prolog-mcp
MCP server wrapping SWI-Prolog for symbolic reasoning, enabling coding agents to assert facts and query rules deterministically.
Caution. Specific findings reduced this grade. They are listed on the page. Grades reflect the full trust pyramid: code, verification depth, and reputation. New projects cap at C until adoption is earned.
How we verified
Verified is a snapshot. Live keeps it current, and builds your track record.
⚡ Connect GitHub → continuous verification on every pushwhy connect →Who stands behind it
umuro
Source: Glama
Claim it to get a verified publisher badge, a free copy of our full audit findings, and direct contact for any high-priority issues we find. Or connect your repo for our deepest verification, Live Monitored: read-only, revoke anytime. What we access →
Install from
The grade above is for the source repository. Registries can serve a different version, so we mark the ones we were not able to read.
These names and descriptions are the publisher's own, read from the source code. We print them as written. Our assessment is the findings above, not this list.
prolog_queryExecute a Prolog goal and return all solutions as JSON
prolog_assertAssert a fact or rule into the KB. Persists to disk and survives daemon restarts. Use agent:main (default) for permanent knowledge; use session:<id> for ephemeral facts tied to the current session.
prolog_retractRetract matching facts or rules from a layer. Removes from disk and reloads — retraction survives daemon restarts.
prolog_write_fileWrite a .pl file to disk and hot-reload it. WARNING: replaces the entire file — not an append. Use for authoring multi-clause rule files (core.pl, scratch/). For individual facts use prolog_assert instead. On syntax error the file is rolled back and the server keeps running.
prolog_load_fileHot-reload an existing .pl file
prolog_list_factsList facts in the KB, optionally filtered by functor
prolog_reset_layerClear a session or scratch layer (core and agent layers are permanent)
Disclosed vulnerabilities in this server's declared npm dependencies (via OSV). Whether each is reachable depends on the installed versions.
When Vitest UI server is listening, arbitrary file can be read and executed
Vitest allows Remote Code Execution when accessing a malicious website while Vitest API server is listening
Model Context Protocol (MCP) TypeScript SDK does not enable DNS rebinding protection by default
Zod denial of service vulnerability
KB_DIRkbDir ~/.local/share/prolog-mcp Knowledge base directory; ~ is expandedPROLOG_MCP_CONFIGConfig file: prolog-mcp.json in the working directory, or ~/.config/prolog-mcp.json. Override with .SWIPL_PORTswiplPort 7474 Port for the SWI-Prolog HTTP daemonTool annotations
No tools have read-only/destructive annotations
Add readOnlyHint or destructiveHint annotations to every tool so hosts can warn users before invoking.
All four hints declared on every tool
7/7 tools missing one or more hints — prolog_query (missing: readOnlyHint, destructiveHint, idempotentHint, openWorldHint); prolog_assert (missing: readOnlyHint, destructiveHint, idempotentHint, openWorldHint); prolog_retract (missing: readOnlyHint, destructiveHint, idempotentHint, openWorldHint), +4 more. OpenAI's directory rejects tools where any of the four hints are missing or non-boolean.
For every tool, set all four hints (readOnlyHint, destructiveHint, idempotentHint, openWorldHint) to explicit true/false values that match the handler’s actual behaviour.
Tool handlers catch errors
Only 0/7 tool handlers wrap calls in try/catch (0%)
Wrap each tool handler body in try/catch and return a structured error response.
License file
No license file
Add a LICENSE file (MIT, Apache-2.0, etc.).
Tool test coverage
5/7 tools referenced in tests (71%)
Write tests that reference each tool by name so every tool has at least one test.
Production dependencies are patched
0 critical, 1 high severity in production deps — @modelcontextprotocol/sdk@1.0.0 (high), zod@3.0.0 (low)
Run npm audit fix, or upgrade the affected packages to a non-vulnerable version.
Dev dependencies
2 critical/high in dev-only deps (does not ship to users)
Upgrade dev dependencies when convenient.
Claim the listing to review these findings one by one and send us a correction where you disagree, straight to the team. Claiming also means we tell you when the grade moves, and reach you first if we find anything urgent.
[](https://m8ven.ai/mcp/umuro/prolog-mcp)?variant=verified from the URL.Vetting this one by hand? Tool Check is an MCP that scores other MCPs. Add it once and ask Claude, ChatGPT, or any MCP client to grade a server, surface CVEs, check the publisher, and suggest safer alternatives — before you install.
https://m8ven.ai/api/mcp/tool-check