justapi — /home
 ~/projects/justapi-app
  •  .git
  •  app
    • main.py
    • routes.py
  •  Cargo.toml
justapi-core 200 OK
[
]
766k RPS ACTIVE
v2.0.9 · PyPI Zero-GIL CPython 3.14t 766k req/s

Python writes the logic.
Rust does everything else.

JustAPI is an ultra-fast Python web framework built on a Rust core. One import, zero config — routing, TLS, request validation, serialization, and connection handling run in Rust.

Performance Overview
766k
req/s hello-world
782k
req/s JSON echo
2.4x
faster than Granian
53x
native async DB queries
181k
native CRUD SELECT req/s
12MB
resident RAM footprint
Quick Start
pip install justapi
python main.py
# ✓ JustAPI running on http://127.0.0.1:8000
Minimal Application
main.py
from justapi import JustAPIApp

app = JustAPIApp()

@app.get("/")
def hello():
    return {"Hello": "World"}

app.run()
server started · OpenAPI auto-generated at /docs
Throughput Benchmarks
JustAPI
766k
Granian
314k
Robyn
39k
FastAPI
36k

hello-world, 100 concurrent connections, 30s benchmark duration on identical hardware — see detailed methodology in BENCHMARKS.md

Framework Features

Rust Core Architecture

Sockets, TLS termination, HTTP parsing (hyper), routing, and response writing run entirely in Rust.

Native Async DB Integration

await app.db.query_async() runs SQL queries on Rust's tokio pool — up to 53× faster on slow queries.

Rust-Native SSE & WebSockets

app.sse_native() streams real-time events with zero Python overhead per emitted message.

Multi-Worker Auto-Scaling

justapi serve --workers N provides 1.88× throughput scaling across multi-core systems.

Free-Threaded CPython 3.14t

Native support for GIL-free CPython — CPU-bound Python routes scale linearly across all CPU cores.

Built-in Rust Security

JWT verification, token bucket rate limiting, CORS headers, and OWASP security middleware run in Rust.

Production Observability

Circuit breakers, OpenTelemetry distributed tracing, Prometheus metrics, and automated health checks.

Type-Checked & Stubbed

Ships with py.typed marker and complete type stubs for 100% clean mypy type validation.

FastAPI Drop-in Compatibility

Uses familiar decorators, Pydantic models, and Depends injection. Migrate with one import change.

FastAPI vs JustAPI Comparison
Metric / Feature FastAPI JustAPI
Runtime Core uvicorn (Python) Rust (tokio + hyper)
Hello World Throughput ~36k req/s ~766k req/s (21x faster)
JSON Echo Throughput ~33k req/s ~782k req/s (23x faster)
Native DB SELECT Python DB Driver 181k req/s (125x faster)
Memory Footprint ~29 MB ~12 MB (58% lower)

Ready to build high-performance APIs?

One import. Powered by Rust. Zero complex configuration.

Read the Documentation
NORMAL master justapi/home.py
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