Skip to content
Online Shipping Calculator logo

Online Shipping Calculator MCP server

Which MCP servers are Online Shipping Calculator's own, from the official registry and from asking its own domain, whether they answer, and what they offer. A program checked each of these, nobody copied them from a product page.

read 2026-10-30

← Back to Online Shipping Calculator

Whose server it is
  • Registry namecom.onlineshippingcalculator/shipping-ratesverified in the MCP registry

The registry name sits under onlineshippingcalculator.com. The registry only lets a publisher use that namespace after proving control of the domain through DNS or HTTP.

When we asked itchecked 2026-10-30
  • Stateanswerschecked 2026-10-30
  • Tools2
  • Server calls itselfshipping-rates-calculator
  • Server version1.0.0
  • Protocol version2025-06-18

On 2026-10-30 the server answered initialize and tools/list without a sign-in. First answer in 308 ms.

Should an agent connect itNot proven either way yet
  • Its tools do compare carrier rates for a package before shipping; see which carrier is cheapest at a given weight, but not check dimensional weight before choosing a box size.
  • Checked on 5 of the 7 days it takes to judge reliability.

Once connected

  • For "compare carrier rates for a package before shipping", the likely first call is get_shipping_rates.
  • For "see which carrier is cheapest at a given weight", the likely first call is get_shipping_rates.

Said by rules from the measurements above. The likely first call is a model's pick from the tool list; read its description before relying on it.

Measured dailydaily checks: 5, the first on 2026-10-30
  • INITE MCP scoreafter a weeka score needs 7 daily checks: 5 so far
  • What an agent can do with it2 of 3 use cases
  • Answeredmeasuring5 of the 7 daily checks it takes to print a share
  • Median first answer147 ms
  • Space in an agent's context≈ 664 tokensthe definitions of all its tools (2), which an agent carries on every turn
  • Tool definitionsA · 100 of 100
  • Typed results0 of 2 toolsdeclared outputSchema: results come typed, read once
  • Every tool passes all six checks.

What an agent can do with it

  • can do · compare carrier rates for a package before shipping
  • cannot · check dimensional weight before choosing a box size
  • can do · see which carrier is cheapest at a given weight

Each of the product's use cases, put to Jev against this server's tool list: can an agent do it with these tools?

Worth a look

None of the five warning signs in these definitions.

A program checks the server once a day: initialize and tools/list, no model. Tokens are the definitions' length at about four characters a token. The grade averages six checks of every tool's name, description, schema and annotations; it says how well the tools are described, not whether they work. The score weighs what was measured and nothing else: answering (25%), doing the product's job (25%), definitions (20%), context (10%), use (10%) and how readily a client connects (10%). A part that was not measured is left out, and a hidden instruction caps the score at 40. The state of vendors' MCP servers: method and numbers →

Tools it offers2 tools · read 2026-10-30
  • get_shipping_rates

    Get live USPS, UPS, and FedEx shipping rates for a package from a US ZIP code to a US or international destination. Returns carrier, service, price in USD, and estimated transit days, sorted cheapest first. IMPORTANT: these are discounted…

  • get_postage_price

    Get the current USPS First-Class postage price for a letter, large envelope (flat), or postcard mailed within the US — including how many Forever stamps to put on it and an exact combination of stamp denominations that covers the postage…

How to connect

Add the server to your MCP client config. Claude Desktop, Cursor and most other clients read this shape:

{
  "mcpServers": {
    "shipping-rates": {
      "type": "http",
      "url": "https://onlineshippingcalculator.com/api/mcp"
    }
  }
}

Add it

Claude Code, in a terminal

claude mcp add --transport http onlineshippingcalculator https://onlineshippingcalculator.com/api/mcp

Add to CursorAdd to VS Code

claude.ai, ChatGPT and other clients: add https://onlineshippingcalculator.com/api/mcp as a custom connector in the settings.

Each line is something a program found when it went looking: the registry entry, the server's own answer, a spec that parses. A missing line means we did not find it, not that it does not exist.