LangWatch agent plugin

One plugin directory, installable by two ecosystems.

• Claude Code reads .claude-plugin/plugin.json and the hooks beside it.
• Any Agent Plugins 1.0 client reads the root plugin.json and the skills/ directory.

What it does

Session context capture. At the start of a session and at the end of every turn, the plugin records which repository, branch and worktree the session is working in, and posts it to LangWatch as a single log record. That is what lets a coding-agent session's traces be joined to the code it worked on.

It reports repository identity only: origin remote host, owner and name, the current branch, and the worktree name. It does not read, send or index your code. It posts nothing when the CLI is not signed in, nothing outside a git repository, and nothing when the context has not changed since the last post. It never writes to the session's output and never fails a session.

A skill. skills/langwatch teaches the agent to read traces back with the langwatch CLI: search, fetch a trace, print a coding-agent transcript, list a session's events.

The hook script (scripts/session-context.mjs) is bundled into the plugin as a single file with no dependencies. It does not call the globally installed langwatch CLI, so upgrading, downgrading or removing that CLI cannot change what an installed plugin does.

Install

In Claude Code:

claude plugin marketplace add langwatch/agent-plugin
claude plugin install langwatch@langwatch

langwatch claude sets this up for you, so you only need the commands above if you are wiring it by hand.

In an Agent Plugins client, install this directory the way that client installs portable plugins. Portable installs get the skill; hooks are a Claude Code feature and are ignored elsewhere.

Sign in

The hook posts to whichever control plane the CLI is signed in to, using the ingest key stored in ~/.langwatch/config.json. Without one, it stays quiet.

langwatch login

An OTEL_EXPORTER_OTLP_ENDPOINT (or the logs-specific variable) in the environment takes precedence over the signed-in control plane, so an existing collector keeps receiving the record.

Uninstall

claude plugin uninstall langwatch@langwatch
claude plugin marketplace remove langwatch

Where the source lives

This repository is published from langwatch/langwatch under plugins/langwatch. Open issues and pull requests there.