ContrastKit
REMOTE · CONTRASTKIT.MIKE-TUSA.WORKERS.DEV
WCAG color contrast checks, nearest accessible color, CSS color conversion and palette pair checks.
Available components
Last scanned (17 hours ago)
Scores higher than 55% of remote servers
Reachable. Last reached 23 Oct 2026.
Category Design and Media
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. How we score → Why this is hard to score →
Endpoint Security63
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one. See how to fix → View diagnostics → Partial
- HTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement. View diagnostics → Unverified
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability66
- AI-judged instruction clarity (excellent).Pass
- 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. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management3
- Stability observed for 1 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
- Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 4 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a current MCP spec version (2026-07-28).Pass
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 23 Oct 26 +1
- Stability: unverified → 0.03 ▲ functional
- 22 Oct 26 65
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 23 Oct 2026 · Probed https://contrastkit.mike-tusa.workers.dev/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=mike-tusa.workers.dev | CN=WE1,O=Google Trust Services,C=US | 12 Oct 2026 | 10 Jan 2027 | ECDSA 256 | ECDSA-SHA256 | f05aa95d8943eeed0e4e86dd1f6f1e02 |
| SANs: mike-tusa.workers.dev, *.mike-tusa.workers.dev | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of contrastkit.mike-tusa.workers.dev. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| dev. | present | 60074 | 8 | Verified |
| workers.dev. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
| Header | Value |
|---|---|
| x-content-type-options | nosniff |
| x-frame-options | DENY |
| referrer-policy | no-referrer |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://contrastkit.mike-tusa.workers.dev/mcp | Verified | 200 | |
| http (plaintext) | http://contrastkit.mike-tusa.workers.dev/mcp | Inconclusive | 405 |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
check_contrast Check WCAG color contrast ~199
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.
| Name | Type | Req | Description |
|---|---|---|---|
| background | string | yes | 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 | yes | 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". |
| Name | Type | Req | Description |
|---|---|---|---|
| background | object | – | – |
| effectiveBackground | string | – | – |
| effectiveForeground | string | – | – |
| foreground | object | – | – |
| notes | array | yes | – |
| pass | object | yes | – |
| ratio | number | yes | – |
| ratioExact | number | – | – |
| version | string | yes | – |
No examples provided.
check_palette Check every pair in a palette ~130
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.
| Name | Type | Req | Description |
|---|---|---|---|
| colors | array | yes | 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). |
| Name | Type | Req | Description |
|---|---|---|---|
| colors | array | – | – |
| count | integer | yes | – |
| level | string | – | – |
| notes | array | – | – |
| pairs | array | yes | – |
| passing | integer | yes | – |
| target | number | – | – |
| version | string | yes | – |
No examples provided.
convert_color Convert a CSS color ~124
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.
| Name | Type | Req | Description |
|---|---|---|---|
| color | string | yes | 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". |
| Name | Type | Req | Description |
|---|---|---|---|
| alpha | number | – | – |
| bestTextColor | string | yes | – |
| contrastOnBlack | number | – | – |
| contrastOnWhite | number | – | – |
| hex | string | yes | – |
| hsl | string | – | – |
| input | string | – | – |
| luminance | number | yes | – |
| rgb | string | – | – |
| version | string | yes | – |
No examples provided.
suggest_accessible_color Suggest the nearest accessible color ~259
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.
| Name | Type | Req | Description |
|---|---|---|---|
| adjust | string | – | Which color may change. |
| background | string | yes | 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 | yes | 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). |
| Name | Type | Req | Description |
|---|---|---|---|
| adjust | string | – | – |
| alreadyPasses | boolean | yes | – |
| background | object | – | – |
| effectiveBackground | string | – | – |
| effectiveForeground | string | – | – |
| foreground | object | – | – |
| level | string | – | – |
| notes | array | – | – |
| pass | object | – | – |
| ratio | number | yes | – |
| ratioExact | number | – | – |
| suggestions | array | yes | – |
| target | number | yes | – |
| version | string | yes | – |
No examples provided.
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.
remote · contrastkit.mike-tusa.workers.dev
claude mcp add --transport http dev-workers-mike-tusa-contrastkit-contrastkit 'https://contrastkit.mike-tusa.workers.dev/mcp'
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.