io.usefulapiPublished by usefulapi.ioOfficial publisherv1.37.4Updated Nov 7, 2026
Verify US & international addresses and send physical mail (postcards, letters, checks) via Lob.
The publisher's own server: Ably MCP by usefulapi
Hosted Lob server that lets an assistant verify US and international addresses and send or track physical postcards, letters and checks.
Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.
Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.
Read https://sourceweft.com/mcp/io.usefulapi%2Flob/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.Add this to your client's mcpServers config.
{
"mcpServers": {
"lob-by-usefulapi": {
"type": "http",
"url": "https://lob.usefulapi.io/mcp"
}
}
}Verify addresses and send physical mail via Lob, from Claude, Cursor, or any MCP client. Hosted, no local install — connect with your Lob API key.
Live endpoint: https://lob.usefulapi.io/mcp · Homepage: https://usefulapi.io/lob
https://lob.usefulapi.io/mcp.claude mcp add --transport http lob https://lob.usefulapi.io/mcp, then run /mcp to log in.Add only the URL. Do not add an Authorization header or an API key to the client config: the server signs you in with OAuth, and the login page asks for your Lob credentials.
Step-by-step setup, where to find your credentials, and FAQ: https://usefulapi.io/lob/
On first connect you'll paste your Lob API key. It's validated, stored per-user, and scoped to you.
read tools are read-only; write tools mutate data (clients should confirm them); meta tools report usage, manage your subscription or send a feature request.
*Pro has a fair use limit of 10,000 tool calls a month on this server. For more, write to [email protected].
Pro covers this server only. Subscribe with lob_upgrade (it returns a Stripe Checkout link). Cancel any time with lob_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running lob_upgrade before then undoes the cancel. Or write to [email protected].
MIT — see LICENSE. Documentation only; the server is hosted.
Source: servers/lob/README.md at commit 4046075
Verify a 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.
citystateaddresszip_codeprimary_linesecondary_lineVerify an international 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.
citystatecountryrequiredpostal_codeprimary_linerequiredsecondary_lineLook up a US ZIP code
Return the cities and state associated with a US ZIP code. Non-mutating. Lob API: POST /v1/us_zip_lookups.
zip_coderequiredAutocomplete a US address
Suggest complete US addresses from a partial primary line — useful for address entry. Non-mutating. Lob API: POST /v1/us_autocompletions.
citystatezip_codeaddress_prefixrequiredList postcards
List sent/scheduled postcards, newest first. Lob API: GET /v1/postcards.
afterlimitbeforeGet a postcard
Retrieve a single postcard by id, including status, PDF url, and expected delivery. Lob API: GET /v1/postcards/{id}.
idrequiredList letters
List sent/scheduled letters, newest first. Lob API: GET /v1/letters.
afterlimitbeforeGet a letter
Retrieve a single letter by id, including status, PDF url, and tracking. Lob API: GET /v1/letters/{id}.
idrequiredList checks
List sent/scheduled checks, newest first. Lob API: GET /v1/checks.
afterlimitbeforeGet a check
Retrieve a single check by id, including amount, status, and check number. Lob API: GET /v1/checks/{id}.
idrequiredList self-mailers
List sent/scheduled self-mailers, newest first. Lob API: GET /v1/self_mailers.
afterlimitbeforeList saved addresses
List saved address records, newest first. Lob API: GET /v1/addresses.
afterlimitbeforeGet a saved address
Retrieve a single saved address record by id. Lob API: GET /v1/addresses/{id}.
idrequiredList templates
List saved HTML templates usable as postcard/letter artwork. Lob API: GET /v1/templates.
afterlimitbeforeSave an address record
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.
namecompanyaddress_zipdescriptionaddress_cityaddress_line1requiredaddress_line2address_stateaddress_countrySend a postcard (COSTS MONEY)
⚠️ 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.
torequiredbackrequiredfromsizefrontrequireduse_typemail_typesend_datedescriptionmerge_variablesSend a letter (COSTS MONEY)
⚠️ 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`. Tracked mail: `extra_service` = certified (U.S. addresses: tracking + proof of delivery), certified_return_receipt (certified + the recipient's electronic signature) or registered (international addresses only); extra cost, first class only, not for us_legal size. The tracking number is on the letter (lob_get_letter). Lob API: POST /v1/letters.
torequiredfilerequiredfromrequiredcolorrequireduse_typemail_typesend_datedescriptiondouble_sidedextra_servicemerge_variablesaddress_placementCancel a scheduled 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}.
idrequired100% of the applicable checks met
How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.
io.usefulapiOfficial publisher
Hosted MCP server for Ably realtime messaging: inspect channel history, presence and occupancy, publish messages, and review app usage and configuration.
io.usefulapiOfficial publisher
Hosted read-only MCP server that lets an assistant look up Woffu company users, employment contracts, departments and offices.
io.usefulapiOfficial publisher
Hosted MCP server for White Label Loyalty: browse rewards, read a customer's points wallet and tier progress, and buy rewards with points.
io.usefulapiOfficial publisher
Hosted Weekdone connector that lets an assistant read weekly reports, teams, objectives and KPIs, and add report items, comments and KPI values.
io.usefulapiOfficial publisher
Hosted read-only MCP server that lets an assistant list WebinarKit webinars, their dates, series, meetings and white-label sub-accounts.
{ "mcpServers": { "lob": { "url": "https://lob.usefulapi.io/mcp" } }}