An opinionated observability UI built on Quickwit. Accepts OpenTelemetry traces and logs, stores everything in Quickwit, and provides a single unified interface for navigating your system.
Born from frustration with Grafana's approach to observability. Instead of a general-purpose dashboarding tool that supports every backend and visualization, Winnow does fewer things and does them well. One storage backend, one interface, no configuration pages.
The service map is the primary entry point. It shows your service topology with call counts, latencies, and error rates at a glance. Click any node to drill into its traces, logs, or operations.
The trace detail view shows a waterfall timeline of all spans in a trace. Select a span to see its attributes, resource metadata, and associated logs in the right panel.
The log viewer supports configurable columns, filters, sortable headers, and a time histogram. Every log with a trace ID links directly to its trace.
Winnow receives OTLP data (traces and logs) over HTTP, transforms it, and ingests it into Quickwit. The frontend provides three connected views: a service map derived from trace data, a trace explorer with span waterfall timelines, and a log viewer. Everything is linked. Click a service to see its traces, click a trace to see its logs, click a log to jump to the span that produced it.
The entire application ships as a single statically-linked binary. The frontend is embedded at build time. Point it at a Quickwit instance and go.
The backend is written in Zig. The frontend is React with TypeScript and shadcn/ui. Quickwit is the only external dependency at runtime. Nix handles all build tooling and packaging.
Build and run directly from the repository:
nix build
./result/bin/winnow
By default the server listens on port 8080 and expects Quickwit at http://localhost:7280. Configure via environment variables:
QUICKWIT_URL=http://quickwit.example.com:7280 ./result/bin/winnow
You can also run without cloning, directly from a flake reference:
nix run github:ourstudio-se/winnow
Point any OpenTelemetry SDK at the server's OTLP HTTP endpoint:
export OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:8080
The server accepts POST /v1/traces and POST /v1/logs in OTLP protobuf format.
Configuration is resolved in order: defaults < KDL config file < environment variables.
Config file (optional):
quickwit url="http://localhost:7280"
traces index="winnow-traces-v0_1" retention="90 days"
logs index="winnow-logs-v0_1" retention="30 days"Pass with --config:
./result/bin/winnow --config /path/to/winnow.kdl
If no --config is given, the server looks for ./winnow.kdl in the working directory. If no file is found, bare defaults are used.
Serve section (optional):
The serve block controls which components run and on which ports. By default (no serve block), both the collector and API run on port 8080.
// Split collector and API onto separate ports
serve {
collector port=4318
api port=8080
}This is useful for production deployments where you want to scale the collector (high-throughput ingest) and API (user-facing queries) independently as separate processes.
// Collector-only instance
serve {
collector port=4318
}
// API-only instance
serve {
api port=8080
}
// Both on same port (equivalent to the default)
serve {
collector
api
}When a component is disabled, its routes return 404. A serve block with no children is an error.
Environment variables (override config file values):
QUICKWIT_URL Quickwit base URL (default: http://localhost:7280)
WINNOW_TRACES_INDEX Quickwit index for traces (default: winnow-traces-v0_1)
WINNOW_LOGS_INDEX Quickwit index for logs (default: winnow-logs-v0_1)
Startup behavior:
- If an index doesn't exist, the server creates it (with retention policy if configured).
- If an index already exists, the server validates its schema against the expected field mappings. On a mismatch (wrong field type, missing field, wrong tokenizer) the server exits with an error. Retention mismatches produce a warning but don't prevent startup.
Everything is managed by Nix. Enter the dev shell:
nix develop
This provides Zig, Node.js, pnpm, protoc, and all other tools needed for development.
Inside the dev shell:
cd backend
zig build gen-proto # generate Zig code from .proto files
zig build # compile the server
zig build run # compile and run
zig build test # run tests
The frontend uses Vite with a dev proxy. In a separate terminal:
cd frontend
pnpm install
pnpm dev
This starts Vite on port 5173 and proxies /api and /v1 requests to the backend on port 8080. During development you work against the Vite dev server and iterate on frontend and backend independently.
To test the production build locally without going through nix build:
cd frontend && pnpm build && cd ..
cd backend
ln -sfn ../../frontend/dist src/frontend-dist
bash ../scripts/embed-frontend.sh src/frontend-dist src/static_assets.zig
zig build run
Then visit http://localhost:8080.
packages.default Single binary with embedded frontend
packages.frontend Frontend dist built via pnpm
devShells.default Development environment with all tools
checks.integration NixOS VM integration test (Linux only)
A docker-compose.yml is provided for running Quickwit locally. The dev shell sets QUICKWIT_URL=http://localhost:7290 (port 7290 to avoid collisions). A data generator is available as generate-data inside the dev shell.
backend/ Zig source code and build files
backend/proto/ Vendored OTLP .proto definitions
backend/src/ Server source (main.zig, api.zig, ingest.zig, etc.)
frontend/ React/TypeScript frontend
scripts/ Build and dev tooling scripts
tests/ NixOS VM integration tests
docs/ Architecture docs, roadmap, and TODO
TBD