OTEL Viewer

A lightweight, single-binary OpenTelemetry viewer for local development. Visualize traces, logs, and metrics from your instrumented applications — no Docker, no databases, no complex setup.

Installation

Homebrew (macOS & Linux)

brew tap mesaglio/otel-front
brew install otel-front

Docker

docker run -p 8000:8000 -p 4317:4317 -p 4318:4318 ghcr.io/mesaglio/otel-front:latest
docker run -P ghcr.io/mesaglio/otel-front:latest

Pre-built binary

Download from Releases (macOS and Linux, x86_64 & ARM64):

tar -xzf otel-front_*.tar.gz
./otel-front

Build from source

Requires Go 1.24+ and Node.js 22+.

git clone https://github.com/mesaglio/otel-front
cd otel-front
make release
./bin/otel-front

Quick Start

otel-front

Opens http://localhost:8000 automatically. Point your app's OTLP exporter at:

Protocol	Endpoint
HTTP	http://localhost:4318
gRPC	localhost:4317

# HTTP
export OTEL_EXPORTER_OTLP_ENDPOINT="http://localhost:4318"
export OTEL_EXPORTER_OTLP_PROTOCOL="http/protobuf"
export OTEL_LOGS_EXPORTER="otlp"
export OTEL_TRACES_EXPORTER="otlp"
export OTEL_METRICS_EXPORTER="otlp"

# gRPC
export OTEL_EXPORTER_OTLP_ENDPOINT="http://localhost:4317"
export OTEL_EXPORTER_OTLP_PROTOCOL="grpc"
export OTEL_LOGS_EXPORTER="otlp"
export OTEL_TRACES_EXPORTER="otlp"
export OTEL_METRICS_EXPORTER="otlp"

The UI includes a copy-paste helper for these variables.

Features

• Traces — waterfall view, flame graph, side-by-side comparison, search by operation/trace ID
• Logs — full-text search, severity/service filters, correlation with traces via trace_id
• Metrics — query builder, time series charts, aggregations (avg, sum, min, max, count)
• Single binary with embedded frontend and in-memory DuckDB — no external dependencies

CLI Options

--port             HTTP server port (default: 8000)
--otlp-http-port   OTLP HTTP receiver port (default: 4318)
--otlp-grpc-port   OTLP gRPC receiver port (default: 4317)
--debug            Enable debug logging
--no-browser       Don't open browser automatically
--version          Show version information

Development

# Backend (with live reload)
go run cmd/viewer/main.go --debug

# Frontend dev server (proxies API to backend)
cd frontend && npm install && npm run dev

# Send test data
go run scripts/send_otlp_data.go --count 20

Contributing

PRs welcome. Run make test before submitting.

License

MIT — inspired by otel-desktop-viewer.