Skip to content
verify mcp Beta VerifyMCP is currently in beta. If you notice any issues, get in touch and we’ll put it right.

Prolog Reasoner

PYPI · PROLOG-REASONER · SCANNED SEP 21

SWI-Prolog as a logic calculator for LLMs

Available components

0 this week 63 Trust /100
Trust breakdown (7 categories)

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. How we score → Why this is hard to score →

Supply Chain Security50
  • Malware scan not yet available for this package.Unverified
  • No known CVEs affecting this package version or its production dependencies.Pass
  • Runs hatchling.build at install time, a recognised native-build step with no shell scripting around it. View diagnostics → Pass
  • 1 of 15 dependencies flagged as unhealthy. View diagnostics → Partial
Provenance & Transparency35
  • Source repository is publicly reachable at the declared URL. View diagnostics → Pass
  • Provenance check failed: no build-provenance attestation is published. See how to fix → View diagnostics → Fail
  • License check failed: the license (MIT License) isn't a recognized OSI-approved license. See how to fix → Fail
  • Actively maintained (last published 142 days ago).Pass
  • Publishes a security disclosure policy (SECURITY.md).Pass
Schema Quality & AI Usability74
  • AI-judged instruction clarity (good).Pass
  • Tool/resource definitions use about 418 tokens (~83/item across 5 items; 5 tools + 0 resources), lean.Pass
  • Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management90
  • Stability observed for 27 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage87
  • 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
  • 56% of tool parameters carry a description.Partial
  • Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Tool Safety75
  • No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
  • 0 of 2 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation; "execute_prolog" implies "execute" and declares no destructiveHint at all, which the MCP spec reads as destructive by default. See how to fix → Fail
  • An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
  • Implements a current MCP spec version (2026-07-28).Pass
Install

How do I install the Prolog Reasoner MCP server?

Prolog Reasoner runs locally as a PyPI package, launched with uvx prolog-reasoner. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

pypi · prolog-reasoner

# add to Claude Code
claude mcp add rikarazome-prolog-reasoner -- uvx prolog-reasoner
// .cursor/mcp.json
{
  "mcpServers": {
    "rikarazome-prolog-reasoner": {
      "command": "uvx",
      "args": [
        "prolog-reasoner"
      ]
    }
  }
}
// .vscode/mcp.json
{
  "servers": {
    "rikarazome-prolog-reasoner": {
      "command": "uvx",
      "args": [
        "prolog-reasoner"
      ]
    }
  }
}
# add to Codex CLI
codex mcp add rikarazome-prolog-reasoner -- uvx prolog-reasoner
// opencode.json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "rikarazome-prolog-reasoner": {
      "type": "local",
      "command": [
        "uvx",
        "prolog-reasoner"
      ],
      "enabled": true
    }
  }
}
# add to OpenClaw
openclaw mcp add rikarazome-prolog-reasoner --command uvx --arg prolog-reasoner
# ~/.hermes/config.yaml
mcp_servers:
  rikarazome-prolog-reasoner:
    command: "uvx"
    args: ["prolog-reasoner"]
// ~/.netclaw/config/netclaw.json
{
  "McpServers": {
    "rikarazome-prolog-reasoner": {
      "Transport": "stdio",
      "Command": "uvx",
      "Arguments": [
        "prolog-reasoner"
      ]
    }
  }
}
# add to Vellum
assistant mcp add rikarazome-prolog-reasoner -t stdio -c uvx -a prolog-reasoner
// mcp.json
{
  "mcpServers": {
    "rikarazome-prolog-reasoner": {
      "command": "uvx",
      "args": [
        "prolog-reasoner"
      ]
    }
  }
}
Changelog

Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.

  • 20 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 83 to 87. That category is still filling its 30-day observation window: 25 days of observed history at the previous scan, 26 at this one. The score rises as the window fills, whether or not the server changes.

  • 18 Sept 26 −3
    • Stability: pass → 0.80 functional
  • 17 Sept 26 +1
    • Stability: 0.97 → pass security
  • 15 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 90 to 93. That category is still filling its 30-day observation window: 27 days of observed history at the previous scan, 28 at this one. The score rises as the window fills, whether or not the server changes.

  • 13 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 83 to 87. That category is still filling its 30-day observation window: 25 days of observed history at the previous scan, 26 at this one. The score rises as the window fills, whether or not the server changes.

  • 12 Sept 26 −3
    • Stability: pass → 0.83 functional
  • 11 Sept 26 +1
    • Stability: 0.97 → pass security
  • 9 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 90 to 93. That category is still filling its 30-day observation window: 27 days of observed history at the previous scan, 28 at this one. The score rises as the window fills, whether or not the server changes.

Diagnostics

Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.

Captured 21 Sept 2026 · Analysed pypi/prolog-reasoner@0.2.1

Provenance No attestation

The registry publishes no build provenance for this version, so there is nothing to verify.

Result No attestation
Ecosystem pypi

Background: How many MCP packages publish verified provenance →

Install scripts 1 script
Hook Tier Command
build_backend allowlisted hatchling.build

Background: Why install scripts are a supply-chain risk →

Dependencies 15 packages
Packages resolved 15
Stale 1
Tree resolution Complete

Background: SBOMs and build attestations, explained →

MCP tools · 5 exposed · ~418 tokens

The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →

Tool Tokens
delete_rule_base ~24

Delete a saved rule base by name.

NameTypeReqDescription
namestringyes

Structured output declared, but exposes no named fields.

No examples provided.

execute_prolog ~197

Execute Prolog code and return reasoning results. Write Prolog facts and rules, then run a query against them. Supports CLP(FD) constraints, negation-as-failure, and all standard SWI-Prolog features.

NameTypeReqDescription
max_resultsintegerMaximum number of results (prevents infinite loops).
prolog_codestringyesProlog code (facts and rules).
querystringyesProlog query to execute (e.g. "mortal(X)").
rule_basesNames of previously saved rule bases to include. Rules are prepended to ``prolog_code`` in the specified order. Use this for domain-specific rules (e.g. game mechanics, legal rules) that should be re…
tracebooleanWhen True, include structured proof trees per solution in metadata.proof_trace. Adds meta-interpreter overhead; opt-in.

Structured output declared, but exposes no named fields.

No examples provided.

get_rule_base ~27

Retrieve the Prolog source of a saved rule base.

NameTypeReqDescription
namestringyes

Structured output declared, but exposes no named fields.

No examples provided.

list_rule_bases ~83

List all saved rule bases with description and tags. Returns ``{"rule_bases": [{"name": str, "description": str, "tags": list[str]}, ...]}`` sorted by name. Metadata is extracted from the leading ``% description:`` / ``% tags:`` comments of each rule base file (see §4.10).

Input schema present but exposes no named parameters.

Structured output declared, but exposes no named fields.

No examples provided.

save_rule_base ~87

Save a named rule base containing Prolog rules that can be reused across ``execute_prolog`` calls. Use this for stable, reusable knowledge (e.g. ``piece_moves`` for chess piece movement rules). For one-time facts, include them directly in ``prolog_code`` instead.

NameTypeReqDescription
contentstringyes
namestringyes

Structured output declared, but exposes no named fields.

No examples provided.

Common questions

What is the Prolog Reasoner MCP server?

Prolog Reasoner is an MCP server listed in the public MCP registry as io.github.rikarazome/prolog-reasoner. SWI-Prolog as a logic calculator for LLMs. This page covers its PyPI package (prolog-reasoner).

Is the Prolog Reasoner MCP server safe to use?

Prolog Reasoner scores 63 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 21 September 2026. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

What tools does the Prolog Reasoner MCP server expose?

Prolog Reasoner exposes 5 tools: execute_prolog, list_rule_bases, get_rule_base, save_rule_base, delete_rule_base. Their descriptions and schemas cost roughly 418 tokens of context every time the server is loaded.

Is the Prolog Reasoner MCP server still maintained?

Prolog Reasoner is still listed as active in the MCP registry. We last reached this channel on 21 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.