Bring Direct Mail
to Claude Desktop
Learn how to connect Lob to Claude Desktop and start using 9 AI agent tools in minutes. Fully managed, enterprise secure, and ready to use without writing a single line of code.
What is the Lob MCP Server?
Connect your Lob account to any AI agent and manage direct mail through natural conversation.
What you can do
- Letter Sending — Create and send letters with PDF or HTML content
- Postcard Campaigns — Send postcards with front/back designs
- Check Printing — Create and mail checks with payment details
- Address Verification — Verify and standardize US addresses
- Template Management — Browse and manage mail templates
- Delivery Tracking — Track mail pieces through the postal system
How it works
1. Subscribe to this server
2. Enter your Lob API Key (test or live)
3. Start sending mail from Claude, Cursor, or any MCP-compatible client
Who is this for?
- Marketing — run direct mail campaigns with postcards and letters
- Finance — automate check printing and mailing
- Operations — verify addresses and track mail delivery
Built-in capabilities (9)
Suggest address completions
Send a physical check
Supports certified mail and custom inserts. Send a physical letter
Supports HTML or PDF for front and back. Send a physical postcard
Track a mail piece
List sent letters
List sent postcards
Verify an international address
Verify a US address
Why Claude Desktop?
Claude Desktop is the definitive way to connect Lob to your AI workflow. Add Vinkius Edge URL to your config, restart the app, and Claude immediately exposes all 9 tools in the chat interface. ask a question, Claude calls the right tool, and you see the answer. Zero code, zero context switching.
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Claude Desktop is the reference MCP client. it was designed alongside the protocol itself, ensuring the most complete and stable MCP implementation available
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Zero-code configuration: add a server URL to a JSON file and Claude instantly discovers and exposes all available tools in the chat interface
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Claude's extended thinking capability lets it reason through multi-step tool usage, chaining multiple API calls to answer complex questions
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Enterprise-grade security with local config storage. your tokens never leave your machine, and connections go directly to Vinkius Edge network
Lob in Claude Desktop
Lob and 3,400+ other MCP servers. One platform. One governance layer.
Teams that connect Lob to Claude Desktop through Vinkius don't need to source, host, or maintain individual MCP servers. Every tool call runs inside a hardened runtime with credential isolation, DLP, and a signed audit chain.
Raw MCP | Vinkius | |
|---|---|---|
| Server catalog | Find and host yourself | 3,400+ managed |
| Infrastructure | Self-hosted | Sandboxed V8 isolates |
| Credential handling | Plaintext in config | Vault + runtime injection |
| Data loss prevention | None | Configurable DLP policies |
| Kill switch | None | Global instant shutdown |
| Financial circuit breakers | None | Per-server limits + alerts |
| Audit trail | None | Ed25519 signed logs |
| SIEM log streaming | None | Splunk, Datadog, Webhook |
| Honeytokens | None | Canary alerts on leak |
| Custom domains | Not applicable | DNS challenge verified |
| GDPR compliance | Manual effort | Automated purge + export |
Why teams choose Vinkius for Lob in Claude Desktop
The Lob MCP Server runs on Vinkius-managed infrastructure inside AWS — a purpose-built runtime with per-request V8 isolates, Ed25519 signed audit chains, and sub-40ms cold starts. All 9 tools execute in hardened sandboxes optimized for native MCP execution.
Your AI agents in Claude Desktop only access the data you authorize, with DLP that blocks sensitive information from ever reaching the model, kill switch for instant shutdown, and up to 60% token savings. Enterprise-grade infrastructure, zero maintenance.
* Every MCP server runs on Vinkius-managed infrastructure inside AWS - a purpose-built runtime with per-request V8 isolates, Ed25519 signed audit chains, and sub-40ms cold starts optimized for native MCP execution. See our infrastructure
How Vinkius secures
Lob for Claude Desktop
Every tool call from Claude Desktop to the Lob MCP Server is protected by DLP redaction, cryptographic audit chains, V8 sandbox isolation, kill switch, and financial circuit breakers.
Frequently asked questions
Can I send letters and postcards through the AI agent?
Yes. Create and send letters with PDF/HTML content and postcards with custom designs. Track delivery through the postal system.
Does Lob use Basic Auth?
Yes. Lob uses HTTP Basic Auth with the API Key as username (no password) against api.lob.com/v1.
Can I verify US addresses?
Yes. Verify and standardize US addresses with CASS certification. Returns deliverability status, corrected addresses, and coordinates.
How does Claude Desktop discover MCP tools?
When Claude Desktop starts, it reads the claude_desktop_config.json file and connects to each configured MCP server. It calls the tools/list endpoint to fetch the schema for every available tool, then surfaces them as clickable options in the chat interface via the 🔌 icon.
What happens if the MCP server is temporarily unavailable?
Claude Desktop handles disconnections gracefully. if the server is unreachable at startup, the tools simply won't appear. Once the server becomes available again, restarting Claude Desktop will re-establish the connection. There is no timeout penalty or error loop.
Can I connect multiple MCP servers simultaneously?
Yes. You can add as many servers as you need in the mcpServers section of the config file. Each server appears as a separate tool provider, and Claude can use tools from multiple servers in a single conversation turn.
Is there a limit on the number of tools per server?
Claude Desktop can handle hundreds of tools per server. However, for optimal LLM performance, Vinkius servers are designed to expose focused, well-documented tool sets rather than overwhelming the model with too many options.
Does Claude Desktop support Streamable HTTP transport?
Yes. Claude Desktop supports both SSE (Server-Sent Events) and the newer Streamable HTTP transport that Vinkius uses. Simply provide the server URL. Claude auto-negotiates the transport protocol.
Server not appearing after restart
Ensure the JSON is valid (no trailing commas). Check the file path: ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\\Claude\\ (Windows).
Authentication error
Verify your Vinkius token is correct. Go to cloud.vinkius.com to regenerate it if needed.
Tools not showing in chat
Click the 🔌 icon at the bottom of the chat input. If it shows 0 tools, the server may still be connecting. wait a few seconds.