This Go library provides a fully spec-compliant implementation of HTML5 Server-Sent Events (SSE) for both server and client use cases. It's designed for developers building applications that require real-time, one-way communication, such as streaming LLM responses, live notifications, or data feeds, offering a robust and flexible solution for integrating SSE functionality into Go applications.

How It Works

The library offers decoupled server and client implementations. The server component is framework-agnostic and relies on a Provider interface for message dispatching, allowing integration with external pub-sub systems like Redis or Kafka, or using the built-in "Joe" provider for in-memory pub-sub. Joe can be configured with Replayer implementations to manage event history and replayability. The client component uses net/http and the cenkalti/backoff library for robust connection management, including automatic retries and reconnection logic.

Quick Start & Requirements

• Install: go get -u github.com/tmaxmax/go-sse
• Recommended: Use tagged versions. The master branch may have breaking changes.
• Go version support: The 2 most recent major releases supported by the Go team.
• LLM response example: https://github.com/tmaxmax/go-sse/blob/main/examples/llm/main.go
• Server "Hello world" example: https://github.com/tmaxmax/go-sse/blob/main/examples/server/main.go
• Client "Hello world" example: https://github.com/tmaxmax/go-sse/blob/main/examples/client/main.go

Highlighted Details

• Supports Go 1.23 iterators (range-over-func) for event reading, with a fallback for Go 1.22 via GOEXPERIMENT=rangefunc.
• The sse.Read function simplifies consuming SSE streams, particularly useful for LLM API responses.
• The sse.Server implements http.Handler for easy integration with existing HTTP servers.
• The Joe provider includes Replayer interfaces for managing in-memory event history and replayability.

Maintenance & Community

• The library is described as being in its "early stages," with contributions actively encouraged.
• Guidance for contributing includes opening an issue first and ensuring changes are well-tested and formatted.

Licensing & Compatibility

• MIT License.
• Permissive license suitable for commercial use and integration into closed-source projects.

Limitations & Caveats

• The master branch is explicitly noted as potentially containing unreleased and undocumented changes that could break backward compatibility.
• Default Replayer implementations store events in memory, which may not be suitable for very high-volume or long-term persistence requirements without custom provider/replayer implementations.