create_letter, lob_create_self_mailer, and lob_create_check print and mail real pieces and are billed, and lob_send_campaign mails a campaign to its audience. Cancel tools such as lob_cancel_letter only work before the piece goes to production.