Warnly
Warnly is a free, open-source exception monitoring platform for development teams.
What Warnly is
Warnly is a free, open-source exception monitoring platform for development teams. It is self-hosted, with Docker, Kubernetes, or bare-metal deployment, keeping stored error information on the team’s infrastructure according to its maker. Warnly receives events through an HTTP API and supports the Sentry envelope format for compatibility with Sentry clients. Related events are grouped into issues using fingerprints and comparisons of error characteristics, stack traces, messages, and context. Event records may include messages, stack traces, environment and release details, user and device context, timestamps, and unique identifiers. Each project has its own API key, and teams or users can receive project access. Sign-in supports local accounts and external providers such as OIDC. The documented setup uses MySQL for primary data and ClickHouse for analytics and event storage, with optional OpenTelemetry tracing and a Prometheus metrics endpoint. The quickstart recommends Docker and Docker Compose; source builds require Go 1.25 or later, MySQL 8.0-compatible storage, and ClickHouse 24 or later. Release tracking is supported, while frontend monitoring is not.
Good
- Self-hosted deployment preserves infrastructure control
- Sentry envelope compatibility via HTTP API
- Groups related events into issues
- Project keys and role assignments manage access
- Free with no premium features or usage limits
Watch out
- Frontend monitoring is not implemented
- Requires Docker, databases, and deployment administration
- Source builds require Go 1.25 or later
Who it suits
Warnly suits development teams that want open-source exception monitoring on infrastructure they control. It is aimed at teams able to operate the listed self-hosted requirements.
Verdict
Warnly provides self-hosted exception monitoring with event grouping, project access controls, and Sentry-compatible ingestion. Its zero-cost, open-source plan has no stated usage limits, but teams must supply and maintain the required infrastructure.
Plans and prices
From Warnly's own pricing page, checked 9 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Free and open source | Free | No premium features or usage limits · self-hosted |
The facts
Each one read from Warnly's own pages, with the date it was checked.
What it does
- Authentication
- Users can authenticate with local accounts or external providers such as OIDC.checked 9 Oct 2026
- Data control
- The maker says self-hosting keeps data on your infrastructure and gives you control over sensitive error information.checked 9 Oct 2026
- Error grouping
- Warnly groups similar error events into issues using fingerprints and similarity matching across error characteristics, stack traces, messages, and context.checked 9 Oct 2026
- Event details
- Events can include an error message and stack trace, environment and release information, user and device context, timestamps, and unique identifiers.checked 9 Oct 2026
- Integrations and infrastructure
- The documented setup uses MySQL for primary data storage and ClickHouse for analytics and event storage.checked 9 Oct 2026
- Limits and roadmap
- The repository roadmap marks mobile and frontend exception monitoring, swappable storage, and SLO and flexible alerting rules as not implemented.checked 9 Oct 2026
- Observability
- The server configuration supports OpenTelemetry tracing and an optional Prometheus metrics endpoint.checked 9 Oct 2026
- Product
- Warnly is an open-source exception monitoring platform designed for development teams.checked 9 Oct 2026
- Project access
- Projects have their own API keys, and teams and users can be assigned to projects to manage access to issues.checked 9 Oct 2026
- Requirements
- The quickstart lists Docker and Docker Compose as recommended, Go 1.25 or later for building from source, MySQL 8.0 or compatible, and ClickHouse 24 or later.checked 9 Oct 2026
- Security and compliance
- The maker describes Warnly as self-hosted and says data stays on your infrastructure; the opened pages did not state a compliance certification.checked 9 Oct 2026
- Self-hosting
- Warnly is designed to run on your infrastructure, with Docker, Kubernetes, or bare-metal deployment listed on its site.checked 9 Oct 2026
- Sentry compatibility
- Warnly accepts error events through an HTTP API and supports the Sentry envelope format for compatibility with Sentry clients.checked 9 Oct 2026
- Support and community
- The site links to GitHub for contributions and community, and to online documentation for setup guidance.checked 9 Oct 2026
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