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io.github.easonwong-de/firefox-css-theme

NPM · FIREFOX-CSS-THEME · SCANNED SEP 20

MCP for building, inspecting, and live-debugging Firefox CSS themes.

Available components

+4 this week 89 Trust /100
Trust breakdown (7 categories)

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. How we score → Why this is hard to score →

Supply Chain Security98
  • No malware found by supply-chain analysis.Pass
  • No known CVEs affecting this package version or its production dependencies.Pass
  • No install/post-install scripts declared.Pass
  • 44 of 131 dependencies flagged as unhealthy. View diagnostics → Partial
Provenance & Transparency97
  • Source repository is publicly reachable at the declared URL. View diagnostics → Pass
  • Cryptographically verified build provenance (signed, bound to easonwong-de/Firefox-CSS-Theme). View diagnostics → Pass
  • Clear OSI-approved license (MIT).Pass
  • Actively maintained (last published 15 days ago).Pass
  • Disclosure check failed: no security disclosure policy was found in the source repository. See how to fix → Fail
Schema Quality & AI Usability80
  • AI-judged instruction clarity (excellent).Pass
  • Tool/resource definitions use about 527 tokens (~47/item across 11 items; 11 tools + 0 resources), lean.Pass
  • Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management63
  • Stability observed for 19 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
Tool Safety75
  • No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
  • 0 of 2 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation; "remove_theme_css" implies "remove" and declares no destructiveHint at all, which the MCP spec reads as destructive by default. See how to fix → Fail
  • An AI judge read all 11 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
  • Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Install

How do I install the io.github.easonwong-de/firefox-css-theme MCP server?

io.github.easonwong-de/firefox-css-theme runs locally as an npm package, launched with npx -y firefox-css-theme. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

npm · firefox-css-theme

# add to Claude Code
claude mcp add easonwong-de-firefox-css-theme -- npx -y firefox-css-theme
// .cursor/mcp.json
{
  "mcpServers": {
    "easonwong-de-firefox-css-theme": {
      "command": "npx",
      "args": [
        "-y",
        "firefox-css-theme"
      ]
    }
  }
}
// .vscode/mcp.json
{
  "servers": {
    "easonwong-de-firefox-css-theme": {
      "command": "npx",
      "args": [
        "-y",
        "firefox-css-theme"
      ]
    }
  }
}
# add to Codex CLI
codex mcp add easonwong-de-firefox-css-theme -- npx -y firefox-css-theme
// opencode.json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "easonwong-de-firefox-css-theme": {
      "type": "local",
      "command": [
        "npx",
        "-y",
        "firefox-css-theme"
      ],
      "enabled": true
    }
  }
}
# add to OpenClaw
openclaw mcp add easonwong-de-firefox-css-theme --command npx --arg -y --arg firefox-css-theme
# ~/.hermes/config.yaml
mcp_servers:
  easonwong-de-firefox-css-theme:
    command: "npx"
    args: ["-y", "firefox-css-theme"]
// ~/.netclaw/config/netclaw.json
{
  "McpServers": {
    "easonwong-de-firefox-css-theme": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "firefox-css-theme"
      ]
    }
  }
}
# add to Vellum
assistant mcp add easonwong-de-firefox-css-theme -t stdio -c npx -a -y firefox-css-theme
// mcp.json
{
  "mcpServers": {
    "easonwong-de-firefox-css-theme": {
      "command": "npx",
      "args": [
        "-y",
        "firefox-css-theme"
      ]
    }
  }
}
Changelog

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.

  • 20 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 60 to 63. That category is still filling its 30-day observation window: 18 days of observed history at the previous scan, 19 at this one. The score rises as the window fills, whether or not the server changes.

  • 18 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 53 to 57. That category is still filling its 30-day observation window: 16 days of observed history at the previous scan, 17 at this one. The score rises as the window fills, whether or not the server changes.

  • 16 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 47 to 50. That category is still filling its 30-day observation window: 14 days of observed history at the previous scan, 15 at this one. The score rises as the window fills, whether or not the server changes.

  • 14 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 40 to 43. That category is still filling its 30-day observation window: 12 days of observed history at the previous scan, 13 at this one. The score rises as the window fills, whether or not the server changes.

  • 12 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.

  • 10 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 27 to 30. That category is still filling its 30-day observation window: 8 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.

  • 7 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.

  • 6 Sept 26 +11
    • Known CVEs: unverified → pass security
    • Dependency health: unverified → 0.86 functional
Diagnostics

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 20 Sept 2026 · Analysed npm/firefox-css-theme@0.2.8

Provenance Verified

A signed build attestation was found and verified, binding this exact artifact to the source repository it claims to come from.

Result Verified
Ecosystem npm
Reason Verified
Discovered via Registry attestation endpoint
Source repo easonwong-de/Firefox-CSS-Theme
Certificate issuer https://token.actions.githubusercontent.com
Certificate SAN https://github.com/easonwong-de/Firefox-CSS-Theme/.github/workflows/publish.yml@refs/heads/main
Rekor log index 2718943177
Predicate type https://slsa.dev/provenance/v1
Subject digest sha512:38857feca1a46f162d32131df3e847980c6a186df8a05f7534b289d77fe8845d2ac297e72de07020994ffafeeee1162de81803615b24a5bfc4f6396b6

Background: How many MCP packages publish verified provenance →

Dependencies 131 packages
Packages resolved 131
Stale 44
Tree resolution Complete

Background: SBOMs and build attestations, explained →

MCP tools · 11 exposed · ~527 tokens

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 →

Tool Tokens
close_browser ~14

Close the running Firefox instance.

Input schema present but exposes no named parameters.

No output schema declared.

No examples provided.

customize_toolbar ~47

Activate or manage the Firefox Customise Toolbar mode in the browser chrome.

NameTypeReqDescription
actionstringAction to perform on customise toolbar mode ('enter' or 'exit'). Defaults to 'enter'.

No output schema declared.

No examples provided.

execute_chrome_javascript ~39

Execute privileged JavaScript code in the Firefox chrome window context.

NameTypeReqDescription
scriptstringyesJavaScript code string to evaluate in chrome context.

No output schema declared.

No examples provided.

get_computed_styles ~56

Extract computed CSS properties for a Firefox UI chrome element.

NameTypeReqDescription
propertiesarrayOptional list of specific CSS property names.
selectorstringyesCSS selector of the UI element (e.g. '#urlbar-background').

No output schema declared.

No examples provided.

get_ui_tree ~48

Retrieve the hierarchical DOM tree of the Firefox chrome user interface window.

NameTypeReqDescription
maxDepthnumberMaximum recursive depth to traverse.
rootSelectorstringCSS selector for root element.

No output schema declared.

No examples provided.

inject_theme_css ~62

Inject or replace a live stylesheet in the Firefox window.

NameTypeReqDescription
cssstringyesCSS rules to inject.
idstringIdentifier for the style.
targetstringyesTarget scope: chrome for browser UI, or content for web pages.

No output schema declared.

No examples provided.

launch_browser ~88

Launch a Firefox instance with chrome debugging capabilities enabled.

NameTypeReqDescription
binaryPathstringOptional path to Firefox executable binary.
headlessbooleanOptional flag to run Firefox in headless mode.
novaUibooleanOptional flag to enable Firefox Nova UI preferences.
profileNamestringOptional name of existing Firefox profile. If omitted, uses an isolated temporary profile.

No output schema declared.

No examples provided.

list_theme_css ~36

List all custom stylesheets currently injected in the Firefox window.

NameTypeReqDescription
targetstringyesTarget scope to list: chrome or content.

No output schema declared.

No examples provided.

query_ui_elements ~47

Find elements in the Firefox UI chrome document matching a CSS selector.

NameTypeReqDescription
selectorstringyesCSS selector to query in chrome document (e.g. '#nav-bar', '#TabsToolbar').

No output schema declared.

No examples provided.

remove_theme_css ~49

Remove an injected stylesheet from the Firefox window.

NameTypeReqDescription
idstringyesIdentifier of the style to remove.
targetstringyesTarget scope of the style to remove: chrome or content.

No output schema declared.

No examples provided.

take_ui_screenshot ~41

Capture a PNG screenshot of the Firefox browser chrome window or a specific UI component.

NameTypeReqDescription
selectorstringOptional CSS selector to screenshot a specific element.

No output schema declared.

No examples provided.

Common questions

What is the io.github.easonwong-de/firefox-css-theme MCP server?

io.github.easonwong-de/firefox-css-theme is an MCP server listed in the public MCP registry as io.github.easonwong-de/firefox-css-theme. MCP for building, inspecting, and live-debugging Firefox CSS themes. This page covers its npm package (firefox-css-theme).

Is the io.github.easonwong-de/firefox-css-theme MCP server safe to use?

io.github.easonwong-de/firefox-css-theme scores 89 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 20 September 2026. It declares no install or post-install scripts. Its build provenance is signed and verified. 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 io.github.easonwong-de/firefox-css-theme MCP server expose?

io.github.easonwong-de/firefox-css-theme exposes 11 tools: launch_browser, close_browser, customize_toolbar, get_ui_tree, query_ui_elements, and 6 more. Their descriptions and schemas cost roughly 527 tokens of context every time the server is loaded.

Is the io.github.easonwong-de/firefox-css-theme MCP server still maintained?

io.github.easonwong-de/firefox-css-theme is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

What licence is the io.github.easonwong-de/firefox-css-theme MCP server under?

io.github.easonwong-de/firefox-css-theme declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.