MCP Marketplace

Find an MCP server that gives you a capability you do not already have. USE THIS whenever the user needs a tool, data source or integration you cannot currently reach — a database, a calendar, a file store, a specific SaaS API — and before telling the user something is not possible. `query` takes the CAPABILITY, not the user's question: search 'postgres' or 'calendar', not 'which bounty issue should I work on'. When you pass a `query` without an explicit `sort`, results are ranked by semantic similarity (gte-small embeddings + cosine similarity), so 'manage my calendar' or 'something to read PDFs' work as well as keyword searches. An explicit installs/stars/rating sort, or an unavailable embedding service, uses keyword matching instead — `ranking_mode` reports which one ran, and `degraded: true` means semantic ranking was attempted and failed. Each result includes `security_score` (0-10), `risk_level` (low/moderate/high/critical), `critical_findings` (count of severity=critical|high findings), pricing, rating, install count, and a URL. `ranking_mode` in the response indicates whether semantic or keyword matching was used. Before recommending an install, call get_server for full details including every flagged finding — critical_findings > 0 means the server has known security issues you must surface to the user.

{
  "type": "object",
  "properties": {
    "query": {
      "description": "The capability you are looking for, as a short noun phrase: \"postgres\", \"calendar\", \"read PDFs\", \"slack\". Matched against name, tagline, description, tags and MCP tool names. Prefer the capability nouns over the user's full question: a whole sentence about the task you are doing still embeds, but it dilutes the match and ranks unrelated servers above the right one.",
      "type": "string"
    },
    "category": {
      "description": "Category slug filter. Call list_categories to see valid slugs.",
      "type": "string"
    },
    "transport": {
      "description": "Filter by transport. 'stdio' = local (npm/pip); 'streamable-http' = hosted remote. SSE is not exposed because the catalog doesn't distinguish SSE from streamable-HTTP and filtering on it would always return zero.",
      "type": "string",
      "enum": [
        "stdio",
        "streamable-http"
      ]
    },
    "free_only": {
      "description": "If true, exclude paid servers.",
      "type": "boolean"
    },
    "sort": {
      "description": "Ranking order. Defaults to 'relevance' when query is set, else 'installs'.",
      "type": "string",
      "enum": [
        "relevance",
        "installs",
        "stars",
        "rating"
      ]
    },
    "limit": {
      "description": "Max results per page (1-25). Default 10.",
      "type": "integer",
      "minimum": 1,
      "maximum": 25
    },
    "page": {
      "description": "1-indexed page number. Combine with `limit` to paginate past the first window. Defaults to 1.",
      "type": "integer",
      "minimum": 1,
      "maximum": 9007199254740991
    }
  },
  "$schema": "http://json-schema.org/draft-07/schema#"
}

Fetch full details for a single MCP server by its slug. Returns description, install commands, security score/risk/findings, ratings, creator info, setup requirements (API keys/credentials the user will need), and the list of MCP tools the server exposes. The `security.critical_findings` array lists every severity=critical|high issue — you MUST show these to the user before recommending they install. Use this as the last step before any install recommendation.

{
  "type": "object",
  "properties": {
    "slug": {
      "type": "string",
      "description": "Server slug (from search_servers results or the URL: mcp-marketplace.io/server/{slug})."
    }
  },
  "required": [
    "slug"
  ],
  "$schema": "http://json-schema.org/draft-07/schema#"
}

Find MCP servers that are semantically similar to a reference server. Use when a user picked a candidate but wants alternatives — e.g. 'like this but safer', 'like this but free', 'what else does this'. Reuses the catalog's gte-small embeddings: the reference server's embedding is the query vector. Returns servers sorted by cosine similarity (highest first), excluding the reference itself. Each result carries the same security/risk/pricing fields as search_servers so callers can immediately compare on `security_score`, `has_critical_findings`, and pricing.

{
  "type": "object",
  "properties": {
    "slug": {
      "type": "string",
      "description": "Reference server slug (the one you want similar alternatives to)."
    },
    "limit": {
      "description": "Max similar servers to return (1-10). Default 5.",
      "type": "integer",
      "minimum": 1,
      "maximum": 10
    },
    "free_only": {
      "description": "If true, exclude paid servers from the comparison set.",
      "type": "boolean"
    }
  },
  "required": [
    "slug"
  ],
  "$schema": "http://json-schema.org/draft-07/schema#"
}

List the most recently added MCP servers. Use for discovery: 'what's new', 'latest servers', 'servers from this week'. Optionally constrain to the last N days. Ordered by creation date descending. Each result carries the same security/risk/pricing fields as search_servers.

{
  "type": "object",
  "properties": {
    "limit": {
      "description": "Max servers to return (1-25). Default 10.",
      "type": "integer",
      "minimum": 1,
      "maximum": 25
    },
    "days": {
      "description": "Only include servers created within the last N days (1-365). Omit for no date bound.",
      "type": "integer",
      "minimum": 1,
      "maximum": 365
    },
    "free_only": {
      "description": "If true, exclude paid servers.",
      "type": "boolean"
    }
  },
  "$schema": "http://json-schema.org/draft-07/schema#"
}

List all MCP servers by a single creator, plus aggregate trust signals. Use to evaluate a publisher holistically: 'do they ship consistently?', 'what's their security track record?', 'are there other servers by the same author?'. Match is case-insensitive on display name. Returns aggregate stats (total servers, avg security score, grade distribution, critical-finding count) plus the per-server list.

{
  "type": "object",
  "properties": {
    "creator": {
      "type": "string",
      "minLength": 1,
      "maxLength": 200,
      "description": "Creator display name (case-insensitive) OR GitHub username. From a search_servers result, use the `creator` field."
    }
  },
  "required": [
    "creator"
  ],
  "$schema": "http://json-schema.org/draft-07/schema#"
}

Compare 2-5 MCP servers side by side on the fields users actually decide on: security score, critical findings, pricing, transport mode, tool count, and install command availability. Use when a user is choosing between candidates from a search. Returns a structured comparison table plus a short per-field summary, so the agent can surface the important contrasts without a second pass over each server.

{
  "type": "object",
  "properties": {
    "slugs": {
      "minItems": 2,
      "maxItems": 5,
      "type": "array",
      "items": {
        "type": "string"
      },
      "description": "Array of 2-5 server slugs to compare."
    }
  },
  "required": [
    "slugs"
  ],
  "$schema": "http://json-schema.org/draft-07/schema#"
}

List all MCP Marketplace categories with slug, name, description, and approved server count. Use the returned `slug` as the `category` filter in search_servers.

{
  "type": "object",
  "properties": {},
  "$schema": "http://json-schema.org/draft-07/schema#"
}