High‑level general‑purpose programming language Python has had what some might describe as a good, if occasionally slightly chequered, history in the security sphere.

With its standard five‑year support cycle for security updates (and with some back‑ported updates also available), key cyber developments in recent times have included the Python Package Index (PyPI) introducing aggressive measures to combat typosquatting and malicious uploads, which were widespread (some say rampant) at times.

Known for its application‑layer security platform built to integrate directly into modern codebases (think Python, Go, Rust… not so much your Fortran), Arcjet has now delivered a new Python SDK designed to extend the company’s core technology platform to Python‑based services and APIs.

Stop The Rot, Protect Your Bot

The new SDK enables teams building with Python to add bot protection, rate limiting and abuse prevention directly into their applications, helping stop unwanted traffic and detect attacks without changing infrastructure or slowing development.

Why this triumvirate of functions?

New, additional and stronger layers of bot protection should sound like a no‑brainer to most software engineers; with bot behavior making up a weighty percentage of total internet traffic, we know that autonomous AI agents can launch so‑called AI predator swarms to create thousands of personalized phishing emails – and that’s just one example.

In the world of autonomous computing with new agentic freedoms being unleashed, rate limiting is often regarded as a “financial circuit breaker” acting to cap the maximum input/output loads a given software service can process. Companies like this because it ensures they only pay for legitimate, throttled traffic. For abuse prevention, we can pretty much take that as read if we consider these first two validations.

Arcjet is out to protect all of these channels. This is why the company has specifically directed its latest services to exist in the jungle that is Python.

Python, Attractive Backend

According to David Mytton, CEO at Arcjet, Python is one of the most widely used languages for backend services and APIs, particularly for AI applications.

“But [despite this popularity] many security tools still operate primarily at the network or edge layer. Arcjet’s Python SDK brings security decisions into application code, where developers have full access to request context and business logic, allowing protections to be more accurate and easier to reason about.”

Mytton suggests that his firm’s new Python SDK represents an opportunity to extend Arcjet’s application‑layer approach to one of the largest developer ecosystems in the world.

“Teams rely on Python for critical services, from public APIs to internal systems. This release gives developers a clear way to apply meaningful security controls directly in‑code without introducing operational overhead,” stated Mytton.

Application‑Layer Protections

The Arcjet Python SDK supports core application‑layer protections, including the aforementioned rate limiting and bot detection, but also extends to email validation and signup spam prevention.

Protections are evaluated using Arcjet’s contextual decision engine and applied as part of normal request handling, allowing teams to tailor behavior based on user activity, request patterns, and application‑specific signals.

By integrating directly into Python services, Mytton says that Arcjet enables developers to enforce security policies alongside application logic rather than relying solely on external tooling. This approach is argued to reduce false positives, improve flexibility, and help teams adapt protections as applications evolve.

Minimal Config, No Mess Infrastructure

The SDK is designed to fit naturally into existing Python codebases and workflows, with support for both FastAPI (asynchronous) and Flask‑style (synchronous) APIs. Developers can get started with minimal configuration and no required infrastructure changes. Arcjet manages analysis and decision‑making, while developers remain in control of how protections are enforced and how requests are handled.

The Python SDK is available as an open‑source technology, with documentation and examples available on GitHub. Arcjet today is deployed in hundreds of production apps and is backed by Plural, Ott Kaukver, Andreessen Horowitz, Seedcamp and over 20+ dev‑tool security angel investors.