HarnessRouter tech stack

World's first unified agent harness interface. Open source

harnessrouter.ai ↗Checked Sep 2026

Foundation

In its subprocessor list: Supabase, Inc. | Marketing website datastore (e.g., waitlist) | United States | 2026-07-30 source · Oct 2026 ↗

Frontend Framework

Next.js

On its website: HTTP: app.harnessrouter.ai responds with x-nextjs-cache; HTTP: harnessrouter.ai responds with x-nextjs-prerender source · Oct 2026 ↗

Transactional Email

Resend

On its website: DNS: resend._domainkey.harnessrouter.ai TXT (record present); DNS: send.harnessrouter.ai MX feedback-smtp.us-east-1.amazonses.com source · Oct 2026 ↗

Money

Payments

Stripe

In its subprocessor list: Stripe, LLC | Subscription payment processing | United States | 2026-07-30 source · Oct 2026 ↗

AI in the product

LLM API

OpenAI API

“More than half of our code is either written by or polished by GPT” — the maker, Sep 2026 ↗

Azure OpenAI

In its subprocessor list: Microsoft Corporation — Microsoft Azure (including Azure OpenAI Service) | Cloud hosting, compute, storage, and AI model processing for the Services | United States | 2026-07-30 source · Oct 2026 ↗

Building with AI

AI Coding Assistants

Claude Code

“We build HarnessRouter with Claude Code, and HarnessRouter runs Claude Code as a product backend for other teams. It is both our daily driver and one of the harnesses we route to.” — the maker, Sep 2026 ↗

OpenAI Codex

“Codex is one of the three harnesses HarnessRouter routes to, and we use it in our own build loop. Its structured output made it one of the cleanest harnesses to normalize against.” — the maker, Sep 2026 ↗