How do I install the prolog reasoner mcp server?

Use a recorded configuration for your client, replace example credential values and paths, and verify the documented runtime. Restart or reconnect the client, then inspect the available tools.

What credentials does it need?

It reads `LLM_API_KEY`, `SWIPL_PATH`, `PROLOG_REASONER_LLM_API_KEY` from the environment. Store these in your client's env block or a secrets manager — never commit them to a repository — and grant the narrowest scope that still covers your use case.

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Prolog Reasoner MCP Server

SWI-Prolog as a "logic calculator" for LLMs — available as an MCP server and a Python library. Eliminate the black box from LLM logical reasoning.

Local serverstdioPython

What is the Prolog Reasoner MCP Server?

SWI-Prolog as a "logic calculator" for LLMs — available as an MCP server and a Python library. Eliminate the black box from LLM logical reasoning.

What it actually does

Prolog handles the combinatorial work LLMs are weak on — constraint satisfaction, multi-step inference, exhaustive search
The reasoning exists as code you can read, re-run, and debug. When it goes wrong, you see the exact Prolog that failed and why

Configuration

Python ≥ 3.10 - SWI-Prolog installed and on PATH (≥ 9.0) - API key for OpenAI or Anthropic — only for library mode, not for the MCP server

More MCP options

Compare MCP servers by category, or browse hosted MCP servers if you prefer an endpoint over a local process.

Maintainer setup documentation.

Recorded tools

Check the linked publisher documentation and your connected client's tool list. Names and availability can vary with the server version and account permissions.

Tool	What it does
prolog_code	Prolog facts and rules (string)
query	Prolog query to run, e.g. "mortal(X)" (string)
rule_bases	optional list of saved rule base names to prepend to prolog_code (in order). Use this to reuse stable domain rules across calls without re-sending them
max_results	cap the number of solutions returned (default 100)
trace	when True, attach a structured proof tree per solution to metadata.proof_trace. Opt-in sub-feature; has performance overhead and does not support CLP(FD), highe

How to install the Prolog Reasoner MCP Server

{
  "mcpServers": {
    "prolog-reasoner": {
      "command": "uvx",
      "args": [
        "prolog-reasoner"
      ]
    }
  }
}

From the project documentation. Replace placeholders and example paths before connecting.

Configuration

Python ≥ 3.10 - SWI-Prolog installed and on PATH (≥ 9.0) - API key for OpenAI or Anthropic — only for library mode, not for the MCP server

Example prompts to try

“Use Prolog Reasoner to Results.”

Frequently asked questions

SWI-Prolog as a "logic calculator" for LLMs — available as an MCP server and a Python library. Eliminate the black box from LLM logical reasoning. Confirm the tools offered by your installed version in the connected client. Tool availability and permissions depend on the server and account configuration.