Lob MCP Server

io.usefulapi/lob

answering

Lob is answering right now. Last checked 13 min ago. It exposes 18 tools. Last commit 1 Aug 2026.

Verify US & international addresses and send physical mail (postcards, letters, checks) via Lob.

Uptime history 42 hours of history · worst hour 0%

42 hours agonow

31.9%

Uptime 24h

29 of 91 checks

Tools

read from the server

181 ms

Response time

average over 24h

Stars

last commit 1 Aug 2026

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 13 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add lob --transport http https://lob.usefulapi.io/mcp

~/Library/Application Support/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "lob": {
      "url": "https://lob.usefulapi.io/mcp"
    }
  }
}

~/.codex/config.toml

[mcp_servers.lob]
url = "https://lob.usefulapi.io/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "lob": {
      "url": "https://lob.usefulapi.io/mcp"
    }
  }
}

.vscode/mcp.json

{
  "mcpServers": {
    "lob": {
      "url": "https://lob.usefulapi.io/mcp"
    }
  }
}

Available tools 18

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

lob

lob_cancel_postcard

Cancel a postcard before its send_date so it is never mailed (and not billed). Fails if the send window has passed. Lob API: DELETE /v1/postcards/{id}.

lob_create_address

Create a reusable saved address record (does NOT send any mail). Returns an address id (adr_…) usable as `to`/`from` in mail tools. Lob API: POST /v1/addresses.

lob_create_letter

⚠️ SENDS A REAL LETTER and charges your Lob account (use a test_ key to avoid real mail/charges). `to`/`from` accept an address id (adr_…) or inline object. `file` accepts an HTML string, a hosted PDF/URL, or a template id (tmpl_…). `color` is required. Cancelable only before `send_date`. Lob API: POST /v1/letters.

lob_create_postcard

⚠️ SENDS A REAL POSTCARD and charges your Lob account (use a test_ key to avoid real mail/charges). `to` and `from` accept an existing address id (adr_…) or an inline address object. `front`/`back` accept an HTML string, a hosted asset URL, or a template id (tmpl_…). Cancelable only before `send_date`. Lob API: POST /v1/postcards.

lob_get_address

Retrieve a single saved address record by id. Lob API: GET /v1/addresses/{id}.

lob_get_check

Retrieve a single check by id, including amount, status, and check number. Lob API: GET /v1/checks/{id}.

lob_get_letter

Retrieve a single letter by id, including status, PDF url, and tracking. Lob API: GET /v1/letters/{id}.

lob_get_postcard

Retrieve a single postcard by id, including status, PDF url, and expected delivery. Lob API: GET /v1/postcards/{id}.

lob_list_addresses

List saved address records, newest first. Lob API: GET /v1/addresses.

lob_list_checks

List sent/scheduled checks, newest first. Lob API: GET /v1/checks.

lob_list_letters

List sent/scheduled letters, newest first. Lob API: GET /v1/letters.

lob_list_postcards

List sent/scheduled postcards, newest first. Lob API: GET /v1/postcards.

lob_list_self_mailers

List sent/scheduled self-mailers, newest first. Lob API: GET /v1/self_mailers.

lob_list_templates

List saved HTML templates usable as postcard/letter artwork. Lob API: GET /v1/templates.

lob_us_autocomplete

Suggest complete US addresses from a partial primary line — useful for address entry. Non-mutating. Lob API: POST /v1/us_autocompletions.

lob_us_zip_lookup

Return the cities and state associated with a US ZIP code. Non-mutating. Lob API: POST /v1/us_zip_lookups.

lob_verify_intl_address

Validate & standardize a non-US address. `country` (2-letter ISO code) is required. Non-mutating (no mail sent). Lob API: POST /v1/intl_verifications.

lob_verify_us_address

Validate & standardize a US address, returning deliverability, corrected components, and a confidence score. Pass either a single freeform `address` string OR structured `primary_line`/`city`/`state`/`zip_code`. Non-mutating (no mail sent). Lob API: POST /v1/us_verifications.

Endpoints

URL	Transport	State	Latency	Checked
https://lob.usefulapi.io/mcp	streamable-http	answering	225 ms	13 min ago

Lob — questions

Answers built from our own checks of this server.

What can Lob do?

It exposes 18 tools, read directly from the server on our last check. Among them: lob_cancel_postcard, lob_create_address, lob_create_letter, lob_create_postcard, lob_get_address, lob_get_check and 12 more. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →

Is Lob working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 29 of 91 checks got a reply (31.9%), average response time 181 ms. The bar chart above shows every period we have measured.

How do I connect Lob?

Copy the ready config from this page — we generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each with the file path that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does Lob need an API key?

No. Lob completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 18 of them are readable on this page. This is what we observed, not what the docs claim.

How fast is Lob?

It answers our handshake in 181 ms on average, which is faster than 67% of all working MCP servers we measure. The comparison comes from our own checks across the whole registry, every 15 minutes.

Is Lob open source?

Yes — it is published under the MIT licence, written in JavaScript and 0 stars on GitHub. The source link is on this page, so you can read exactly what it does with your data before you connect it.