Trace Claude Code

Claude Code is one of the most impressive and useful AI coding tools to date. Claude code emits events for monitoring and observability. LangSmith can collect and display these events to give you a full detailed log on what Claude Code does under the hood.

Quick Start

You can integrate LangSmith tracing with Claude Code by setting the following environment variables in the environment in which you run Claude Code.

# Enables Claude Code to emit OTEL events
export CLAUDE_CODE_ENABLE_TELEMETRY=1

# Sets the output format to use Open Telemetry Protocol
export OTEL_LOGS_EXPORTER=otlp

# LangSmith ingests JSON format events
export OTEL_EXPORTER_OTLP_LOGS_PROTOCOL=http/json

# Claude Code Logs are translated to Spans by LangSmith
export OTEL_EXPORTER_OTLP_LOGS_ENDPOINT=https://api.smith.langchain.com/otel/v1/claude_code

# Pass your API key and desired tracing project through headers
export OTEL_EXPORTER_OTLP_HEADERS="x-api-key=<api-key>,Langsmith-Project=<project-name>"

# Set this to true in order to log the input user prompts
export OTEL_LOG_USER_PROMPTS=1

# Once these are set, start Claude Code, and events will be traced to LangSmith
claude

Claude Code emits open telemetry standard events for monitoring usage, but this does not include the actual prompts and messages that go to the LLM.

If you’re self-hosting LangSmith, replace the base endpoint with your LangSmith api endpoint and append /api/v1. For example: OTEL_EXPORTER_OTLP_LOGS_ENDPOINT=https://ai-company.com/api/v1/otel/v1/claude_code

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