# ContrastKit (remote · contrastkit.mike-tusa.workers.dev)

WCAG color contrast checks, nearest accessible color, CSS color conversion and palette pair checks.

- Trust score: 66/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-23

## Components

- remote · `contrastkit.mike-tusa.workers.dev`: 66/100 (this document), [markdown](https://verifymcp.io/servers/dev-workers-mike-tusa-contrastkit-contrastkit/contrastkit.md), [page](https://verifymcp.io/servers/dev-workers-mike-tusa-contrastkit-contrastkit/contrastkit)

## Channel facts

- Endpoint: `https://contrastkit.mike-tusa.workers.dev/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 2026-10-23.

- **Endpoint Security**: 63/100
  - 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 enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - 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**: 66/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 985 tokens (~246/item across 4 items; 4 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 3/100
  - Stability observed for 1 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 4 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a current MCP spec version (2026-07-28).

## Install

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

ContrastKit is a hosted endpoint at https://contrastkit.mike-tusa.workers.dev/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 dev-workers-mike-tusa-contrastkit-contrastkit 'https://contrastkit.mike-tusa.workers.dev/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "dev-workers-mike-tusa-contrastkit-contrastkit": {
      "url": "https://contrastkit.mike-tusa.workers.dev/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "dev-workers-mike-tusa-contrastkit-contrastkit": {
      "type": "http",
      "url": "https://contrastkit.mike-tusa.workers.dev/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.dev-workers-mike-tusa-contrastkit-contrastkit]
url = "https://contrastkit.mike-tusa.workers.dev/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "dev-workers-mike-tusa-contrastkit-contrastkit": {
      "type": "remote",
      "url": "https://contrastkit.mike-tusa.workers.dev/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add dev-workers-mike-tusa-contrastkit-contrastkit --url 'https://contrastkit.mike-tusa.workers.dev/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  dev-workers-mike-tusa-contrastkit-contrastkit:
    url: "https://contrastkit.mike-tusa.workers.dev/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "dev-workers-mike-tusa-contrastkit-contrastkit": {
      "Transport": "http",
      "Url": "https://contrastkit.mike-tusa.workers.dev/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add dev-workers-mike-tusa-contrastkit-contrastkit -t streamable-http -u 'https://contrastkit.mike-tusa.workers.dev/mcp'
```

### Other

```json
{
  "mcpServers": {
    "dev-workers-mike-tusa-contrastkit-contrastkit": {
      "type": "http",
      "url": "https://contrastkit.mike-tusa.workers.dev/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.

### 2026-10-23 (score 66, +1)

- [functional improvement] Stability: unverified → 0.03

### 2026-10-22 (score 65)

First indexed and scored.

## MCP tools (4)

### `check_contrast` (~199 tokens)

Check WCAG color contrast

Compute the WCAG 2.x contrast ratio between a text (foreground) color and a background color, with pass/fail for AA, AA large text, AAA, AAA large text and non-text UI (3:1). Handles translucent colors. Read-only. Same engine as GET /api/contrast.

Input parameters:

- `background` (string, required): Background color as a CSS color: "#1a73e8", "#fff", "rgb(26 115 232)", "hsl(217 80% 51%)", "rgba(0,0,0,.6)" or a name like "navy".
- `foreground` (string, required): Text / foreground color as a CSS color: "#1a73e8", "#fff", "rgb(26 115 232)", "hsl(217 80% 51%)", "rgba(0,0,0,.6)" or a name like "navy".

Output parameters:

- `background` (object)
- `effectiveBackground` (string)
- `effectiveForeground` (string)
- `foreground` (object)
- `notes` (array)
- `pass` (object)
- `ratio` (number)
- `ratioExact` (number)
- `version` (string)

### `suggest_accessible_color` (~259 tokens)

Suggest the nearest accessible color

For a failing color pair, find the closest color (same hue and saturation, lightness changed as little as possible) that meets the chosen WCAG level. Adjust the foreground (default), the background, or both (best first). Read-only. Same engine as GET /api/suggest.

Input parameters:

- `adjust` (string): Which color may change.
- `background` (string, required): Background color as a CSS color: "#1a73e8", "#fff", "rgb(26 115 232)", "hsl(217 80% 51%)", "rgba(0,0,0,.6)" or a name like "navy".
- `foreground` (string, required): Text / foreground color as a CSS color: "#1a73e8", "#fff", "rgb(26 115 232)", "hsl(217 80% 51%)", "rgba(0,0,0,.6)" or a name like "navy".
- `level` (string): WCAG target: aa 4.5:1 (default), aa-large 3:1, aaa 7:1, aaa-large 4.5:1, ui 3:1 (non-text).

Output parameters:

- `adjust` (string)
- `alreadyPasses` (boolean)
- `background` (object)
- `effectiveBackground` (string)
- `effectiveForeground` (string)
- `foreground` (object)
- `level` (string)
- `notes` (array)
- `pass` (object)
- `ratio` (number)
- `ratioExact` (number)
- `suggestions` (array)
- `target` (number)
- `version` (string)

### `convert_color` (~124 tokens)

Convert a CSS color

Convert a CSS color to hex, rgb() and hsl(), with its relative luminance, its contrast on white and on black, and the better text color (black or white) to put on it. Read-only. Same engine as GET /api/convert.

Input parameters:

- `color` (string, required): Color as a CSS color: "#1a73e8", "#fff", "rgb(26 115 232)", "hsl(217 80% 51%)", "rgba(0,0,0,.6)" or a name like "navy".

Output parameters:

- `alpha` (number)
- `bestTextColor` (string)
- `contrastOnBlack` (number)
- `contrastOnWhite` (number)
- `hex` (string)
- `hsl` (string)
- `input` (string)
- `luminance` (number)
- `rgb` (string)
- `version` (string)

### `check_palette` (~130 tokens)

Check every pair in a palette

Contrast ratio for every pair of 2 to 12 colors (up to 66 pairs), highest first, each flagged against the chosen WCAG level. Use it to see which brand colors can be used together for text. Read-only. Same engine as GET /api/palette.

Input parameters:

- `colors` (array, required): 2 to 12 CSS colors.
- `level` (string): WCAG target: aa 4.5:1 (default), aa-large 3:1, aaa 7:1, aaa-large 4.5:1, ui 3:1 (non-text).

Output parameters:

- `colors` (array)
- `count` (integer)
- `level` (string)
- `notes` (array)
- `pairs` (array)
- `passing` (integer)
- `target` (number)
- `version` (string)

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/dev-workers-mike-tusa-contrastkit-contrastkit/contrastkit#diagnostics

## Score history

- 2026-10-23: 66
- 2026-10-22: 65

## Common questions

### What is the ContrastKit MCP server?

ContrastKit is an MCP server listed in the public MCP registry as dev.workers.mike-tusa.contrastkit/contrastkit. WCAG color contrast checks, nearest accessible color, CSS color conversion and palette pair checks. This page covers its hosted endpoint (https://contrastkit.mike-tusa.workers.dev/mcp).

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

ContrastKit scores 66 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 ContrastKit MCP server expose?

ContrastKit exposes 4 tools: check_contrast, suggest_accessible_color, convert_color, check_palette. Their descriptions and schemas cost roughly 712 tokens of context every time the server is loaded.

### Does the ContrastKit MCP server require authentication?

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

### Is the ContrastKit MCP server still maintained?

ContrastKit is still listed as active in the MCP registry. We last reached this channel on 23 October 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://contrastkit.mike-tusa.workers.dev/mcp
- Website: https://contrastkit.mike-tusa.workers.dev/
- Changelog RSS feed: https://verifymcp.io/servers/dev-workers-mike-tusa-contrastkit-contrastkit/contrastkit.xml
- Changelog JSON feed: https://verifymcp.io/servers/dev-workers-mike-tusa-contrastkit-contrastkit/contrastkit.json
- HTML version of this page: https://verifymcp.io/servers/dev-workers-mike-tusa-contrastkit-contrastkit/contrastkit