Crate stream_rs 

stream-rs

A zero-dependency, spec-compliant streaming toolkit for LLM responses.

It gives you the low-level plumbing that sits underneath an LLM client — none of the model, transport, or API-key concerns, just the parsing that turns a raw byte stream into usable values:

• sse — a WHATWG-compliant Server-Sent Events push parser.
• incremental_json — a byte-level splitter that finds complete top-level JSON values in a chunked stream (NDJSON or bare concatenation).
• accumulators — fold provider-specific streaming deltas (OpenAI, Anthropic, and Gemini) back into the final message content.

The core has no runtime dependencies. An optional stream feature adds a futures_core::Stream adapter (stream::SseStream) for async byte sources; enable it with features = ["stream"].

no_std

The crate is #![no_std] and needs only alloc. The default std feature merely adds std::error::Error impls for the error types; disable it for embedded / wasm targets:

stream-rs = { version = "0.1", default-features = false }

Quick start

use stream_rs::sse::SseParser;

let mut parser = SseParser::new();
let mut events = Vec::new();
parser.feed(b"data: {\"hello\":true}\n\n", &mut events);

assert_eq!(events[0].data, "{\"hello\":true}");

Re-exports

pub use error::AccumulateError;

pub use error::MalformedJson;

pub use error::TruncatedJson;

pub use incremental_json::FinishError;

pub use incremental_json::JsonSplitter;

pub use sse::SseEvent;

pub use sse::SseParser;

Modules

accumulators

Provider-specific delta accumulators.

error

Error types for the streaming toolkit.

incremental_json

Incremental scanning of concatenated / partial JSON.

sse

A spec-compliant Server-Sent Events stream parser.

streamstream

Async adapter: turn a byte Stream into a Stream of SseEvents.