ToolHive Registry Catalog is Stacklok's open catalog of MCP servers and skills that bounds each skill's tools via an allowedTools array — Apache-2.0.
Yes, ToolHive Registry Catalog is open source under the Apache-2.0 license.
ToolHive Registry Catalog is free to use.
ToolHive's catalog is a working example of a registry that maintains **twin catalog streams**: servers for executable MCP components and skills for reusable prompt workflows.
Each registered skill pairs a skill.json config with an adjacent SKILL.md payload. The config declares ownership namespace, semantic version, license, and an **allowedTools** array listing the exact tool names the skill may invoke. Restricting tool access inside the skill definition prevents agent privilege escalation and keeps execution bounded within declared parameters.
This registry borrows the twin-stream idea: tool entries describe executables, while a bundled Agent Skill (consume-registry) describes how to *use* the registry itself, with a bounded allowedTools.