MCP.Market

Clef MCP server

online · 100% uptime
by MelMayssonOwen·io.github.MelMayssonOwen/clef·v1.0.0
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Read-only music guides, chord transposition, piano chord spelling and guitar-tab pitch mapping.

C67/100grade C
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Safety scan
C67/100

full report

Adoption
New

Little public usage data yet

Reviews

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If you have run it, two minutes of your experience saves the next person an afternoon.

Clef tools (4)

write = sends, deletes, buys or posts
  • find_music_guidesFree

    Find Clef instructional guides by words in the title and description. Guides are not file converters.

  • spell_piano_chordFree

    Spell a supported chord as piano pitches with octave and MIDI values. This does not create a rhythmic arrangement.

  • tab_to_piano_notesFree

    Convert six-string ASCII guitar tab to sounding piano pitches. Tab spacing does not specify note duration. No GP files or audio uploads.

  • transpose_chordsFree

    Transpose chord symbols, including slash bass notes. Does not process audio, lyrics, or notation files.

Public scan report

scanner v0.1.10 · 2026-10-03 · same rubric, same numbers if you re-run it

1 low
  • –Code scanremote-only server, no package to scann/a
  • Live reliabilityremote reachable in 583ms20/20
  • Tool poisoning4 tool descriptions checked15/15
  • Auth qualityopen endpoint, read-only tools10/15
  • Maintenanceno repository listed3/15
  • Maintainer identityno repository or website to verify2/10

Findings (1)

  • lowNo source repository listedmaint.no-repo
Overall 67/100. Components that don't apply are left out of the denominator. Any critical finding is an F.RubricAppeal a findingJSON

How Clef compares

Against every graded MCP server, from our own scans and uptime checks. Updated after each scan run.

Safety score
67/100
higher than 25% of 48,243 servers
Tools
4
the typical server has 7
Tools that change things
0%
typical: 0%. Fewer write tools means less an agent can break
Uptime
100%
of our recent checks; the typical remote server answers 100%
Response time
150 ms
faster than 74% of 30,027 servers

What its tools let an agent do: 4 read

Install Clef in Claude Code, Cursor or VS Code

claude mcp add --transport http clef https://clefdrills.com/mcp
Add to Cursor

Clef: common questions

Is Clef MCP server safe?
With care: it is graded C, so read the findings first (67/100). Read the Clef safety report
How do I install Clef?
It runs remotely at clefdrills.com. Add it to Claude Code, Cursor, VS Code or Claude Desktop with the snippets above, or call it through the mcp.market gateway without installing anything.
Does Clef need an API key?
Not as far as the registry entry and our scan can tell: no credentials are declared or required.
Is Clef maintained?
The latest release is v1.0.0.
Is Clef up?
100% of our last 28 checks got an answer. We check remote servers about four times a day.
How does Clef compare with other MCP servers?
safety score 67/100 (higher than 25% of 48,243 servers); tools 4 (the typical server has 7); tools that change things 0% (typical: 0%. Fewer write tools means less an agent can break). Full comparison.

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