Spring Lens

Spring Lens is a developer observability and diagnostics tool for Spring Boot applications that provides deep visibility into your application's runtime behavior with zero application code changes. Inspired by Laravel Telescope, Spring Lens helps developers understand what happens inside their application by collecting and visualizing information about:

• Spring Beans
• HTTP Requests and Responses
• SQL Queries
• Method Executions
• Events
• Caches
• Scheduled Tasks
• Async Operations
• Application Startup

Simply add Spring Lens as a dependency and start exploring your application's internals.

Modern Spring Boot applications are highly dynamic and heavily rely on auto-configuration, proxies, asynchronous execution, and runtime infrastructure.

Understanding:

• why startup is slow,
• which beans depend on each other,
• which SQL queries were executed,
• how requests flow through your application,
• or where performance bottlenecks exist

often requires multiple tools, log analysis, and custom instrumentation.

Spring Lens aims to provide all of these insights in one place.

Inspect your application's Spring container in real time.

Features include:

• Bean definitions
• Bean instances
• Initialization duration
• Scope information
• Dependency graph
• Lazy initialization visibility
• Factory methods
• Bean origin and resource location
• Proxy information
• Startup timeline

Observe incoming HTTP traffic similar to Laravel Telescope's request watcher.

Captured information includes:

• HTTP method
• URI and query parameters
• Request headers
• Request body
• Response headers
• Response body
• Response status
• Execution duration
• Client IP address
• Correlated SQL executions

Monitor database activity generated during request processing.

Features:

• Executed SQL statements
• Execution duration
• Bound parameters
• Exception information
• Request correlation
• Slow query detection

Track application method execution timings.

Features:

• Method name
• Class name
• Execution duration
• Exception information
• Request correlation
• Package filtering

Understand exactly how your application starts.

Features:

• Bean initialization timeline
• Slow bean detection
• Startup bottleneck analysis
• Dependency chain visualization

Explore your Spring application as an interactive graph.

Visualize:

• Bean dependencies
• Bean dependents
• Circular dependencies
• Application architecture

Spring Lens is designed around a simple principle:

Developers should not modify application code to gain observability.

No annotations.

No custom APIs.

No manual registration.

Simply add the dependency:

<dependency>
    <groupId>com.sdlc.pro</groupId>
    <artifactId>spring-lens-starter</artifactId>
    <version>1.0.0</version>
</dependency>

and Spring Lens automatically integrates with your application.

Spring Lens consists of several independent modules:

spring-lens-core
spring-lens-insight
spring-lens-storage
spring-lens-exposure
spring-lens-ui
spring-lens-autoconfigure
spring-lens-starter

Provides shared abstractions and infrastructure:

• Repository API
• Pagination
• Filtering
• Sorting
• Shared contracts

Responsible for runtime information collection:

• Bean observations
• HTTP observations
• SQL observations
• Method observations

Persistence implementations for collected data.

Supported storage providers:

• In-memory
• Redis
• Custom implementations

Exposes collected data through:

• REST API
• Actuator endpoints
• CLI integration
• JMX support

Default modern UI for insight visualization

Connects modules together using Spring Boot auto-configuration.

Convenient dependency for end users.

Spring Lens is built around the following principles:

• Zero application code changes
• Production-safe defaults
• Low overhead
• Modular architecture
• Extensible storage model
• Framework-native integration
• Developer-first experience

• SQL query monitoring
• Cache monitoring
• Event monitoring
• Scheduler monitoring
• Async execution tracking
• Distributed tracing support
• And many more...

Spring Lens is not intended to replace:

• Spring Boot Actuator
• Micrometer
• OpenTelemetry
• Prometheus

Instead, Spring Lens focuses on one specific problem:

Giving developers a clear and intuitive understanding of what their Spring application is doing internally.

Contributions, ideas, feature requests, and discussions are welcome.

If you have suggestions or would like to contribute, please open an issue or submit a pull request.

Spring Lens is heavily inspired by:

• Laravel Telescope
• Spring Boot Actuator
• OpenTelemetry
• Micrometer
• Spring Boot Admin

Spring Lens is currently under active development.