Bring Direct Mail
to Claude Desktop

Lob supports three main mail types: Letters (formal correspondence, invoices, notifications with customizable color, double-sided printing), Postcards (marketing campaigns, invitations, reminders in 4x6, 6x9, or 6x11 sizes), and Checks (vendor payments, payroll, refunds, rebates with customizable memo lines and company logos). All mail is printed and mailed within 24 hours via USPS.

Lob's address verification validates and standardizes addresses using USPS data. It corrects formatting, adds missing ZIP+4 codes, fixes typos, and confirms deliverability. The service returns a deliverability status: 'deliverable' (valid and deliverable), 'undeliverable' (cannot be delivered), or 'deliverable_unnecessary' (valid but additional info not needed). This reduces returned mail by up to 5% and ensures your mailings reach the correct destination.

Yes! Lob supports HTML templates with merge variables using the Handlebars templating engine. Create a template with placeholders like {{name}}, {{order_number}}, {{delivery_date}}, then pass actual values when creating letters or postcards. This enables personalized, scalable direct mail campaigns. Templates are reusable and can be referenced by ID when creating mailings. You can also embed CSS styling for professional-looking mail designs.

Lob prints and mails all items within 24 hours of creation. Delivery time depends on the mail type selected: USPS First Class Mail typically delivers in 2-5 business days, while USPS Standard Mail takes 3-7 business days. You receive a tracking number for each piece of mail to monitor delivery status. Lob also provides expected delivery dates in API responses for planning purposes.

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.

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.

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.

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.

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.

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).

Verify your Vinkius token is correct. Go to cloud.vinkius.com to regenerate it if needed.

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.