Rule34 MCP server

mcp-rule34

rule34.xxx is a large image board whose posts are indexed entirely by tags, and it publishes an API for reading them. A post carries its identifier, the address of its page and of its file, its dimensions, the score its viewers gave it, its rating, and the full list of tags it was filed under. The site holds tens of millions of posts and answers a tag search with the number it matched.

This server connects a chat client to that index. You can search the posts by tags, combining required tags, alternatives and exclusions, read one post's record by its identifier, and look up how the site spells a tag before searching on it. It needs an account and an API key, which the site issues per person.

Version française

Install

Claude Code

claude mcp add rule34 --env RULE34_USER_ID=your-id --env RULE34_API_KEY=your-key -- npx -y mcp-rule34

Claude Desktop, Cursor, and any client using the standard config format

{
  "mcpServers": {
    "rule34": {
      "command": "npx",
      "args": ["-y", "mcp-rule34"],
      "env": {
        "RULE34_USER_ID": "your-id",
        "RULE34_API_KEY": "your-key"
      }
    }
  }
}

Node 24 or later is required. The two credentials are required; everything else under Configuration is optional.

With Docker

{
  "mcpServers": {
    "rule34": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e",
        "RULE34_USER_ID",
        "-e",
        "RULE34_API_KEY",
        "ghcr.io/smeet666/mcp-rule34:2.0.2"
      ]
    }
  }
}

-i keeps stdin open, which is where the protocol travels, and -t is left out because a TTY rewrites the stream. The container needs outbound HTTPS to api.rule34.xxx and rule34.xxx, and the two credentials from your environment: no volume, no port.

Bundle, without npm

Download mcp-rule34-2.0.2.mcpb from the latest release and open it. A client that supports MCP bundles installs it on its own, with no npm to run. The credentials are still set in the client's configuration.

What you can ask

• "How does the site spell that tag?"
• "Find posts tagged with those two, sorted by score."
• "Same search, leaving out monochrome."
• "Read me the record for post 1234567."
• "How many posts does that search match?"

The ordinary path runs from a tag lookup to a search: findtags gives the spelling the site uses, and searchposts takes it.

Tools

Look a tag up before searching on it. The site indexes by tag alone, and a tag it does not hold matches nothing, which reads as an empty result rather than as a misspelling.

find_tags

Finds how the site spells a tag.

Shortened. The full README is on GitHub.