Postage Stamp Price MCP

io.github.theluckystrikePublished by GitHub account theluckystrikev1.0.0Updated Nov 5, 2026

How much is a stamp: USPS Forever stamp, postcard, international and letter postage by weight.

The publisher's own server: PriceWin

VerifiedStreamable HTTPWeb executableLocation & Lifestyle

Server details

Identifier: io.github.theluckystrike/postage-stamp-price-mcp
Transport: Streamable HTTP
Runtime: Web executable
Trust: Verified
Published: Nov 5, 2026

Security note

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The registry verified the GitHub account theluckystrike for this listing. That does not show the account is the product's maker.

SourceWeft's checks cover whether the listing is complete and the endpoint answered; they do not review the server's code or what its tools do.

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Overview

AI-generated overview

Remote MCP server that gives an assistant current USPS retail postage prices, read from USPS Notice 123 at call time, plus letter postage calculations.

What you can do: Look up current stamp prices: Forever, postcard, international, metered and weight-step letter prices, with the effective date
Calculate postage for a letter, postcard or large envelope by weight to the US, Canada, Mexico or other countries, including the nonmachinable surcharge, quantity totals and Forever stamps per piece
Look up Priority Mail and Priority Mail Express flat rate envelope and box prices
Return structured JSON with a summary, as-of date and source for each answer
When to use it: Useful when someone asks what a stamp costs, how much postage a specific mailing needs, or what a flat rate box costs, and you want the current price rather than a remembered one that may be out of date.
Requirements: A remote streamable HTTP endpoint; no API key, token or sign-up. The hosted server fetches the USPS price list at call time and caches it for up to 6 hours. A local npm package is mentioned but not yet published.

Before you install

Read-only price lookups; no accounts, payments or personal data are involved. Prices are USPS retail rates only, so commercial, metered and Click-N-Ship rates can be lower, and packages beyond flat rate and international large envelopes are not covered. Cached prices may lag by up to 6 hours.

Installation

In SourceWeft

Open Postage Stamp Price MCP in the dashboard and add it to a workspace.
Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

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.github.theluckystrike%2Fpostage-stamp-price-mcp/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.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "postage-stamp-price": {
      "type": "http",
      "url": "https://postage-stamp-price-mcp.lipmichal.workers.dev/mcp"
    }
  }
}

README

postage-stamp-price-mcp

How much is a stamp, for AI assistants. Ask what a Forever stamp costs, what it takes to mail 40 square holiday cards, or what a letter to Germany costs, and get the current USPS price with its effective date.

This is a Model Context Protocol (MCP) server. It reads USPS Notice 123, the official retail price list on Postal Explorer, at call time. Prices are matched by the USPS SKU on each price cell. It needs no API key.

Tools

Tool	What it returns
`get_stamp_price`	The current Forever stamp price (1 oz First-Class Mail letter), 2, 3 and 3.5 oz prices, metered prices, postcard, 1 oz large envelope, nonmachinable surcharge and the 1 oz international letter (Global Forever) price, with the effective date.
`calculate_letter_postage`	Postage for a letter, postcard or large envelope by weight, to the US, Canada, Mexico or another country, with the nonmachinable surcharge, a total for a quantity and the number of Forever stamps per piece.
`get_flat_rate_prices`	Retail Priority Mail and Priority Mail Express flat rate envelope and box prices.

Every result has structured JSON, a one-paragraph summary, as_of, source and more (a page on mcpstamp.com).

What it knows that your model does not

The price in force today. USPS changes prices once or twice a year, so a remembered stamp price is often wrong.
The effective date of the price list, so the answer can say when the price started.
Surcharges and weight steps, so "two stamps or one?" has an exact answer.

Install

Hosted (Claude.ai custom connector, ChatGPT developer mode)

Paste this URL. No token, no sign-up. It works now.

Claude Code

claude mcp add --transport http stamp-price https://postage-stamp-price-mcp.lipmichal.workers.dev/mcp

claude mcp add --transport http stamp-price https://postage-stamp-price-mcp.lipmichal.workers.dev/mcp

Claude Desktop

Claude Desktop adds remote servers under Settings, Connectors, Add custom connector. Paste the URL above.

Cursor

Add to ~/.cursor/mcp.json:

json

{  "mcpServers": {    "stamp-price": { "url": "https://postage-stamp-price-mcp.lipmichal.workers.dev/mcp" }  }}

{  "mcpServers": {    "stamp-price": { "url": "https://postage-stamp-price-mcp.lipmichal.workers.dev/mcp" }  }}

VS Code

Add to .vscode/mcp.json:

json

{  "servers": {    "stamp-price": { "type": "http", "url": "https://postage-stamp-price-mcp.lipmichal.workers.dev/mcp" }  }}

{  "servers": {    "stamp-price": { "type": "http", "url": "https://postage-stamp-price-mcp.lipmichal.workers.dev/mcp" }  }}

Local stdio (after npm release)

The npm package is not published yet. After it is, run it locally with Node 20 or newer:

Example prompts

"How much is a stamp right now?"
"How much postage do I need for 40 square Christmas cards that weigh 1.2 oz?"
"How much does it cost to mail a letter to Germany?"
"How much is a medium flat rate box?"
"How much is a postcard stamp?"

Data sources

Full list with fetch dates in DATA_SOURCES.md.

USPS Notice 123 Price List, read at call time.

Limitations

Retail prices at the Post Office. Commercial, metered and Click-N-Ship prices can be lower; metered letter prices are included.
Packages (Ground Advantage, Priority Mail by zone) are not covered beyond flat rate. Use https://postcalc.usps.com/ for those.
International large envelopes are not covered yet.
The hosted server caches the price list for up to 6 hours.

More MCP servers that answer questions your assistant cannot answer alone are on mcpstamp.com.

Part of the Zovo MCP collection: https://mcp.zovo.one

Built by theluckystrike.

Development

npm installnpm test                              # builds, then runs the fixture tests and an offline stdio testnode scripts/stdio-transcript.mjs     # live stdio round trip, writes .live/stdio-transcript.jsonl

npm installnpm test                              # builds, then runs the fixture tests and an offline stdio testnode scripts/stdio-transcript.mjs     # live stdio round trip, writes .live/stdio-transcript.jsonl

License

MIT

Source: README.md at commit 6bed223

Tools

get_stamp_price

Get stamp price

The current USPS Forever stamp price (First-Class Mail 1 oz stamped letter), the 2, 3 and 3.5 oz prices, metered letter prices, postcard, 1 oz large envelope, the nonmachinable surcharge and the 1 oz international letter (Global Forever) price, read at call time from USPS Notice 123 with its effective date.

Takes no parameters.

calculate_letter_postage

Calculate letter postage

Retail postage for one letter, postcard or large envelope (flat) by weight, to the US, Canada, Mexico or any other country, with the nonmachinable surcharge for square or rigid cards, the total for a quantity, and the number of Forever stamps per piece. Letters up to 3.5 oz, US large envelopes up to 13 oz.

Parameterstypequantityweight_ozdestinationnonmachinable

get_flat_rate_prices

Get flat rate box prices

Current USPS retail prices for Priority Mail Flat Rate envelopes and Small, Medium, Large and APO/FPO/DPO Flat Rate Boxes, and Priority Mail Express Flat Rate envelopes, from Notice 123.

Takes no parameters.

Version history

v1.0.0LatestNov 5, 2026

Score

100% 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.

Reached in the last 30 daysRequired25 pts
Auth declaredRequired10 pts
Tools listedRequired15 pts
DescriptionRequired15 pts
Logo10 pts
Documentation15 pts
License10 pts

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