# Postbye MCP examples

> For AI agents: a plain-text index of this site is at https://postbye.com/llms.txt

Four things to ask your assistant once the Postbye MCP server is connected, the tool call each one makes and the server's real answer, shortened.

## What to ask

Each prompt below makes the assistant call one tool:

- "Which subscription is Netflix, and how do I cancel it?" calls search_companies.
- "What do I need to check before cancelling Netflix?" calls get_cancellation_guide.
- "Write a cancellation letter for my Netflix account." calls get_cancellation_letter.
- "Which kinds of subscriptions does Postbye cover?" calls list_categories.

## Getting good answers

A few habits that help the assistant pick the right tool:

- Name the company, for example Netflix or Planet Fitness, so search_companies can find its slug.
- Ask for what you need to check first, such as the notice period or the traps, and the assistant will read get_cancellation_guide.
- Give your full name and your account or membership number when you ask for a letter. Anything left out stays as a [bracketed] placeholder.
- Ask the assistant to show the guide URL it used, so you can read the same facts on postbye.com.

## A typical conversation

The tools are built to be used in this order:

- search_companies turns a name such as "netflix" into a slug and a guide URL.
- get_cancellation_guide returns how that company takes cancellations, the notice period, the traps to check and the mailing address on file.
- get_cancellation_letter writes the letter for the same slug, with the address to send it to. Anything you did not give stays as a [bracketed] placeholder.
- list_categories shows what else is covered when you are not sure which company to ask about.

## Calls and answers

The arguments the assistant sends and the answer the server returns. Answers are cut to the first lines.

### search_companies

Example call

```json
{
  "name": "search_companies",
  "arguments": {
    "query": "netflix",
    "limit": 1
  }
}
```

Answer (shortened)

```
1 match for "netflix":
1. Netflix (slug: netflix), Streaming & entertainment. Online. https://postbye.com/cancel/netflix
All guides: https://postbye.com/cancel
Postbye can mail this letter by certified mail: https://postbye.com/how-it-works
```

### get_cancellation_guide

Example call

```json
{
  "name": "get_cancellation_guide",
  "arguments": {
    "slug": "netflix"
  }
}
```

Answer (shortened)

```
How to cancel Netflix (Streaming & entertainment)
Slug: netflix. Accepts cancellations: Online.

Directly with Netflix, the way to cancel is: Online. Notice rule: Cancel anytime; access continues to the end of the paid billing period.

Notice period: Cancel anytime; access continues to the end of the paid billing period

...
```

### get_cancellation_letter

Example call

```json
{
  "name": "get_cancellation_letter",
  "arguments": {
    "slug": "netflix",
    "customer_name": "Alex Example"
  }
}
```

Answer (shortened)

```
Alex Example
[Your street address]
[City, state and ZIP code]
[Your email address]

[Today’s date]

...
```

### list_categories

Example call

```json
{
  "name": "list_categories",
  "arguments": {}
}
```

Answer (shortened)

```
30 categories of cancellation guides:
- News & magazines (884 guides, 71 verified by hand): https://postbye.com/cancel/category/news-magazines
- Insurance & protection plans (732 guides, 31 verified by hand): https://postbye.com/cancel/category/insurance
- Software & apps (653 guides, 314 verified by hand): https://postbye.com/cancel/category/software
- Phone & internet (467 guides, 66 verified by hand): https://postbye.com/cancel/category/telecom
- Streaming & entertainment (446 guides, 156 verified by hand): https://postbye.com/cancel/category/streaming
- Finance & credit (438 guides, 57 verified by hand): https://postbye.com/cancel/category/finance
...
```

## Call a tool over HTTP

No MCP client is needed: any HTTP client can POST a JSON-RPC message to /mcp. This request runs search_companies:

```bash
curl -s -X POST https://postbye.com/mcp \
  -H 'content-type: application/json' \
  -H 'accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"search_companies","arguments":{"query":"netflix","limit":1}}}'
```

## A failed lookup

An unknown company comes back as a result with isError set to true, with a message the assistant can act on. The real answer for the slug no-such-company:

```
Unknown company slug: no-such-company. Did you mean: nordvpn, noom, norton? Use search_companies to find the slug.
All guides: https://postbye.com/cancel
Postbye can mail this letter by certified mail: https://postbye.com/how-it-works
```

```json
{
  "isError": true,
  "structuredContent": {
    "error": "Unknown company slug: no-such-company. Did you mean: nordvpn, noom, norton? Use search_companies to find the slug."
  }
}
```

## Keep reading

The other documentation pages for the server:

- [Postbye MCP Server for AI Assistants](https://postbye.com/mcp-server): Overview of the server: what it does, the endpoint and the four tools.
- [Install the Postbye MCP Server](https://postbye.com/mcp-server/install): Set-up for Claude, Claude Code, Cursor, VS Code and ChatGPT, and how access works.
- [Postbye MCP Tools Reference](https://postbye.com/mcp-server/tools): Inputs, limits and results of the four tools.
- [Postbye MCP Server FAQ](https://postbye.com/mcp-server/faq): Access, cost, data, limits and how the server relates to postbye.com.
- [Connect the Postbye MCP Server](https://postbye.com/mcp-server/clients): Steps and configuration for Claude, Cursor, VS Code, ChatGPT, the OpenAI API and other clients.

## Want the letter mailed for you?

Postbye prints the letter, sends it by certified mail and emails you the signed delivery proof.

[Find your company](https://postbye.com/cancel)