What is Hub (hub.fx42.ai)?

Hub is a catalogue of MCP servers, REST APIs and open-source projects that language-model agents can use as tools, with the tools each one really exposes, and a deployer that writes the files to run the ones you pick on your own machines. It lists 45 393 entries and 365 451 tools at the catalogue snapshot of 2026-10-17.

Where do the entries come from?

MCP servers come from the official MCP registry and the Docker MCP catalog, REST APIs from APIs.guru and Google's API Discovery Service, and open-source projects from GitHub repositories by topic, reviewed before they are listed. That makes 40 317 MCP servers, 2 528 APIs and 2 548 projects at the catalogue snapshot of 2026-10-17.

How is Hub different from the official MCP registry?

The registry publishes what a server's author says about it (its name, packages and web endpoints) and checks who owns the name; it does not run servers. Hub takes those records and adds what it found by trying them: the tools each server lists, its tier, its repository's score, a scan of its source and the recipes that run it.

What does probed mean on Hub?

A probed entry is one whose tools the hub read from the server itself: its worker connects to a web service, or starts a package or a build in an isolated sandbox, and asks for the tool list. Each run records the worker, the method, the MCP protocol version, the result, the number of tools and the time, and the entry page shows the latest runs, failed ones included. 18 330 entries had a working listing at the catalogue snapshot of 2026-10-17.

What do the tiers open · remote, open · package, key · package and auth · remote mean?

A tier says how you reach an entry before you install anything. open · remote: a web service with no credentials: connect and go (22 315). open · package: an npm or PyPI package that runs locally, nothing to configure (5 763). key · package: a package that needs an API key or token in its environment (6 105). auth · remote: a web service behind a header: an API key or OAuth (5 569). other: container images, other package types and projects to build; the record says how (5 641).

Which MCP servers work without an API key?

28 078 entries need no credentials at the catalogue snapshot of 2026-10-17: the tiers open · remote and open · package. The server list filters by tier: https://hub.fx42.ai/servers?tier=remote_open and https://hub.fx42.ai/servers?tier=stdio_open.

How do I run an MCP server on my own machine with systemd?

Add it to a toolset, pick the baremetal target and download the files. Each server gets a systemd unit that runs it as an unprivileged mcp user (NoNewPrivileges, ProtectSystem=strict, PrivateTmp) and listens on 127.0.0.1: a stdio package behind a stdio-to-HTTP bridge, a container under systemd. install.sh sets them up and smoke.sh checks that each endpoint answers tools/list.

How do I run MCP servers on Kubernetes?

Pick the kubernetes target for a manifest with a Deployment and a Service per server, or helm for a chart with the same containers. A stdio package runs behind a stdio-to-HTTP bridge, so every server is an HTTP endpoint your client can reach.

Which clients does Hub write configuration for?

Claude Desktop, Claude Code, VS Code and a generic mcp.json, which Cursor and most other clients read. Every target gets them, with a toolset.yaml and a lock that pins every tool.

Does Hub see my data or my tool calls?

No. Hub hosts no servers and passes no tool calls through: the files it writes run on your machines and your agent talks to the servers directly. Credentials never enter the files; each one is left as a ${VAR} for you to fill in.

What is the repository score?

A score out of 100 for a server's GitHub repository, read nightly from GitHub: popularity 35 (stars), activity 30 (recent commits), maintenance 25 (licence, releases, closed issues) and ownership 10 (an organisation, a verified one). It ranks upkeep and is not a security audit; below 40 an entry is listed lower.

What does official mean on Hub?

An official entry is one whose publisher is proven by someone else and whose code is its own: an API in Google's directory or with its spec on the provider's own domain, a registry name whose domain matches the GitHub account of its repository, or the repository of a verified GitHub organisation. 2 664 entries are official at the catalogue snapshot of 2026-10-17.

Does Hub check the code it builds?

Yes. Before its worker builds a repository it scans that commit: the dependencies with OSV-Scanner and the code itself with GuardDog. A version with a known malicious package, or with code that looks malicious, is offered no way to run until a new version passes or an operator has looked at the findings.

Can I deploy to the cloud from Hub?

Yes. An entry page's in the cloud links open Koyeb's, Azure Container Apps' or Google Cloud Run's own deploy form, filled in, in your own account. Nothing is deployed through fx42, and no credential goes into a link: you fill them in on the provider's form.

How does a server get listed on Hub?

Publish it to the official MCP registry or the Docker MCP catalog, which the hub syncs nightly, or an OpenAPI spec to APIs.guru, synced weekly. GitHub repositories with the mcp-server topic are found as proposals and listed once their repository passes the daily triage. A signed-in GitHub user can suggest a server, an API or a project on the suggest page; the hub's daily triage or an operator decides.

How do I get an entry removed from Hub?

Ask on the removal page, linked from every entry page. Signed in with GitHub, the owner of a repository under their own account removes its entries at once; any other request (an organisation's repository, a third party's) waits for an operator.

Is there an API?

Yes, a JSON API under /api/v1, which needs a token from the hub's operators. The site itself, the converted OpenAPI specs and the cloud templates need none.

Who builds Hub?

Hub is an fx42 project (https://fx42.ai). Contact: [email protected].