Fulcru MCP Server

fulcru

Get named by AI search engines.

When someone asks ChatGPT "what's the best CRM for a small team", the answer names two or three products. Those get the customer. Everyone else is invisible.

fulcru finds the questions where an AI assistant names a competitor instead of you, writes the page that closes the gap, and measures what publishing it did. It runs as a CLI, an MCP server, and an agent skill, so a human or an agent can run the whole loop.

This repo is the open, self-hostable agent surface. The measurement engine is the hosted Fulcru service; everything here is a thin client that talks to it with your token.

We run it on ourselves and publish the result, whichever way it goes. Today it scores us 0 out of 34 prompts: we sell AI visibility and we score zero on our own product, with the full run and the source data.

npm install -g fulcru
export FULCRU_TOKEN=pk_...        # Settings -> Integrations at fulcru.app

Or run it in Docker, with nothing installed on the host:

docker build -t fulcru .
docker run --rm -e FULCRU_TOKEN=pk_... fulcru gaps

No secrets are baked into the image; the token is passed at run time. Verified on node:20-alpine, 2026-07-27.

The loop

$ fulcru gaps
  0%  k57jc...  best AI visibility tracker for a SaaS startup -> AI names Profound, Peec AI
  0%  k57bw...  how do I know if ChatGPT recommends my brand -> AI names Otterly AI
 33%  k57xz...  tools to track brand mentions in Perplexity -> AI names Semrush

Write the top one:  fulcru write k57jc...

$ fulcru write k57jc... > page.md     # the drafted article, grounded in what AI cites
$ fulcru publish k57jc... https://mysite.com/blog/ai-visibility-trackers
Published. Baseline: AI names you in 0% of 9 measured answers.

$ fulcru delta
    0% ->  44%  +44pts  Best AI Visibility Trackers, Compared

That last line is the whole point.

Commands

Add --json to any command for the raw payload.

Built for agents

Output is terse lines, not JSON blobs, because the caller is usually an LLM and its context is the scarce resource. fulcru gaps costs an agent about 50 tokens; the same data as raw API JSON costs about 800. fulcru write sends the Markdown to stdout and everything else to stderr, so fulcru write <id> > page.md gives a clean file.

MCP

Two ways to wire the five Fulcru tools into an agent.

Remote (hosted). Point any MCP client at the hosted endpoint with your token:

{
  "mcpServers": {
    "fulcru": {
      "url": "https://little-orca-977.convex.site/mcp",
      "headers": { "Authorization": "Bearer pk_..." }
    }
  }
}

Local (stdio). For hosts that prefer a subprocess, this package ships a stdio MCP server that proxies to the hosted endpoint:

{
  "mcpServers": {
    "fulcru": {
      "command": "npx",
      "args": ["-y", "-p", "fulcru", "fulcru-mcp"],
      "env": { "FULCRU_TOKEN": "pk_..." }
    }
  }
}

The -p is not decoration. This package ships two commands, and without it npx runs the one named after the package, which is the CLI: the host gets a usage screen instead of an MCP server.

Tools: fulcru_gaps, fulcru_write_page, fulcru_publish_page, fulcru_delta, fulcru_visibility.

Both speak protocol revision 2026-07-28 and the older handshake-based revisions, and pick per request from what the client sends. A client on the new revision gets server/discover, per-request _meta, and a cacheable tool list; one still sending initialize is served exactly as before. Nothing needs configuring either way.

Skill

The skills/fulcru skill runs the whole playbook using nothing but web access — audit a domain, find the gaps, write the page, re-measure — with no account and no token. Install it into an agent that supports skills:

# Claude / OpenClaw
npx skills add gsmmediaro/fulcru

# Hermes
hermes skills install gsmmediaro/fulcru

Hermes scans third-party skills before installing and prints the verdict, so you can see what you are agreeing to run. If you would rather track this repo as a source and pick up updates, tap it instead:

hermes skills tap add gsmmediaro/fulcru
hermes skills install fulcru

The CLI and MCP above are what you use when you want it measured continuously across every engine, with the before/after delta tracked for you.

Configuration

No secrets are baked into this repo. The token is read from the environment only.

Self-hosting

The skill needs nothing. The CLI and MCP need a Fulcru account for the continuous, measured loop; point FULCRU_ENDPOINT at your own instance if you run one.

A Docker image is provided:

docker build -t fulcru .
docker run --rm -e FULCRU_TOKEN=pk_... fulcru gaps

Contributing

Issues and PRs welcome. The tool logic lives in the hosted service; this repo is the CLI, the stdio MCP proxy, and the skill. If AI names a competitor instead of you, open an issue with the question — that is exactly the gap this is built to close.

If this is useful, a ⭐ genuinely helps.

License

AGPL-3.0-or-later. See LICENSE.