rqx 0.1.3

Rust-backed Python HTTP client with an httpx-compatible API.

rqx

A Rust-backed Python HTTP client with an httpx-compatible API.

rqx replaces httpx's pure-Python internals with a Rust core built on reqwest and tokio. The goal: keep the API your code already targets, but eliminate the structural performance ceilings of pure-Python HTTP under concurrent load.

Origin

rqx is a personal learning project for PyO3 and maturin. The structure of the work was a forcing function: I wrote a normal product spec, then asked Claude to rewrite it in the form of an academic course-project spec (CS 262A — Advanced Topics in Computer Systems). The academic framing pushed the design toward sharper engineering decisions — measurable acceptance criteria, explicit architectural trade-offs, and concrete performance targets — than a casual spec would have produced.

Two documents capture this:

• docs/reqx_project_spec.md — the original project specification: problem statement, design constraints, acceptance criteria.
• docs/report.md — the write-up: design decisions, benchmark methodology and full measurement results, lessons learned.

If you only have time for one, read the report. The benchmark numbers, the architectural trade-offs (sync vs async paths, retry placement, JSON parsing strategy, runtime singleton), and the things that didn't work all live there.

Quick look

import rqx

# Sync
with rqx.Client() as client:
    resp = client.get("https://httpbin.org/get")
    print(resp.json())

# Async
async with rqx.AsyncClient() as client:
    resp = await client.get("https://httpbin.org/get")
    print(resp.json())

# Module-level convenience (one-off requests)
resp = rqx.get("https://httpbin.org/get")

# With retries
transport = rqx.HTTPTransport(
    retries=rqx.Retry(total=3, backoff_factor=0.5, status_forcelist={503}),
)
with rqx.Client(transport=transport) as client:
    resp = client.get("https://example.com/api")

The API targets feature parity with httpx — clients, transports, retries, streaming, mTLS, base URLs, granular timeouts, and the full exception hierarchy. See python/rqx/_types.pyi for the current surface.

Installation

pip install rqx

To build from source (Rust toolchain + Python 3.9+ required):

git clone https://github.com/rodcochran/rqx.git
cd rqx
just setup        # uv venv + maturin develop + dev deps
just test         # full test suite

Benchmarks

Measured on a paired AWS c7i.large client/server (2 vCPU each, dedicated CPU) in us-east-1, hitting nginx over an intra-VPC private IP. Each cell is the median of 5 runs; each (client, concurrency, run) executes in its own Python subprocess to keep clients from contaminating each other's measurements. Full methodology and raw data: docs/launch_report.md.

httpx is the modern successor to requests, aiohttp is the de-facto async HTTP library, and httpr is another Rust-backed alternative.

Status

Pre-0.1.0. Usable but the API may shift in small ways before the first tagged release. Performance results in the project report. Open issues track the v0.x roadmap — anything labeled httpx-feature-parity is a known surface gap.

Contributing

This started as a learning project and stayed one. Contributions are welcome — especially around the httpx-parity surface (URL/QueryParams classes, MockTransport, event hooks, full streaming surface). See open issues for the working set, particularly anything labeled good first issue, and CONTRIBUTING.md for setup, conventions, and how to run the benchmarks.

Acknowledgements

rqx builds on the work of several excellent projects:

• httpx — the API design this project mirrors
• reqwest — the Rust HTTP client powering rqx
• PyO3 and maturin — Rust/Python FFI and build tooling
• tokio — async runtime

License

MIT