Send handwritten letters, cards and postcards through the mail with real pen and USPS delivery.
Premier Letters connects to a handwriting and mailing service. Muse can help you quote, preview, order and track real pen-written letters and postcards sent via USPS, with options for handwriting style, paper type and delivery method.
Try asking Muse: "Send a handwritten thank-you letter to my client and track when it arrives."
Source: Found in the official MCP Registry (com.premierletters/mcp) · First listed September 24, 2026
Each bar is one check, every 15 minutes. Green means it answered. Last checked 3 h ago.
What Muse can see: It does not ask you to sign in, so it cannot see your accounts. It only sees what Muse sends it from your request.
Before it acts: Read what Muse plans to do before you approve it, and remove the app from Muse when you stop using it.
musedirectory.ai is not part of Meta. More about how Muse handles your information
Not in Muse's Connectors list yet, but Muse can still use it. Copy the request below and paste it into Muse. Muse asks before it shares anything with the app's site. Meta does not review apps used this way, so only use ones you trust. We tested this in the Muse app on September 24, 2026: Muse used an app's link directly this way and returned a live answer.
https://www.premierletters.com/api/mcpNot in Muse's Connectors list yet. Muse can still use it: its page gives you a request to paste into Muse.
Premier Letters is a remote MCP server, so any assistant that can add a custom connector by link can use it. Same link, same tools.
In ChatGPT, open Settings, then Connectors (called Apps & Connectors on some accounts).
Under Advanced settings, switch on Developer mode. That is what lets you add a connector by link.
Choose Create, give it a name, paste the link as the MCP server URL, and save. If it needs a sign-in, ChatGPT asks for it here.
Start a chat, open the tools menu, pick the connector, and ask. ChatGPT asks before it runs a tool the first time.
Custom connectors need a paid ChatGPT plan, and on Team, Enterprise and Edu accounts only an admin can add them. Our "Working" label means the server answered us; it cannot tell whether your plan lets you add it. All connectors that work in ChatGPT
In Claude, open Settings, then Connectors.
Choose Add custom connector, give it a name, and paste the link.
If it needs a sign-in, Claude sends you to it. Then turn the connector on in a chat from the tools menu and ask.
Custom connectors are available on paid Claude plans; on Team and Enterprise accounts an admin may need to add them. Our "Working" label means the server answered us; it cannot tell whether your plan lets you add it. All connectors that work in Claude
https://www.premierletters.com/api/mcpResponse time at the last check: 155ms. Worked in 99.1% of checks over 30 days.
Screened, no issues found
Screening looks for known threats and hidden instructions at the time of the check, and runs again weekly and whenever the tool list changes. It cannot see the server's code, so only connect what you need and review what Muse asks to do. How screening works.
connect_accountGet a Premier Letters API key without the user copying one by hand. Pass the user's email and your name; we email them a link to approve (they can sign up from it if they have no account). Then call check_connection with the returned request_id and poll_secret every 10-30 secondscheck_connectionCheck whether the user approved a connect_account request. Returns status pending, denied, expired or claimed, or, exactly once, status approved with the api_key. Poll every 10-30 seconds.get_pricingGet a live price quote for a Premier Letters order. Pass char_count (or letter_count for a rough estimate) plus optional mailing_option and paper_type to get a per-piece and total price, in cents. No account needed. Orders under 5 pieces carry a $0.99 per-piece handling fee (incllist_handwriting_stylesList available handwriting styles (fonts) for a letter order. Use the returned "id" as options.handwriting_style / handwriting_style when creating an order or previewing.list_templatesList the authenticated user's saved letter templates.verify_addressVerify and standardize a US mailing address via USPS. Use before create_order to catch typos and get the USPS-standardized form.preview_letterRender a preview of a handwritten letter (as an SVG image) and get its price, before creating an order. Does not save anything.list_extrasList the extra pieces that can go in each envelope with a Premier Letters order: printed inserts, printed letters, your own inserts, flyers, postcards, business cards. Each has options, a per-unit price in cents, a lead time and a purchase mode: "instant" pieces are charged with create_orderCreate and pay for a Premier Letters order — a real, handwritten letter mailed via USPS. Requires a Premier Letters API key. Use get_pricing or preview_letter first to confirm the price. For payment, "card_on_file" charges the caller's saved card immediately, "balance" pays from get_order_statusGet an order's status, delivery/tracking summary, and per-recipient mail status.list_ordersList the authenticated user's recent orders.get_balanceGet the authenticated account's prepaid balance (balance_cents) and the top-up rules: minimum and maximum top-up, bonus tiers and suggested amounts. Orders paid with payment.method "balance" skip the small-order handling fee. Use create_topup_link to add funds.create_topup_linkCreate a Stripe Checkout link that adds prepaid credit (plus any bonus tier) to the authenticated account. Give checkout_url to the human to pay in a browser; the balance updates once they pay (check with get_balance). amount_cents must be a whole number between min_cents and maxhttps://www.premierletters.com/api/mcpNot in Muse's Connectors list yet, but Muse can still use it. Paste this into Muse: "Use Premier Letters to help me. It is a free service with an MCP server at https://www.premierletters.com/api/mcp. It does not need an API key. Ask me before you share anything with it." Muse asks before it shares anything with the app's site. Meta does not review apps used this way, so only use ones you trust. We tested this in the Muse app on September 24, 2026: Muse used an app's link directly this way and returned a live answer.
At the last check (November 13, 2026, 11:45 UTC) the endpoint was working, answering in 155ms. Over the last 7 days it answered 100% of health checks. It is checked every 15 minutes.
It was screened on September 24, 2026 with the result "screened, no issues found". Screening checks the domain against threat feeds and reads the tools for hidden instructions and requests for passwords or card numbers. It cannot see the server's code, so grant only the access you need.
It exposes 13 tools, including connect_account, check_connection, get_pricing, list_handwriting_styles. For example, you could ask Muse: "Send a handwritten thank-you letter to my client and track when it arrives."
This listing was added from public sources (Found in the official MCP Registry (com.premierletters/mcp)). If you build Premier Letters, claim it to correct the details and get your badge.
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<a href="https://musedirectory.ai/connector/premier-letters"><img src="https://musedirectory.ai/badge/premier-letters.svg" alt="Premier Letters on musedirectory.ai" width="236" height="40"></a>