# PostAgent MCP server

Print & mail PDF/HTML/Markdown/text/DOCX/images to US addresses; pay per call in x402 USDC on Base.

## Links
- Registry page: https://www.getdrio.com/mcp/tech-interpretai-postagent
- Repository: https://github.com/interpretai-tech/agent-tools
- Website: https://api.postagent.sh

## Install
- Endpoint: https://api.postagent.sh/mcp
- Auth: Not captured

## Setup notes
- Remote endpoint: https://api.postagent.sh/mcp

## Tools
- check_postagent_updates (Check latest PostAgent skill and MCP versions) - Fetches the live PostAgent agent manifest. Call this before using PostAgent in a new session, after reconnecting the MCP server, or when an installed PostAgent skill may be stale. If the installed skill is older than latestSkillVersion, read latestSkillUrl and follow those instructions for this turn; if updateRequired is true, do not perform paid or irreversible PostAgent actions until the user updates. Endpoint: https://api.postagent.sh/mcp
- create_letter (Upload a finished letter (identical content, no mail merge)) - Upload and normalize a FINISHED, ready-to-mail document to PDF. Choose this when the content is final and IDENTICAL for every recipient — including when you mail the same letter to many people (just quote/pay once per recipient with the same documentId). The exact bytes you give are what gets printed. Use create_template instead only when the content must vary per recipient via {{fields}}. Returns a documentId, the stored page count, byte size, and source format. Free; no payment required.

Provide the document EXACTLY ONE way: `content` (inline text, for html/markdown/text), `contentBase64` (base64-encoded binary, for pdf/docx/image), or `url` (a publicly reachable URL the server fetches). Supplying none, or more than one, is an error. Maximum upload size is 31457280 bytes (~30 MB); output page size is US Letter.

Any `{{...}}` text is printed LITERALLY here — it is NOT treated as a merge field. If you want personalized mail merge across recipients, use `create_template` instead.

Reserved address zone: a recipient address block is printed over the top ~3 inches of page 1, so the server reserves that space for you automatically. For text/html/markdown/docx, page-1 content is pushed below the block (content may therefore flow onto an additional page); for pdf and image inputs, a blank first page is prepended. As a result the returned page count — and the selected-provider cost behind the resulting quote — can be higher than your source document (e.g. a single-page PDF is stored as 2 pages). You do NOT need to leave the top of your document blank yourself. See the postagent://formats resource for per-format details. Endpoint: https://api.postagent.sh/mcp
- create_template (Upload a mail-merge template (content varies per recipient)) - Upload a REUSABLE template containing `{{field}}` placeholders (e.g. `Dear {{name}},` or `Balance due: {{amount}}`). Choose this ONLY when the content must vary per recipient (mail merge) — recipient count is irrelevant, so a single personalized letter belongs here too. If the content is identical for everyone, use create_letter instead (this tool rejects input with no `{{fields}}`). Returns a documentId with `kind: "html_template"`, a `mergeFields` list of the detected field names, and an `estimatedPageCount`. Free; no payment required.

Template source must be TEXT-BASED (html, markdown, or text) and must contain at least one `{{field}}`, or the upload is rejected — for a finished document with no merge fields, use `create_letter`.

Provide the template EXACTLY ONE way: `content` (inline text), `contentBase64` (base64-encoded text), or `url` (a publicly reachable URL the server fetches). Supplying none, or more than one, is an error. Maximum upload size is 31457280 bytes (~30 MB); output page size is US Letter.

Reuse one template documentId across recipients: call create_mail_quote ONCE PER RECIPIENT, supplying that recipient's values via `mergeVariables` (every field in `mergeFields` must have a non-empty value). The server substitutes the values and renders that recipient's personalized PDF at quote time, so `estimatedPageCount` is only a baseline — the binding page count and price are set per quote from the actual rendered output.

Reserved address zone: a recipient address block is printed over the top ~3 inches of page 1, so the server reserves that space automatically (page-1 content is pushed below the block and may flow onto an additional page). You do NOT need to leave the top blank yourself. See the postagent://formats resource for details. Endpoint: https://api.postagent.sh/mcp
- create_mail_quote (Get a locked price quote for a print-and-mail job) - Verifies the recipient and sender US addresses and locks a 15-minute USDC price for a documentId. Does not charge or mail anything. Returns a `paymentUrl` (a per-quote x402-payable URL); the preferred way to actually mail the letter is for the agent's wallet to perform an in-band x402 payment against that URL (e.g. `npx awal@latest x402 pay <paymentUrl>`). The MCP `submit_paid_mail_job` tool is a fallback for clients that can emit a standalone signature header. In all cases, show the recipient, sender, options, selected-route `design` constraints, price, AND any `fulfillment.warnings` to the user and get explicit confirmation before paying. The response includes a `fulfillment` block with `requested` (what you asked for), `selected` (what will actually be printed/mailed) and `warnings` (any soft-preference downgrades — e.g. `service_level_downgraded` or `extra_service_unavailable`); do not pay through a non-empty warnings list without re-confirming the trade-off with the user. The response also includes a provider-neutral `design` block; inspect it and the preview before paying because the selected delivery method determines print address/no-ink zones. Endpoint: https://api.postagent.sh/mcp
- create_card_checkout (Create a hosted credit-card checkout link for a quote) - Creates a Stripe-hosted Checkout page for a locked quote and returns a `checkoutUrl` plus a `statusUrl`. Use this as the LAST-RESORT payment rail, when the payer is a human paying by credit card (the agent cannot complete card entry itself). Hand the `checkoutUrl` to the user to open in a browser and pay; payment is asynchronous — once they finish, the letter is created automatically by Stripe's webhook. To track it without a job id, GET the returned `statusUrl` (`/v1/quotes/:quoteId/job`): it returns `found:false` with status `pending`/`processing` until the webhook creates the job, then the full job (id, status, tracking). Prefer x402 (or MPP, if available) for autonomous agent payment. Returns an error if Stripe Checkout is not enabled on the server. No charge occurs until the human completes the hosted page. Endpoint: https://api.postagent.sh/mcp
- pay_mail_with_shared_payment_token (Pay a quote autonomously by card/wallet via a Shared Payment Token (MPP)) - Autonomous, no-browser FIAT payment for a locked quote using a Stripe Shared Payment Token (SPT / Machine Payments Protocol). Use this when the agent can mint an SPT on the buyer's behalf and wants to pay by card/wallet without a human in a browser (prefer x402 first if the agent has a USDC-on-Base wallet; this is the autonomous fiat alternative). CHARGES MONEY AND IS IRREVERSIBLE: the server authorizes the SPT, prints the letter, then captures — a job comes back inline (no polling needed). Only call after the user has explicitly confirmed the recipient, sender, content, and price from create_mail_quote.

Minting the token (the agent's responsibility, NOT this server): the SPT must be scoped to THIS seller's Stripe profile and to at least the quote amount. The quote's `paymentOptions` entry for `mpp` carries the `stripeProfileId`, `currency`, `maxAmountCents`, and `expiresAt` you need. Mint it with the buyer's payment method via the Stripe `@stripe/link-cli` (`spend-request create … --network-id <stripeProfileId> --credential-type shared_payment_token`) or the SharedPaymentIssuedToken API, then pass the resulting `spt_…` here. SPTs are US-only and cards carry a 0.50 USD minimum. Returns an error if MPP is not enabled/configured on the server. Endpoint: https://api.postagent.sh/mcp
- prepare_mail_payment (Fetch the x402 payment challenge for a quote) - Returns the x402 PAYMENT-REQUIRED challenge for a locked quote so an x402-capable wallet client can sign it. No payment is taken at this step. Probes the canonical per-quote pay URL (`/v1/quotes/:quoteId/pay`). The preferred way to actually pay is for the wallet to perform the standard x402 in-band handshake against `paymentUrl`; this tool is for inspection or for the detached-signature flow via `submit_paid_mail_job`. Endpoint: https://api.postagent.sh/mcp
- submit_paid_mail_job (Submit a signed x402 payment to create and mail the letter) - Detached-signature fallback for x402 wallets that can emit a standalone PAYMENT-SIGNATURE header. THE PRIMARY/RECOMMENDED PATH is for the agent's wallet to pay the quote's `paymentUrl` in-band (e.g. `npx awal@latest x402 pay <paymentUrl>`); use this tool only if your wallet client cannot do that. Charges the agent in USDC on Base mainnet and creates a physical letter for printing and mailing. THIS IS IRREVERSIBLE. Only call after the user has explicitly confirmed the recipient, sender, content, and price returned by create_mail_quote, and after obtaining the signed x402 payment header (see prepare_mail_payment). Endpoint: https://api.postagent.sh/mcp
- get_mail_job_status (Get the current status of a mail job) - Returns normalized status, carrier/tracking/proof data, and tracking events for a previously created job. Endpoint: https://api.postagent.sh/mcp
- create_postcard_art (Upload postcard artwork (front or back)) - Upload ONE side of a postcard (front or back) as single-page PDF, PNG, or JPEG artwork. The file is stored VERBATIM — no page-size normalization and no reserved address zone — so you are responsible for the correct trim size plus bleed: 4x6 cards need 4.25"x6.25" artwork, 6x9 needs 6.25"x9.25", 6x11 needs 6.25"x11.25" (0.125" bleed on each edge). The selected delivery method prints the recipient address block over part of the BACK, so keep that area clear of critical content and review the quote's `design` block before payment. Returns a documentId with kind "postcard_art". Upload front and back separately, then quote with create_postcard_quote. Free; no payment required.

Provide the artwork EXACTLY ONE way: `contentBase64` (base64-encoded pdf/png/jpeg) or `url` (publicly reachable). Text-based formats are rejected — postcards are artwork, not documents. Endpoint: https://api.postagent.sh/mcp
- create_postcard_quote (Get a locked price quote for printing and mailing a postcard) - Verifies the recipient and sender addresses and locks a 15-minute USDC price for mailing a postcard built from two postcard_art documents (front + back, uploaded via create_postcard_art). Sizes: 4x6 (default), 6x9, 6x11 — postcards always print in full color. US recipients use the strict US address shape; INTERNATIONAL recipients are supported on 4x6 only (set `to.country` to the 2-letter ISO code; the sender must still be a US address). Payment works exactly like letters: pay the returned `paymentUrl` via x402, or use the MPP/checkout fallbacks. Show the recipient, sender, size, selected-route `design` constraints, price, AND any `fulfillment.warnings` to the user and get explicit confirmation before paying — service level is a soft preference and may have been downgraded (e.g. international economy is upgraded to standard) with a `service_level_downgraded` warning the agent must surface verbatim. Endpoint: https://api.postagent.sh/mcp
- verify_address (Verify a postal address for deliverability (paid, flat fee)) - Standalone paid address verification — no mail is sent. Checks whether an address is deliverable and returns the standardized form (US: CASS with ZIP+4; international: per-country matching). Costs a small flat USDC fee per call via x402 (a fraction of a cent vs. mailing).

Two-step flow, like the mail rails: call WITHOUT `paymentSignature` to get the 402 challenge and `paymentUrl` (preferred: have the agent's x402 wallet pay `paymentUrl` in-band with the address as the JSON POST body `{"address":{...}}`); or sign the challenge and call again WITH `paymentSignature` to verify and get the result in one round trip. US addresses need line1 + (city+state or zip). International addresses need line1 + country.

Note: when mailing through PostAgent you do NOT need this tool — create_mail_quote already verifies sender and recipient for free as part of the quote. Endpoint: https://api.postagent.sh/mcp
- create_campaign_quote (Get a locked price quote for a bulk mail campaign (KYC required)) - Quote ONE bulk send to MANY recipients (up to 500): a single template or static document, fulfilled through PostAgent's campaign workflow. Price is an inclusive customer-facing total, locked for 15 minutes. Payment is x402 ONLY.

IMPORTANT — KYC WALL: campaigns require the paying wallet to be identity-verified with PostAgent. Verification is operator-run, not self-serve: until the wallet is verified this tool returns `kyc_required` (403). Do not retry the same wallet — instead either mail recipients individually with create_mail_quote, or request campaign access at https://interpretai.tech/contact (this URL is also returned in the 403's details.contactUrl) to get the wallet enabled.

Usage once the wallet is verified: upload a template with create_template (using {{fields}}) or a finished letter with create_letter, then call this with `recipients` (each `to` a US address, plus per-recipient `mergeVariables` for templates) and the `payerWallet` that will pay the quote. The print partner validates every recipient address after payment; failed recipients are excluded and their share refunded (processed manually). Track via get_campaign_status. Endpoint: https://api.postagent.sh/mcp
- get_campaign_status (Get the status of a bulk mail campaign) - Returns a campaign's validation/sending progress: status (validating | sent | partial | failed), recipient counts (total / validated / failed), and a failures report URL when some recipients could not be validated. Polling this endpoint also advances the campaign (it releases the campaign for mailing once the print partner finishes validating the audience). Find the campaign id on the quote's job status (GET jobStatusUrl) after payment. Endpoint: https://api.postagent.sh/mcp

## Resources
- postagent://agent-manifest - PostAgent agent manifest Live skill/MCP version manifest and self-update contract. Read before using PostAgent if the installed skill version may be stale. MIME type: application/json
- postagent://terms - Terms of Service PostAgent Terms of Service (markdown). MIME type: text/markdown
- postagent://privacy - Privacy Policy PostAgent Privacy Policy (markdown). MIME type: text/markdown
- postagent://formats - Accepted document formats Describes the document formats accepted by create_letter and create_template. MIME type: application/json
- postagent://payment-methods - Supported payment methods and how to set one up Enumerates every payment rail PostAgent accepts, with concrete examples and explicit follow-up steps for a customer that does not yet have any payment method. Read this when a quote's paymentOptions cannot be satisfied (no wallet, no Shared Payment Token) so the agent/user has a clear path to become payable instead of dead-ending at hosted checkout. MIME type: application/json
- postagent://pricing - Pricing and payment terms Describes how quotes are priced and paid. MIME type: application/json

## Prompts
Not captured

## Metadata
- Owner: tech.interpretai
- Version: 0.5.0
- Runtime: Streamable Http
- Transports: HTTP
- License: Not captured
- Language: Not captured
- Stars: Not captured
- Updated: Jun 25, 2026
- Source: https://registry.modelcontextprotocol.io