Arch – an intelligent prompt gateway built on Envoy

In plain words

Arch is an open-source intelligent prompt gateway built on Envoy that helps developers build generative AI applications faster. It handles prompt processing tasks including detecting jailbreak attempts, routing requests to backend APIs and multiple LLMs with failover support, and centralizing observability of LLM interactions. Written in Rust and running alongside application servers, Arch offloads these critical functions from application business logic, leveraging Envoy's proven HTTP management and scalability features.

written from the facts on this page · September 2026

From the sources

Plano is an AI-native proxy server and data plane for agentic apps. Smart LLM routing, observability, agent orchestration, and guardrails so you stay focused on your agents core logic. - katanemo/plano

In the maker’s words, at launch

Hi HN! My name is Adil Hafeez, and I am the Co-Founder at Katanemo and the lead developer behind Arch - an open source project for developers to build faster, generative AI apps. Previously I worked on Envoy at Lyft. Engineered with purpose-built LLMs, Arch handles the critical but undifferentiated tasks related to…

• 
  Arch – an intelligent prompt gateway built on Envoy2024 · github.com · ▲31

  Hi HN! My name is Adil Hafeez, and I am the Co-Founder at Katanemo and the lead developer behind Arch - an open source project for developers to build faster, generative AI apps. Previously I worked on Envoy at Lyft. Engineered with purpose-built LLMs, Arch handles the critical but undifferentiated tasks related to the handling and processing of prompts, including detecting and rejecting jailbreak attempts, intelligently calling “backend” APIs to fulfill the user’s request represented in a prompt, routing to and offering disaster recovery between upstream LLMs, and managing the observability…

• 
  Arch2024 · github.com · ▲314

  Hey HN — I’m Adil from Katanemo (with Salman, Shuguang, and Meiyu) We previously shared an early version of this project as ArchGW. Based on customer feedback, the scope expanded from “LLM routing and model access” into something broader: delivery infrastructure for agentic applications. We renamed it to Plano and reworked the architecture accordingly. The problem On-the-ground AI practitioners will tell you that calling an LLM is not the hard part. The really hard part is delivering agentic applications to production quickly and reliably, then iterating without rewriting system code every…

• AG
  Arch GW – Distributed gateway for agents, engineered with small LLMs2024 · docs.archgw.com · ▲7

  Hi HN My name is Salman and I work on Arch GW - the intelligent gateway designed to protect, observe, and personalize LLM applications with your APIs. https://github.com/katanemo/arch Our team built Envoy Proxy at Lyft, and re-imagined it with the belief that: Prompts are nuanced and opaque user requests, which require the same capabilities as traditional HTTP requests including secure handling, intelligent routing, robust observability, and integration with backend (API) systems for personalization – all outside business logic. Engineered with purpose-built LLMs, Arch…

• 
  Arch-Router – 1.5B model for LLM routing by preferences, not benchmarks2025 · ▲66

  Hi HN — we're the team behind Arch (https://github.com/katanemo/archgw), an open-source proxy for LLMs written in Rust. Today we're releasing Arch-Router (https://huggingface.co/katanemo/Arch-Router-1.5B), a 1.5B router model for preference-based routing, now integrated into the proxy. As teams integrate multiple LLMs - each with different strengths, styles, or cost/latency profiles — routing the right prompt to the right model becomes a critical part of the application design. But it's still an open problem. Most routing systems fall into two…

• 
  Twitch Installs Arch Linux – A cooperative text-based horror game2015 · twitchinstalls.com · ▲802
• 
  ArchGW – An intelligent edge and service proxy for agents2025 · github.com · ▲118

  Hey HN! This is Adil, Salman and Jose and and we’re behind archgw [1]. An intelligent proxy server designed as an edge and AI gateway for agents - one that natively know how to handle prompts, not just network traffic. We’ve made several sweeping changes so sharing the project again. A bit of background on why we’ve built this project. Building AI agent demos is easy, but to create something production-ready there is a lot of repeat low-level plumbing work that everyone is doing. You’re applying guardrails to make sure unsafe or off-topic requests don’t get through. You’re clarifying vague…

• 
  Spira Maxima▲578

  Video model that turns script into viral social media videos

  AI · 19d ago · spira.ai

• 
  Rill Browser▲540

  The browser where Claude Code and Codex work beside you

  AI · 18d ago · rill.love

• 
  Germany's new sovereign AI model Kolibri▲424

  Kolibri is Aleph Alpha

  AI · 20d ago · tej.as

• 
  Giving Opus 5.5 a simulated paint canvas▲392

  Paintings by AI models: programs run through a simulation of oil paint.

  AI · 22d ago · stillwet.art

• 
  Beam.win▲379

  Run AI agents on one Mac and use its windows on another

  AI · 5d ago · beam.win

• 
  FastRouter.ai▲364

  Route requests to the right LLM for cost, latency & quality

  AI · 23d ago · fastrouter.ai

• 
  buzzabout▲1,267

  Audience insights from 1B+ online discussions in 2 mins

  AI · 2024 · buzzabout.ai

• 
  bolt.new▲1,230

  Build and scale high-performing websites & apps using your words. Join millions and start building today.

  AI · 2024 · bolt.new

• 
  Feta▲1,217

  Run smarter stand-ups, build better products

  AI · 2024 · feta.io

• 
  Trag▲955

  AI code review companion

  AI · 2024 · usetrag.com

• 
  Softr for Notion▲923

  Turn Notion databases into portals & apps with no code

  Dev tools · 2024 · softr.io

• 
  General Collaboration▲910

  One inbox for all your work discussions

  Work · 2024 · generalcollaboration.com