Claude Code plugin - CoreWeave Docs

The Weave plugin for Claude Code automatically traces every Claude Code session and sends the structured data to Agent Lens. The plugin logs every turn, tool call, and subagent with no code changes required. Use these traces to debug sessions, audit tool usage, and monitor cost and latency across runs. This guide walks you through installing the plugin, viewing your Claude Code traces in Agent Lens, configuring the plugin, and managing its lifecycle.

This is a Weights & Biases Weave plugin. A CoreWeave Forge version isn’t available yet. Traces the plugin sends appear in Agent Lens, because Agent Lens and Weave share the same trace data.

This plugin sends Claude Code session data to Agent Lens. That data can include user prompts, Claude responses, tool inputs and outputs, file contents read by Claude Code tools, shell commands and output, and fetched URLs and page content.PII scrubbing and sensitive-data redaction aren’t implemented. If you can’t send this data to Agent Lens under your security or compliance requirements, don’t install this plugin.

Prerequisites

Node.js v18 or later (includes npm).
Claude Code installed and authenticated.
A CoreWeave Forge account and API key set as a WANDB_API_KEY environment variable.
An Agent Lens project ([YOUR-TEAM]/[YOUR-PROJECT]) to receive traces.

Install the plugin

Install the CLI, run the installer to register the plugin with Claude Code, then start a Claude Code session to begin tracing.

Install the CLI

npm install -g weave-claude-code

Run the installer

weave-claude-code install

The installer does the following:

Creates ~/.weave-claude-code/settings.json.
Registers the plugin in Claude Code.
Prompts for your Agent Lens project ([YOUR-TEAM]/[YOUR-PROJECT]) and Forge API key if they aren’t already set.

To skip prompts in CI, bootstrap scripts, or other automated systems, set environment variables before running:

WEAVE_PROJECT=[YOUR-TEAM]/[YOUR-PROJECT] \
WANDB_API_KEY=[YOUR-API-KEY] \
weave-claude-code install --non-interactive

In non-interactive mode, the installer still creates the config file and registers the plugin. It uses WEAVE_PROJECT and WANDB_API_KEY from the environment and warns if either is missing.

Start Claude Code

claude

The plugin traces sessions automatically from this point. Run a prompt or two, then open your Agent Lens project to see the traces appear.

View Claude Code traces in Agent Lens

After running at least one Claude Code session, open your project in the Agent Lens UI:

Navigate to CoreWeave Forge, select Agent Lens from the product menu, and then select your project in the project selector at the top of the side menu.
In the side menu, select Conversations.
Select the Conversations tab to view all agent conversations saved for your project.
Select a conversation to inspect the full conversation tree.

For more information about the Conversation tab, see View agent activity. Each user prompt produces one OTEL trace that follows the GenAI semantic conventions. The trace shows a full turn hierarchy:

invoke_agent claude-code               (Root, one trace per user prompt.)
├─ chat <model>                        (Each LLM call within the turn.)
├─ execute_tool <tool_name>            (Each tool call such as Read, Bash, Grep.)
└─ invoke_agent <subagent_type>        (Subagent dispatched through the Agent tool.)
   ├─ chat <model>
   └─ execute_tool <tool_name>

The root invoke_agent claude-code span uses the top-level agent name, which defaults to claude-code. You can change it with the agent_name setting or the WEAVE_AGENT_NAME environment variable (see Configure the plugin). Subagents keep their own type names. Multi-turn conversations are linked server-side by conversation ID, so you can follow a conversation across multiple traces. Each span includes token usage, model name, tool inputs and outputs, timing, and the textual content of prompts and responses. For more information about traced data, see What Gets Traced in GitHub.

Configure the plugin

Use the weave-claude-code config commands to view or update plugin settings after installation:

# Show all current settings.
weave-claude-code config show

# Set your Weave project.
weave-claude-code config set weave_project [YOUR-TEAM]/[YOUR-PROJECT]

# Set your Forge API key.
weave-claude-code config set wandb_api_key [YOUR-API-KEY]

# (Optional) Customize the agent name shown in the Conversations tabs.
weave-claude-code config set agent_name [YOUR-AGENT-NAME]

By default, conversations appear under the agent name claude-code in the Conversations tab. Set agent_name to use a different name, for example to distinguish teams or projects. The name can’t be empty, and surrounding whitespace is trimmed. Environment variables take precedence over the settings file:

export WEAVE_PROJECT=[YOUR-TEAM]/[YOUR-PROJECT]
export WANDB_API_KEY=[YOUR-API-KEY]
export WEAVE_AGENT_NAME=[YOUR-AGENT-NAME]

Agent Lens skills

After installation, three Agent Lens-specific skills are available directly inside any Claude Code session.

Skill	Command	Description
Install	`/weave:weave-install`	Walks through the installation and configuration flow interactively. Use this on a fresh machine or to diagnose a broken setup.
Status	`/weave:weave-status`	Checks the current plugin status and explains any issues. Equivalent to running `weave-claude-code status`, but Claude interprets the output and tells you what to fix.
Config	`/weave:weave-config`	Read or update plugin configuration without leaving Claude Code.

You can use the weave:weave-config skill to set Agent Lens values from within Claude Code:

/weave:weave-config set weave_project [YOUR-TEAM]/[YOUR-PROJECT]
/weave:weave-config set wandb_api_key [YOUR-API-KEY]
/weave:weave-config set agent_name [YOUR-AGENT-NAME]

Check plugin status

You can use these CLI commands to check plugin status or troubleshoot issues:

weave-claude-code status

Each line shows ✓ (OK), ✗ (action needed), or - (not yet active but not an error). If conversations aren’t appearing in Agent Lens, check the daemon log:

weave-claude-code logs

To tail the log in real time:

weave-claude-code logs --follow

The log file is also at ~/.weave-claude-code/logs/daemon.log.

Uninstall

To remove the plugin from Claude Code, run:

weave-claude-code uninstall

Pass --keep-logs to preserve the log directory.

​Prerequisites

​Install the plugin

​View Claude Code traces in Agent Lens

​Configure the plugin

​Agent Lens skills

​Check plugin status

​Uninstall

Prerequisites

Install the plugin

View Claude Code traces in Agent Lens

Configure the plugin

Agent Lens skills

Check plugin status

Uninstall