Pounce

A Python ASGI server for deployments, streaming responses, and free-threaded Python

Get Started API Reference

Python ASGI Server for Free-Threaded Python

Pure Python. Frozen config. True parallelism.

Pounce is a pure-Python ASGI server for Python 3.14t with a low-overhead HTTP/1.1 fast path, immutable shared server config, and thread-worker reload draining. No C extensions in the server core.

import pounce

pounce.run("myapp:app")

Why Use Pounce

Free-Threading Native

True OS thread parallelism on Python 3.14t. N workers share one interpreter with frozen immutable server configuration.

Fast-Path Parsing

Built-in HTTP/1.1 parser for sync workers covers method validation, header size limits, duplicate Content-Length, and Content-Length/Transfer-Encoding ambiguity. Pure Python.

Thread-Worker Reload

Rolling restart in thread-worker mode spawns a new worker generation while draining the old. Other worker modes document their own lifecycle limits.

Observable by Default

Typed lifecycle events, Prometheus /metrics, OpenTelemetry tracing, and Server-Timing headers. Subscribe to structured events from your framework code.

Common Use Cases

  • Running standard ASGI apps with a Python-native server
  • Replacing Uvicorn deployments while keeping a familiar CLI
  • Serving streaming responses with low buffering overhead
  • Deploying free-threaded Python apps with shared-memory worker threads
  • Runningpounce benchto measure and compare server performance
  • Building framework-level observability on typed lifecycle events

Protocols

Protocol Backend Install
HTTP/1.1 h11 (pure Python) built-in
HTTP/2 h2 (stream multiplexing, priority) bengal-pounce[h2]
WebSocket wsproto (HTTP/1 WebSocket; WS-over-H2 also requires h2) bengal-pounce[ws]
TLS stdlib ssl + truststore bengal-pounce[tls]
HTTP/3 bengal-zoomies (QUIC/UDP) bengal-pounce[h3]
All Everything above bengal-pounce[full]

The Bengal Ecosystem

A structured reactive stack — every layer written in pure Python for 3.14t free-threading.
ᓚᘏᗢ Bengal Static site generator Docs
∿∿ Purr Content runtime —
⌁⌁ Chirp Web framework Docs
=^..^= Pounce ASGI server ← You are here Docs
)彡 Kida Template engine Docs
ฅᨐฅ Patitas Markdown parser Docs
⌾⌾⌾ Rosettes Syntax highlighter Docs

Python-native. Free-threading ready. No npm required.