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Litmus

Grade MCP servers A to F with the open behavioral litmus.

Connector by polygraphso · GitHub account verified by the MCP Registry

IndexedApache-2.0Local (stdio)Remote (HTTP)★ 8
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Install

Works with Claude Code, VS Code, Codex, Cursor, Windsurf, Claude Desktop. Read the repository before you give any tool access to your data.

npx agentmarket install connector/polygraphso-litmus

Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.

Remote endpoint

  • https://polygraph.so/api/mcp Remote (HTTP)

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About

Grade MCP servers A to F with the open behavioral litmus. npm: full toolset; hosted: lookups only.

Reviews

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No reviews yet. Installed it? Reviews come from verified installers only. How reviews work

Permissions

What this server can do and what it asks for, from its tool list and install config. Checked Oct 25, 2026.

Tools
2 read · 1 write · 0 delete
Secrets
None asked for
Install scripts
Not scanned yet
Runs as
Node.js package

Tools by what they do 3

From the running server's own tool list (tools/list) on Oct 25, 2026.

Read 2 · Look things up without changing anything.

  • check_server
  • list_servers

Write 1 · Create, change, send or run things.

  • request_grade

Secrets and settings it asks for

Other settings (environment variables or headers).

  • NEXT_PUBLIC_POLYGRAPH_NETWORK
  • POLYGRAPH_API_URL

Network hosts it talks to 1

  • polygraph.so · found in remote endpoint, install command

Tools (3)

As the server listed them on Oct 25, 2026. Descriptions are the server’s own words; hidden characters are shown as [U+…].

  • check_serverCheck a server's published polygraph graderead-only

    Read a server's published behavioral grade (A-F) from polygraph.so in under a second; no execution. The pre-flight check before recommending or installing an MCP server. On a miss it returns not_available (unevaluated: neither safe nor unsafe) with next steps.

  • list_serversList servers with a published graderead-only

    Servers with a published polygraph grade, sorted A-first then by ref. Returns up to `limit` rows starting at `offset` (default limit 25, capped at 100 per call); `grade` restricts to one letter. `summary` always covers the full graded corpus (a total plus a count per grade), regardless of `grade`, `limit`, or `offset`.

  • request_gradeRequest a polygraph grade for an MCP server

    Hosted grading is discontinued. This tool returns gone. Existing published grades remain available via check_server / list_servers. To grade a server yourself, run the open harness: npx -y -p @polygraphso/litmus polygraphso-litmus litmus <server_ref>.

Signals

Stars
8
Forks
1
Open issues
1
Last commit
Jul 20, 2026 (3 months ago)
Last release
Jul 20, 2026 (3 months ago)

From GitHub (fetched Oct 24, 2026).

Details

Registry name
io.github.polygraphso/litmus
Version
0.36.0
Auth
Auth not stated
Packages
npm @polygraphso/litmus
License
Apache-2.0
Repository
github.com/polygraphso/litmus
Website
polygraph.so
First seen
Oct 24, 2026
Last checked
Oct 24, 2026
Source
Official MCP Registrygithub-graphql
Cite this page

Litmus MCP server. Agent Mart. https://agentmart.dev/connectors/polygraphso-litmus (last updated 2026-10-24)