Hub

The hub is a package registry for CrabTalk extensions. Install MCP servers, agents, and commands in one command. Browse available packages.

Installing a package

crabtalk pull <scope>/<package>

A package can contain any combination of MCP servers, agents, and commands. The install clones the source repo, copies the manifest, and merges resources into your config.

Uninstalling

crabtalk rm <scope>/<package>

Removes the manifest and prunes cached repos.

How it works

The hub is a Git repository at github.com/crabtalk/hub. On first install, CrabTalk shallow-clones it to ~/.crabtalk/hub/. Each package is a TOML manifest describing what it provides.

Manifest format

[package]
name = "my-package"
description = "Short description"
repository = "https://github.com/org/repo"
keywords = ["search", "mcp"]

[mcps.my-server]
command = "npx"
args = ["-y", "my-mcp-server"]
env = { API_KEY = "" }

[agents.my-agent]
description = "An agent that does useful work"
thinking = true

[commands.my-cmd]
description = "A CLI command"
crate = "my-crate-name"

Fields like model, thinking, and mcps are supported on agents:

[agents.my-agent]
description = "An agent that does useful work"
thinking = true
model = "claude-sonnet-4-20250514"
mcps = ["filesystem", "my-server"]

Setup hooks

Packages can run a setup step after install — either a shell script or an inference prompt:

[package.setup]
script = "npx playwright install chromium"

[package.setup]
prompt = "setup.md"

Skills

Skills are not declared in manifests. They are auto-discovered from SKILL.md files in the package's source repository after install. See Skills for how skill discovery works.

Publish your own

The hub is open to contributions. Add a <scope>/<name>.toml manifest and open a pull request at github.com/crabtalk/hub. Once merged, anyone can install it with crabtalk pull.

See the manifest reference for the full schema.

What's next

• Skills — how skills work
• MCP Servers — how tool servers connect
• Commands — how commands extend CrabTalk