AIREITERA Claude Code mod can add a live dashboard, intercept a shell command, or change what the model sees. Anthropic’s official announcement says mods are TypeScript extensions distributed as plugins, with the same machine access as Claude Code, while the API remains early access.
Start with the trust boundary, not the install command
Claude Code mods are small TypeScript functions packaged inside Claude Code plugins. A mod can observe an event, rewrite it before normal behavior runs, or answer it directly. Anthropic’s examples include context tracking, command-impact previews, edit replay, and follow-up prompt suggestions.
Mods are not sandboxed. A third-party mod should therefore be treated as installed code, not as a harmless theme or prompt file.
“Mods run with the same access to your machine as Claude Code itself.” — PJFP’s October 1, 2026 guide
A real-user scan of 31 mods tracked whether extensions could execute commands, access the network, or observe prompts and tool calls (u/wh4avy). Inspect each mod’s reach before installation.
What Claude Code mods actually change
A mod lives in a plugin’s hooks module and exports a register function. The function registers typed handlers for events such as tool.call, turn.start, turn.complete, command.run, and ui.render, as described in the community learning reference.
The three operating modes are:
- Observe: inspect an event, call
next(e), and leave the result unchanged. - Rewrite: modify the event before forwarding it, such as adding a guardrail to a command.
- Answer: return a result directly, for example denying a tool call without sending it onward.
The official showcase makes these capabilities concrete. Token Weather displays context usage; Blast Radius shows that rm -rf build would affect 9 files and 1.1 MB before offering Proceed or Cancel; Replay Theater presents a five-step sequence of edits across three files.
Mod vs plugin, classic hook, MCP server, and skill
The terms overlap, but they answer different extension needs.
| Mechanism | Best understood as | Main job | Key limitation |
|---|---|---|---|
| Mod | A plugin using TypeScript function hooks | Intercept engine events and draw UI | Early access; not sandboxed |
| Plugin | A package containing extensions | Bundle skills, agents, hooks, MCP servers, or mods | A plugin does not automatically have mod behavior |
| Classic hook | A configured lifecycle handler | Run a shell command, HTTP endpoint, prompt, or subagent at an event | Less direct typed control; often relies on handler output or exit codes |
| MCP server | An external tool or data connection | Give Claude access to an issue tracker, database, or API | Not an engine-event interception layer |
| Skill / slash command | Instructions loaded for a procedure | Teach Claude a repeatable workflow | Does not directly control tool execution or UI rendering |
Every mod is a plugin, but not every plugin is a mod. Choose a classic hook when an external command is enough, MCP for external tools or data, and a mod when you need in-process event control or persistent UI.
Install a mod without widening access by accident
Anthropic says mods can be installed through the Claude directory or /plugin, and can target the CLI, desktop app, or both. Check the plugin’s current README and official documentation for the exact command supported by your Claude Code version.
A typical marketplace flow looks like this:
/plugin marketplace add your-org/my-mods
/plugin install token-weather@my-mods
/reload-pluginsFor local development, the official announcement’s workflow supports creating or loading a plugin in the current session. A local directory can be loaded with:
claude --plugin-dir ./token-weatherKeep the plugin source in version control, pin the approved version, and remove it if the publisher changes its behavior without a reviewable release.
A minimal function-hook shape
A small TypeScript observer can look like this:
export function register(on) {
on("tool.call", { tool: "Bash" }, async ($, e, next) => {
return next(e)
})
}This forwards Bash events without changing them. A rewrite would pass a modified event to next; a denial would return a refusal instead. Do not assume the snippet is a permanent contract: the function-hook API may change with Claude Code releases.
Review a mod by its reachable surface
The Awesome Claude Code Mods scanner reported, in its September 17, 2026 snapshot, 72 mods: 30 ran host processes, 11 wrote files, 24 read files, 14 reached the network, 24 saw every tool call, and 23 saw every prompt.
Its reach levels are L0, draws and remembers; L1, reads; L2, writes files or runs processes; and L3, reaches the network. These levels describe footprint, not quality. The question is whether each capability is necessary, visible, and reviewable.
Before enabling a mod, check:
- Which events does it hook: prompts, tool calls, commands, or UI only?
- Can it write files, run processes, call the network, or spawn agents?
- Does it inspect secrets before redacting them?
- Is the repository public, licensed, and maintained by an identifiable author?
- Does its README explain what data leaves the machine?
- Is there a test or validation command for your Claude Code version?
- Can you disable or remove it without leaving settings or credentials behind?
Where mods are useful—and where I would not deploy them yet
Useful first projects are narrow guardrails and visibility tools: a confirmation pane for production commands, a secret redactor, a context or cost meter, a CI-status panel, or a replayable edit view. Each has a clear event boundary and a user-visible benefit.
Do not begin with a mod that silently reroutes traffic, approves permissions automatically, or reads every prompt without a clear need. Those choices expand the trust boundary before you have tested the extension.
For a team, start with one small mod from an approved marketplace, log the approved version, test whether a later mod can bypass a deny rule, and keep a rollback path.
Claude Code mods FAQ
What is the difference between a mod and a plugin?
A mod is a plugin whose behavior uses TypeScript function hooks. A general plugin can instead package skills, agents, classic hooks, or MCP servers.
Do mods work in the CLI and desktop app?
Anthropic says mods can target the Claude Code CLI, desktop app, or both. A specific plugin’s manifest and documentation determine its actual support.
Are Claude Code mods sandboxed?
No. Anthropic says mods have the same machine access as Claude Code. Review the source and permissions before installing one.
Can Claude Code build a mod?
Anthropic says Claude Code can generate the TypeScript, install the mod, and hot-reload it into the current session. Generated code still needs source review and testing.
Do Claude Code mods cost extra?
The official announcement does not list a separate fee for mods. A mod can still call an external service or API with its own cost.
What is the safest first mod?
Choose a narrow, observable tool such as a context meter, a review pane for destructive commands, or a CI-status display. Avoid broad prompt interception or automatic permission approval until you understand its full footprint.
Install one locally with claude --plugin-dir, review its requested capabilities, and validate it before moving it into a shared marketplace.