Skip to content
Courio logo

Courio MCP server

Which MCP servers are Courio'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 2026-11-03

← Back to Courio

Whose server it is
  • Registry namesi.courio/courioverified in the MCP registry

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

When we asked itchecked 2026-11-03
  • Stateanswerschecked 2026-11-03
  • Tools4
  • Server calls itselfcourio
  • Server version1.0.0
  • Protocol version2025-06-18

On 2026-11-03 the server answered initialize and tools/list without a sign-in. First answer in 501 ms.

Should an agent connect itNot proven either way yet
  • Whether its tools do the product's job has not been judged yet.
  • Checked on 1 of the 7 days it takes to judge reliability.

Once connected

  • For "get an upfront price before paying for a letter", the likely first call is quote_letter.
  • Keep approval on for send_letter: they delete, send or pay without saying so.
  • send_letter change data without a sign-in: anyone with the address can call them.
  • Parameters are untyped or undescribed in 3 of 4 tools: check arguments before calling.

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: 1, the first on 2026-11-03
  • INITE MCP scoreafter a weeka score needs 7 daily checks: 1 so far
  • Answeredmeasuring1 of the 7 daily checks it takes to print a share
  • Median first answer494 ms
  • Space in an agent's context≈ 1,559 tokensthe definitions of all its tools (4), which an agent carries on every turn
  • Tool definitionsB · 88 of 100
  • Typed results0 of 4 toolsdeclared outputSchema: results come typed, read once
  • Parameters without a description: in 3 of 4

What an agent can do with it

  • not sure · mail a PDF to a postal address in another country
  • can do · get an upfront price before paying for a letter
  • not sure · send a letter without creating an account

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

  • Tools that delete, send or pay, marked as not destructive: send_letter
  • Tools that change data, on a server that answers without a sign-in: send_letter

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 offers4 tools · read 2026-11-03
  • get_coverage

    Lists which destination countries and service levels Courio can mail a physical paper letter to, with an indicative "from" price (EUR including VAT, 1 black-and-white page), typical delivery time and the legal product name. No account or…

  • quote_letter

    Prices a physical letter (printed, enveloped and posted by Courio) and returns a quote_id. Free and commits to nothing: no account, no payment, nothing is mailed. Give the service level, sender and recipient postal addresses, and the…

  • send_letter

    Creates the letter for a quote and returns a payment link (Stripe Checkout). No account is needed. YOU CANNOT PAY: show the price and the payment link to the human and ask them to open it and pay. The letter is mailed right after payment…

  • get_letter_status

    Returns the current status of a letter (awaiting_payment, paid, submitted, in_transit, delivered, failed, expired, ...), its timeline and, once available, proof links (proof of deposit for "registered", proof of delivery for…

How to connect

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

{
  "mcpServers": {
    "courio": {
      "type": "http",
      "url": "https://api.courio.si/mcp"
    }
  }
}

Add it

Claude Code, in a terminal

claude mcp add --transport http courio https://api.courio.si/mcp

Add to CursorAdd to VS Code

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

OpenAPI spec

4 paths, read 2026-11-03. Open the spec ↗

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.