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Syl Guardian

MCP server · hosted · v0.2.0 · io.sylai/guardian
Online · tested 2h agoNEW · 3h agoSeen in the registry 2h ago

Causal guardrail: pass/caution/hold verdict on a causal claim before an agent acts.

Website ↗Source code ↗How to connect ↓

What it does

Syl Guardian is an MCP server, a connector that lets an AI assistant use it as a tool. It is hosted: an assistant connects to it over the internet, nothing to install.

No capability identified yet from its description.

Facts come from the Official MCP Registry, as declared by the publisher. Capabilities are matched automatically (low confidence) and are not a test of the tool.

At a glance

Hosted (remote)YES
Local installNO
Version0.2.0
PriceNot in the registry
First seen22 Oct 2026
Last checked2h ago

How to connect

As declared in the Official MCP Registry · hosted endpoint tested by Electra Index 2h ago (live check)

Hosted endpoint

  • https://guardian.sylai.io/mcp streamable-http

Required: X-API-Key (get it from the publisher)

MCP settings (Claude Desktop, Cursor and other MCP clients)

{
  "mcpServers": {
    "syl-guardian": {
      "url": "https://guardian.sylai.io/mcp",
      "headers": {
        "X-API-Key": "<your X-API-Key>"
      }
    }
  }
}

Replace the values in <angle brackets>.

Live check

Electra Index connected to the hosted endpoint 2h ago

ONLINE Syl Guardian answered an MCP connection on 22 Oct 2026 and introduced itself as Syl Guardian 1.30.0 (MCP protocol 2025-06-18).

1 tool offered to AI assistants

  • guardian_review · Sanity-check a causal claim ("cause drove effect") before acting on it. Provide exactly one of ``csv`` (CSV text) or ``data`` (list of row objects) containing columns named by ``cause`` and ``effect``. Returns a verdict -- ``pass`` (act), `

What "online" means: the server answered an MCP connection at the time of the check. It is not a guarantee of security, quality or continuous uptime. How we test: we open an MCP session and ask for the tool list, as an AI assistant would. We never run a tool and never send a key. Checked every few days. Method

Is this your server? Monitoring Pro: a check every 30 minutes and an email within the hour when it stops answering. $9.99/month.

Facts & evidence

Each fact shows where it was seen and when.
FactValueEvidenceSourceLast confirmed
Hosted endpointhttps://guardian.sylai.io/mcpDECLAREDSRC-001 Official MCP Registry2h ago
Local install (package)noDECLAREDSRC-001 Official MCP Registry2h ago
Remote access (hosted)yesDECLAREDSRC-001 Official MCP Registry2h ago
Websitehttps://sylai.io/guardianDECLAREDSRC-001 Official MCP Registry2h ago
Repositoryhttps://github.com/connor274/syl-guardian-mcpDECLAREDSRC-001 Official MCP Registry2h ago
Registry statusactiveDECLAREDSRC-001 Official MCP Registry2h ago
Version0.2.0DECLAREDSRC-001 Official MCP Registry2h ago
MCP serveryesDECLAREDSRC-001 Official MCP Registry2h ago

Change history

  • NEW22 Oct 2026
    first seen in the index

Is this page accurate?

Flag it and our robot re-checks the official source. Reports never change a score.

Questions about Syl Guardian

How do I connect Syl Guardian?

Use the hosted endpoint https://guardian.sylai.io/mcp in your assistant's MCP settings. The exact settings are in "How to connect" above, as declared in the Official MCP Registry.

Does Syl Guardian need an API key or token?

Yes. The registry entry lists a required value: X-API-Key. Get it from the publisher.

What tools does Syl Guardian offer?

When Electra Index connected on 22 Oct 2026, it listed 1 tool: guardian_review. The full list is in "Live check" above.

Is Syl Guardian online?

Yes. Its hosted endpoint answered an MCP connection from Electra Index 2h ago.