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8 clients · secrets stay placeholders

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{
  "mcpServers": {
    "litmus": {
      "type": "http",
      "url": "https://polygraph.so/api/mcp"
    }
  }
}

claude mcp add --transport http litmus https://polygraph.so/api/mcp

[mcp_servers.litmus]
url = "https://polygraph.so/api/mcp"

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "litmus": {
      "type": "remote",
      "url": "https://polygraph.so/api/mcp",
      "enabled": true
    }
  }
}

{
  "mcpServers": {
    "litmus": {
      "type": "http",
      "url": "https://polygraph.so/api/mcp"
    }
  },
  "deeplink": "cursor://anysphere.cursor-deeplink/mcp/install?name=litmus&config=eyJ0eXBlIjoiaHR0cCIsInVybCI6Imh0dHBzOi8vcG9seWdyYXBoLnNvL2FwaS9tY3AifQ%3D%3D"
}

{
  "servers": {
    "litmus": {
      "type": "http",
      "url": "https://polygraph.so/api/mcp"
    }
  }
}

{
  "mcpServers": {
    "litmus": {
      "httpUrl": "https://polygraph.so/api/mcp"
    }
  }
}

extensions:
  "litmus":
    enabled: true
    name: "litmus"
    type: streamable_http
    uri: "https://polygraph.so/api/mcp"
    timeout: 300

Quality 84 / 100good

protocol75 · weight 25

warn
protocol.modernnewest supported version is 2025-11-25; 2026-07-28 not supported, older versions are deprecated until 2027-07-28
n/a
protocol.statelessonly applies to 2026-07-28 servers
pass
protocol.transportstreamable HTTP
n/a
protocol.list_ttlonly applies to 2026-07-28 servers

authorizationn/a · weight 15

n/a
auth.prm, auth.as_metadata, auth.cimdno remote uses OAuth
n/a
auth.secret_in_urlno templated URL

tool hygiene93 · weight 30

pass
tools.descriptionsevery tool has a description
pass
tools.description_lengthdescriptions are concise
pass
tools.schemasevery tool has an object input schema
pass
tools.annotations3 of 3 tools declare readOnlyHint or destructiveHint
warn
tools.directory_hints1 of 3 tools declare all four hints; missing: check_server (destructiveHint, idempotentHint); list_servers (destructiveHint, idempotentHint)
pass
tools.token_costabout 574 tokens to load every tool
pass
tools.api_dumptools are not a one-to-one API dump

stability100 · weight 15

pass
stability.changesno tool changes in 30 days
pass
stability.rug_pullno tool changed its meaning under the same name

dependencies67 · weight 15

pass
deps.known_vulnsno known advisory in 136 resolved packages
fail
deps.mcp_sdk_version@modelcontextprotocol/sdk 1.30.1 has 1 known advisory (GHSA-6qxp-vccf-f47h); update @modelcontextprotocol/sdk to 1.31.0 or later
pass
deps.resolvable@polygraphso/[email protected] resolved: 136 packages

3 tools, about 574 tokens to load them all · tool set 90df4c2b4653 · checked 2026-10-19 15:48 UTC

Tool changes

No tool definition changes recorded. A server's first observation is its baseline; later probes record what changes.

Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed. How it is computed.

Trust 90 / 100

provenance90

liveness100

freshness65

hygiene100

+repository +namespace-matches-repo +website +reachable +uptime-100% ~updated-91d-ago

Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed. How it is computed.

Dependencies

@polygraphso/[email protected] npm135 dependencies, resolved · MCP SDK @modelcontextprotocol/sdk 1.30.1 · advisories checked 2026-10-19

advisory	severity	package	fixed in
GHSA-6qxp-vccf-f47hMCP TypeScript SDK: OAuth client could send credentials to an authorization server chosen by the MCP server	high	`@modelcontextprotocol/[email protected]`MCP SDK, direct	fixed in `1.31.0`

Dependency graphs from deps.dev; advisories from OSV.dev, including the GitHub Advisory Database and the PyPI Advisory Database; all CC BY 4.0. The graph is what a clean install of this version resolves today; nothing was installed or run. How it is checked.

Endpoints

remote	auth	reachable	uptime 30d	p50	protocol	last ok
`https://polygraph.so/api/mcp` streamable-http	none	yes	100%	377 ms	2025-11-25	2026-10-19

package	registry	version	runtime	secrets
`@polygraphso/litmus`	npm	0.36.0	–

Tools (3)

`check_server`read-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_servers`read-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_grade`	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>.

Schemas: list_tools.

Similar MCP servers

Official server.json

{
  "name": "io.github.polygraphso/litmus",
  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json",
  "remotes": [
    {
      "url": "https://polygraph.so/api/mcp",
      "type": "streamable-http"
    }
  ],
  "version": "0.36.0",
  "packages": [
    {
      "version": "0.36.0",
      "transport": {
        "type": "stdio"
      },
      "identifier": "@polygraphso/litmus",
      "registryType": "npm",
      "registryBaseUrl": "https://registry.npmjs.org",
      "packageArguments": [
        {
          "type": "positional",
          "value": "polygraphso-litmus-mcp"
        }
      ],
      "environmentVariables": [
        {
          "name": "POLYGRAPH_API_URL",
          "default": "https://polygraph.so",
          "description": "Base URL for published-grade lookups (check_server, list_servers, request_grade) and attestation resolution."
        },
        {
          "name": "NEXT_PUBLIC_POLYGRAPH_NETWORK",
          "default": "base",
          "description": "Which network to read attestations from: 'base' (mainnet, default) or 'base-sepolia' (testnet)."
        }
      ]
    }
  ],
  "repository": {
    "url": "https://github.com/polygraphso/litmus",
    "source": "github"
  },
  "websiteUrl": "https://polygraph.so",
  "description": "Grade MCP servers A to F with the open behavioral litmus. npm: full toolset; hosted: lookups only."
}