Lob for AI agents
Lob provides direct mail automation and address verification APIs, letting businesses validate addresses and send physical mail programmatically as part of a workflow. Connect it once through Arc0, and your agent, or Claude, ChatGPT and Cursor, can use it through one MCP endpoint, limited to what each user approved.
What agents do in Lob.
Validate a mailing address
Check a customer's address for deliverability before it is used on a shipment or mailer.
Check a shortened link's clicks
Pull click analytics for a QR code or link used in a direct mail piece, read-only.
Approve before deleting an upload
Require approval before deleting an upload used for a mail campaign, since it may still be in production.
13 Lob actions, graded by risk.
Every Lob action is tagged read, write or destructive, so one policy covers the whole app and new actions inherit the right default.
read
7Look things up. Allowed by default.
- lob.get_linkGet Link
- lob.get_domainGet Domain
- lob.list_linksList Shortened Links
- lob.list_domainsList Domains
- lob.list_uploadsList Uploads
- lob.list_qr_code_analyticsList QR Code Analytics
- lob.validate_identityValidate Identity
write
3Create and change things. Allow, or ask the user first.
- lob.create_linkCreate Link
- lob.update_linkUpdate Link
- lob.create_domainCreate Domain
destructive
3Delete, cancel or archive. Ask first, or deny outright.
- lob.delete_linkDelete Link
- lob.delete_domainDelete Domain
- lob.delete_uploadDelete Upload
Lob in three steps.
- 01Your users connect LobThey add their Lob api key on Arc0 Connect, under your brand. It goes straight into the vault.
- 02You set the rulesReads run, writes like “create Link” can wait for the user, and “delete Link” can be denied outright.
- 03Any agent can actYour agent calls Lob through the Arc0 SDK or MCP, and so can Claude, ChatGPT and Cursor. Every call lands on the audit log.
await arc0.policies.set('lob', { read: 'allow', write: 'ask', // create_link destructive: 'deny', // delete_link }) # Claude Code: the same connection, one URL $ claude mcp add --transport http arc0 \ https://mcp.arc0.ai/u/u_8f2
How Lob connects.
Users add their Lob api key on Arc0 Connect. It is encrypted in the vault, never shown to the model, and each user can rotate or revoke it at any time.
The same Lob connection serves your agent over MCP and your own backend over REST and the proxy, so a user connects once. How Arc0 handles credentials →
- AUTH
- API key
- CREDENTIALS
- Per-tenant encrypted vault
- MODEL SEES
- Results only, never credentials
- AUDIT LOG
- Every call, on every plan
Use Lob from any agent.
ClaudeChatGPTCursor
Codex
VS CodeOpenAI Agents SDKClaude Agent SDK
Vercel AI SDK
Mastra
LangGraph
Lob and Arc0, answered.
Can I use Lob with Claude, ChatGPT or Cursor?
Yes. Connect Lob to Arc0 once, then add your Arc0 MCP URL to Claude, ChatGPT, Cursor, Claude Code or any other remote-MCP client. Each assistant only gets the Lob actions you allow.
How do users connect Lob?
Users add their Lob api key on Arc0 Connect. It is encrypted in the vault, never shown to the model, and each user can rotate or revoke it at any time.
Which Lob actions can my agent take?
13 in total: 7 read, 3 write and 3 destructive, such as “create Link”. Your policies decide which of them each agent may call.
Can I stop my agent from deleting things in Lob?
Yes. Actions like “delete Link” are graded destructive. Set destructive actions to deny, or to ask so the user approves each one, and blocked calls still show up on the audit log.
Can my own backend call Lob too?
Yes. The same Lob connection is available over REST and through the Arc0 proxy, so your product and your agent share one connection per user.
Plug Lob into your agent.
Your users connect Lob once, under your brand. Your agent gets 13 actions behind your policies, with every call on the record.
Free to build · MCP + REST · Audit log on every plan