datalust.co

# Seq

> Seq is a self-hosted observability platform for structured logs, traces, and metrics: collect application telemetry via OpenTelemetry and a wide range of logging libraries, search and analyze it in real time, and alert on the results — all without data leaving your infrastructure.

Seq is built by Datalust. The documentation below is the best source of detailed information about installing, using, and administering Seq.

## Documentation

- [An Overview of Seq](https://datalust.co/docs/an-overview-of-seq): Seq is a real-time search and analysis server for structured application logs, traces and metrics. Its carefully designed user interface, JSON event store, and familiar query language make it an efficient platform for detecting and diagnosing issues in complex applications and microservices.
- [Getting Started](https://datalust.co/docs/getting-started): Seq is a telemetry server that runs on a central machine. Your application uses a library like Serilog, Microsoft.Extensions.Logging or OpenTelemetry to send structured events and metrics to Seq's HTTP API, which stores them and makes them searchable through Seq's web interface.
- [What's New in 2026.1?](https://datalust.co/docs/whats-new): Seq 2026.1 is another huge release, adding support for metrics. With metrics Seq can scale to previously impossible volumes.
- [Upgrading Seq](https://datalust.co/docs/upgrading): To upgrade from:
- [Getting Logs into Seq](https://datalust.co/docs/getting-logs-into-seq): Most languages and frameworks have existing logging libraries or logging APIs.
- [Logging from .NET](https://datalust.co/docs/logging-from-net): Seq has package integrations with a few popular .NET logging frameworks.
- [Serilog](https://datalust.co/docs/using-serilog): Seq has excellent support for all of Serilog's features including complex event data, enrichment and structured events. To collect traces as well as logs see SerilogTracing.
- [Microsoft.Extensions.Logging](https://datalust.co/docs/microsoft-extensions-logging): Seq fully supports the advanced structured logging provided by .NET Core and ASP.NET Core. To collect traces as well as logs see Tracing from .NET.
- [NLog](https://datalust.co/docs/using-nlog): NLog is a flexible and mature logging implementation for .NET. Since NLog 4.5, structured logging with message templates is fully supported, making Seq and NLog a powerful combination.
- [log4net](https://datalust.co/docs/using-log4net): A log4net appender is provided that writes events to Seq via HTTP.
- [OpenTelemetry .NET SDK](https://datalust.co/docs/opentelemetry-net-sdk-logs): ASP.NET Core and other .NET applications that use Microsoft.Extensions.Logging without Serilog can use the OpenTelemetry.Exporter.OpenTelemetryProtocol.Logs NuGet package to send data. To collect traces as well as logs see Tracing from .NET.
- [Logging from Node.js](https://datalust.co/docs/using-nodejs): Seq has package integrations with a few popular JavaScript logging frameworks.
- [Logging from Python](https://datalust.co/docs/using-python): Python applications can log to Seq through the Python logging API with seqlog (recommended), with pygelf and GELF, or via direct HTTP and JSON.
- [Logging from Java](https://datalust.co/docs/using-java): Java/JVM applications can log to Seq through GELF, serilogj, or via HTTP and JSON.
- [Logging from Ruby](https://datalust.co/docs/using-ruby): For Ruby applications, in addition to raw HTTP ingestion, the semlogr gem and its Seq sink can be used to send structured log events efficiently to Seq.
- [Logging from Go](https://datalust.co/docs/using-go): Seq can accept logs from Go programs via GELF or directly from Logrus with Logruseq.
- [Logging from OpenTelemetry](https://datalust.co/docs/ingestion-with-opentelemetry): OpenTelemetry is a suite of protocols, libraries, and related software built around a single model for diagnostic data. The OpenTelemetry protocol (OTLP) can be used to transfer structured logs from instrumented applications through to receivers like Seq, without the need for log parsing, adapters,…
- [Ingestion with HTTP](https://datalust.co/docs/posting-raw-events): In some situations it may be desirable to send events to Seq without using a telemetry library like Serilog or OpenTelemetry. In that case, batches of events can be sent in newline-delimited JSON format directly to Seq's HTTP API.
- [Ingestion with GELF](https://datalust.co/docs/using-gelf): GELF (Graylog Extended Log Format) is a structured log event format that's implemented for logging libraries in many programming languages. Seq can receive GELF events via TCP and UDP, and supports common features such as compression and chunking.
- [Collecting Docker Container Logs](https://datalust.co/docs/collecting-docker-container-logs): The easiest way for applications running in a Docker container to log to Seq is to use a native logging library and HTTP ingestion. Some applications, however, will choose to write plain text or JSON to STDOUT or STDERR, and have the Docker logging infrastructure route this to an appropriate log…
- [Collecting Kubernetes Logs](https://datalust.co/docs/collecting-kubernetes-logs): The ideal way for applications running in a Kubernetes cluster to log to Seq is to use a native logging library and HTTP ingestion with the Seq instance's cluster internal DNS record, like http://seq.logging.svc.cluster.local. Seq natively supports the OpenTelemetry logs protocol, so using it as a…
- [Other Log Sources](https://datalust.co/docs/seq-input-apps): Input apps are Seq Apps that extend Seq to support new protocols and queuing systems.
- [Syslog](https://datalust.co/docs/syslog): Ingest syslog RFC 5424 and RFC 3164 messages via UDP into Seq.
- [RabbitMQ](https://datalust.co/docs/using-rabbitmq): The Seq.Input.RabbitMQ input makes it possible to pull JSON-formatted events from RabbitMQ.
- [Windows Event Logs](https://datalust.co/docs/from-the-windows-event-log): The Seq.Client.EventLog application can be installed on Windows machines to forward events from the Windows Event Log.
- [PowerShell](https://datalust.co/docs/using-powershell): It can be useful to write events from Windows PowerShell in some scenarios. For this purpose a sample PowerShell module Seq is provided inline below.
- [Scripts & Automation](https://datalust.co/docs/seqcli): Events can be logged from the command-line using the Seq command-line client, seqcli.
- [Log Files](https://datalust.co/docs/importing-log-files): Applications that need to log to a local file can write them in JSON format for easy importing into Seq.
- [Application Health Checks](https://datalust.co/docs/health-checks): The Seq.Input.HealthCheck app periodically GETs an HTTP or HTTPS URL and logs various response metrics to Seq.
- [Getting Traces into Seq](https://datalust.co/docs/getting-traces-into-seq): Seq receives traces across the network from applications, infrastructure, and agents.
- [Tracing from .NET](https://datalust.co/docs/tracing-from-net): .NET has rich tracing support built into popular libraries and the platform itself. Traces can be sent to Seq using either SerilogTracing or the OpenTelemetry .NET SDK.
- [OpenTelemetry .NET SDK](https://datalust.co/docs/opentelemetry-net-sdk-traces): .NET applications can use the OpenTelemetry .NET SDK to send logs, traces and metrics to Seq. Refer to the OpenTelemetry documentation for more details.
- [SerilogTracing](https://datalust.co/docs/serilogtracing): SerilogTracing is a tracing client alternative to the OpenTelemetry SDK. It integrates Serilog with the System.Diagnostics.Activity types provided by the .NET base class library. This makes it possible to:
- [Tracing from Node.js](https://datalust.co/docs/tracing-from-nodejs): To send traces from Node.js to Seq use the OpenTelemetry JavaScript SDK and its OTLP exporter.
- [Tracing from OpenTelemetry](https://datalust.co/docs/tracing-from-opentelemetry-sdks): OpenTelemetry SDKs exist for the following programming languages:
- [Tracing from Python](https://datalust.co/docs/tracing-from-python): To send traces from Python to Seq use the OpenTelemetry Python SDK and its OTLP exporter. See the OpenTelemetry documentation for more details.
- [Ingestion with HTTP](https://datalust.co/docs/trace-ingestion-with-http): Seq's HTTP API supports sending traces directly as log events. An event that includes the @tr top-level property is part of a trace. If it additionally includes @sp and @st it is considered a span. See the corresponding logs docs for more details.
- [Getting Metrics into Seq](https://datalust.co/docs/getting-metrics-into-seq): Seq receives metrics across the network from applications, infrastructure, and agents.
- [Metrics from .NET](https://datalust.co/docs/metrics-from-net): .NET includes support for collecting metrics in the System.Diagnostics.Metrics namespace. The Open Telemetry SDK integrates with System.Diagnostics.Metrics to read metric values and publish them via Open Telemetry exporters.
- [Metrics from OpenTelemetry](https://datalust.co/docs/metrics-from-opentelemetry-sdks): OpenTelemetry SDKs exist for the following programming languages:
- [Search and Analyze Logs and Traces](https://datalust.co/docs/the-seq-query-language): This page covers everything you need to know in order to understand your systems, find bugs, and spot trends using telemetry data in Seq!
- [Search Expression Syntax](https://datalust.co/docs/query-syntax): Read the primer?
- [Simple Functions and Operators](https://datalust.co/docs/scalar-functions): These built-in functions and operators work with individual values. See Aggregate Functions for information on functions like count() and distinct() that work with sets of values.
- [Built-in Properties](https://datalust.co/docs/built-in-properties-and-functions): All Seq events expose a set of built-in properties that are distinguished by the @ symbol in their name:
- [Query Syntax](https://datalust.co/docs/sql-queries): Read the primer?
- [Aggregate Functions](https://datalust.co/docs/aggregate-operators): The following operators can be used in aggregate queries.
- [Working with Dates and Times](https://datalust.co/docs/working-with-dates-and-times): Seq works with event and time-series data, and has many features for working with date and time data.
- [Variables](https://datalust.co/docs/variables): Variables allow values to be assigned to identifiers to shorten and simplify searches and queries.
- [Using Seq](https://datalust.co/docs/using-seq): In this section you'll learn how the Seq UI supports day-to-day tasks.
- [AI Coding Agents](https://datalust.co/docs/ai-coding-agents): The same first-class visibility into application logs, traces and metrics that developers access through the Seq UI is also available to agentic tools (through seqcli) to help them diagnose issues, produce solutions and verify results.
- [API Keys](https://datalust.co/docs/api-keys): Applications sending events to Seq can provide an API key to identify themselves. API keys can be created at the system level (under Settings > API Keys), or for a user's personal access under (username) > API keys.
- [Saved Signals](https://datalust.co/docs/signals): Structured events are designed for easy filtering and correlation. If you monitor apps in multiple environments for example, you'll pretty quickly turn to structured properties like Environment as a way to distinguish between logs from different locations:
- [Tracing](https://datalust.co/docs/tracing): Tracing reveals how systems and components work together in a complex operation. This comes in handy when:
- [Making Traces Useful](https://datalust.co/docs/making-traces-useful): To support monitoring and diagnostics, high-quality spans should have:
- [Metrics](https://datalust.co/docs/metrics): High volumes of logs and traces can become difficult to manage on busy systems. Metrics provide a more efficient way to record and analyze numeric telemetry.
- [Dashboarding](https://datalust.co/docs/dashboards): Once you've started collecting structured event data, you'll be amazed how much interesting and useful information you can find in it. Dashboards are great for keeping track of important indicators of application and business behavior.
- [Alerting](https://datalust.co/docs/alerts): Seq can notify you when your app is broken, when an operation is slow, when particular business events occur, or when something you expect to happen, doesn't.
- [Organizing Workspaces](https://datalust.co/docs/workspaces): Workspaces help organize your view of Seq by collecting related signals, queries, and dashboards.
- [Visualization](https://datalust.co/docs/visualization): Three data visualizations are immediately available when viewing a set of events on the events screen: frequency histogram, @Elapsed heatmap and trace viewer. Other data visualizations are available for the results of SQL queries.
- [Sending Notifications](https://datalust.co/docs/installing-output-apps): Since structured events are so easy to process, you naturally want to start reacting to them. It might be as simple as sending an email to operations when an integration point is slow, or to the support team if a site crashes during a particular transaction.
- [Notifying with Email](https://datalust.co/docs/formatting-html-email): Seq can automatically send email when events are logged – this is accomplished using the apps Seq.App.Mail.Smtp and Seq.App.Mail.Microsoft365
- [Notifying with Slack](https://datalust.co/docs/slack-notifications): This is accomplished using Seq.App.Slack, a plug-in (originally contributed by David Pfeffer and the Seq community) developed and maintained on GitHub.
- [Calling Webhooks](https://datalust.co/docs/calling-webhooks): Seq can call HTTP GET/PUT/POST/DELETE endpoints using the Seq.App.HttpRequest output app.
- [Alert Notification Properties](https://datalust.co/docs/alert-properties): Notifications from Alerts (including template-based HTML Email) can include the following fields:
- [Template Syntax](https://datalust.co/docs/template-syntax): Many Seq apps can format output, for example email notifications or HTTP request bodies, using the Seq.Syntax templating library .
- [Administration](https://datalust.co/docs/administration): This section of the guide covers everything you need to know about administering a running Seq instance.
- [Managing Users](https://datalust.co/docs/managing-users): When Seq is first installed, it will start in Single User mode.
- [OpenID Connect Authentication](https://datalust.co/docs/openid-connect): Seq can authenticate users with an external OpenID Connect (OIDC) provider. Many identity providers support OpenID Connect as a standard authentication protocol layered over OAuth 2.0.
- [IdentityServer Setup](https://datalust.co/docs/identityserver-setup): To configure IdentityServer as an OpenID Connect Authentication provider for Seq:
- [Microsoft Entra ID Authentication](https://datalust.co/docs/azure-active-directory): Seq can authenticate users in Microsoft Entra ID. This makes it easier for organizations to centrally manage user accounts.
- [Active Directory Authentication](https://datalust.co/docs/active-directory): Active Directory authentication is not available when deploying Seq to Docker/Linux.
- [Retention Policies](https://datalust.co/docs/retention-policies): Retention policies support the management of telemetry storage by allowing the administrator to control what data is retained and for how long.
- [Seq Apps](https://datalust.co/docs/installing-seq-apps): Seq Apps are plug-ins that process events and alerts, or ingest events from an external source. Many are provided by the user community, and you can also create your own.
- [Managing Storage](https://datalust.co/docs/managing-storage): Data > Storage gives you an idea of how effectively retention policies are reclaiming disk space. It includes a chart that shows how much space is being used now by events ingested in the past. It does not track disk usage over time, which should remain fairly constant on a healthy server.
- [Deleting Events](https://datalust.co/docs/deleting-events): Events should normally be cleaned up using retention policies. Use the technique on this page only when "one-off" deletion is necessary. Manual deletion is resource-intensive, will temporarily block critical system functions and should be avoided when the system is under heavy load.
- [Indexing](https://datalust.co/docs/indexing): Indexes potentially make queries faster by reducing the volume of data from disk that queries must search. Each index adds a small amount of overhead to the server.
- [How do Signal Indexes work?](https://datalust.co/docs/how-do-signal-indexes-work): Each file in the log stream managed by Seq is naturally partitioned into pages by the host operating system and virtual memory manager:
- [Internal Error Reporting](https://datalust.co/docs/internal-error-reporting): Internal error reporting allows administrators to opt-in to providing Datalust with error details when an unhandled error condition or exception occurs within a Seq instance.
- [Usage Telemetry](https://datalust.co/docs/usage-telemetry): Seq includes a usage telemetry feature that, if enabled, sends anonymous data about feature usage back to Datalust. This helps the Seq development team to improve the product.
- [Exporting Log Data](https://datalust.co/docs/exporting-log-data): Seq uses a newline-delimited JSON format for import and export of event data.
- [Event backup with JSON Archive](https://datalust.co/docs/event-backup-with-json-archive): The JSON Archive app can be used to stream ingested events into rolling files of line-delimited JSON. These files are suitable as a long-term archive or for data recovery.
- [Migrating Seq Data](https://datalust.co/docs/migrating-seq-data): This page documents the process of replacing the event data in one Seq server with the event data from another Seq server. All data on the destination Seq server will be overwritten.
- [The Secret Key](https://datalust.co/docs/secret-key-storage): Seq uses AES-256 to encrypt secrets that are required at runtime. A single encryption key is used for this purpose, which Seq refers to as the "secret key".
- [Auditing](https://datalust.co/docs/audit-logging): Auditing is not supported by all Seq subscription types. Please refer to the subscription tier details on datalust.co and contact us if you need any help with licensing.
- [Audit Schema](https://datalust.co/docs/audit-event-schema): All Seq audit events carry the following properties.
- [Audit Events](https://datalust.co/docs/audit-events): Events relating to alerts.
- [Recovery Keys](https://datalust.co/docs/recovery-keys): What should you do if you're locked out of your Seq instance? Perhaps your OIDC or Entra ID client secret expired, you fumbled an admin password change, or the only user with an admin account for Seq left the organization without a forwarding address?
- [Recovering without a Recovery Key](https://datalust.co/docs/recovering-from-broken-authentication-settings): When configuring authentication it's possible to end up locked out, either because of Seq configuration problems, external provider issues, or loss of network connectivity.
- [Monitoring Seq](https://datalust.co/docs/monitoring): Monitoring a Seq installation makes it easier to preempt or remediate issues.
- [Deployment on Windows](https://datalust.co/docs/windows-deployment-overview): Seq is a log and trace server that runs on a central machine. Your application uses a library like Serilog or Microsoft.Extensions.Logging to send structured events to Seq's HTTP API, which stores them and makes them searchable through Seq's web interface.
- [System Requirements](https://datalust.co/docs/system-requirements): Seq runs on most modern Windows configurations. Your requirements will depend on the volume of log events you intend to process.
- [Storage](https://datalust.co/docs/storage-paths-and-urls): Seq stores log data and configuration on the file system. The location it uses is called the storage path.
- [URLs](https://datalust.co/docs/urls): By default, Seq will listen on http://localhost:5341, accepting all requests on that port (regardless of the hostname specified by the incoming request).
- [HTTPS (TLS/SSL)](https://datalust.co/docs/https-on-windows): Seq fully supports HTTPS on Windows. To enable HTTPS, you'll need a valid SSL certificate that matches the hostname of your Seq server.
- [Configuring HTTPS with HTTP.sys](https://datalust.co/docs/ssl): On Windows, Seq can use the HTTP.sys web server provided by the operating system. This was the default web server used by earlier Seq versions, and provides some functionality not available using Kestrel, which is the default web server for new Seq installs.
- [Service Account Requirements](https://datalust.co/docs/service-account-requirements): When Seq is deployed on Windows, it is best practice to run the Seq Windows Service using a service account with non-administrative permissions.
- [Backup and Restore](https://datalust.co/docs/backup-and-restore): For Docker/Linux and Kubernetes instructions, see Backup and Restore in Docker.
- [Using SQL Server as a Metastore](https://datalust.co/docs/using-sql-server-as-a-metastore): Seq stores two kinds of data. Events are stored in Seq's embedded storage engine, called Flare. Documents, like users and signals, are stored in a separate metastore, which may be Flare (the default), or a SQL database like SQL Server or PostgreSQL.
- [Unattended Installation](https://datalust.co/docs/unattended-installation): This document contains useful information when automating/scripting the installation and configuration of a Seq server on Windows, or when installing Seq in a headless Server Core environment.
- [Deployment Checklist](https://datalust.co/docs/production-deployment): Seq is extremely fast and easy to set up in its default configuration, and going to production isn't much harder. There are a few things to take care of that will ensure smooth, secure operation of Seq as a critical part of your operations infrastructure.
- [Deployment with Docker](https://datalust.co/docs/docker-deployment-overview): Seq is distributed as an officially supported datalust/seq container image on Docker Hub and as datalust/seq on the Amazon ECR Public Gallery.
- [Image Tags](https://datalust.co/docs/tags): The datalust/seq image on Docker Hub uses the following tagging scheme:
- [Configuration](https://datalust.co/docs/environment-variables): If you haven't yet read Getting Started, we recommend you start there first.
- [Init Scripts](https://datalust.co/docs/init-scripts): It can be difficult to access a container directly to configure it. Seq supports running one-time initialization scripts from a mounted directory in a container before it starts the server itself.
- [Storage](https://datalust.co/docs/docker-storage): The Seq Docker container stores configuration and log events in its /data directory. For this directory to survive container restarts, it needs to be mapped to a persistent volume using -v on the command-line, as in the Docker Deployment Overview.
- [Memory](https://datalust.co/docs/docker-memory): For Seq to accurately measure available memory, depending on the hosting infrastructure, it's often necessary to specify memory limits for the container. If the Seq container exits unexpectedly, or fails with out-of-memory errors, specify the --memory and --memory-swap arguments to docker run:
- [HTTPS (TLS/SSL)](https://datalust.co/docs/https-tlsssl): The datalust/seq container can serve its web user interface and event ingestion endpoint over HTTPS. This page documents how to configure Seq to serve HTTPS directly. Another deployment option may be to use a reverse proxy to terminate SSL for you. This may let you take advantage of more advanced…
- [Running Server Commands](https://datalust.co/docs/running-server-commands): The full Seq Server Command Line is accessible through the Docker container.
- [Getting a Shell to a Seq Container](https://datalust.co/docs/getting-a-shell-to-a-container): Sometimes you'll need to get direct access to a Seq container to make configuration changes or run diagnostics.
- [Backup and Restore](https://datalust.co/docs/backup-and-restore-docker): For Windows instructions, see Backup and Restore on Windows.
- [Using PostgreSQL as a Metastore](https://datalust.co/docs/using-postgresql-as-a-metastore): Seq stores two kinds of data. Events are stored in Seq's event store. Documents, like users and signals, are stored in a separate metastore, which may be Seq's built-in one, or a SQL database like SQL Server or PostgreSQL.
- [Deployment in Kubernetes](https://datalust.co/docs/using-helm): Kubernetes is a container orchestration platform that standardizes many of the concerns around deploying, integrating, exposing, and maintaining applications. If you're deploying apps and supporting infrastructure to Kubernetes then Seq can be deployed there too. The best way to get started is using…
- [Storage](https://datalust.co/docs/kubernetes-storage): Storage and helm uninstall
- [Memory](https://datalust.co/docs/kubernetes-memory): For Seq to accurately measure available memory, depending on the hosting infrastructure, it's often necessary to specify memory limits for the deployment.
- [Ingress](https://datalust.co/docs/ingress): Seq doesn't need an ingress to accept logs from applications within the cluster, but it does if you want to access Seq externally.
- [Deployment in Azure](https://datalust.co/docs/deployment-in-azure): In Microsoft Azure, the three supported deployment models for Seq are:
- [Using a Virtual Machine](https://datalust.co/docs/azure-installation): It's easy to install your own Seq instance in the cloud using an Azure Virtual Machine. This section provides some advice on how to pick the right machine for your workload.
- [Using Kubernetes Services](https://datalust.co/docs/using-aks): You can deploy the Seq Helm chart to an AKS cluster.
- [Using Azure Container Instances (ACI)](https://datalust.co/docs/using-azure-container-instances-aci): For hosting in Azure without a virtual machine, Seq can be deployed to Azure Container Instances.
- [Using Azure Websites, Container Apps, or App Service](https://datalust.co/docs/using-azure-websites-or-app-service): Azure Websites, Container Apps, and App Service are unsupported
- [Clustering](https://datalust.co/docs/clustering-overview): Seq clustering increases query performance, reduces opportunities for data loss, and improves availability in the event of machine failures.
- [Setting up a Seq HA Cluster](https://datalust.co/docs/setting-up-a-seq-ha-cluster): This page is an overview of setting up a new HA cluster from scratch. See Migrating Legacy DR Clusters to HA or Converting a Standalone Seq Instance into a Cluster for alternative instructions in those cases.
- [Configuring a Cluster Load Balancer](https://datalust.co/docs/configuring-a-cluster-load-balancer): The cluster load balancer receives traffic from applications sending log and trace data, and from users interacting with the Seq UI.
- [Configuring a Cluster State Database](https://datalust.co/docs/configuring-a-cluster-state-database): The cluster state database stores a single copy of Seq configuration (users, API keys, signals, dashboards, etc.) shared by all Seq nodes in the cluster.
- [Configuring a Cluster Diagnostic Instance](https://datalust.co/docs/configuring-a-cluster-diagnostic-instance): The cluster diagnostic instance is an optional, but strongly recommended, aid to monitoring the health and performance of the Seq cluster. Seq nodes in the cluster send OpenTelemetry logs, metrics, and traces to the diagnostic instance for:
- [Configuring a Clustered Seq Node](https://datalust.co/docs/configuring-a-clustered-seq-node): The nodes in a Seq cluster each store a replica of the ingested log stream and participate in distributed queries.
- [Securing Intra-cluster Communication](https://datalust.co/docs/securing-intra-cluster-communication): Because a Seq cluster is deployed behind a load balancer it is often sufficient to secure access to the load balancer and leave communication between cluster nodes unsecured. This configuration offers easier setup and slightly better performance.
- [Finalizing Cluster Configuration](https://datalust.co/docs/finalizing-cluster-configuration): The steps below improve the reliability and manageability of your Seq cluster.
- [Adding, Updating, and Removing Nodes](https://datalust.co/docs/adding-updating-and-removing-nodes): To add a Seq node to the running cluster:
- [Cluster Monitoring and Diagnostics](https://datalust.co/docs/cluster-diagnostics): Seq clusters are designed for low maintenance. For the most part, Seq clusters should just work, with little intervention required. Clusters provide active notifications for potentially serious problems, and record detailed data to the cluster diagnostic instance for performance analysis and…
- [Converting a Standalone Seq Instance into a Cluster](https://datalust.co/docs/converting-a-standalone-seq-instance-into-a-cluster): It's possible to convert an existing standalone Seq node to a cluster node, then add additional nodes to the cluster. This slightly modifies the sequence of steps performed to set up the cluster.
- [Migrating Legacy DR Clusters to HA](https://datalust.co/docs/migrating-legacy-dr-clusters-to-ha): Seq versions up to and including 2024.3 include a two-node clustering capability focused on disaster recovery (DR). This clustering technology is no longer supported by new Seq versions, which replace it with more capable HA/scale-out clustering.
- [Developer Guide](https://datalust.co/docs/developer-guide): Seq provides a comprehensive HTTP API and command-line API client that can be used to configure Seq and integrate it into other systems.
- [Using the HTTP API](https://datalust.co/docs/using-the-http-api): Seq provides a complete HTTP API for manipulating events, queries, apps, and so on.
- [Server API Endpoints](https://datalust.co/docs/server-http-api): This document lists the API endpoints provided by the Seq server. These can also be called using the C# API client.
- [Writing Seq Apps in C#](https://datalust.co/docs/writing-seq-apps): Seq apps can be written as simple C# classes packaged into standard NuGet .nupkg files.
- [Writing Seq Apps in Other Languages](https://datalust.co/docs/seq-apps-in-other-languages): Seq apps can be written as standard processes in any language: configuration is read from environment variables, events are read from stdin, and output events are written to stderr.
- [Writing Custom Inputs](https://datalust.co/docs/writing-custom-inputs): Seq can host Seq Apps that act as high-performance log event inputs. As with other Seq Apps, inputs can be written in C# as plug-in assemblies, or as standalone executables.
- [Command-line Client](https://datalust.co/docs/command-line-client): The Seq client command-line app supports logging (seqcli log), searching (search), tailing (tail), querying (query) and JSON or plain-text log file ingestion (ingest), and much more.
- [Troubleshooting](https://datalust.co/docs/troubleshooting): What should you do if Seq isn't working as expected? Don't panic! Ease of management is a first-class feature that we design for, and chances are your problem will be solved by one of the guides in this section.
- [Ingestion Troubleshooting](https://datalust.co/docs/ingestion-troubleshooting): Are events missing from Seq? Has an application stopped logging? The steps in this section should help you resolve the issue or gather enough information that our support team can help.
- [Performance Troubleshooting](https://datalust.co/docs/performance-troubleshooting): If Seq query performance is lagging, this page will help you track down the issue or collect the information our support team will need to help you out.
- [Stability Troubleshooting](https://datalust.co/docs/stability-troubleshooting): Is the Seq process crashing? Are unexpected errors reported in the UI? Seq is normally rock-solid stable, but if something's going wrong this page will help you gather information so that our support team can help you out.
- [Data Recovery](https://datalust.co/docs/data-recovery): If Seq's internal storage becomes corrupted you may lose access to some log data. Depending on the nature of the corruption, you might be able to recover some or all of it.
- [Reference](https://datalust.co/docs/reference): In this section:
- [Server Command Line](https://datalust.co/docs/server-command-line): Syntax:
- [Server Configuration](https://datalust.co/docs/json-config): Many Seq options can be configured through the Settings section of the web user interface. Lower-level settings, especially those that control the HTTP endpoint, or require a restart to be applied, are stored in the Seq.json configuration file, and manipulated using <span…
- [Security](https://datalust.co/docs/security): Seq is designed for use in sensitive environments, and we take the security of our users seriously at all stages of software development. Recognizing our own fallibility, we also strive for a secure-by-default mindset, and aim for full transparency when communicating about the security of Seq.
- [Data Storage](https://datalust.co/docs/data-store): Seq internally uses two distinct storage subsystems:
- [Version Support Policy](https://datalust.co/docs/version-support-policy): This page explains the support lifecycle for Seq software versions.
- [Acknowledgements](https://datalust.co/docs/acknowledgements): Seq is made possible by many excellent tools, libraries, and frameworks built by others.

## Website

- [Download Seq](https://datalust.co/download): Installers for Windows, and instructions for Docker/Linux.
- [Pricing](https://datalust.co/pricing): Subscription pricing and licensing.
- [Free trial](https://datalust.co/trial): 30-day trial licenses for teams.
- [Blog](https://datalust.co/blog): Engineering articles and release announcements.
- [Roadmap](https://datalust.co/roadmap): Features planned for near-future Seq releases.
- [Case studies](https://datalust.co/case-studies): How organizations use Seq.