# Contraptify (remote · mcp.contraptify.com)

Design redstone machines with your AI and test them tick by tick with Java Edition 26.3 rules.

- Trust score: 67/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `mcp.contraptify.com`: 67/100 (this document), [markdown](https://verifymcp.io/servers/torsviklabs-contraptify/mcp.md), [page](https://verifymcp.io/servers/torsviklabs-contraptify/mcp)

## Channel facts

- Endpoint: `https://mcp.contraptify.com/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.1.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-05.

- **Endpoint Security**: 80/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one.
  - HTTPS is enforced; there's no plaintext access path.
  - The HSTS (Strict-Transport-Security) header is present.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 30/100
  - 0% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 4643 tokens (~773/item across 6 items; 5 tools + 1 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 13/100
  - Stability observed for 4 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 93/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 80% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 5 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 7 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.
  - Supports UI / widget rendering.

## Install

### How do I install the Contraptify MCP server?

Contraptify is a hosted endpoint at https://mcp.contraptify.com/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http torsviklabs-contraptify 'https://mcp.contraptify.com/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "torsviklabs-contraptify": {
      "url": "https://mcp.contraptify.com/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "torsviklabs-contraptify": {
      "type": "http",
      "url": "https://mcp.contraptify.com/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.torsviklabs-contraptify]
url = "https://mcp.contraptify.com/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "torsviklabs-contraptify": {
      "type": "remote",
      "url": "https://mcp.contraptify.com/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add torsviklabs-contraptify --url 'https://mcp.contraptify.com/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  torsviklabs-contraptify:
    url: "https://mcp.contraptify.com/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "torsviklabs-contraptify": {
      "Transport": "http",
      "Url": "https://mcp.contraptify.com/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add torsviklabs-contraptify -t streamable-http -u 'https://mcp.contraptify.com/mcp'
```

### Other

```json
{
  "mcpServers": {
    "torsviklabs-contraptify": {
      "type": "http",
      "url": "https://mcp.contraptify.com/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-05 (score 67, +1)

- [security] Resource “contraptify-viewer” now points somewhere else: ui://contraptify/viewer-9118fb9ac21e.html → ui://contraptify/viewer-367990eb2bbd.html

### 2026-11-03 (score 66, +1)

- [security] Resource “contraptify-viewer” now points somewhere else: ui://contraptify/viewer-152d365a3c27.html → ui://contraptify/viewer-9118fb9ac21e.html
- [security] The server rewrote its instructions, which are the text every model session reads
- [security] Tool “show” rewrote its description, which is the text the model reads

### 2026-11-02 (score 65, 0)

- [functional improvement] Stability: unverified → 0.03

### 2026-11-01 (score 65)

First indexed and scored.

## MCP tools (5)

### `simulate` (~133 tokens)

Simulate and test a design

Run a redstone design with its own test (inputs and expectations) and return which expectations hold and which fail (with what the block was instead, and when), what visibly changed (lamps, pistons, doors, dispensers) and when, dispenser shots, and notes on what broke. Without a test it just runs the machine and reports what changed. Use it on every candidate before showing it. Do not use it to display a design to the user: use show.

Input parameters:

- `design` (object, required): A machine: a list of blocks plus what it is for. See the server instructions for block types and rules.

### `explain` (~84 tokens)

Check a design's part explanations

List a design's parts with their explanations, how many blocks each covers, and any blocks without a part. Use it before show to make sure every block is explained. Do not use it to test whether the machine works: use simulate.

Input parameters:

- `design` (object, required): A machine: a list of blocks plus what it is for. See the server instructions for block types and rules.

### `list_examples` (~56 tokens)

List example designs

List the built-in example designs (clocks, counters, a piston door, a lock, a flying machine). Use it to find a known-good starting point. Do not use it to fetch a design's blocks: use get_example.

### `get_example` (~88 tokens)

Get an example design

Return one built-in example design with its blocks, part explanations and its own test, by id from list_examples. Large designs (the 0-9 counter has about 2,500 blocks, the 00-59 clock about 5,100) are long. Do not use it to show an example to the user: use show with example set.

Input parameters:

- `id` (string, required)

### `show` (~152 tokens)

Show a design in 3D

Show a design to the user in an interactive 3D viewer in the chat: they can press its button or flip its lever, watch it run tick by tick, move around, and click any part to read what it does. Give either design, or example (an id from list_examples). Call it once per answer, at the end, after the last simulate passes: every call adds another viewer to the chat. Do not use it to test a design: use simulate.

Input parameters:

- `design` (object): A machine: a list of blocks plus what it is for. See the server instructions for block types and rules.
- `example` (string): Id of a built-in example to show instead of a design

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/torsviklabs-contraptify/mcp#diagnostics

## Score history

- 2026-11-05: 67
- 2026-11-04: 66
- 2026-11-03: 66
- 2026-11-02: 65
- 2026-11-01: 65

## Common questions

### What is the Contraptify MCP server?

Contraptify is an MCP server listed in the public MCP registry as io.github.torsviklabs/contraptify. Design redstone machines with your AI and test them tick by tick with Java Edition 26.3 rules. This page covers its hosted endpoint (https://mcp.contraptify.com/mcp).

### Is the Contraptify MCP server safe to use?

Contraptify scores 67 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Contraptify MCP server expose?

Contraptify exposes 5 tools: simulate, explain, list_examples, get_example, show. Their descriptions and schemas cost roughly 513 tokens of context every time the server is loaded.

### Does the Contraptify MCP server require authentication?

No. We connected to Contraptify without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the Contraptify MCP server still maintained?

Contraptify is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://mcp.contraptify.com/mcp
- Repository: https://github.com/torsviklabs/contraptify
- Website: https://contraptify.com/
- Changelog RSS feed: https://verifymcp.io/servers/torsviklabs-contraptify/mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/torsviklabs-contraptify/mcp.json
- HTML version of this page: https://verifymcp.io/servers/torsviklabs-contraptify/mcp